Burro Genius Essay Example | Topics and Well Written Essays - 750 words

Burro Genius - Essay Example The one belief they instill in the child is that one should not lose perspective in order to excel or make progress in life. As a little boy aged six, I used to be extremely playful and forgetful at the same time. One day after school, I happened to bump into my toy as I was approaching my room, without thinking twice I dropped my bag, picked my toy and started playing with it. The game became more attractive, and I ended up in the garage, back in the house my little sister came across my bag, started playing with it and ended up messing with my homework. Since I had nobody to blame but myself, it meant I had to inform my mother so that she can go and explain to the teacher for me to get the homework. This situation also applies to Victor’s case, which left the car windows opened, and ended up with a cloth full of feathers. He learned that one does not need to be angry for every mistake one make nor does he need to look for someone blame for not correcting his mistakes for him but, embrace the mistake and work towards ensuring that it does not happen again. By helping me out on explaining to the te acher what happened to my initial homework, my mother instilled the lesson that helped me learn that no one is perfect, and people are not gauged on mistakes they made but how well they progress after the mistake. The thesis of this paragraph is, just like Victor no one is perfect not even parents, but the best thing they do is ensuring that the same mistake does not happen again (Villasenor p56). My mother was doing some work on a computer one night at home, being a mother of two she had to hop from one task to another. Since, my sister was still too young, and she required much attention she had to juggle from looking after her, cooking for all of us as well as finish the work she had on the computer. In the process of juggling, she had to leave the computer open, as I was passing around the house I

Prigogine Investigation Essay Example for Free

Prigogine Investigation Essay The origination and evolution of living organisms is considered by many scientists, due to general laws of nature, especially the second law of thermodynamics. In this paper this idea is explored, taking in account the dissipative structures and Prigogine’s thermodynamics. Introduction The use of thermodynamics in biology has a long history rich in confusion (Morowitz, 92) (Klyce, Brigg, http://www. panspermia. org/seconlaw. htm) The second law of thermodynamics was discovered by Clausius, who coined the term Entropy, which is usually defined as the degree of disorder. In the most general sense, Evolution of life means, growing in ordered combinations from cells, to tissues and organs, to plants and animals, families, communities, and ecosystem. It can be seen that these two terms: evolution and entropy express totally contradictory concepts. According to second law, Entropy of a closed system can never decrease, i. e. dSV ? 0 (Gibbs, 1928). But, in case of evolution, the living systems increasingly go on to complex state of more order, suggesting that entropy in this closed system has decreased. This is the paradox that has baffled both biologists and physicists alike. Hence, an initial theory which both physicists and biologists agreed upon was: life violates the second law of thermodynamics. Evolution of life and Entropy The contradiction can however be explained, by subscribing to one of the two very different schools of thought. Either we can accept that the order that is seen in the evolution and growth biological systems is maintained at the expense of thermodynamic order. That is to say, sustenance in the form of external energy is always provided to the organism from external environment and entropy of this larger system is increasing. Hence, living beings attract negative entropy, in order to compensate for this increase in the entropy, which explains the order. This concept was formed by Schrodinger. There is another explanation, which was proposed by Prof. Ilya Prigogine. According to him, the living organisms function as dissipative structures, i. e. thermodynamically open systems operating in non-equilibrium environment. These have the capacity for self-organization in the face of environmental fluctuations. In other words, they maintain their structure by continuously dissipating energy. Such dissipative structures are permanently in states of non-equilibrium. Ds/dt 0 away from steady state Ds/dt = 0 steady state (Prigogine, 1977) In this case, equilibrium is the state of maximum entropy. A system that is not in equilibrium exhibits a variation of entropy, which is the sum of the variations of entropy due to the internal source of entropy, plus the variation of entropy due to the interaction with the external world. The former is positive, but the latter can be negative. Therefore, total entropy of the system can decrease. Life according to this theory can then be summarized as: An organism lives because it