Monday, September 30, 2019

Middle Childhood Development Essay

Middle childhood development is a big time in a child life. They begin to become more independent and rely more on themselves without the help of their parents. This is also a great time to still create solid bonds with your child before they enter the adolescence stage which begins at 13 (Dr.Laura Markham, 2013). With the peer pressure from friends and associates having a good foundation with your child early can save you a ton of stress. During middle childhood stage, children develop more independence from parents and family. They understand more and can differentiate between right and wrong. Children at this age give more attention to friendship and teamwork, but continue to be strongly influence by their parents’ judgment. At this age children have the ability to experience and describe feelings and thoughts with parents and friends. Middle childhood is a time when children develop social relationships. The social skills learned through family and peers give them ability to participate in meaningful communication that later provide foundation for challenges as adolescence. This improves their relationship and encourages them to be successful in future. According to Piagets theory of Cognitive Development between the ages of 6-11 children are at the stage of concrete operational thought. This involves a growing ability for children to use logic and thought. For example, a child age 8 will understand that it is wrong to steal even if they only did it because they were hungry. A toddler may take the food and eat it while knowing that it was wrong but not feel bad because in their mind they only did it because they were hungry. Same situation but different thought processes because of the age and development of the child. Stable and supportive families are crucial during middle childhood development  stage. Supportive family members and friends improve social development and children’s self-concept is basically shaped by relationships with parents, teachers and peers. Often they have little concern about their physical appearance though certain pressure during the later years 9-11 to look like the traditional boy and girls’ body image declines, especially with puberty. At this stage lower self-control and emotional stability may be observed. At this stage parents should be very careful about how they say and do things because children especially look to their parents at this age for confirmation on how to act as such. Culture also plays a major role in child self esteem because if influence your children to be strong and independent as children they take that into adolescence and early adulthood. In conclusion, middle childhood is an important stage in a person’s development in life. These are the crucial years that you start to see a change in your child and you can either change with them or have a hard time adjusting to them. I myself have a child that is 11, and I can honestly say that she has grown so much over years both physic al and emotionally. References Berk, L. E. (2012) Infants, Children, and Adolescents. (7th Ed). Boston, MA: Pearson. www.health.gov.sk.ca/middle-childhood

Sunday, September 29, 2019

Gender and Family Essay

It can be said the males make up the vast majority of the prison population. It can also be said that men are just plain different than women when it comes to ethics, morals, and violence. Whether gender has any influence on whether or not a crime is committed is not fully understood, but there are many theories. What are some current explanations for gender differences as they relate to delinquency? * * There are many views and theories as to if and how gender affects delinquency. One of the major theories is the gender-schema theory which basically states that society influences create girls feminine and boys masculine and that they are expected to adhere to those gender roles. Others theorize that differences are based on traits and that it is the â€Å"interaction of biological and psychological traits with the social environment that produces delinquency† (Siegel & Welsh, p. 142). Much of this has to do with child development. Other theorists believe social factors such as family life and friendships play a major role in criminal behavior. The feminists hold that crime rates have fluctuated because of the increased role women have in today’s society .Another contributor to the debate is the power-control theory which attests that women commit less crime because men have a role as the breadwinner for the family. How does family affect delinquency? * Much of our life is based on relationships and family is a big part of that. Family relationships, or the lack of relationships, can influence a  person in many ways. The affect is unique to the person and their situation so it is hard, if not impossible, to determine if family interactions can influence criminal behavior. * How does family makeup affect delinquency? * Factors in regards to family makeup that affect delinquency can include divorce or separation, economic stress, abuse, as well as lack of adequate or positive adult supervision. The family interactions can either be a positive influence or a negative one which could increase the risk for delinquent behavior. * How does family behavior influence delinquency? * * There are four categories of family behavior that are possible contributors to delinquent behavior. These include family breakup, conflict, deviance, and neglect (Siegel & Welsh, p. 159). These factors can combine or work individually to create a high risk environment for delinquent behavior. Research done in regards to these four relationship theories and their applicability is still controversial. * Unhappy marriages, separation, divorce, and remarriage all contribute to an unstable home environment. The institution of marriage is no longer what it used to be. There have been studies done, but none have concluded with substantial results on this issue. Although the divorce rate has increased to, it has not been shown that this has been caused by family breakup. The theory that family conflict can lead to delinquency has shown in research to be a contributing factor in delinquency. †Adolescents who are incarcerated report growing up in dysfunctional homes† (Siegel & We lsh, 161). This can mean anything from parents who argue a lot to parent-child conflicts based on rules or punishment. Other family members who exhibit deviant behavior can also have a negative influence. When delinquent behavior appears to be acceptable and other family members are participating in criminal acts, children or other siblings may view it as an appealing practice or condoned behavior. Neglect can come in many forms and is also a theory behind what causes delinquent behavior. Although each family structure is different with  contributing cultural factors, there may be a link between children who do not have a strong parent-child connection. Problems may arise due to inconsistent discipline, inadequate supervision, or family resources being stretched too thin due to family size or economic situations. Are delinquent females treated differently than delinquent males by members of the juvenile justice system? * Yes, female juvenile offenders are treated differently than male offenders. They are less likely than males to get arrested and charged for a crime. However, once charged, females typically receive a harsher punishment. Are they treated unfairly? * Typically, female offenders are under more scrutiny of stereotypes than males. Society, and those employed in the juvenile justice system hold females to a different moral standards than men. However, this is dependent upon the situation as well as the location. * Do they benefit from being female? Why or why not? * In some ways, females benefit from gender inequality, but in other ways it works against them. While they may not get arrested as often, once in the system they often deal with unfair conditions. In fact, â€Å"Institutionalized girls report that they are given fewer privileges and less space, equipment, programs, and treatment than institutionalized boys† (Siegel & Welsh, p.152). References Siegel, L. J. & Welsh, B. C. (2005). Juvenile delinquency: The core. (2nd ed.). Belmont, CA: Thomson Wadsworth.

Saturday, September 28, 2019

Descartes and Plato Essay

Explain both of descartes Arguments for the existence of God Descartes proof of God’s existence comes from his third meditation and is based on three ideas. He argues that innate idea exists within us, the fictitious or invented ideas are a result of our own imagination and adventitious ideas result from our experiences in the world. Descartes said, the idea of God is innate and cannot be invented. Descartes presents some arguments that lead to his conclusion. The first argument is that nothing can result to something and the cause of an idea will always have a formal reality because the idea must have an objective reality. He argues that if an individual have God, then the idea has an infinite objective reality and therefore, the individual cannot be the cause of the idea, because he is not infinite or a perfect being or he doesn’t have enough formal reality. It’s only a perfect and infinite being who can be the cause of the idea. Therefore, God as an infinite reality must exist. A perfect being, is benevolent and good; implying that God is benevolent and would not deceive or allow making errors without giving a way of correcting the errors. The second argument Descartes gives is based on the premise that I exist, and my existence must have a cause. He gives the only possible causes are: my existence, existence of something less perfect than God and existence of God. Out of this Descartes argues that if I had created myself, I would have created myself perfect and that if my existence have a cause, then it doesn’t solve the problem. If I’m not an independent being, then I would need the sustenance of another being. And that the perfection in me could not originate from a less perfect being. Therefore God exists. Descartes second proof of God’s existence is based on the fifth meditation on essence of material objects and it’s called the ontological argument. Descartes identifies external objects that can either be distinct and clear or obscure and confused. Descartes argues that without any sure knowledge of existence of a supreme and perfect being it would be impossible to have any assurance of any truth. Descartes defined God as an infinitely perfect being and that perfection will include existence. Meaning therefore, God exists. Explain the Allegory of the Cave and relate it to Platos metaphysical and epistemological theory The allegory of cave is about prisoners who have spent their lives chained to the wall of a cave and facing the wall. The prisoners are watching shadows cast on the wall by objects passing in front of the fire behind them, and they start to attribute the forms of these shadows. It is a figurative show of how a man is trapped in the illusion of material existence and how he can free himself from such trappings by philosophical thoughts of personal and social awareness through constant self examination. These shadows are the close the prisoners can get to reality. When the one who actually is able to free himself from the cave, returns back to the cave to tell his fellow man about the world outside the cave he is ridiculed for his free thoughts by the ones not knowing the real truth yet. Thats how a philosopher feels, he is like the prisoner who has freed himself from the cave and realizes that shadows on the wall are not the reality of things in life but merely shadows. This allegory of the cave is related to Plato’s theory of Metaphysics and Epistemology. Seen as an epistemological account, it attempts to determine the importance of ideas which we can only comprehend through reason resulting from our experiences from the physical world. The allegory of the cave is a philosopher’s effort to enlighten the society which can be seen as prisoners, imprisoned by their dark ignorance. The cave could represent our daily experiences and how we always accept the dictates of the society without questioning them.

Friday, September 27, 2019

Explain the general concepts of proto-oncogenes and oncogenes and Essay

Explain the general concepts of proto-oncogenes and oncogenes and further describe different types of changes that underpin activation of proto-oncogenes - Essay Example Tumor suppressors and proto-oncogenes act in the same way as the brakes and accelerator in a vehicle respectively. Controlled growth of cells is maintained through the regulative activity of tumor suppressors that slow growth of cells and proto-oncogenes that accelerate cell growth (Hanahan & Weinberg 2011, p. 650). Uncontrolled cell growth will occur when proto-oncogenes mutate to form oncogenes and accelerate growth of cells or if tumor suppressors mutate to prevent growth inhibition. Proto-oncogenes in normal cells are responsible for the production of proteins that stimulate division of the cell through signals to the nucleus. The proteins involved in this signaling process, act through the signal transduction pathway or cascade that is made up of a series of steps (Bock & Marsh 2010, p. 32). The pathway is inclusive of a membrane receptor that binds the signal molecule, cytoplasmic proteins that convey the signal, and transcription factors that activate the cell division-related genes in the nucleus. Each of the cascade’s steps has a protein or factor that activates another, although some of these factors have the ability to activate more than one cellular protein. Oncogenes, on the other hand, are altered proto-oncogenes that are involved in coding for the molecules in signaling. They continuously activate the signaling pathway, which results in heightened factor or protein production, especially those involved in the stimulation of growth (Schwab 2013 , p. 21). For example, the MYC proto-oncogene codes for transcription factors and is converted to an oncogenes that is related to over two thirds of all cancers. Ras, on the other hand, is an oncogene that acts as a switch in the pathways and mutations cause the pathway to remain in the on mode and causes uncontrolled growth of cells. In order for a proto-oncogene to be converted to an oncogene, its original function is modified through any of three basic activation methods. The first activation method

