Category: Sciences 2502

Introduction

Strawberries are a group of perennial plants which belong to the Rosaceae family. They thrive well in soil that has good drainage, is moderately acidic (pH range 5.0 to 6.0) and require plenty of sunshine grow. They are capable of viable fruit production for a period of up to 3 years and the ideal planting conditions for strawberries are those that enable the plants to obtain sufficient quantities of moisture, especially during root formation. Organic fertilizer can be applied onto the plants twice a month for best results (Michaels, 2008). The plants should also be provided with adequate aeration to ward off fungal infections, and the beds should be covered with mulch to act as a weed-control. The crowns of the plants should be grown above ground level to prevent them from rotting. Spacing for the plants should be maintained at 12 to 18 inches between one plant and another in a row. The rows should also be kept at a distance of about 3 to 4 inches apart for adequate aeration (Aarons Creek Farms, Inc., 2011).

Horticultural maintenance of the plants includes regular weeding, watering (using drip irrigation technique) and the pruning of the runners to promote optimal development of the berries (Michaels, 2008). Strawberries are usually picked by hand and care should be exercised during harvesting to prevent bruising the berries. The berries are preferably eaten raw and so a lot of premium should be placed on maintaining their freshness. Post-harvest quality can be maintained by a variety of means such as refrigeration which has been shown to lessen the rate of decay and the preserving the general appearance of the fruit. If on transit, they should be kept at a constant storage temperature of 0°C so as to slow down their ripening and darkening (Forney, 2009).

Through a variety of techniques, the fruit can also be processed to avail a wide selection of food products that are strawberry flavored such as milk-shakes, yoghurt and even ice cream. This entails a series of washing steps, draining, sorting, and calyx removal and then the fruit is ready for pulping. The resulting puree is preserved by either refrigerating it or it can also be made into a concentrate followed by pasteurizing to increase its shelf life. Strawberry puree is widely used in several food industry applications ranging from confectionary making, dairy products, beverage making among others. The fruit can also be frozen and packaged in cans of whole or slices of strawberry which have a longer shelf life (Deuel and Plotto, 2005).

The most common means of preserving the fruit is through preparation of strawberry jam. This entails mixing the cleaned fruit pulp with sugars and coking this mixture at a low to medium heat while stirring.

Objectives

• To examine the method used in production of strawberry jam.
• To study the effect of pH and sugar concentration on the consistency of the jam produced.

Methodology

Procedure for processing strawberry jam

Harvesting

This is done by hand and the picked fruit is transported ion buckets to the processing plant where the total strawberry yield is weighed. The harvested fruit is first examined for quality before being processed.

Cleaning

The strawberries are thoroughly washed to clean off any debris or dirt. This is done by washing in the sink using cold water. After washing, they are rinsed and left to drain on a wire sieve. Drying of the berries is done using paper towels before the calyx is removed. Before discarding the resulting waste, it is first weighed and noted down.

Bottling

Each kg of fruit requires six jars each with a capacity of 400g. The jars together with their lids are first thoroughly cleaned using soap and water, rinsed, and arranged on trays for the water to drain off. After they are dry, both the jars and their lids are sterilized by heating them for about twenty minutes at a temperature of 130°C.

Jam Making

This is done in batches of the strawberries each weighing 1kg. The cleaned and trimmed are weighed to divide them into batches of equal weight. For each batch, the fruits are subdivided into slices and transferred into a pot. The acidity (pH) of each batch is measured. For each batch of fruit, 1kg of sugar and 43g of pectin are required, these two ingredients are mixed in a different container.

Bring the strawberries to boil, using moderate heat for about two minutes, while mashing them into pulp. Add the sugar and pectin mixture and stir continuously for the sugar to dissolve. Allow the mix to boil for about twenty minutes, up to a temperature of 104°C, while stirring so as to form concentrate. At this temperature, the sugar concentration in °Brix can be measured with the ideal value being 66 °Bx. Transfer the hot jam into the sterilized jars and cover them with the lids. Using a wet cloth, wipe off any jam thats split on the jars, then weigh and note the weight of each jar.

Results

Table 1: Strawberry Preparation

Table 2: Mass Balance for Strawberry

Table 3: Jam Characteristics

Table 4: Jars Weight and Gross Weight of Jam

Discussion

As illustrated in Table 1, the strawberries used weighed 1002.30 g and after trimming, only 807.50 g remained. The percentage loss in weight is 19.435 %.