absorbs energy from the external world and processes it to generate an internal state of lower entropy. It can live as long as it can avoid falling in the equilibrium state. According to the second law, only irreversible processes contribute to entropy production. This means the existence of a function in an isolated system which can only increase in time. It follows that the positive time direction is associated with entropy (Prigogine, 1977). Now, biological evolution is hierarchical and can be considered as an irreversible process of the variation of life with respect to the evolutionary time scale. The Law of Temporal Hierarchies makes it possible to identify quasi-closed thermodynamic systems and subsystems within open biological systems (Gladyshev, 2003). This facilitates the study of individual development (ontogenesis) and evolution (phylogenesis) of these subsystems. For instance, it is seen that the specific Gibbs function for the formation of supramolecular structures of biological tissues, G tends towards its minimum in the course of both ontogenesis and phylogenesis. (Gladyshev, 2005) The above model implies that, the mean flow of matter is quasi-stationary and the nature of incoming matter to the system remains practically unchanged. In other words, the supramolecular phase (structure) of the organism evolves against the background of the incoming flow of chemical substances of practically constant composition. This principle of the stability of chemical substances is a thermodynamic principle. Accordingly, the tendency of biological systems during evolution to generate relatively highly stable structures of higher hierarchies leads to the selection of relatively less stable structures of lower hierarchies. This rejuvenates the lower hierarchical structures and causes nearly unbounded evolution of the biological world. (Gladyshev, 2005) Conclusion The findings of hierarchical thermodynamics, specifically supramolecular thermodynamics of quasi-closed systems, confirm the thermodynamic tendency of biological evolution. Additional experiments could refine this model and further verify that second law can be applied in its classical definition to explain the origin and evolution of life References 1. Gladyshev, Georgi P. â€Å"What is Life- A physical chemist’s viewpoint†, 12th Dec. 2005 http://www.panspermia.org/seconlaw.htm

Their Eyes Were Watching God Essay -- Character Analysis, Janie

Speech is arguably the primary source of communication for humanity, enabling us to experience and share life with one other through our words. However, we see a different path of life in Janie, the main character in the book Their Eyes Were Watching God. Janie’s character evolves with using control of silence to her benefit, helping her find what she has always struggled to have: Individuality and independence. The relationships Janie has with her three husbands revolve around three versions of silence, while in pursuit of what she calls her â€Å"pear tree†, her true love. Logan forces silence from Janie which becomes an oppressor; Joe exploits Janie’s silence and uses it as a manipulator; and Janie’s only true love, Tea Cake, allows Janie to control silence, which becomes her liberator. In the book Their Eyes Were Watching God, silence is manifest as an evolving source of empowerment and identity for Janie, in that her character is molded not only by her speech but, more importantly, by her silence. In Janie’s journey to find herself, she initially has limited control of her own life, being forced into marriage by Nanny. Nanny wants what she feels is best for Janie, wishing for her to have security and protection. This marriage provides the perfect solution in Nanny’s eyes; Nanny promises Janie that all will go well with her marriage even though it may not seem so at the time. Janie reluctantly agrees, but soon realizes that Logan does not have her best interest at heart, causing her to quickly tire of him. Soon after Nanny’s death, the reader sees Logan change entirely. He commands Janie by ordering her around, expecting her to do whatever he demands of her. With Janie being a child, she is somewhat helpless to defend herself ... ...of love the reader sees from Tea Cake is his rescuing Janie from the dog attack. This unravels the mystery, revealing that Tea Cake does really love Janie; he is her pear blossom on her pear tree. Hurston successfully uses speech and silence to create a fascinating story about a young woman who grows up to find her individuality and in the end, her pear blossom. Logan, Joe, and Tea Cake all play an integral part in Janie becoming the strong, independent woman she is, ultimately allowing her to break the chain of abuse suffered by her mother and grandmother. Silence is the barrier in Janie’s life that she endures; through the suffering, Janie emerges to honor the struggles in her life, transformed into a woman who is beautiful, mature, and strong. Janie is rewarded with peace and happiness that her life now offers, with the pear tree that is forever hers to embrace.