Thursday, September 26, 2019

The making of australia Essay Example | Topics and Well Written Essays - 1750 words

The making of australia - Essay Example To arrive at the beginning of the understanding, the life of aborigines of Australia depicted by Grimshaw is helpful. The rustic lifestyle of aborigines was found to be in equilibrium wherein confrontation between men and women was minimal. The cultural significance of giving birth to a child had been well understood to its grass root by the aborigines. The baby’s birthplace entrenched its niche in the social and physical world. The governments’ approach towards the pregnant women convicts and the care provided by the governments in the period of colonization and settlement could be seen as the aborigines’ basic attitude towards child nurturing. The economic status of aborigines was well depicted in the book by Grimshaw (1994). British elite group of women had around sixty eight essential materials like head bands, swaddling cloth etc, at the time of delivery for making a pregnant women to give birth to a child; even a poorer woman of British had forty to forty-five essentials. But Aboriginals had very little preparation for giving birth. The encounter between two sets of women reveals some of the ways in which British technological superiority and cultural arrogance were to determine future relations between the two groups. On several occasions, Aboriginal women used Government House and its well-guarded grounds as a refuge from attacks by their men, a function which the British upper class were pleased to perform in the name of chivalry. Here also, the game of chivalry was enjoyed by the British elite society, which fuelled the latent barbaric instinct in aborigines. The physical strength and the way Aboriginal women acted upon during and after delivery amazed many upper middle class British women and even Aboriginal men frown on their own women for doing lengthy walks and strenuous work during and after delivery. Aborigines’ treatment of male role in

Analysis report of Bernini's Angel with Crown of Thorns Research Paper

Analysis report of Bernini's Angel with Crown of Thorns - Research Paper Example Through its huge size and magnificent form, it became a grand architectural element together with the rest of the ten Angels of Passion in Ponte Sant’Angelo. A grand sentry looking over the people as they traverse the bridge to and from the Castle. The sculpture depicts an angel represented as a young man with a crown of curly hair. His wings are quite huge and are partially spread out as if about to take flight. He is wearing a somewhat diaphanous material draped over his body exposing a good portion of his shoulders and his right leg. He is holding a crown of thorns and his arms are placed sideways towards the left side of his body at the level of his chest. The angel’s right leg is exposed up to mid thigh and is bent on the knee as if in a walking motion. His left foot, on the hand, is also exposed. His feet are parted slightly apart with an indistinguishable object of swirls in between his feet and beside his left feet. The Ponte Sant’Angelo, also known as the Bridge of Angels, in Rome was decorated with ten marble sculptures of angels, or the Angels of Passion, as proposed by Italian sculptor Gian Lorenzo Bernini.1 He was commissioned by Pope Clement IX to create two out of the ten angel sculptures and the rest of the angel sculptures are believed to be made by Bernini’s students. The ten marble sculptures are to replace the 14 stucco sculptures of angels set up by Rafaella da Montelupo under Pope Paul III.2 The ten marble sculptures of angels each hold a symbol of the Passion of the Christ. The ten angel sculptures are the â€Å"Angel with the Column† by Antonio Raggi, â€Å"Angel with the Whips† by Lazzaro Morelli, â€Å"Angel with the Crown of Thorns†Ã‚  by Gian Lorenzo Bernini, â€Å"Angel with the Sudarium or Veronica’s Veil† by  Cosimo Fancelli,  Ã¢â‚¬Å"Angel with the Garment and Dice† by Paolo Naldini, â€Å"Angel with

Wednesday, September 25, 2019

Tools, stucture & sing in Design Assignment Example | Topics and Well Written Essays - 500 words - 1

Tools, stucture & sing in Design - Assignment Example Surprisingly, there was not permanent structure with caves been the first to be developed (Bramle & IDMME Conference, 2005, p. 156). Need for protection from animals led to development wood and mud structures driven by designer/maker/user. Structures developed based on age of needs with people disturbed by the need to protect themselves from animals and hence constructing mud and wooden based structure such as cliff dwellings of American Southeast. The color forms the basic element evident here as red color has been used to indicate need for life savers. It matches earlier signs that printed such signs in red and black using charcoals while ochre stones were painted by yellow oxides. The signs have used red colors and a plus sign to visually create a perception on the significant of such signs, red color is always attached to blood and danger and hence a person is attracted to pay attention to such

Tuesday, September 24, 2019

Insurance Is Not Always Beneficial to Emplyees Essay

Insurance Is Not Always Beneficial to Emplyees - Essay Example In the United States, for example, many employees get Insurance policy through their employers where the employers help pay the Insurance policy. When the employer insures one, it is usually through a managed care plan that are health insurance plans that provide health care facilities to members at reduced costs by laying down contracts with medical facilities and health care providers. Employer based Insurance is often much cheaper as compared to buying individual Insurance, hence many people rather have their insurance bill cut from their salaries. The United States unlike other industrialized countries has a different case in that it does not have a national Insurance System. It is important to be insured because one cannot always tell when they are going to need the medical attention. There are vast advantages of getting employee-based health insurance. In the essay, I will look at health insurance in group verses individualized context, explore the advantages of employer based health insurance plan and discuss that insurance is not always beneficial. Group verses Individualized Insurance Employment based Insurance is an example of group based Insurance. ... e of group insurance policy is that it is much easier to obtain in that there are little procedures to be followed, which would in turn delay or even terminate the whole application process like inquiring about the health history of individual members. Group insurance policy is definitely the cheapest form of insurance available. However, as compared to group insurance, there are numerous advantages of individualized insurance plans. Firstly, one is able to customize the provisions they may want included or neglected in their package. They may also choose to regulate on the deductible amount of payment that the insurance company does. It also enables individual to choose the doctor that would be conducting their services. Here the price range may be elevated as compared to group insurers, but the services are better. It may also be exceptionally costly particularly when one runs a high risk being ill or has high health risk qualities. Advantages of Employment Based Health Insurance P lans A health plan would gain more if groups of individuals with low health risks were enrolled in it as compared to unhealthy list of individuals. In the United States where the employee health insurance benefit scheme is purely voluntary, there is a great chance that a group of highly unhealthy individuals are registered in the plan. Insurers would often prefer to enroll a group of individual as compared to the specific individual. Employment based insurance groups are one of the individual groups that are always considered to be formed for the sole purpose to offer their employees health insurance. It does not discriminate and whether the individual in the group posses a high health risk than the other, they will automatically qualify for the system. Not only are employers capable of

Monday, September 23, 2019

Value & Risk Management Assignment Example | Topics and Well Written Essays - 4500 words

Value & Risk Management - Assignment Example Value drivers can be defined as elements within a project which improve the product quality, and also minimise costs. These drivers become essential during project management as they provide assistance to auditors on possible value adding elements. The utilisation of value drivers remains fundamental to successful completion of many development projects, within the construction industry. These elements remain fundamental towards ensuring projects remain within their allocated budgetary requirements, and produce satisfactory outcomes. Several value drivers can be identified for the project as defined below Ensure effective project management and delivery Achievement of required financial targets Minimising operation and maintenance costs, and environmental impact for the building Complying with various third party requirements Effective project management Effective project management process involves proper utilisation of available resources as a method of minimising wastage at differ ent project development stages. Effective management remains the most fundamental element for ensuring efficacy in development projects. This involves the proper utilisation of available resources in meeting the requirements of the project as defined in the planning stages. This value driver remains focused at ensuring projects achieves excellence through compliance with required project outcomes. Ensuring presence and application of this value driver remains fundamental to successful project completion. The incorporation of effective management begins with the appointment of a project team. In ensuring effectiveness, the management team should be selected from individuals possessing the essential skills and expertise in the construction industry. The utilisation of independent client advisors could be applied where the team lacks experts in a specified profession, While selecting individuals with essential expertise and skills, a consideration for cost should also be factored to en sure functionality of the team. The team must become fully engaged into the project from the beginning stages. Efficacy in the management skills of the team should be displayed through coordination, integration and communication among the team members, consequently ensuring the team functions as a single unit. Other than communication among team members, external communication with stakeholders remains a fundamental component for ensuring success in development projects. Management teams should involve users, contractors and all members involved in the supply chain delivery continuously, to get their expertise and opinions on the project. The management team should develop an execution plan, which should act as a guideline during the project lifetime. The effectiveness of the team remains the main reason behind utilising a project management team, fully engaged in the operations of the project. The effectiveness should be measured according to the desired industry standards, develop ed by regulatory organisations. Compliance to these regulatory requirements remains a key performance indicator

Sunday, September 22, 2019

Literacy Narrative Essay Example for Free

Literacy Narrative Essay Due Date: Friday night, September 6th by midnight in the digital dropbox on Angel Desired Learning Outcomes: 1.Understand our personal development as readers and writers or persons 2.Explore writing as a means of self-discovery 3.Choose the appropriate voice, diction, and audience for a personal literacy narrative 4.Use various invention, drafting and revising/editing strategies as needed 5.Demonstrate appropriate conventions of grammar and style of written English 6.Use technology effectively and correctly to complete the assignment READINGS FOR PAPER: 1.Norton, Chapter 7: Writing a Literacy Narrative, Chapter 40: Narrating, and Chapter 57: additional examples of literacy narratives to be selected by the instructor 2. Quick Access Concise, Chapter 1: Understanding College and Other Writing Situations and Chapter 7a c: Strategies for Writing Typical Kinds of College Papers ASSIGNMENT: After completing the readings for this assignment, follow the guidelines in Chapter 7 of your Norton Field Guide, particularly pages 43-46. Additional tips on the writing process itself appear in the chapter, as well as samples from professional writers. As your text advises, follow these steps. 1.Choose a topic. A single event that you recall vividly would be a good choice. See the suggestions on page 43. 2.Consider the rhetorical situation, particularly your audience and stance. Your instructor will discuss conventions in more detail, but this type of writing does not require a formal tone and may use the first person (â€Å"I†). Grammar and  format, however, need to be correct. 3.Be sure you understand the nature of narrating (Chapter 40) and have the kinds of details and stance that motivate and excite your readers. A good narrative always has an element of conflict. 4.Apply the information in your Field Guide on generating ideas, drafting, and revising under the direction of your instructor.