The strawberry trimmers, sugar, pectin and water that were used to produce the jam had a total weight of 1951.90g. The total weight of the jar of strawberry jam was recorded as 1287.20 g. from this we can deduce that the percentage yield and percentage loss was 65.94 % and 34.10 % respectively.

The strawberry trimmings used for making the jam had an acidity of pH value of 3.4 and had a sugar concentration of 6.20 °Bx. The jam produced had a sugar concentration of 67.20°Bx at a temperature of 104°C.

The jars that were used to package the jam, together with their lids, were weighed. After the jam was placed inside the jars, their lids were replaced and then the gross weight of the jam was weighed.

The consistency of the resulting gel-like mixture is dependent on the pH and the amount of pectin present in the fruit. For best results, the required pH should be between 2.8 and 3.5, (this translates to 0.5% acidity by weight). In addition, the sugar and pectin concentration should be in the range of 60 to 65% and 0.5 to 1.0% respectively (Baker, 2005). The following table illustrates the effect both pH and sugar concentrations (measured in Degrees Brix, °Bx) have on the consistency of the resulting gel formation.

Pectin is a naturally occurring complex sugar molecule that is found in the cell walls of most plants. It is a made up of chains of simple sugar residues, usually D-galacturonic acid, that are joined through bonds (1-4) glycosidic bonds). Since strawberries naturally have low pectin levels, it is necessary to supplement that by the addition of commercially prepared pectin powder so as to optimize the gelling process (Baker et al. 2005).

From the results in Table 3, the trimmings used for making the jam had a pH value of 3.4 and had a sugar concentration of 6.20 °Bx. The jam produced had a sugar concentration of 67.20°Bx at a temperature of 104°C. All these were within the ideal range of conditions according to (Baker et al. 2005). This led to the production of a consistent jelly that had an average aw value of 0.73.

The critical control point during the production of strawberry jam include quality inspection of the harvested berries, weighing of the trimmings after calyx removal, cleaning and sterilization of the bottles or jars to be used and measurement of the sugar concentration of the jam at a temperature of 104°C.

Conclusion

The quality of the produced strawberry jam is directly linked to the pH of strawberry trimmings as well as the concentration of the added sugars.

Reference list

Aarons Creek Farms, Inc. 2011. Growing Strawberry Plants, Planting Guide.

Baker, R. A. et al. 2005. Fruit preserves and jams, Chap 6. In Barrett D.M. Somogyi. L. Ramaswamy H. eds. Processing fruits, science and technology. 2^nd ed. CRC Press. Boca Raton, Florida.

Deuel, C.L. and Plotto, A. 2005. Strawberries and Raspberries. Chap 22 in Barrett D.M. Somogyi L. Ramaswamy H. eds. Processing fruits, science and technology. 2^nd ed. CRC Press. Boca Raton, Florida.

Forney, C.F. 2009. Strawberry Harvesting and Postharvest; Handling for Improved Shelf Life.

Michaels F. 2008. Strawberry Growing Information. Green Harvest.

Voca, S. et al. 2008. Fruit Quality of New Early Ripening Strawberry Cultivars in Croatia. Food Technol. Biotechnol. 46 (3) 292298.

A lot of recombinant glycoproteins, and erythropoietin, and tissue plasminogen activator (tPA) are among them, are used as therapeutics aimed at mimicking the native human protein. The efficient and safe use of glycoprotein drugs requires determining the mixed structures of their carbohydrate moieties because the attachment of oligosaccharides (glycans) to glycoproteins has proven to influence various properties of glycoproteins.

The structures of oligosaccharides vary in different expressions especially from those in the native human structures. Lactoferrin is an iron-binding glycoprotein that is expressed in most human bodily fluids, including saliva, bile, and most highly in milk. The goal of this experiment is to compare the glycosylation of the native lactoferrin isolated from human milk and the same protein as recombinantly expressed in rice.

The method of the experiment is the analysis of the N-linked oligosaccharides after releasing them from the glycoproteins enzymatically. After the reduction and alkylation of the glycoproteins, they are digested with trypsin. N-Glycosidase F (PNGase F) and N-glycosidase A (PNGase A) will be used as enzymes for releasing oligosaccharides from the glycopeptides. The technique of the capillary carbon liquid chromatography (LC) combined with an Electrospray Ionisation (ESI) mass spectrometer is used for the analysis of the isolated glycans.