Customer Lifetime Value Essay

Marketing Engineering for Excel is a Microsoft Excel add-in. The software runs from within Microsoft Excel and only with data contained in an Excel spreadsheet. After installing the software, simply open Microsoft Excel. A new menu appears, called â€Å"MEï€ ´XL.† This tutorial refers to the â€Å"MEï€ ´XL/Customer Lifetime Value† submenu. Overview Customer Lifetime Value (CLV) represents a metric of a customer’s value to the organization over the entire span of that customer’s relationship with a firm. Short-term sales influence CLV, but so do overall customer satisfaction, the churn rate in the segment, and the costs to acquire a new customer and retain an existing customer. The CLV approach helps firms answer such questions as: How much is my customer base â€Å"worth†? Taking into account observed churn rates, how many of the currently active customers will still be active in a few years? How much is a customer worth, depending on the segment to which he or she belongs? If acquiring a new customer costs $150, after how many periods can we recoup this investment? Customer lifetime value analysis considers your database at a segment level, using the answers you provide to the following questions: How many segments do you have in your database, and how many customers per segment? For a given period, how much is a customer worth, on average, in each segment (margins and costs)? What is the likelihood that a customer in segment A will switch to segment B during the next period? Getting Started A CLV analysis allows you to use your own data directly or a template preformatted by the MEXL software. The next section explains how to create an easy-to-use template to enter your own data. If you want to run a CLV analysis immediately, open the example file â€Å"OfficeStar Data (CLV).xls† and jump to â€Å"Step 3: Running analysis† (p. 4). By default, the example files install in â€Å"My Documents/My Marketing Engineering/.† Step 1 Creating a template Using the interactive assistant In Excel, if you click on MEï€ ´XL ï  § CUSTOMER LIFETIME VALUE ï  § CREATE TEMPLATE, a dialog box appears. This box represents the first step in creating a template to run the CLV analysis software. The first dialog box prompts you to use an interactive assistant. Unless you are already familiar with the methodology, you should select â€Å"yes.† Listing segments The first step of the template generation process requires you to label and list the segments that you want taken into account. Enter the names of segments to which a customer can belong. Press ENTER or click the â€Å"Add to list† button to add it to the â€Å"List of Segments.† Note that a segment of â€Å"lost customers† always appears in your list. This segment has the following properties: There is no activity by these customers (margins and costs equal 0). It entails an absorbing relationship state. As soon as a customer reaches this segment, he or she stays there forever. In other words, there is 100% chance the customer stays in that segment in the next period, and all other transition probabilities will be equal to 0%. After entering all your segments (at least one), click the OK button to proceed to the next step of the template creation process. Clicking on the OK button generates a template. Not using the interactive assistant You may skip this intermediary step and create a blank template. When you are prompted to use the interactive assistant, just click â€Å"no.† The following dialog box appears: When you click OK, you generate a new blank spreadsheet. You must enter the segment labels manually in the spreadsheet. In this example, if you update the names of the segments in cells B6, B7, and B8, the names of the segments automatically update in the other cells of the spreadsheet. Entering your data In this tutorial, we use the example file â€Å"OfficeStar Data (CLV).xls,† which in the default conditions appear in â€Å"My Documents/My Marketing Engineering/.† To view a proper data format, open that spreadsheet in Excel. A snapshot is reproduced below. A typical CLV analysis spreadsheet contains: Number of customers per segment. As of today, how many customers does the company have in each segment? Gross margins, or the average margins that the company expects from a customer over each period (e.g., year, quarter), on the basis of the segment to which this customer belongs during that period. In the OfficeStar example, a customer who belongs to the â€Å"Warm Customer† segment should generate $15 of gross margins on average during the next period (e.g., first quarter). Marketing costs, or how much money the company plans to spend per customer during the next period, according to the segment to which this customer belongs at the beginning of the period. Typically, active customers are followed more closely, receive more attention (e.g., direct marketing solicitations, sales representatives visits), and cost more to the firm. Transition matrix, which summarizes the likelihood a customer will switch segments during each period. This matrix should be read horizontally, and each line sums to 100% (because all customers appear in some segment). In the OfficeStar example, an active customer has a 75% likelihood of remaining in the same segment and a 25% chance of switching to the warm customer