Saturday, September 21, 2019

Three Phase System Outline

Three Phase System Outline Single phase systems are defined by having an AC source with only one voltage waveform. Figure 1 is a simple AC circuit. Single-phase power distribution is widely used especially in rural areas, because the cost of a single-phase distribution network is low. Figure 1:- Single phase system schematic diagram Today most of the electrical power generated in the world is three-phase. Three-phase power was first conceived by Nikola Tesla. Three-phase power was the most efficient way that electricity could be produced, transmitted, and consumed. A three-phase generator has three separate but identical windings that are 1200 electrical apart from one another. 5.2 Three Phase Circuit Three-phase voltage systems are composed of three sinusoidal voltages of equal magnitude, equal frequency and separated by 120 degrees, as shown in Figure 2. It is one voltage cycle of a 3 phase system. It is labeled 0 to 360 ° (2 Ï€ radians) along the time axis. The plotted lines show the variation of instantaneous voltage (or current) over time. This power wave cycle will repeat usually  50 (50Hz), 60 (60Hz), or 400 (400Hz)  times per second, depending on the power system  frequency (Hz). The colors of the lines are in the  American Color Code for 3-phase wiring. It is black=VL1  red=VL2blue=VL3. Figure 2:- Three phase waveforms Three phase systems may or may not have a neutral wire. The neutral wire allows 3 phase systems to use a higher voltage while still supporting lower voltage 1 phase appliances. In  high voltage 3 phase distribution  situations it is common not to have a neutral wire as the loads can simply be connected between phases (phase-phase connection). 5.2.1 Advantage over Single Phase system Three phase system is better to single phase system. The reason for the advantage over single phase system is given below. The horsepower rating of three-phase motors and the KVA (kilo-volt-amp) rating of three-phase transformers is about 150% greater than for single-phase motors or transformers with a similar frame size. Figure 3:- Single-phase power falls to zero three times each cycle. Figure 4:- Three-phase power never falls to zero. The power delivered by a single-phase system pulsates, as shown in Figure 3. The power falls to zero three times during each cycle. The power delivered by a three-phase circuit pulsates also, but it never falls to zero, as shown in Figure 4. In a three-phase system, the power delivered to the load is the same at any instant. This produces superior operating characteristics for three-phase motors. In a balanced three-phase system, the conductors need be only about 75% the size of conductors for a single-phase two-wire system of the same KVA rating. This helps offset the cost of supplying the third conductor required by three-phase systems. If a magnetic field is rotate through the conductors of a stationary coil then a single phase alternating voltage can be produced. This explanation is shown in Figure 5. Figure 5:- A single-phase voltage. Since alternate polarities of the magnetic field cut through the conductors of the stationary coil, the induced voltage will change polarity at the same speed as the rotation of the magnetic field. The alternator shown in Figure 5 is single phase because it produces only one AC voltage. Figure 6:- The voltages of a three-phase system are 120 ° out of phase with each other. If three separate coils are spaced 120 ° apart, as shown in Figure 6, three voltages 120 ° out of phase with each other will be produced when the magnetic field cuts through the coils. This is the manner in which a three-phase voltage is produced. 5.2.2 Classification Three-phase supply voltages and load systems have two basic configurations: a). wye or star connection and b). delta connection. 5.3 Star and Delta connection The Wye is a 4-wire system. Wye configurations typically include a neutral line (N) connected to the common point (3 phase plus neutral for a total of four wires), as shown in Figure 7. Figure 7:- A wye connections is formed by joining one end of each of the windings together. The Delta, as shown in Figure 8, is a 3-wire system which is primarily used to provide power for three-phase motor loads. The system is normally ungrounded and has only one three-phase voltage available. The lack of a system ground makes it difficult to protect for ground faults. Often, a ground detection scheme, employing ground lamps, is used to provide an indication or alarm in the event of a system ground. The Delta System is sometimes corner grounded to protect for ground faults on the other two phases. Figure 8:- Three-phase delta connection 5.4 Phasor diagrams 5.4.1 Star connection The voltage measured across a single winding or phase is known as the phase voltage, as shown in Figure 9. The voltage measured between the lines is known as the line-to-line voltage or simply as the line voltage. The currents flowing in the phases are called phase currents and currents flowing in the lines are called line currents. Figure 9:- Line and phase voltages are different in a wye connection. The parallelogram method of vector addition for the voltages in a wye-connected three-phase system is shown in Figure 10. Figure 10 shows how the line voltage may be obtained using the normal parallelogram addition. Figure 10:- Phasor diagram of Star connection Voltage However, the line voltage is not equal to the phase voltage. The line voltage V1-2 is equal to the phasor difference of VA and VB. The line voltage V2-3 is equal to the phasor difference of VB and VC. The line voltage V3-1 is equal to the phasor difference of VC and VA. The line voltages are defined as: V1-2 = VA VB, V2-3 = VB-VC, and V3-1 = VC-VA. Here V1-2, V2-3, V3-1 are the line voltage (VLine) and VA, VB, VC are the phase voltage (VPhase) of Wye connection. VA, VB, VC are the reverse phase voltage of VA,VB, VC. The two phasors VA and VB are 600 apart. V1-2 = VLine = VA VB = [VPhase (-VPhase)] cos(600/2) = 2 VPhase cos300 = √3 VPhase The two phasors VB and VC are 600 apart. V2-3 = VLine = VB-VC = √3 VPhase The two phasors VC and VA are 600 apart. V3-1 = VLine = VC-VA = √3 VPhase  Ã…“ V1-2 = V2-3 = V3-1 = line voltage = VLine =√3 VPhase Current On a Wye system or star connected supply, the phase unbalance current is carried by the neutral. On a Wye system, the line current (current in the line) (ILine) is equal to the phase current (current in a phase) (IPhase) i.e. ILine = IPhase Power Total power P = 3 Power in each phase = 3 VPhase IPhase cosÃŽ ¦ = 3 (VLine/√3) ILine cosÃŽ ¦ [for Wye connection] = √3 VLine ILine cosÃŽ ¦ Where VLine and ILine are the line voltage and the line current of a star connected supply. The term cosÃŽ ¦ is called power factor of the circuit and its value is given by; cosÃŽ ¦ = R/Z Where R and Z are the resistance and impedance of a circuit. 5.4.2 DELTA CONNECTIONS In Figure 11, voltmeters have been connected across the lines and across the phase. Ammeters have been connected in the line and in the phase. Figure 11:- Voltage and current relationships in a delta connection The delta connection is similar to a parallel connection because there is always more than one path for current flow. Since these currents are 120 ° out of phase with each other, vector addition must be used when finding the sum of the currents, as shown in Figure 12. Figure 12:- Phasor Diagram of Delta connection Voltage In the delta connection, the three voltages are equal in magnitude but displaced 1200 from one another. In the delta connection, line voltage (VLine) and phase voltage (Vphase) are the same. VLine = Vphase Current In the delta connection, the line current and phase current are different. The line current is the vector sum of two individual phase currents. The line current I1 is equal to the phasor difference of IA and IC. The line current I2 is equal to the phasor difference of IB and IA. The line current I3 is equal to the phasor difference of IC and IB. The line currents are defined as: I1 = IA IC, I2 = IB IA and I3 = IC IB. Here I1, I2, I3 are the line current (ILine) and IA, IB, IC are the phase current (IPhase) of Wye connection. IA, IB, IC are the reverse phase current of IA, IB, IC. The two phasors IA and IC are 600 apart. I1 = ILine = IA IC = [IPhase (-IPhase)] cos(600/2) = 2 IPhase cos300 = √3 IPhase The two phasors IB and IA are 600 apart. I2 = ILine = IB IA = √3 IPhase The two phasors IC and IB are 600 apart. I3 = ILine = IC IB = √3 IPhase  Ã…“ I1 = I2 = I3 = ILine = line current = √3 IPhase However, the line current of a delta connection is higher than the phase current by a factor of the square root of 3 (1.732). Power Total power P = 3 Power in each phase = 3 VPhase IPhase cosÃŽ ¦ = 3 VLine- (ILine/√3) cosÃŽ ¦ [for delta connection] = √3 VLine ILine cosÃŽ ¦ Where VLine, ILine and cosÃŽ ¦ are the line voltage, the line current and power factor of a delta connected supply. 5.5 Relationship between line and phase quantities 5.5.1 Star connection On a Wye system, the line current is equal to the phase current i.e. ILine = IPhase Where ILine and IPhase are the line current and phase current of Wye connection. In a wye connected system, the line voltage is higher than the phase voltage by a factor of the square root of 3 (1.732). Two formulas used to compute the voltage in a wye connected system are: VLine = √3 VPhase = 1.732 VPhase  Ã…“ VPhase = VLine / 1.732 Where VLine and VPhase are the line voltage and phase voltage of Wye connection. 5.5.2 Delta connection In the delta connection, line voltage and phase voltage are the same. VLine = Vphase Where VLine and VPhase are the line voltage and phase voltage of delta connection. Formulas for determining the current in a delta connection are: Where ILine and IPhase are the line current and phase current of delta connection. 5.6 Power measurement by two watt meters method In two wattmeters method, current coils of the two wattmeters are connected in any two terminals of Wye system, as shown in Figure 13. The algebraic sum of two wattmeters gives the total power consumed whether the load is balanced or not i.e. Total power = W1 + W2 Figure 13:- Wye connected load Figure 14:- Phasor Diagram The power factor angle of load impedance being ÃŽ ¦ lag. The currents will lag behind their respective phase voltages by ÃŽ ¦ as shown in Fig. 14. Current through current coil of W1 = IA. Potential difference across potential coil of W1, V1-2 = VA VB. The phase angle between V1-2 and IA is (300 + ÃŽ ¦).  