The post-translational modifications (PTMs), particularly glycosylation can affect the structure, stability and functions of the glycoproteins. Dealing with glycosylation requires considering the main characteristics of the process and possible results of the experiment for enhancing its effectiveness. Sawa et al (2006) noted that glycosylation is an important posttransnational modification affecting >50% of eurokaryotic proteins (p. 12371).

Like many other eurokariotic proteins, human lactoferrin is modified by N-linked glycosylation which consists of the three possible sites, namely Asn ^138, Asn ⁴⁷⁹ and Asn ^624. The study of Berkel et al (1996) has determined the extent to which each of the three sequons is used, concluding that glycosylation at Asn⁴⁷⁹ in the Asn ¹³⁸ mutant as well as in natural hLF decreases the glycosylation efficiency at Asn⁶²⁴ (p. 121). Along with the glycosylation heterogeneity, this relationship needs to be taken into consideration for making the analysis of the results more comprehensive.

The release of oligosaccharides from glycopeptides presupposes elucidation of the structure of the glycan component. The sequential isolation of individual monosaccharides is required for completing the release. The PNGase F is recognized as the most effective method of removing the oligosaccharides from the glycoproteins. However, the oligosaccharides commonly found in the glycoproteins of plants and parasitic worms can be resistant to this method.

In these cases PNGase A can be used for removing the oligosaccharides which are resistant to the PNGase F. The study by Moloney (2000) has demonstrated that particular types of the oligosaccharides released from the human cells can also be resistant to the PNGase F. Considering the fact that the native lactoferrin is compared to the same protein as recombinantly expressed in rice, both methods need to be used in the experiment. A comprehensive analysis of the achieved results requires implementing the recent advances in mass spectrometry such as capillary carbon liquid chromatography (LC) (Pan et al 2010).

The glycoproteins have become the important research targets related to the spheres of disease diagnosis, prognosis and reaction of the human organism to the therapeutic drugs containing the recombinant glycoproteins. The comparison of native lactoferrin and the same protein as recombinantly expressed in rice can be helpful for safer and more effective use of the glycoprotein drugs.

References

Berkel, H., Veen, H., Ceerts, M., Boer, H. and Nuijens, J. (1996). Heterogeneity in utilization of N-glycosylation sites Asn624 and Asn138 in human lactoferrin : a study with glycosylation-site mutants. Biochem J., 319: p. 117  122.

Moloney, D., Shair, L., Lu, F., Xia, J., Locke, R. (2000). Mammalian notch1 is modified with two unusual forms of O-linked glycosylation found on epidermal growth factor0like modules. The Journal of Biological Chemistry, 275: 9604-9611.

Pan, S., Chen, R., Aebersold, R. and Brentnall, T. (2010). Mass spectrometry based glycoproteomics  From a proteomics perspective. Molecular and Cellular Proteomics. 10.

Sawa, M., Hsu, T., Itoh, T., Sugiyama, M., Hanson, S., Vogt, P. (2006). Glycoproteomic probes for fluorescent imaging of fucosylated glycans in vivo. PNAS, 103 (33): p. 12371  12376.

The political economy of Brazil

According to popular political scholars of the 19^th century such as Karl Marx and Adam Smith, the political events of a country affect its economic performance. Consequently, a country could be wealthy in terms of natural resources but perform poorly due to bad governance. However, modern governments have various tools to measure health and stabilize their countries economies. Tools such as the gross domestic product (GDP) and the gross national income (GNI) measure the wealth of the country and its people, usually every year (Dickovick and Eastwood 81). These indicators help the government in regulating inequality, the cost of living and the level of unemployment in the country. In most democracies, such as Brazil, the government acts to control the political economy to protect the vulnerable population and to provide opportunities to its citizens. Brazil is one of the fastest-rising economies whose economic policies are shifting from being state-led to market-based ones.