segment. A customer’s behavior during the previous period determines into which segment that customer is classified, and his or her segment membership then determines the marketing dollars the company should allocate to that customer in the next period. In the OfficeStar example, a customer who belongs to the â€Å"Active Customer† segment generates $90 of gross margins per period (e.g., quarter). Step 3 Running analyses After entering your data in the Excel spreadsheet using the appropriate format, click on MEï€ ´XL ï  § CUSTOMER LIFETIME VALUE ï  § RUN ANALYSIS. The dialog box that appears indicates the next steps required to perform a CLV analysis of your data. CUSTOMER LIFETIME VALUE – V130522 5/10 Number of periods: Specify the number of periods for which you want a detailed CLV analysis. Note that this choice does NOT affect the CLV computations, because the value of a customer always gets estimated over an infinite time horizon (though as time passes and discount rates apply, future revenues have less relative impact). The number of periods affects only the level of output. Discount factor: Indicate the discount rate to apply for the value of a dollar spent or received in the future as compared to the current period. A discount rate of 15% means that $100 profit in the next period is only â€Å"worth† $85 in today’s dollars. A greater discount factor reduces the impact of future revenues on CLV computations and thus focuses on shortterm  profits. You should increase the discount rate for turbulent or rapidly evolving markets, in which conditions change rapidly and future revenues therefore are highly uncertain. Setting: Select either Transactional or Contractual depending on the nature of the product or service you are modelling. Contractual models imply the existence of a contract between the transacting parties (e.g., a mobile phone contract between the provider and consumer). Contractual relationships imply continuous transactions and a known end to the contract. Transactional models imply discrete transactions with no implied end to the relationship. For use with our CLV model, the impact of this setting will affect the first period of the analysis. A Contractual setting implies no loss/gain in first month (since the customer is under contract) while the Transactional setting will reflect loss/gain in the first month. The discount factor gets applied after each period, regardless of how you define a period. If you define a period as a quarter, a discount factor of 15% translates into an effective yearly discount rate of almost 48% (15% discount rate applied four times per year). Remember to take this multiplicative effect into account when selecting an appropriate discount factor. After selecting these options, you must select the cells containing the data. First, the software asks for ranges of the current segment sizes and profits and costs for each segment, including a row dedicated to permanently lost  customers. If you use a template generated by Marketing Engineering for Excel, it has already pre-selected the cell ranges. Second, the software asks for a square range that shows the likelihood that a customer in each segment (row) will switch to each segment (column) in the following period. The newly generated spreadsheet contains the results of your CLV analysis. Step 4 Interpreting the results Customer lifetime value The last column of the CLV table outputs the expected CLV of a customer who currently belongs to a given segment, determined by summing the stream of all future gross margins, minus all future marketing costs, and taking into account both the discount factor and the likelihood of customers switching from one segment to another. These figures also appear in the â€Å"Lifetime Value† chart, shown below. A customer with a negative CLV actually means a loss of money for your firm. Number of customers per segment The next table (and chart) shows how many customers will be in each segment at each period of time in the future. The time horizon displayed on the chart matches the number of periods you specified in the â€Å"Run Analysis† options. Note that the â€Å"Lost Customers† segment is not displayed. In most applications, all customers eventually become lost customers, and over sufficient time, all other segments become empty. Customer base’s lifetime value The third table in the â€Å"CLV Analysis† sheet, labeled the Customer Base’s Lifetime Value, summarizes the future stream of revenues and marketing costs over a specified number of future periods (whether cumulative or not) at the global level. Some key elements of this table plot in the third (and last) chart of the spreadsheet. In particular, the Discounted Net Margins (cumulated) provide an answer to the question: â€Å"Over the next x periods, how much is my customer base worth?† Retention rates The final tables depict the likelihood that a customer will belong to any segment in any period of time in the future, depending on the segment to which he or she currently belongs. There are as many tables as there are segments in the analysis. In most applications, all customers eventually join the â€Å"Lost Customers† segment. The probability of belonging to that segment thus slowly reaches 1 (100%), and the probabilities of belonging to any other segment trend toward 0 over time.