Ã…“ W1 = V1-2 IA cos(300 + ÃŽ ¦) Current through current coil of W2 = IB. Potential difference across potential coil of W2, V2-3 = VB-VC. The phase angle between V2-3 and IB is (300 ÃŽ ¦).  Ã…“ W2 = V2-3 IB cos(300 ÃŽ ¦) Here load is balanced, V1-2 = V2-3 = VLine = line voltage and IA = IB = ILine = line current.  Ã…“ W1 = VLine ILine cos(300 + ÃŽ ¦)  Ã…“ W2 = VLine ILine cos(300 ÃŽ ¦)  Ã…“ W1 + W2 = VLine ILine [cos(300 + ÃŽ ¦) + cos(300 ÃŽ ¦)] = VLine ILine(2cos300cosÃŽ ¦) = √3VLine ILine cosÃŽ ¦  Ã…“ W2 W1 = VLine ILine [cos(300 ÃŽ ¦) cos(300 + ÃŽ ¦)] = VLine ILine(2sin300sinÃŽ ¦) = VLine ILine sinÃŽ ¦ tanÃŽ ¦ = [√3 (W2 W1)] / (W1 + W2) Thus from the two wattmeter method, we can find ÃŽ ¦. PROBLEM 1. Three coils, each having a resistance of 20- and an inductive reactance of 15-, are connected in star to a 400V, 3-phase, 50Hz supply. Calculate (i) the line current (ii) power factor and (iii) power supplied. Solution:- VPhase = VLine / 1.732 = 400/1.732 = 231V ZPhase = √(202 + 152) = 25- (i) IPhase = VPhase/ ZPhase = 231/25 = 9.24A = ILine (ii) Power factor = cosÃŽ ¦ = RPhase/ ZPhase = 20/25 = 0.8 lag (iii) P = √3VLine ILine cosÃŽ ¦ = √3 400 9.24 0.8 = 5121W 2. A balanced star-connected load of impedance (6 + j8)- per phase is connected to a 3-phase, 230V, 50Hz supply. Find the line current and power absorbed by each phase. Solution:- ZPhase = √(62 + 82) = 10- VPhase = VLine / 1.732 = 230/1.732 = 133V Power factor = cosÃŽ ¦ = RPhase/ ZPhase = 6/10 = 0.6 lag IPhase = VPhase/ ZPhase = 133/10 = 13.3A = ILine P = √3VLine ILine cosÃŽ ¦ = √3 230 13.3 0.6 = 1061W 3. Three similar coils, connected in star, take a total power of 1.5kW at a power factor of 0.2 lagging from 3-phase, 400V, 50Hz supply. Calculate the resistance and inductance of each coil. Solution:- VPhase = VLine / 1.732 = 400/1.732 = 231V P = √3VLine ILine cosÃŽ ¦  Ã…“ ILine = P / (√3VLine cosÃŽ ¦) = 1500 / (1.732 400 0.2) = 10.83A = IPhase ZPhase= VPhase/ IPhase = 231 / 10.83 = 21.33- RPhase = ZPhase cosÃŽ ¦ = 21.33 0.2 = 4.27- XPhase = √(21.332 4.272) = 20.9- LPhase = XPhase/ 2Ï€f =20.9 / (2Ï€ 50) = 0.0665H 4. The load to a 3-phase supply comprises three similar coils connected in star. The line currents are 25A and kVA and kW inputs are 20 and 11 respectively. Find (i) the phase and line voltages (ii) the kVAR input and (iii) resistance and reactance of each coil. Solution:- VPhase = Apparent power / (3 IPh) = (20-103) / (3 25) = 267V VLine= √3 VPhase=1.732-267 = 462V Input kVAR = √ (kVA2 kW2) = √ (202 112) = 16.7kVAR Power factor = cosÃŽ ¦ = kW/kVA = 11/20 ZPhase= VPhase/ IPhase = 267 / 25 = 10.68- RPhase = ZPhase cosÃŽ ¦ = 10.68 11/20 = 5.87- XPhase = √(10.682 5.872) = 8.92- 5. A balanced 3-phase, delta-connected load has per phase impedance of (25+j40)-. If 400V, 3-phase supply is connected to this load, find (i) phase current (ii) line current (iii) power supplied to the load. Solution:- ZPhase = √(252 + 402) = 47.17- IPhase= VPhase/ ZPhase = 400 / 47.17 = 8.48- ILine= √3 IPhase=1.732-8.48 = 14.7A Power factor = cosÃŽ ¦ = RPhase/ ZPhase = 25/47.17 = 0.53 lag P = √3VLine ILine cosÃŽ ¦ = √3 400 14.7- 0.53 = 5397.76W 6. A balanced 3-phase load consists of three coils, each of resistance 6-, and inductive reactance of 8-. Determine the line current and power absorbed when the coils are delta-connected across 400V, 3-phase supply. Solution:- ZPhase = √(62 + 82) = 10- cosÃŽ ¦ = RPhase/ ZPhase = 6/10 = 0.6 lag VPhase = VLine = 400V IPhase= VPhase/ ZPhase = 400 / 10 = 40A ILine= √3 IPhase=1.732-40 = 69.28A P = √3VLine ILine cosÃŽ ¦ = √3 400 69.28 0.6 = 28799W 7. Two-wattmeter method is used to measure the power absorbed by a 3-phase induction motor. The wattmeter readings are 12.5kW and -4.8kW. Find (i) the power absorbed by the machine (ii) load power factor (iii) reactive power taken by the load. Solution:- W2 = 12.5kW ; W1 = -4.8kW Power absorbed = W2 + W1 = 12.5 + (-4.8) = 7.7kW tanÃŽ ¦ = [√3 (W2 W1)] / (W1 + W2) = (12.5+4.8) / 7.7 = 3.89 ÃŽ ¦ = tan-13.89 = 75.60 Power factor = cosÃŽ ¦ = cos75.60 = 0.2487lag Reactive power = √3 (W2-W1) = √3 (12.5 + 4.8) = 29.96kVAR P O I N T S TO REMEMBER 1. The voltages of a three-phase system are 120 ° out of phase with each other. 2. The two types of three-phase connections are wye and delta. 3. Wye connections are characterized by the fact that one terminal of each device is connected together. 4. In a wye connection, the phase voltage is less than the line voltage by a factor of 1.732. The phase current and line current are the same. 5. In a delta connection, the phase voltage is the same as the line voltage. The phase current is less than the line current by a factor of 1.732. IMPORTANT FORMULAE 1. On a wye system, the relation between line and phase current is: ILine = IPhase 2. On a wye system, the line voltages are defined as: V1-2 = VA VB, V2-3 = VB-VC, and V3-1 = VC-VA. 3. In the delta connection, the relation between line and phase voltage is: VLine = Vphase 4. In the delta connection, the line currents are defined as: I1 = IA IC, I2 = IB IA and I3 = IC IB 5. On a wye system, the relation between line and phase voltage is: VPhase = VLine / 1.732 6. In the delta connection, the relation between line and phase current is: OBJECTIVE QUESTIONS 1. In a two phase generator, the electrical displacement between the two phases or winding is: (a) 1200 (b) 900 (c) 1800 (d) none of these 2. The advantage of star-connected supply system is that: (a) line current is equal to phase current (b) two voltages can be used (c) phase sequence can be easily changed (d) it is a simple arranged 3. In a balanced star-connected system, line voltage are ahead of their respective phase voltages. (a) 300 (b) 600 (c) 1200 (d) none of these 4. In a star connected system, the relationship between the line voltage VL and phase voltage VPh is: (a) VL = VPh (b) VL = VPh / √3 (c) VL = √3VPh (d) none of these 5. The algebraic sum of instantaneous phase voltages in a three-phase circuit is equal to: (a) zero (b) line voltage (c) phase voltage (d) none of these 6. If one line conductor of a 3-phase line is cut, the load is then supplied by: (a) single phase voltage (b) two phase voltage (c) three phase voltage (d) none of these 7. The resistance between any two terminals of a balanced star-connected load is 12-. The resistance of each phase is: (a) 12- (b) 24- (c) 6- (d) none of these 8. A 3-phase load is balanced if all the three phases have the same (a) impedance (b) power factor (c) impedance and power factor (d) none of these REVIEW QUESTIONS 1. How many degrees out of phase with each other are the voltages of a three-phase system? 2. What are the two main types of three-phase connections? 3. A wye-connected load has a voltage of 480 V applied to it. What is the voltage drop across each phase? 4. A wye-connected load has a phase current of 25 A. How much current is flowing through the lines supplying the load? 5. A delta connection has a voltage of 560 V connected to it. How much voltage is dropped across each phase? 6. A delta connection has 30 A of current flowing through each phase winding. How much current is flowing through each of the lines supplying power to the load? 7. A three-phase resistive load has a phase voltage of 240 V and a phase current of 18 A. What is the power of this load? 8. If the load in question 7 is connected in a wye, what would be the line voltage and line current supplying the load? 9. An alternator with a line voltage of 2400 V supplies a delta-connected load. The line current supplied to the load is 40 A. Assume the load is a balanced three-phase load, what is the impedance of each phase? 10. If the load is pure resistive, what is the power of the circuit in question 9? PRACTICE PROBLEMS 1. Three similar coils are star connected to a 3-phase, 400V, and 50Hz supply. If the inductance and resistance of each coil are 38.2mH and 16- respectively, determine (i) line current (ii) power factor (iii) power consumed. 2. Three 50- resistors are connected in star across 400V, 3-phase supply. (i) Find phase current, line current and power taken from the main. (ii) What would be the above value if one of the resistors were disconnected? 3. Calculate the active and reactive components of current in each phase of a star-connected 10,000 volts, 3-phase generator supplying 5,000kW at a lagging power factor 0.8. Find the new output if the current is maintained at the same value but the power factor is raised to 0.9 lagging. 4. Three 20 µF capacitors are star-connected across 420V, 50Hz, 3-phase, three wire supplies. (i) Calculate the current in each line. (ii) If one of the capacitors is short-circuited, calculate the line currents. (iii) If one of the capacitors is open-circuited, calculate the line currents and potential difference across each of the other two capacitors. 5. If the phase voltage of a 3-phase star connected alternator be 231V, what will be the line voltages (i) when the phases are correctly connected (ii) when the connections of one of the phases are reversed? 6. Calculate the phase and line currents in a balanced delta connected load taking 75kw at a power factor 0.8 from a 3-phase 440V supply. 7. Three identical resistances, each of 18-, are connected in delta across 400V, 3-phase supply. What value of resistance in each leg of balanced star connected load would take the same line current? 8. Three similar resistors are connected in star across a 415V, 3-phase supply. The line current is 10A. Calculate (i) the value of each resistance (ii) the line voltage required to give the same line current if the resistors were delta-connected. 9. Two wattmeters are used to measure power in a 3-phase balanced load. The wattmeter readings are 8.2kW and 7.2kW. Calculate (i) total power (ii) power factor and (iii) total reactive power. 10. A balanced 3-phase load takes 10kW at a power factor of 0.9 lagging. Calculate the readings on each of the two wattmeters connected to read the input power. 11. Three identical coils, each having a resistance of 20- and a reactance of 20- are connected in (i) star (ii) delta across 440v, 3-phase lines. Calculate for each method of connection the line current and readings on each of the two wattmeters connected to measure the power.