One of the ways that the government relinquishes economic power to the private sector is privatization. The pro-market perspective drives the government to auction some companies in major sectors of the economy. This school of thought holds that only market players (the private sector) can fully understand complex market forces. For instance, in a bid to stabilize the economy after the slump associated with the Covid 19 pandemic, the Brazilian government offered a portfolio of 115 public assets for privatization through a public auction. Some of the assets to be relinquished to the private sector players include 16 ports, 24 airports, 6 parks and forest reserves, 6 roads, mining rights and oil reservoirs, among others. These concessions are expected to generate over $70 billion for the government in 2021 (McCoy and Traiano).

This privatization drive is necessary for the Brazilian government to advance industrial production in the republic and to stimulate investment. This move is healthy for the countrys economy because it liberates these organizations from corrupt political actors whose decisions will stall the growth of the economy, especially in the Covid era. The pandemic has preceded the loss of many jobs due to lockdowns and the government aims to reverse this trend by encouraging the expansion of the companies through privatization. This privatization drive supplements other decisions such as the revisions of fiscal and monetary policies in place in the country to shield the countrys populations from the ravages of the recent global economic downtown. On the other hand, the funds raised by the government can be used to improve the human development index if the revenue is allocated to the overwhelmed healthcare system. If more people get treatment for respiratory disease, then the government would have bolstered the human capital and the economy.

The levels of inequality in Brazil

There are several indicators of a countrys development levels. Some of the most pertinent ones include economic growth, social and cultural relations, among others. Whereas it is easier to measure the rate of economic growth in a country using tools such as the nations GDP and GNI, it is much more difficult to measure development in terms of cultural and social growth (Dickovick and Eastwood 109). The Human Development Index (HDI) combines aspects such as the level of education of a countrys citizens, poverty levels, economic inequality. Moreover, it includes cultural, environmental sustainability, gender, and racial relations that determine the level of satisfaction of the general populace.

Fahad Mustafa and Deepti Kakkars documentary Powerless is a movie that illuminates the class struggles of the people of Kanpur, India. The city is underdeveloped and there is a wide berth between the privileges enjoyed by the economic elite and the underprivileged. In the densely populated industrial city, only the rich have access to a steady supply of electrical power. The levels of public satisfaction and the constant civil protests indicate a malfunctioning economy where people living below the poverty line are underserved (Mustafa and Kakkar). It takes the intervention of Loha Singh to illegally connect the poor to the power grid. The corrupt electricity company personnel prove that the local government agrees with state-led economy proponents. The documentary illuminates how the local government limits the supply of power to the poor population in order to collect high power bills from the privileged few. The Marxist structure in the town maintains the status quo in the town despite the efforts of Ritu Maheshwari and Loha Singh.

The outbreak of the Covid-19 pandemic has provided economists with one more indicator with which to measure the levels of inequality in Brazil. Just like in the documentary Powerless, the poor, illiterate people account for more than ¾ of all Covid deaths in the country. They are powerless against the disease because most of them lack health insurance and the level of education that would help them contain its spread. The life expectancy of the poor is lower than that of the rich by a decade, because of their inability to deal with infectious diseases. The rich can afford excellent medical cover and care while the poor have to line up for hours on end to get the attention of the medics. Such a dysfunctional medical system shows that Brazil is losing its reputation as a rapidly burgeoning economy due to the inequalities.

The case of the Bolsonaro presidency

Democracy is a highly complicated idea since its definition and depth changes over time. However, it is clear that some of the basic tenets of governance such as elections, social welfare, civic participation and devolution of powers have to be upheld for a government to be considered democratic. In democracies, the elections to elect the countrys leaders are regular, multiparty, free and fair (Touchton 68). Additionally, the citizens enjoy liberties such as free speech, access to information and unionization. On the other hand, democratization is the process by which a country transitions from authoritarianism to democracy. Some of the causes of democratization include cultural theories, the international system, modernization theories, and the actions of institutions. In a nutshell, functional democracies uphold the will of the populace.

The case of the Bolsonaro presidency in Brazil is a prime example of a dysfunctional democracy, despite regular elections. Last year, the country elected the former soldier to counter the nations perennial struggles with corruption, crime and impunity. However, the campaign pledges of the president have gone largely unfulfilled. The handling of the Coronavirus pandemic has brought an even sharper focus on the presidency. Considering that the country democratized in 1985, it is a relatively young democracy that is being sabotaged by a former military man. The will of the people matters little to the executive and many high-profile government officials have either resigned or have been sacked for voicing the concerns of millions of Brazilians.