Brian Montgomery

What skills do you believe manages should possess? A: Leadership, organizational and interaction skills, good communication. Planning Q: Why do you think Managers need to plan? A: You need to have agreed plans and goals; I?s how you measure yourselves and the business against planned targets Q: There are different kinds of Plans including, Mission statements, vision, marketing operational. What type of plans do you use in your business? A: In my division we use all of those, the company has our mission statement and vision, which we live but the operational plans are the day to day business for us.Q: How often do you refer to each of the plans? A: It really depends on the plan and situation but I would say at least weekly. Q: Do you discuss the plans with you your teams and why? A: Yes we discuss these in all of our meetings at different levels. Staff, supervisor and management meetings. Q: How effective do you think these plans are? A: There is always room for improvement, but at th is time they are good. They are achievable and relevant to the core business. Our plans have to be somewhat flexible due to the changing environment we work in. Q: What benefits do you think you get from each of those plans?A: The team get a sense of achievement, moving forward, setting new goals. We achieve then move the goals forward. It's great for the team to see the plan coming to fruition. Organizing Q: Why do you think businesses need to have organizational structures? A: Accountability and growth. Q: There are different kinds of Organizational structures in the workplace, Formal/informal, functional, and divisional and matrix. Which one or combination Of these is used in your business? A: would say Divisional due to the multiple sites. Q: What benefits do you think you get from those structures you use?A: loud say time is the biggest benefit. When you find something that works well at one site you can adapt that to fit another site. With not having to come up with a complete new system then have time to focus on other issues. Q: Do you see any drawbacks to any of the structures you use? A: Having too many sites sometimes mean you spread yourself a little thin. That's when you have to look at staff and co-leaders. Leadership Q: Why do you think leadership is important in business? A: Overall accountability, but part of that is ensuring that the whole team work together to achieve the desired outcome.Q: There are several types of adhering, Autocratic, Democratic Laissez-fairer, situational etc. Which of these do you use in your organization? A: Democratic for me, having said that there are occasions when time constants mean a directive needs to be the way to move forward quickly. Q:How would you describe your leadership style? A: Adaptable depending on the climate at the time and proactive. Q: What benefits do you think you get from this style? A: Success, great time management and good interactions with staff. This means we meet timeliness. Q:DO you see any drawbacks to this style?A: Sometimes if you don't stay focused on delivery, things can get interpreted Rooney. You really have to make sure you invest time on learning so everyone understands their part in the overall plan. Control Q: What does controlling mean for you? A: Guidelines are put in place sows have a structured approach. Q: What control systems are used in your business? A: Mainly Kepi's (Key Performance Indicators) Q: Why are controlling systems important in your business? A: So we can achieve and show that we have achieved. Q: What control functions that you use monitor your planning functions?A: The Kepi's are what shows how we are progressing against our plan and working towards our targets. With no Kepi's where are we really. 1 . The Planning Function of Management 1. 1 . A There are a variety of reasons that managers plan although to me the first reason would be to set the direction and priorities of the company or sector of the company. You want to ensure tha t everyone in the team is working towards a similar goal and understands what that goal is. 1 . 2. A Vision Statement: Describes what a company would like to achieve, their aspirations to be the leader or best at what they do.Mission Statement: This is really the overall aim of the company, it tells prospective customers who the company are and what they stand for. Strategic plans: these are the long term plans the company has to grow. The overall direction it wants to take to achieve its desired goals. Marketing plans: This is the companies plan outlining how they plan to achieve the strategic goal they set. Here they need to look at what they deliver how well and what gives them the competitive edge over others out there. How they show that information to prospective clients. Contingency plan: This is the ‘what if plan.As we all know â€Å"If anything can go wrong, it will. † Murphy's law With that in mind we need to put plans in place for possible events that were to originally planned for (the contingency plan). Operational plans: This is a short term plan often set at a lower level in the company to ensure the team or section of the company have a clear understanding of what they need to do in the short term to ensure the company as a whole is achieving its higher level plans. 1 . 2. B The company I studied has a variety of plans, they have a vision (what they want to be), Mission (Why they exist), Values(what is important to them).They also have a strategic plan looking at the goals of increasing contracts and turnover by a percentage each year for the next five years. They have a marketing plan, for how they plan to sell the business to prospective clients. All these plans are driven from their National Office. Then there is the operational planning side of things, this is how they plan their work week to week to ensure they carry out the work the client wants within the timeshare set. 1. 