Friday, September 20, 2019

Nitrification Process in Landfill Leachate Treatment

Nitrification Process in Landfill Leachate Treatment CHAPTER 1 INTRODUCTION Overview Landfilling is one of the oldest and common methods used for waste disposal. It is perceived as the most economical and environmentally acceptable technique. It is a complex system with physical, chemical, and biological processes. While undergoing the process of wastes degradation, there is the production of highly contaminating liquid, leachate, and polluting gases. If discharged in an uncontrolled and non-engineered manner, leachate will contaminate groundwater bodies and subsequently jeopardizing the ecosystem. There is a network for the collection the contaminants. The gases such as methane and carbon dioxide are flared before they can affect the atmosphere. The leachate generated, requires treatment before discharge and it is the main problem. In Mauritius, there has been an upsurge in the amount of wastes generated due to rapid industrialization. A structure for solid waste management was necessitated which resulted in the construction of Mare Chicose Sanitary Landfill Site. Over the years, there has been an increase the volume of wastes being disposed and consequently, a rise in the amount of leachate generated. As previously mentioned, the polluting liquid requires treatment prior to disposal. Nowadays, we do have laws that are regulated by the Wastewater Management Authority Act and the organization operates under the aegis of the Ministry of Public Utilities. After treatment leachate shall comply with the standard limits for effluent discharge as shown in Appendix C. Many studies have been carried out for the treatment of leachate and various methods are available. There are several parameters that define the treatment method. The treating technique shall be efficient, cost-effective with minimum input, flexible and if possible usage of the effluent. Aim and Objectives The aim of the project is the study of the nitrification process in the treatment of landfill leachate. The project had the following objectives set: To determine the suitability and efficiency of a SBR and co treatment method for the treatment of landfill leachate. To find the concentration at which ammonia nitrogen is toxic to microorganisms. To design a suitable tank for the method being adopted. To assess the cost-effectiveness of the treating system Structure of Thesis The remainder of this thesis is organized as follows: Chapter 2: gives a brief overview of landfilling process, describing the various components of a landfill. There is a description of the Mare Chicose Sanitary Landfill Site and a summary of typical leachate effluent. Chapter 3: deals with the treating options available for wastewater treatment particularly leachate. The efficiency for ammonia nitrogen removal is outlined and a reviewing some case studies on biological treatment of landfill leachate. Chapter 4: describes the methodology adopted for leachate treatment. Chapter 5: gives a detailed analysis of the results obtained and assessment of various parameters. Chapter 6: consists of the design a treating system for leachate. Chapter 7: describes the cost effectiveness of the treatment methods and some recommendations for improvement of the designs. CHAPTER 2 REVIEW of LITERATURE 2.1. Landfill A landfill may be defined as a physical facility used for the disposal of residual solid wastes in the surface soils of the earth (Tchobanoglous et al.). Nowadays, the term sanitary landfill is more usually utilized to describe an engineered facility, designed, operated and monitored with the foremost objective of reducing environmental and health hazards. According to Tchobanoglous, a landfill may be categorized with respect to the incoming waste materials. There are various criteria that are considered before the design and construction phases. The site cannot be close to water bodies, highways, any residential areas or even airports. The main reason is the pollution accompanied by the operation of such a site which will eventually disturb its surrounding environment. Another factor is the hydrogeology of the site, groundwater maps are prepared by studying the different soil stratum. This helps in determining the permeability of the soil, the depth to groundwater, the direction of groundwater flow and hydraulic gradients. If clay is to be used as a liner, then borrow sources are found. Landfill Components Liner: It is a barrier that will prevent the leachate and other liquids from penetrating the soil. It can be made of clay, synthetic materials or both which is known as composite liner. This barrier also restricts the underground migration of landfill gases. Cap system: Usually a soil cover placed over the landfill at completion of filling, also known as final cover, with vegetation grown over it. The cover may consist of geosynthetic materials also, thus hindering the escape of landfill gases to the air and restricting the infiltration of rain into the landfill (Bagchi, 1994). Gas management system: As shown in the diagram above, these are a series of gas wells that removes methane and other decomposition gases from the landfill for flaring and reuse. The methane gas may be used in the electricity production. Leachate management system: A number of horizontal and vertical pipes placed just above the liner that drains and collects leachate. Afterwards the polluting liquid may be brought to a retention pond. Mare Chicose Sanitary Landfill Site Over the last few years, a rapid development at socio-economic levels has brought an upsurge in the amount of wastes generated in Mauritius. There was a need for an integrated solid waste management programme. The Mare Chicose Sanitary Landfill is the only waste disposal site for Mauritius till date. The site is located in the southern part of the island near a small village called Cluny. It receives mostly municipal solid wastes and therefore categorized as a Class à Ã‚ ¨ type. The site was previously operated by STAM Ltà ©e, from 1997 to 2006, and presently by Sotravic Limità ©e/ Bilfinger-Berger consortium. The amount of wastes disposed at the landfill has nearly tripled over the years, reaching to a daily value of about 1,200 tonnes. The percentage of incoming wastes is summarized below: The field capacity of the landfill was already attained and currently there is an extension of works on existing cells. The site is comprised of six cells and actually the fifth one is in use. Prior to disposal at the landfill, the wastes are compacted at transfer stations. The wastes are dumped from a tipping point and soon, they are spread over existing wastes by means of specialized vehicles. At the end of the day, a cover is placed to reduce the amount of windblown debris. Both clayey and geosynthetic liners were used on the site. The amount of leachate being carted away for the period of January 2007 December 2007 is 110 858 m3. Actually, no leachate treatment is being carried out. Among the landfill gases produced methane is the most dangerous and it is dealt with in a controlled environment. The gas is being collected by means of pipelines and subsequently flared. Leachate The definition according to EPA is as follows; â€Å"Water that collects contaminants as it trickles through wastes, pesticides or fertilizers. Leaching may occur in farming areas, feedlots, and landfills, and may result in hazardous substances entering surface water, ground water, or soil.† Leachate can be described as a highly contaminated liquid, containing a considerable amount of dissolved and suspended solids that has percolated down through wastes. The leachate quality varies throughout the operational life of a landfill and long after its closure. There are three broad and overlapping phases of waste decomposition, in which chemical and biological processes give rise to both landfill gas and leachate during and beyond the active life of the site (Carville et al.). Phase 1: Oxygen present in the wastes is rapidly consumed by aerobic decomposition. This phase has duration of less than one month and is normally relatively unimportant in terms of leachate quality. This phase is exothermic and high temperatures may be produced. If some of this heat is retained, then as a result of that the rate of the upcoming phases is increased. Phase 2: Anaerobic digestion is comprised of the following four phases; Hydrolysis: A chemical reaction where large polymers are converted to simple monomers. Acidogenesis: A biological reaction where the monomers are converted to volatile fatty acids. Acetogenesis: A biological reaction where the fatty acids are converted into hydrogen, carbon dioxide and acetic acid. Methanogenesis: The acetic acid is converted into acetates. Hydrogen is used up to convert the acetates into methane and carbon dioxide. Anaerobic and facultative microorganisms hydrolyze cellulose and other putrescible materials such as complex carbohydrates, fats and proteins to soluble organic compounds. These hydrolysis products are then fermented during acidogenesis to various intermediates such as volatile fatty acids and alcohols. Finally, these intermediates are converted during acetogenesis to acetic acid, carbon dioxide and hydrogen. The high content of putrescible material in the waste may sustain acidogenic conditions for quite some time and provide a rich feed stock for methanogens subsequently. Leachate from this acidic phase typically contains a high concentration of free fatty acids. It therefore has low pH of 5 or 6, and will dissolve other components of the wastes, such as the alkaline earths and heavy metals, which can be mobilized in the leachate, possibly as fatty acid complexes. The leachate also contains high concentrations of ammoniacal nitrogen and has both a high organic carbon concentration and a biochemical oxygen demand (BOD). Phase 3: Conditions become more anaerobic as waste degradation proceeds and methanogenic bacteria gradually become established. These start to consume the simple organic compounds, producing a mixture of carbon dioxide and methane that is released as landfill gas. The carbon dioxide tends to dissolve producing the very high bicarbonate concentrations typical of Phase 3 leachates. The rate at which this phase becomes established is controlled by a number of factors, including the content of readily putrescible waste. Since the majority of the organic compounds are high molecular weight humic and fulvic acids, the leachates are characterized by relatively low BOD values. Ammoniacal nitrogen continues to be released by areas of the waste where phase 2 is continuing and generally remains at high concentrations in the leachate. Falling redox potential immobilizes many metals as sulphides in the waste. (Source: www.wikipedia.com/leachate) Typical leachate effluent Leachate is usually termed as a high strength wastewater. The polluting liquid has a high concentration of contaminants and varies throughout the landfill age as shown in the table below. From the above table, it noticed that leachates are normally alkaline having a pH of 6.0-8.4. The average COD value is found to be 5000 mg/l and the ammoniacal nitrogen remains within a similar range 900-3000 mg/L for all most of the sites. As it has been portrayed, the leachate does not meet the requirements for discharge either in sewers or surface water (see Appendix C) and this clearly indicates a need for treatment. CHAPTER 3 Treatment Options Overview Most landfills operate their own onsite leachate pretreatment and treatment facilities. Three types of treatment are possible physical, chemical and biological. Usually they are used in conjunction with one another. The constituents of leachate and availability of resources determine the treatment method to be adopted. Therefore, it should be efficient, flexible and an economical option. The leachate quality is highly dependent on the waste materials being disposed and the stage of their anaerobic decomposition. Hence, there is a variation in the constituents concentration. It has been observed that throughout the life cycle of a landfill, the ammonia nitrogen concentration remains very high. Amongst several usual parameters, ammonia nitrogen is a key one as it influences the selection and the design of the treating system. Physical Treatment Ammonia Stripping Ammonia can be removed by the air stripping technique which consists of blowing air through the wastewater. The method is based on the following equation; The above equation is highly dependent on the pH so that an exchange of ionic forms can take place. The equilibrium constant for this reaction is 10-9.25 at 18 ° C (Sorensen, 1993). pH = 9.25 + log [NH3] / [NH4+] From the above equation a pH greater than 10 is needed for releasing the ammonia gas. At normal temperature only 2% of the gas is liberated and therefore the wastewater should be heated to increase the efficiency of the treatment process. In achieving relatively low effluent values of ammoniacal-N (e.g. Reverse Osmosis The process consists of applying a pressure to the wastewater, i.e. the leachate, which passes through a semi permeable membrane. The water molecules present in the wastewater will pass the membrane forming the permeate and the contaminants remaining are the concentrate. The main advantage of using such a system is the removal of non-biodegradable compounds such as residual COD, heavy metals and chloride ions together with other large molecules present in leachate. The concentrate produced is a major issue as it is highly toxic to the environment. It is usually recirculated in the landfill or disposed off-site for storage. The removal rate of the contaminants is usually greater than 99.6 %. The plant is usually operated in more than one stage and occupies less space when compared to other treating systems. The process is currently in use in several countries such as France, Germany and Holland (IPCC, 2007). Activated Carbon Adsorption Activated carbon is used as an adsorbent for the removal of organic compounds. It is used in one of the following forms, powdered and granular. Due to the high cost of activated carbon, it is normally utilized for polishing after biological treatment. With an optimum dose and sufficient contact time, a considerable decrease in COD and BOD concentration can be achieved by this method. In the powdered form, the carbon is meant for single use and it loses its adsorption capacity and therefore cannot be reactivated. The mixed liquor must then be treated to remove the