The sacking of the federal chief of police earlier this year sparked outrage, which culminated in the resignation of the countrys justice minister Sergio Moro. The minister had implicated the president of the wrongful dismissal of Maurício Valeixo, as well as overstepping his mandate because he is constitutionally incapable of sacking the police chief. Further, the president overruled the will of the people when he sacked the countrys health minister in April 2020 when he advocated for social distancing to contain infectious respiratory disease. All these events prove that Brazils democracy is still a work in progress and that it is being undermined by the president himself.

Since his takeover, the president has overseen the irresponsible development of Amazon land. The deforestation and development of the Amazon have affected the livelihoods and the survival of aboriginal populations who depend on the forest. The democratization process is stalling because the president has placed his personal ambitions of re-election in 2022 ahead of civic participation in the democratic process (Chibba). Many political analysts in the country are worried that the country could be reverting to authoritarianism if the trend is not reversed. The president has effectively made politics and the economy dichotomous. Corruption and impunity have seen the country lose an annual revenue of more than $38 billion because gangs are taking over some government functions in some cities.

Authoritarian regimes

Authoritarian regimes are those whose leaders overrule the will of the people. Oftentimes, these leaders will violate human rights to protect their own interests. However, there is a form of governance that disguises its autocratic nature with some tenets of democracy. The leaders of such governments will violate rules and use political authority to protect their dynasties. Despite allowing regular multiparty elections, the leaders rig them and retain their seats. The elections are competitive only at face value since many of the opposition leaders are harassed, jailed and in some instances exiled or killed. In many modern competitive autocracies, the elite few control much of the nations wealth (Levitsky and Way 53). In countries where such regimes form the government, the press does not have enough freedom to report the governments misdeeds explicitly. In some instances, such as in persistence authoritarianism, one autocratic leader paves the way to another through an electoral process.

In many cases, competitive authoritarianism arises from the need for elected leaders to protect their wealth and to guarantee preferential treatment by the law throughout their lives. However, some other causes of such regimes include rising levels of poverty and inequality in growing economies. Furthermore, if democracy fails, such as when the judiciary and other government institutions are infiltrated by members of the ruling elite, then the governance will be autocratic despite being competitive. For instance, in Brazil, the opposition is so weakened that the media has no option but to assume its role. In recent times, there have been high-profile cases of political violence and intimidation. Popular leaders such as the openly gay Jean Wyllys and former gubernatorial contestant Marcia Tiburi were forced to flee the country due to death threats.

Some scholars have argued that it is impossible to have a democratic government when the countrys wealth is under the control of a few individuals. In Brazil, the elite few control most of the wealth and thus will serve their own interests at the expense of the poor people. President Bolsonaro has surrounded himself with more than 130 military officials in his government (Pahnke). The country, therefore, qualifies as a competitive authoritarian nation because the military has made a comeback through a clever electoral process. The ruling party is nonchalant about how other people view them and their partially autocratic rule. The current government is not outright authoritarian. Rather, major players in the executive, the judiciary, the evangelical leaders and agribusiness leaders have ganged up to harass their opponents and stifle democracy. As such Brazilian activists have the herculean task of breaking the semi-authoritarian regime through collective action.

The multiparty system of governance

Government executives are the officials elected to execute and implement policies. In most democracies, the executive is headed by the president, who is the head of state and a prime minister, who is the head of government. In the presidential system, the head of government is elected directly by the voters while the president in a parliamentary system is elected by members of the legislature (Dickovick and Eastwood 243). The president often has formal powers, which he uses to execute his/her constitutional authority or partisan powers which he uses to influence the votes of other members of his party. Additionally, the head of state can possess the informal powers which enable him or her to set the agenda for the general population due to charisma. Many scholars argue that the parliamentary system of governance is more effective and that the presidential system allows for some form of autocracy.

Many democracies have multiparty systems where several parties are allowed to take part in national and presidential elections. However, in most industrialized and middle-income countries there are two parties that dominate the legislature and the executive. The party system is complemented by other institutions and organizations such as civil societies which champion the rights of the citizens. In a perfect democracy, all these stakeholders in the government will articulate their interests and thereafter aggregate them to make collective decisions. Such decisions are often inclusive and the benefits of the policies made after widespread consultation and the electoral process are typically healthy for any democracy. However, in an autocracy, or single-party state, the opposition is often crushed by outlawing other parties. On the other hand, there are states where multiple parties exist but only the ruling party is powerful enough to produce the head of state. The different party systems are created to suit different systems of governance.

