Athen Essay essays

Athen Essay essays There were three types of government in Ancient Greece: an oligarchy, monarchy, and a democracy. An oligarchy was governed by a few wealthy and powerful people. A monarchy was governed by only one person. A democracy is when citizens voted on who the leader was and public matters. Citizens were only men who had Greek origin and were not slaves. If citizens did not care for a politician, when they voted, they wrote on a clay tablet which person they wanted to leave Athens. If one person got more than 6,000 votes against him, he couldn't come back to Athens for 10 years. Ancient Greece was divided into areas called city-states. There were many city-states and each one had its own government. Athens and Sparta were two of the most powerful city-states. Sparta was ruled by the military. In early times, Athens was governed by a monarchy. A monarchy is a Greek work meaning "ruled by one." Soldiers hand-picked their new leader and put him into power. Monarchy did not last long in Athens. The Athenians build a new government called an oligarchy, which means "ruled by the few." Some leaders were known as tyrants. A tyranny is an unjust government led by someone who has taken power. By 508 B.C. democracy started in Athens. Greece had one of the first democracies ever! In Athens, democracy meant "Power of the people," although women couldn't vote or run for office. Citizens who were 18 and male could be council members, judges or government officials. All three jobs last only one year and not one single person got paid for their services! The assembly would meet at the Acropolis four days every month. Democracy is important because it gives everyone a say in the government, so everyone is treated fairly. In a democracy, anyone can run the country, but in a monarchy, sometimes a bad person rules and will do bad things. In Athens there were originally three archons: the archon basilieus, or king archon, the eponymous a ...

How to Make Tris Buffer Solution for Medical or Lab Use

How to Make Tris Buffer Solution for Medical or Lab Use Buffer solutions are water-based liquids that include both a weak acid and its conjugate base. Because of their chemistry, buffer solutions can keep pH (acidity) at a nearly-constant level even when chemical changes are taking place. Buffer systems occur in nature, but they are also extremely useful in chemistry. Uses for Buffer Solutions In organic systems, natural buffer solutions keep pH at a consistent level, making it possible for biochemical reactions to occur without harming the  organism. When biologists study biological processes, they must maintain the same consistent pH; to do so they used prepared buffer solutions. Buffer solutions were first described  in 1966; many of the same buffers are used today.  Ã‚   To be useful, biological buffers must meet several criteria. Specifically, they should be water soluble but not soluble in organic solvents. They should not be able to pass through cell membranes. In addition, they must be non-toxic, inert, and stable throughout any experiments for which they are used. Buffer solutions occur naturally in blood plasma, which is why blood maintains a consistent pH between 7.35 and 7.45. Buffer solutions are also used in: fermentation processesdying fabricschemical analysiscalibration of pH metersDNA extraction What Is Tris Buffer Solution? Tris is short for  tris(hydroxymethyl) aminomethane, a chemical compound which is often used in saline because it is isotonic and non-toxic. Because it has a Tris has a pKa of 8.1 and a pH level between 7 and 9, Tris buffer solutions are also commonly used in a range of chemical analyses and procedures including DNA extraction. It is important to know that pH in tris buffer solution does change with the temperature of the solution. Emeldir  / Wikimedia Commons /  CC0 1.0 How to Prepare Tris Buffer It is easy to find commercially available tris buffer solution, but it is possible to make it yourself with the appropriate equipment. Materials: Calculate the amount of each item you need based on the molar concentration of the solution you want and the quantity of buffer you need. tris(hydroxymethyl) aminomethane  distilled deionized waterHCl Procedure: Start by  determining what concentration (molarity) and volume of Tris buffer you want to make. For example, Tris  buffer solution  used  for  saline  varies from 10 to 100 mM.  Once you have decided what you are making, calculate the number of moles of Tris that are required by multiplying the molar concentration of buffer by the volume of the buffer that is being made.  (moles of Tris mol/L x L)Next, determine how many grams of Tris this is by multiplying the number of moles by the molecular weight of Tris (121.14 g/mol).  Ã‚  grams of Tris (moles) x (121.14 g/mol)Dissolve the Tris into the distilled deionized water, 1/3 to 1/2 of your desired final volume.Mix in HCl (e.g., 1M HCl) until the pH meter gives you the desired pH for your Tris buffer solution.Dilute the buffer with water to reach the desired final volume of solution. Once the solution has been prepared, it can be stored for months in a sterile location at room temperature. Tris buffer solutions long shelf life is possible because the solution does not contain any proteins.

Quantitative vs. Qualitative research Essay Example | Topics and Well Written Essays - 500 words

Quantitative vs. Qualitative research - Essay Example of the measures of concepts, then the research respondents are selected, the next step is issuing research instruments and data collection, what follows is data processing and analysis, after this process finding are drawn and conclusions made. The main steps involved in qualitative research are: setting the overall research questions, then selecting necessary subjects and sites, then relevant data ought to be collected, then interpretation follows, then theoretical and conceptual work follows, the last step is writing up conclusions and findings. In quantitative research, the quality issues involved are issues such as reliability, this deal with the measure of stability and consistency. Replication seeks to find out whether the study is repeatable. Validity seeks to establish whether what is measured is the one intended or if the conclusions are well founded. In qualitative research, quality issues are trustworthiness that entails credibility of the findings, transferability in terms of the applicability of the findings to other contexts; dependability is whether the findings apply at other times. Conformability is whether the investigator’s values have intruded to a high degree. Relevance is the importance of a topic in the field of study and the contribution made by the literature in that field. Quantitative research has major preoccupations such as measurement and reliability validity, causality which entails explanation on reason as to why things are the way they are and the direction taken by the causal influence, that is, dependent and independent variables. Another of these preoccupations is generalization which covers the question on the scope of the context, sample and population, as well as the extent to which the samples are representative. Replication is a value that seeks to reduce contamination of results by researcher values or biases, thorough procedure descriptions, and ability to duplicate in varying context. In qualitative research, the