PAC, by subsequent processes, such as coagulation, flocculation, or filtration. In the granular form, the carbon can be used again but must be removed which requires specialized equipment (IPCC, 2007). Biological Treatment Processes The treatment process is comprised of growing and reproducing microorganisms in a controlled environment to stabilize organic matter. There are two forms of growth process attached and suspended. In suspended growth treatment systems, microorganisms are maintained in suspension within the wastewater whereas in the attached growth process, the biomass grows and is retained on a medium. Attached Growth Processes Percolating filters Rotating biological Contactors (RBC) Suspended Growth Processes Aerated lagoons Activated Sludge Process (ASP) Sequencing Batch Reactor (SBR) Combined treatment with domestic wastewater (co treatment) Percolating Filters It is an aerobic biological treatment system. Wastewater flows over a fixed and inert medium to which biofilms are attached and trickles down under gravity. The medium may be made up of different materials such as plastics and gravels and the depth of the filter is normally 2-4 m. The effluent is passed through a clarifier to remove biological solids. The percolating filter has many disadvantages concerning the treatment of landfill leachate. The system is efficient mostly for the treatment of low strength leachate. A recurrent problem is the clogging of the filter media and vulnerability to shock-term load (IPCC, 2007). Rotating Biological Contactors The process consists of large diameter steel or corrugated plastic media centered around a horizontal shaft, usually placed in a concrete tank. The media is slowly rotated (mechanical or air drive). At any given time during the rotation, about 40% of the media surface area is in the wastewater. Organisms in the wastewater are attached and, multiply on the rotating media until they form a thin layer of biomass. RBC is most effective for treating methanogenic than acetogenic leachates and for concentrations of ammoniacal-N below 500mg/l. The rotating biological contactor may have operational problems, since high concentrations of degradable COD can result in excessive sludge growth, and clogging of interstices within rotors (IPCC, 2007). Aerated Lagoons Aerated lagoons are operated by a combination of aerobic and anaerobic processes. The lower part of the lagoon converts the settled solids and sludge into carbon and methane by the action of anaerobic decomposition. The upper part is usually aerated, surface aeration or by algae present, to oxidize compounds from the anaerobic zone. Effluent is withdrawn from the upper zone, generally over an overflow arrangement. For discharge into surface waters, a secondary settlement lagoon or reed bed filtration system is needed for wastewater polishing. The constraints of the system are as such it requires large space and is quite sensitive to temperature changes. There is the possibility of odurs emanating from the lagoon. The main concern is the inability to provide consistent and reliable design in order to meet the discharge limits. Activated Sludge Process It is the most widely used aerobic biological process for treatment of domestic wastewater. It operates on the basis of a continuous inflow of wastewater. The latter is completely mixed and aerated for certain period of time, giving rise to mixed liquor. For nitrification to occur the sludge age must be greater than 8 days, so that the nitrifying bacteria can grow sufficiently large in numbers to exert an oxygen demand. The mixed liquor is allowed to settle in the clarifier and the biomass is returned to the aeration tank. The clarified effluent is decanted for disposal or tertiary treatment. The ASP is a continuous process and leachate cannot be treated directly, it requires dilution due to ammonia toxicity. Sequencing Batch Reactor The reactor is a slight modification of the ASP. It operates on a fill-and-draw basis using the suspended growth process. The SBR utilizes a single tank which accommodates aerobic biological treatment, flow equalization, settlement of solids, effluent clarification and decanting. Thus, it is usually described as operating in time rather than space when compared to conventional ASP. The reactor consists and operates under the following cycles: Fill: During the fill operation, volume and substrate (raw wastewater or primary effluent) are added to the reactor. The fill process typically allows the liquid level in the reactor to rise from 75% of capacity (at the end of idle period) to 100%. During fill, the reactor may be mixed only or mixed and aerated to promote biological reactions with the effluent wastewater. React: During the react period, the biomass consumes the substrate under controlled environmental conditions. Settle: Solids are allowed to separate from the liquid under quiescent conditions, resulting in a clarified supernatant that can be discharged as effluent. Decant: Clarified effluent is removed during the decant period. Many types of decanting mechanisms can be used, with the most popular being floating or adjustable weirs. Idle: An idle period is used in a multitank system to provide time for one reactor to complete its fill phase before switching to another unit. Because idle phase is not a necessary phase, it is sometimes omitted. Advantages of the system It requires small space as a common tank is used for the various unit processes. Flexibility in operating the reactor. The reaction time can be controlled and settling can be achieved under quiescent conditions. There the elimination of the return sludge pumping when compared to the ASP. Disadvantages of the system A higher level of sophistication is required (compared to conventional systems), especially for larger systems, of timing units and controls. Potential of discharging floating or settled sludge during the draw or decant phase with some SBR configurations. Combined Treatment with Domestic Wastewater It is a combined method for treating domestic wastewater and landfill leachate. Both wastewater and leachate can be treated at suitable mixing ratios (Aktas, 2001). Domestic wastewater can provide phosphate while leachate can provide nitrogen based nutrients, thus compensating for nutrients deficiency. Hence, nutrients need not to be supplied. Leachates from older landfills have a lower BOD/COD value and a smaller biodegradable organic fraction. There may not be sufficient COD to support denitrification of nitrate, a supplementary source of organic carbon is required to ensure adequate denitrification. Synthetic chemicals, such as methanol or acetic acid, are effective but quite expensive. It is necessary to find an alternative cost effective source of easily biodegradable carbon (Zhang, 2005). The mixing ratios are determined or else there will be nitrification inhibition by the presence of excess free ammonia. Case studies for biological treatment of landfill leachate The Buckden Landfill Site has been operational since 1994 and has been successful in treating landfill leachate for more than 10 years. The landfill site uses twin sequencing batch reactors, each designed for treating up to 100 m3/day. The effluent is then treated by means of reed bed and an ozonation plant for wastewater polishing and removal of pesticides. The plant has a design loading rate of 0.02 0.040 kg N/kg MLVSS. The plant has been successful in removing ammonia nitrogen from 331 mg/L to 0.27 mg/L. Only the COD value has not met the discharge limits ( The main running costs are due to electricity for aeration and for ozonation. There is also the use of sodium hydroxide for automatic pH control, and of phosphoric acid for provision of phosphorus as a nutrient, which are relatively small costs. Another case is a South-African landfill which receives up to 2000 tonnes of MSW each day. Up to 80 m3/day of leachate are generated, which have to be treated to very high standards. The treatment system is made up of a SBR with final polishing through a reed bed planted with Phragmites. The SBR is highly efficient for ammoniacal nitrogen removal from over 1200 mg/l to less than 1.0 mg/l. COD values are reduced by 60% from raw leachate values of over 2000 mg/l (Robinson et al., 2005). CHAPTER 4 MATERIALS AND METHODS 4.1. Overview This chapter deals with the methodology adopted and is comprised of the following phases: Sampling Sample preservation Wastewater characterization Leachate Wastewater from SMTP Sludge Biological treatment of landfill leachate using a SBR Co-treatment of landfill leachate with wastewater from SMTP Testing Results and analysis Conclusions Sampling Sampling is done to represent a certain population, in this case wastewater, on which tests are performed and the results symbolize the wastewater characteristics. This can be achieved by two methods: composite sampling and grab sampling. A composite sample consists of collecting samples at regular interval in time. This will be representative of the average wastewater characteristics. A grab sample is based upon obtaining a distinct sample regardless to its flow or time of the day. If the wastewater quality is not highly variable, the results obtained from grab sampling will tend to corroborate composite ones. Both methods are used and for this project the grab sampling technique was adopted. Sample Preservation Soon after the samples were collected, they were tested and if not possible, they were preserved. The latter is crucial step as most of the wastewater constituents have to be kept as are in their original state. They were incubated at 4 ° C and when necessary pH control was done by adding sulphuric acid. Subsequently, this will stop all the biological activities. Wastewater Characterization The next step after sampling is characterization, i.e. determining the level of constituents present in the wastewater. As a fact of that, the treatment method is selected and applied to the polluting material. Each time, when new samples were obtained, they were characterized in compliance with Standard Methods of Testing. For the project, characterization has to be done for these materials; Leachate The leachates were delivered at the UOM Public Health Laboratory, on the 23rd October 2007 and 9th January 2008, and were characterized for the main polluting parameters. Then the sample was preserved till the treatment starts. Domestic Wastewater The domestic wastewater was collected at SMTP. The sample was collected from the primary clarifier after degriting has been done on the following dates: 26th February and 3rd March 27, 2008. The samples were immediately characterized and then used. Sludge For nitrification to take place there should be microorganisms feeding on the organic matter, but leachate does not contain any. Therefore, the returned sludge from SMTP was collected and brought to the UOM Public Health Laboratory. The sludge was allowed to settle and the supernatant was discarded, the residual left was used for testing. As a result of that the sludge concentration was increased and smaller amount is required for biological treatment. A TSS was carried out and the value obtained was used for calculations. The sludge was also studied under the microscope determining the microorganisms present and their conditions. Biological Treatment of Landfill Leachate using a SBR The first option for treating leachate was the biological treatment by making use of a SBR. It was made up of the following phases: fill, react, settle and decant. The reactor consisted of sludge, water and leachate with varying composition. Their volumes were calculated such that the ammonia nitrogen concentration is about 50 mg/L in the reactor. The latter was aerated for a period of 24 hours. The main polluting parameters were monitored and accentuating upon the level of ammonia nitrogen and nitrate nitrogen. The system was run for a number of cycles and then denitrification phase was operated. Experimental Procedure A reactor of capacity 20 L was considered with an MLSS concentration of 4000 mg/l. The dissolved oxygen concentration had to be greater than 2 mg/l and this was achieved by the means of air diffusers. The diffusers provided the mixing within the reactor. Immediately after the setting out of the reactor, a grab sample was collected and was tested. These values were set as baseline. After 24 hours of aeration, another sample was collected from the reactor and tests were performed. The critical parameter i.e. ammonia nitrogen was observed and if, the value is not within the discharge limits then it aerated till the expected result is obtained. The biomass required nutrients which provided in the form of Potassium Hydrogen Phosphate. In order for the treatment to take place, we had to cater for alkalinity and this was achieved by the addition of concentrated sodium hydroxide. Thus the nitrification process was being monitored until no further treatment. A total of 3 sequential batch reactors were operated. After the operation of the third reactor, the denitrification phase was initiated. All the air diffusers were switched off and acetic acid was added to the reactor. The dissolved oxygen concentration was monitored till it reached the zero value and the nitrate nitrogen concentration was measured. Co-treatment of Landfill Leachate with Wastewater from SMTP The other alternative is a combined method, treating domestic wastewater and leachate together. The treatment is biological in nature using a SBR with phases; fill, react, settle and decant. The treating system consisted of aerating the SBR, composed of sludge, domestic wastewater and leachate, for a period of 24 hours. The volume of leachate was gradually increased until no further treatment was observed. The main parameters were monitored, laying emphasis on the nitrification process. The values were recorded and analyzed. Experimental Procedure Small reactors of capacity 5 L each were considered with an MLSS concentration of 1500 mg/l. The first SBR was made up of 100% DWW and sludge only, the second one 95% DWW, 5% leachate and sludge, the third one 90% DWW, 10% leachate and sludge and so on. An example is being shown below. The dissolved oxygen concentration was kept greater than 2 mg/l by the use of air diffusers which also provided the mixing within the reactor. Immediately after the setting out of the reactor, a grab sample was collected and was tested. These values were set as baseline. After 24 hours of aeration, another sample was collected from the reactor and tests were performed.