3. From what observed I think overall the company st udied has some good plans at each level.My study was more focused on the operational plans and at interview and at first look it appears that the plans are sound and have some clear expectations of how things would be done in order to achieve the goals. Looking closer showed that there were some things that could possibly be done to make it more effective 1 . 3. B I was able to see the operational plans and how these were looked at from week to week. They have various focuses form current week to next and then longer focus into months ahead. I was shown the targets for completions of set work and the actual percentages achieved week on week against the plans.They have set themselves some high goals for the year and are close to achieving. I did notice from discussions that where they appear to fail is due to not cooking at the contingency side of things fully. A lot of the day to day jobs are dependent on weather or plant access and often there is no plan for what they will do if th ey cannot do that. This means that the overall focus then becomes more reactive than proactive. 2. The Organizing Function of Management 2. 1 . A Businesses need to have organizational structures in order to allow them to function effectively.This is because the structure defines the roles and tasks undertaken by staff. â€Å"An idea can only become a reality once it is broken down into organized, actionable elements. † Scott Belles 2. 2. The main kinds Of organizational structures are: Formal: Generally roles and responsibilities are set out in writing and staff generally don't venture outside their job description. Informal: Is how people work together in practice, day to day interactions. This structure generally develops alongside a formal structure. Divisional: Is where an organization is split into a number of separate units.These can be grouped according to product, market, geographical location or a mix of these. Each division is self-managed. Functional: Is where sta ff are grouped according to the function or role they perform Matrix: Is where staff are grouped by both function and product, often this structure is used for project work. 2. B The company I studied had a combination Of the Structures discussed. The company as a whole have a formal structure with an organizational chart to show the positions, with each position having a formal job description.But alongside that the staff have developed good communication and day to day talking to ensure the jobs are completed which is really the informal addition. The company has certainly got a divisional side to mainly based on location, and there is somewhat of a functional split at the location I looked at where hey have a roofing team with team leader, a handyman team with team leader, an industrial cleaning team with team leader and a commercial cleaning team with team leader. 2. 3. A The impression I was left with is that the mix of organizational structures works very well in this company. There appear to be a good balance between the formal and informal. The functional structure impressed me in that each of the individual teams had a clear understanding of their roles and took pride in achieving and meeting their targets. 2. 3. B During my visit I was able to see the organizational chart and some of the position descriptions. Away the team members within the office and how they interacted with the team leaders to get tasks achieved. 3. The Leadership Function of Management 3. 1 . A Leadership is important because without it a business will fail to function to its full potential. Leadership is the capacity to transform vision into reality. † Warren G. Bennie 3. 2. A To me the business I studied relies heavily on the democratic style of leadership, with a little delegating added to the mix. Democratic: There were a lot of notes from meetings with the manager and her supervisors and team leaders, where you could see issues discussed and he thoughts of the team wit h the decision made and agreed as the way to move forward. I noted from the tone used by the manager at interview and the dealings I saw with staff that she asked for their thoughts and input to assist in the decision making process.Delegating: I could often see actions for tasks or monitoring being assigned to the supervisor and team leaders. 3. 2. B Compared to the democratic style the autocratic does not look for a collaborative approach. Generally it is a more solely directive or authoritarian approach. Whereas the democratic style assists staff in feeling that they are a ajar part of the process and engaging them the autocratic would not be the way to get the best from a team. The team with the autocratic leader often feel less loyal, have less commitment and in the end, less satisfaction from the job as those with a democratic leader.Having said this a few of the staff I came across liked the go to work and be told what to do and how, although it was a minority. Although not i deal in my view there are occasions where autocratic works, this is usually in situations where an emergency has occurred and a decision needs to be made sooner rather than waiting to see if a consensus can be reached. . 3. A I believe that the leadership in the business I studied was adequate. There seemed to be systems in place and all those I spoke to or observed seemed to be aware of their part in achieving.