Brazil, a middle-income nation, uses the multiparty system of governance. Voting in the country is not just a right for the countrys citizens, it is a legal obligation for adults. However, the government system is presidential and thus the executive wields more power because they obtain it directly from the electorate. That explains why the country, unlike parliamentary systems such as Britain regularly has periods of military rule. Bolsonaro, the countrys current president used populism ideologies to ascend to power. He convinced the electorate that he would combat corruption and crime but has gone against his word and is using his powers as the president of the nation to advance his own agenda. Instead of combating the Coronavirus as many would expect, he openly defies safety guidelines and reopened the economy prematurely to cater to his business and political agenda.

As a result of a series of poor decision-making processes and a weakened opposition, the president has almost singlehandedly spearheaded the transition of Brazil from a growing democracy into a country under subtle military rule. The president has appointed senior members of the executive and judiciary from the military (Costa). Moreover, by destroying the PT, the other major political party in the country, he is laying the groundwork for Brazil to become a single-party state. By the time he leaves office, he may have weakened the opposition so much that none of the presidential hopefuls from the other parties will successfully challenge him for the presidency in 2022.

Corruption in Brazil

The influence of political power on corruption remains a contentious issue in academic discourse. While reformers claim that policies such as public subsidies reduce corruption, observes note that such measures do not affect it. Hummel et al. argue that reforms regulating political finance reduce corruption by limiting the significance of private money in politics (2). Most governments control the availability and use of money in politics by offering subsidies to political parties. It has been shown that such policies promote good governance and enhance representative democracy. However, corruption has become a significant issue in subsidies involving the most advanced political finance systems. Despite laws being enacted to control money in politics, officials find ways to circumvent these regulations. Considerable literature posits that political finance plays a significant role in fueling corruption, even in the most efficient democracies. This results from poor implementation of political finance subsidies that mask endemic corruption in most countries. However, other studies have pointed out that political subsidies do not have a marked impact on corruption. Therefore, the current study sought to determine whether this proposition is correct, relying on interviews from officials involved in Paraguays political finance.

The authors note that the relationship between the quality of governance and the political subsidies in a given democracy remains untested. The unavailability of substantial data to test this correlation hampers the implementation of a comprehensive system to analyze this proposition. More so, the influence of political finance in the quality of governance has not been recognized and is mostly undermined. However, political reforms affecting finance might have an essential impact on mitigating corruption by controlling the use of private money in politics. Besides, policies that establish sanctions on political corruption enhance reducing the practice in most democracies. The study focused on the 1996 reforms in Paraguay affecting political finance to determine their effectiveness in reducing the overall systemic corruption. The researchers used a dataset that measures the subsidies offered to political parties during campaigns to evaluate corruption in Paraguay. The study found that finance subsidies are integral in reducing political corruption in various government offices.

Reformers have remained skeptical about the undue influence of private money in corruption scandals within political parties. The central argument holds that subsidies can insulate parties while promoting competition and representation. Countries such as Costa Rica have developed post-election subsidies that regulate controversial practices, enhance transparency and accountability. Other democracies such as Mexico and Argentina borrowed ideas of implementing political finance reforms from pioneers such as Spain which had already established effective subsidies. In Brazil, many cases of political scandals have been reported in the recent past, and those implicated continue to enjoy successful political careers. For instance, Paulo Maluf has received numerous allegations of money laundering and corruption of public funds. Despite these issues, Maluf was elected as the federal deputy and continued to experience protection from the court (Jucá et al. 4). The case of Brazil shows that although corruption related to campaign finance affects the reputation of lawmakers, most incumbents continue to serve in the government. Many federal deputies in Brazil have been involved in numerous corruption scandals, which makes corruption a critical issue in the countrys politics.

Brazil requires a careful evaluation to determine the underlying factors that support systemic corruption in campaign finance. Although Hummel et al. (3) have shown that political subsidies reduce corruption, the same cannot be said for Brazil. Mostly, this can be attributed to the fact that the country has not established a transparent democracy.