Thursday, September 19, 2019

classroom management plan for grades 7-12 :: essays research papers

Classroom Management Plan for Day one of class (for grades 7-12) Classroom Procedures Entering the Classroom Students will come into the classroom quietly and in an orderly fashion without running. They will unload their backpacks as quickly and quietly as possible and begin to prepare for the day. End of Class Dismissal Students will be allowed to leave the classroom only when the teacher says so. The students will leave the classroom quietly and in an orderly fashion without running or shoving. Bell Work Bell work will be utilized every day. When each student enters the classroom and gets settled into their seat, they will pull out their â€Å"bell work† folder and begin the assignment that is written on the board under the title â€Å"bell work†. Quieting the Class When the teacher wants to quiet the class she will clap once. The first clap will be the â€Å"warning† clap that will signal to the students that it is time to settle down. The teacher will then clap twice. By the time the second clap is done, the students should be completely quiet. Taking Class Roll Roll will be taken at the beginning of each class period after the bell signaling the beginning of class has sounded. A student will be assigned to do this each week. Class Motto The class motto, â€Å"Failure is not an option†, will be posted at the top of the chalkboard and never erased. The motto will be referred to at the discretion of the teacher. Collecting Seat Work Seat work will be collected according to the configuration of the desks. The â€Å"U shaped† seating arrangement will be used in the classroom. All papers will be sent to the ends of the U and then collected there by the teacher. Turning in Work All other work that is not designated as seat work such as tests, worksheets, or essays will be turned in on the teachers desk where there will be a basket for each class period. Notes from Home Students should gives their notes from home directly to the teacher who will then read the note and place it into her file folder labeled, â€Å"notes from home† Restroom Breaks Restroom breaks will be allowed only when extreme circumstances warrant them such as vomiting, a pen bursting and creating a mess, or a note form a parent specifying that their child needs to use the restroom due to some illness. Going to Lunch Students will go to the cafeteria in a straight line, quietly, while keeping their hands to themselves.

Wednesday, September 18, 2019

Anger of Gods Depicted in the Old Testament and Kafkas Book, Metamorph

The anger of Gods throughout both stories leads you to believe that the Gods will not hesitate to take revenge on mankind for creating a world of evil in a world they created for good. The Gods from Metamorphoses and the God from the Old Testament create a world full of life, to live happy and full of grace. The destruction and recreation of the world by the Gods of each book, however similar they may seem, are full of differences as they both teach mankind lessons that should not be forgotten. â€Å"Whatever God it was, who brought order to the universe, and gave it division, subdivision, he molded earth† Metamorphoses pg 685. In the beginning the earth had nothing, no light to call sun, no water to bath in, and no human to walk on the ground that we call land that was not land. The Gods choose to make a playground of sorts. In both literature pieces the Gods divide the heavens and the earth, split the water from the land, light from the dark. The God’s made animals for this land and water and creatures for the air. â€Å"But something else was needed a finer being, more capable of mind, a sage, a ruler, so man was born, It may be in God’s image† Metamorphoses pg 686. â€Å"And the Lord God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul† The Old Testament pg 54. The Old Testament God thought it was not good for man to be alone so from the bone of man’s r ib he made a woman. The first murder in the Old Testament is the beginning of God realizing that man was evil, â€Å"god saw the wickedness of man† Old Testament pg 56. Cain murdered his brother Abel, out of jealousy of the Lord’s love. Able a Sheppard who brought the fat of the animals and the Lord had respect fo... ...s to repopulate the earth, â€Å"Go from the temple, cover your heads, loosen your robes, and throw your mothers bones behind you† pg 692. Pyrrha being so innocent could not throw the bones of her mother and refused until she would never insult her mother in such a way. Themis over and over told them to do this until Deucalion thought maybe he meant to throw stones behind them. When Deucalion and Pyrrha did this the stones â€Å"began to lose their hardness, to soften, slowly, to take on form, to grow in size, a little, become less rough, to look like human beings† pg 693. All the stones that Deucalion threw turned to man and all the stones that Pyrrha threw behind her became women. Life began to form from other things as well. The moist mud from the waters drying turned to animals that now roam our earth, swim in our seas and oceans, birds that fly in our skies.