lemon v kurtzman 1971 essays

lemon v kurtzman 1971 essays The name of the case is Lemon v. Kurtzman; the Chief Justice in charge of the case was Warren Burger. The case was argued on March 3, 1971 and decided on June 28, 1971. These three cases from Pennsylvania and Rhode Island involved public assistance to private schools, some of which were religious. Pennsylvania's law included paying the salaries of teachers in parochial schools, assisting the purchasing of textbooks, and other teaching supplies. In Rhode Island, the State paid 15% of the salaries of private school teachers. A federal court upheld the Pennsylvania law while a District Court ruled that the Rhode Island law fostered 'excessive entanglement'. The case is about actions challenging constitutionality of state aid to, or for the benefit of, nonpublic schools. A three-judge United States District Court for the District of Rhode Island said that the Rhode Island statute was unconstitutional, while a three-judge United States District Court for the Eastern District of Pennsylvania, dismissed the complaint that challenged the Pennsylvania statute, and appeals were taken. The Supreme Court, Chief Justice Burger, held that both statutes, Pennsylvania and Rhode Island, were unconstitutional under the religion clauses of the First Amendment. The Courts decision was unanimous 8-0; it determined that the case was unconstitutional. The decision stated that there are three criteria that should be used to assess legislation: "First, the statute must have a secular legislative purpose; second, its principal or primary effect must be one that neither advances or inhibits religion; finally, the statute must not foster and excessive government Entanglement with religion." The teachers whose salaries are partially being paid by the State are religious agents who work under the rule of religious officials. There is an innate conflict in this situation of which the state should remain clear. To guarantee that tea ...