Tuesday, September 17, 2019

Concussions In the NFL

Concussions in the NFL have become much more prevalent, and the effects of these concussions appear to have become more severe, as this is a direct result of the development of player training systems. Over the past decade there has been vast improvements made in the training equipment and techniques used to train NFL players. This has inevitably resulted in players getting much stronger, faster, and bigger. Over the same period of time concussions have also systematically became more frequent as well.This has led many people to believe that there is some type of relationship between the improvements in player training and the increase of concussions over the course of a NFL season. The focus of the first paragraph of this essay will be on the overall increase of strength and size of players and how this relates to concussions. The second paragraph will focus on the amount of season and career ending concussion that have occurred this last season opposed to the amount before it.The t hird paragraph will focus on the studies, which have been conducted on past players that have showed they have some sort of brain damage, which has resulted from football related activity. The overall strength and size increase is most obvious on the offensive and defensive lines. Consider this in the mid 1970’s Randy white starred at defensive tackle for the Dallas Cowboys. White weighed 257 pounds, he lined up across from centers weighing 240 or 250 pounds and guards who were considered huge if they weighed 265.Last year's Super Bowl featured defensive tackles B.J. Raji who weighs 337 pounds and Casey Hampton who weighs 330 pounds versus guards Chris Kemoeatu who weighs 344 pounds and Josh Sitton who weighs 318 pounds. To put it in perspective Randy White who played Defensive Tackle and weighed 257 pounds weighs almost 20 pounds less than Baltimore Ravens rookie outside linebacker Courtney Upshaw who weighs in at a whopping 271 pounds. Upshaw is also much faster than White was. This is a prime example of how players have increased in size and strength over the years, and have become more effective in there positions.Which means that players at certain positions will have programs specifically designed for them to get bigger and stronger. But players have not just gotten bigger they have also gotten faster. This increase in weight, overall strength, and speed is clearly a result of the developments that have been over the years in player training systems. With players looking more like modern day Roman Gladiators than football players, there is no wonder why concussions have been occurring more frequently. Over the past decade there has been a drastic increase in recorded concussions over the course of an entire NFL season including practice.From pre-season week 1 of the 2011-12 of the NFL season until week 17 regular season 2011-12 there was 167 concussions 12 of those resulted in players being placed on IR (Injured Reserve) which means they are inact ive for the entire season (season ending). Over the exact same period of time in the 2007-08 season there were only 115 documented concussions and only 4 of those resulted in Players being placed on the IR. That is a 48% increase in total concussions and 33% in season ending concussions, in just 4 seasons.So one can only imagine the increase that you would see from the early 1990’s to now, if concussions were documented as thoroughly then as they are now. This increase in concussions over such a short period of time is a direct result of player training systems, because in 2008 most NFL teams ran 5 2 a day practices per week in training camps, which only included 3 2 hour weight training sessions. But heading in to 2011-12 season most teams were running 5 2 a day practices and 1 3 a day practices, and the majority of those camps ran 4 3 hour weight training sessions.There have been several studies conducted on brains of ex-NFL players the most recent of those players is Junio r Seau. Seau committed suicide on May, 2, 2012 after a lengthy 19 year NFL career. Junior Seau suffered from chronic traumatic encephalopathy CTE, which is believed to have been partially induced by all the blows to the head that he has taken. Junior started showing symptoms of CTE at the conclusion of the 2007-08 season these symptoms include impulsivity, forgetfulness, depression, and sometimes-suicidal ideation.The time period in which Seau’s family said he started showing signs of CTE is coincidentally the same period of time that NFL teams started to increase the length of practice and conditioning exercises. Throughout the course of Seau’s 19 year playing career he played at least 13 games in every season up until the 2004-05 season and up until his retirement after the 2008-09 season he only managed a measly average of 8 games per season. He suffered 3 undocumented concussions according to his family and 2 more documented ones over the same time period.Junior is not the only ex-NFL player to be diagnosed, more than 30 NFL players have in recent years been diagnosed with CTE, a condition once known as â€Å"punch drunk† because it affected boxers who had taken multiple blows to the head. The increase of player’s size and strength in the NFL in recent years has a direct correlation with the increase in concussions. This evident by the 48% increase in total concussions since the 2007-08 season, and the 33% increase in season ending concussions.The facts that Junior Seau was virtually concussion free his entire career, which spanned 19 years up until the 2004-05 NFL season. Despite the advances in medical sciences and protective player equipment, it is just not enough to protect these mammoth NFL players from concussing one another. The first of two literary devices that I used was a metaphor â€Å"With players looking more like modern day Roman Gladiators than football players† This sentence suggests modern NFL players ex hibit many of the same traits that Roman Gladiators once exhibited.This sentence supports my argument because; the increase in player training technologies has essentially turned players into gladiators. The second literary device that I used was Irony â€Å"he started showing signs of CTE is coincidentally the same period of time that NFL teams started to increase the length of practice† this is ironic because it is not a coincidence at all there is clearly a direct correlation between length of conditioning/weight training exercises and amount of sustained concussions. Concussions In the NFL Concussions in the NFL have become much more prevalent, and the effects of these concussions appear to have become more severe, as this is a direct result of the development of player training systems. Over the past decade there has been vast improvements made in the training equipment and techniques used to train NFL players. This has inevitably resulted in players getting much stronger, faster, and bigger. Over the same period of time concussions have also systematically became more frequent as well.This has led many people to believe that there is some type of relationship between the improvements in player training and the increase of concussions over the course of a NFL season. The focus of the first paragraph of this essay will be on the overall increase of strength and size of players and how this relates to concussions. The second paragraph will focus on the amount of season and career ending concussion that have occurred this last season opposed to the amount before it. The third paragraph will focus on the studies, which have been conducted on past players that have showed they have some sort of brain damage, which has resulted from football related activity.The overall strength and size increase is most obvious on the offensive and defensive lines. Consider this in the mid 1970’s Randy white starred at defensive tackle for the Dallas Cowboys. White weighed 257 pounds, he lined up across from centers weighing 240 or 250 pounds and guards who were considered huge if they weighed 265. Last year's Super Bowl featured defensive tackles B.J. Raji who weighs 337 pounds and Casey Hampton who weighs 330 pounds versus guards Chris Kemoeatu who weighs 344 pounds and Josh Sitton who weighs 318 pounds. To put it in perspective Randy White who played Defensive Tackle and weighed 257 pounds weighs almost 20 pounds less than Baltimore Ravens rookie outside linebacker Courtney Upshaw who weighs in at a whopping 271 pounds. Upshaw is also much faster than White was.This is a prime example of how players have increased in size and strength over the years, and have become more effective in there positions. Which means that players at certain positions will have programs specifically designed for them to get bigger and stronger. But players have not just gotten bigger  they have also gotten faster. This increase in weight, overall strength, and speed is clearly a result of the developments that have been over the years in player training systems. With players looking more like modern day Roman Gladiators than football players, there is no wonder why concussions have been occurring more frequently.Over the past decade there has been a drastic increase in recorded concussions over the course of an entire NFL season including practice. From pre-season week 1 of the 2011-12 of the NFL season until week 17 regular season 2011-12 there was 167 concussions 12 of those resulted in players being placed on IR (Injured Reserve) which means they are i nactive for the entire season (season ending). Over the exact same period of time in the 2007-08 season there were only 115 documented concussions and only 4 of those resulted in Players being placed on the IR.That is a 48% increase in total concussions and 33% in season ending concussions, in just 4 seasons. So one can only imagine the increase that you would see from the early 1990’s to now, if concussions were documented as thoroughly then as they are now. This increase in concussions over such a short period of time is a direct result of player training systems, because in 2008 most NFL teams ran 5 2 a day practices per week in training camps, which only included 3 2 hour weight training sessions. But heading in to 2011-12 season most teams were running 5 2 a day practices and 1 3 a day practices, and the majority of those camps ran 4 3 hour weight training sessions.There have been several studies conducted on brains of ex-NFL players the most recent of those players is J unior Seau. Seau committed suicide on May, 2, 2012 after a lengthy 19 year NFL career. Junior Seau suffered from chronic traumatic encephalopathy CTE, which is believed to have been partially induced by all the blows to the head that he has taken. Junior started showing symptoms of CTE at the conclusion of the 2007-08 season these symptoms include impulsivity, forgetfulness, depression, and sometimes-suicidal ideation.The time period in which Seau’s family said he started showing signs of CTE is coincidentally the same period of time that NFL teams started to increase the length of practice and conditioning exercises. Throughout the course of Seau’s 19 year playing career he played  at least 13 games in every season up until the 2004-05 season and up until his retirement after the 2008-09 season he only managed a measly average of 8 games per season. He suffered 3 undocumented concussions according to his family and 2 more documented ones over the same time period. J unior is not the only ex-NFL player to be diagnosed, more than 30 NFL players have in recent years been diagnosed with CTE, a condition once known as â€Å"punch drunk† because it affected boxers who had taken multiple blows to the head.The increase of player’s size and strength in the NFL in recent years has a direct correlation with the increase in concussions. This evident by the 48% increase in total concussions since the 2007-08 season, and the 33% increase in season ending concussions. The facts that Junior Seau was virtually concussion free his entire career, which spanned 19 years up until the 2004-05 NFL season. Despite the advances in medical sciences and protective player equipment, it is just not enough to protect these mammoth NFL players from concussing one another.The first of two literary devices that I used was a metaphor â€Å"With players looking more like modern day Roman Gladiators than football players† This sentence suggests modern NFL pla yers exhibit many of the same traits that Roman Gladiators once exhibited. This sentence supports my argument because; the increase in player training technologies has essentially turned players into gladiators. The second literary device that I used was Irony â€Å"he started showing signs of CTE is coincidentally the same period of time that NFL teams started to increase the length of practice† this is ironic because it is not a coincidence at all there is clearly a direct correlation between length of conditioning/weight training exercises and amount of sustained concussions.

Monday, September 16, 2019

Home Education: For better or for worse Essay

A home school, as the name implies, is basically an alternative form of education that allows students to receive their education at their own homes instead of going to traditional public or private schools. Students who study at home are either taught by personal tutors, their own parents, or sometimes the school sends the whole curriculum or all the lessons that need to be learned to them. Most of the time, home school students only need to go to their respective schools when they need to take an exam, for example, but in several cases, they take their quizzes or examination at home as well. There are several reasons why parents opt to have their children study at home instead of sending them to educational institutions. These reasons may include: the parents’ belief that they can give their child better education at home, the child’s disabilities or psychological disorders which need special attention; the parents inability to afford sending their child to traditional schools, the child’s failure to learn anything in private or public schools, the desired school is too far from the child’s home, the child’s failure to pass the entrance exams in any school, problems with policies of the school, and even religious reasons. At present home education has helped a lot of students who are unable to study in traditional schools all around the world. However, while I acknowledge that there are millions of students that are home schooled and that the trend is growing almost every year, I am not entirely in favor of the concept due to various reasons. Although it may be true that home education provides a number of benefits for students, especially those who are impoverished, I believe that it defeats the other purposes of private and public schools, which is to ensure the child’s emotional, intellectual, and social growth and to prepare the child for the life after graduation. It is a well-known fact that a traditional school teaches not only the lessons found in textbooks but also certain aspects of life itself. In private or public schools, students get to interact with their peers. Interaction between students facilitates the exchange of new information, new insights, and new ideas which is highly essential for intellectual growth. Moreover, interacting with peers enables a student to create his own circle or network of friends which is important for social stability and growth. In addition, making friends can also be educational especially if it involves people from different cultures or nationalities. For example, an American student can learn a lot from his or her Chinese best friend regarding the lifestyle, food, beliefs, traditions, and history of China or vice versa. On the other hand, a home schooled student is strictly contained within the four corners of his or her house so he or she is unable to meet and interact with new people. In addition, since this student becomes isolated, he or she may develop a fear of other people or even the outside world in general. Moreover, although a home schooled student may be more intellectual than his or her traditionally educated counterparts since he or she is primarily focused on studying, he or she may not learn new information because of his or her dependence on textbooks. In short, he or she will have a narrower perspective about a lot of things as compared to a student in a traditional classroom setting where he or she can ask questions and give their own opinions regarding certain matter about the lesson. Furthermore, since a home-educated student is basically confined in his or her house, he or she may have a tendency of slacking off because there are no school rules. Home schooled students may study and may work when they want to provided that they pass the exams given to them. However, this defeats the purpose of having school rules and regulations which develop discipline in students. In traditional schools, students generally have to follow rules such as wearing of proper uniform, observing silence in hallways, displaying proper behavior while in the campus, and throwing of trash in the proper garbage cans, among many others. If they fail to abide by the rules and regulations of the schools they will be penalized. This â€Å"penalty system† in traditional schools instills in students the fear of breaking a rule due to the corresponding punishments and in effect, they become disciplined and follow the law. In addition, this system also teaches students to respect the authority and the law in general, which is basically what is lacking in home schools. Although the parents may have taught their home-educated children proper manners and respect, these children may only apply this when dealing with their parents since they never got to interact with other people. Furthermore, possibly the major disadvantage of home education is that it lacks an avenue for physical growth. Home-educated students generally have no physical activities such as sports which could lead to weight gain and possible health problems. In addition, since home education does not have extracurricular activities, students are unable to showcase the possible potentials they may have. For example, a home- schooled student may have the makings and traits of a leader, however, he or she cannot show his or her capabilities since there are no opportunities to show them. Moreover, a home-schooled student may have amazing talent in basketball and has the potential to be granted a scholarship in a prestigious university but is unable to do so since he or she is restricted within the comforts of his or her own home. In short, what home schools also lack is the avenue for students to be recognized for their talents and skills in activities other than academics. In fact, they may not be even recognized in academics since it is already an advantage for them to be studying at home. Basically, what I would like to point out is that there are necessary lessons in life that cannot be learned inside a home school or even inside a classroom. For a student to be well-equipped to face the real world, he or she should have experienced the little realities of life which are present in traditional schools. For me, I believe that home schools should only be applicable to students who have disabilities and psychological defects and who are too poor to afford private education. The other reasons are not justifiable since traditional schooling is basically a necessity for everyone. Parents who force their children to receive their education at home without valid are actually impeding their personal growth. If this is the case, they should not be surprised if their children grow up with various problems in life. Over-all, I believe that while a home school can provide intellectual growth for students, it lacks an avenue for equally important aspects of personal growth such as emotional, social, and sometimes even spiritual growth, which are all important for a student to understand and face life itself.