Zirconium Facts (Atomic Number 40 or Zr)

Zirconium Facts (Atomic Number 40 or Zr) Zirconium is a gray metal that has the distinction of being the last element symbol, alphabetically, of the periodic table. This element finds use in alloys, particularly for nuclear applications. Here are more zirconium element facts: ZirconiumBasic Facts Atomic Number: 40 Symbol: Zr Atomic Weight: 91.224 Discovery: Martin Klaproth 1789 (Germany); zircon mineral is mentioned in biblical texts. Electron Configuration: [Kr] 4d2 5s2 Word Origin: Named for the mineral zircon. Persian zargun: gold-like, which describes the color of the gemstone known as zircon, jargon, hyacinth, jacinth, or ligure. Isotopes: Natural zirconium consists of 5 isotopes; 28 additional isotopes have been characterized. The most common natural isotope is 90Zr, which accounts for 51.45 percent of the element. Of the radioisotopes, 93Zr has the longest half-life, which is 1.53x106 years. Properties: Zirconium is a lustrous grayish-white metal. The pure element is malleable and ductile, but the metal becomes hard and brittle when it contains impurities. Zirconium resists corrosion from acids, alkalis, water, and salt, but it does dissolve in hydrochloric or sulfuric aicd. Finely-divided metal may ignite spontaneously in air, especially at elevated temperatures, but the solid metal is relatively stable. Hafnium is found in zirconium ores and is difficult to separate from zirconium. Commercial-grade zirconium contains from 1% to 3% hafnium. Reactor-grade zirconium is essentially free of hafnium. Uses: Zircaloy(R) is an important alloy for nuclear applications. Zirconium has a low absorption cross section for neutrons, and is therefore used for nuclear energy applications, such as for cladding fuel elements. Zirconium is exceptionally resistant to corrosion by seawater and many common acids and alkalis, so it is used extensively by the chemical industry where corrosive agents are employed. Zirconium is used as an alloying agent in steel, a getter in vacuum tubes, and as a component in surgical appliances, photoflash bulbs, explosive primers, rayon spinnerets, lamp filaments, etc. Zirconium carbonate is used in poison ivy lotions to combine with urushiol. Zirconium alloyed with zinc becomes magnetic at temperatures below 35 °K. Zirconium with niobium is used to make low temperature superconductive magnets. Zirconium oxide (zircon) has a high index of refraction and is used as a gemstone. The impure oxide, zirconia, is used for laboratory crucibles that will withstand heat sh ock, for furnace linings, and by the glass and ceramic industries as a refractory material. Occurrence: Zirconium does not exist as a free element, primarily due to its reactivity with water. The metal has a concentration of around 130 mg/kg in the Earths crust and 0.026 ÃŽ ¼g/L  in sea water. Zirconium is found in S-type stars, the Sun, and meteorites. Lunar rocks contain a zirconium oxide concentration comparable to that of terrestrial rocks. The primary commercial source of zirconium is the silicate mineral zircon (ZrSiO4), which occurs in Brazil, Australia, Russia, South Africa, India, the United States, and in smaller amounts elsewhere in the world. Health Effects: The average human body contains about 250 milligrams of zirconium, but the element serves no known biological function. Dietary sources of zirconium include whole wheat, brown rice, spinach, eggs, and beef. Zirconium is found in antiperspirants and water purification systems. Its use as a carbonate to treat poison ivy has been discontinued because some people experienced skin reactions. While zirconium exposure is generally considered safe, exposure to the metal powder can cause skin irritation. The element is not considered to be either genotoxic or carcinogenic. Crystal Structure: Zirconium has an alpha phase and a beta phase. At room temperature, the atoms form close-packed hexagonal ÃŽ ±-Zr. At 863  Ã‚ °C, the structure transitions to body-centered ÃŽ ²-Zr. Zirconium Physical Data Element Classification: Transition Metal Density (g/cc): 6.506 Melting Point (K): 2125 Boiling Point (K): 4650 Appearance: grayish-white, lustrous, corrosion-resistant metal Atomic Radius (pm): 160 Atomic Volume (cc/mol): 14.1 Covalent Radius (pm): 145 Ionic Radius: 79 (4e) Specific Heat (20 °C J/g mol): 0.281 Fusion Heat (kJ/mol): 19.2 Evaporation Heat (kJ/mol): 567 Debye Temperature (K): 250.00 Pauling Negativity Number: 1.33 First Ionizing Energy (kJ/mol): 659.7 Oxidation States: 4 Lattice Structure: Hexagonal Lattice Constant (Ã…): 3.230 Lattice C/A Ratio: 1.593 References Emsley, John (2001). Natures Building Blocks. Oxford: Oxford University Press. pp. 506–510. ISBN 0-19-850341-5.Lide, David R., ed. (2007–2008). Zirconium. CRC Handbook of Chemistry and Physics. 4. New York: CRC Press. p. 42. ISBN 978-0-8493-0488-0.Meija, J.; et al. (2016). Atomic weights of the elements 2013 (IUPAC Technical Report). Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305 Return to the Periodic Table