Inequalities based on race, gender, and class

Political empowerment in American and Latin American countries has seen people from socially disadvantaged groups being elected to positions of power. However, this does not imply that inequalities based on race, gender, and class do not exist. Economic inequality remains a potent issue that threatens good governance and the implementation of democratic policies. The elite few continue to dominate in political positions of influence. Gender disparity shows that women are underrepresented in political positions that influence reforms. In addition, race and ethnicity have a significant impact on political representation, especially with the current social diversity in many countries. Racial and ethnic inequalities are reflected in laws such as the Jim Crow laws in the US (Dickovick and Eastwood 336). Similarly, gender has been socially constructed to restrict certain groups that are discriminated against by the dominant society. The concepts of race and gender remain important issues that define modern political representation in culturally diverse countries. These ideologies have been used to create social distinctions of particular groups marked by the idea of gender and race. The stratification observed in society results inon people in different groups competing while excluding others to uphold their social status.

Racial inequalities are apparent in many countries, including the United States, which has been described as the melting pot of racism. Particularly, immigrants in the 19^th century faced significant racial discrimination. Today, African Americans continue to experience systemic and institutional racism in the country. Despite these inequalities, various advances have been made to reduce segregation and discrimination based on race and ethnicity (Dickovick and Eastwood 336). In the US, race plays an essential role in determining the political advantages of minority groups. The election of Barrack Obama as the president marked a significant milestone in the fight against racial prejudice. However, racial concerns remain imminent among African Americans and other minority groups in the country. The economic empowerment of these groups can help alleviate the low social status often associated with the black community.

Gender is another important issue that affects the global culture since inequalities are observed in almost every country. In Brazil, the oppression of women has been persistent, although feminists have made major strides in liberating women. Gender discrimination in political fronts is evident as women occupy fewer positions both elected and appointed. Although laws have been developed to empower women and other minority groups, the actual efforts should see these individuals occupying positions in political offices (Dickovick and Eastwood 343). The institutional design can be developed in a way that specific seats are reserved for women in political offices. Lastly, political parties can address gender issues by encouraging female candidates to participate in elections.

I have learned many insights into the issues affecting the global economy in relation to inequalities that are observed in most countries. While race and gender are important features, economic inequalities between the wealthy and the poor affect distribution of democracy. The topics of gender and race are major concerns that should not be affecting the current society. In that case, proactive approaches need to be adopted to ensure that people receive equal political and economic representation despite their gender or ethnicity. Further, global economic inequalities should be addressed to bridge the gap between the extremes of wealth and poverty. In the documentary Powerless, it is clear that the less disadvantaged people in society endure extreme poverty that lowers their quality of life. I believe that political institutions have the ability to change these conditions and ensure that resources are equally distributed.

Works Cited

Chibba, Michael. Political Economy and Democracy in Brazil Under Bolsonaro. OpenDemocracy, 2020.

Costa, Petra. Brazil has become a Cautionary Tale for the Worlds Democracies. The Guardian, 2019.

Dickovick, James Tyler, and Jonathan Eastwood. Comparative Politics: Integrating Theories, Methods, and Cases. Oxford University Press, 2019.

Hummel, Calla, John Gerring, and Thomas Burt. Do Political Finance Reforms Reduce Corruption? British Journal of Political Science, 2019, pp. 1-21.

Jucá, Ivan, Marcus André Melo, and Lucio Rennó. The Political Cost of Corruption: Scandals, Campaign Finance, and Reelection in the Brazilian Chamber of Deputies. Journal of Politics in Latin America, vol. 8 no. 2, 2016, pp. 3-36.

Levitsky, Steven, and Lucan A. Way. Elections without Democracy: The Rise Of Competitive Authoritarianism. Journal of Democracy vol. 13, no. 2, 2002, pp. 51-65.

McCoy, Terrence, and Heloísa Traiano. One Disease. Two Brazils. The Washington Post, 2020.

Mustafa, Fahad, and Deepti Kakkar. Powerless (Katiyabaaz). Globalistan Films ITVS, 2013.

Pahnke, Anthony R. The Brazilian Crisis and the New Authoritarianism. Monthly Review, 2020, Web.

Touchton, Michael, Natasha Borges Sugiyama, and Brian Wampler. Democracy at Work: Moving Beyond Elections to Improve Well-Being. American Political Science Review, vol. 111, no. 1, 2017, pp. 68-82.

There are two main types of the research in the scientific field, quantitative and qualitative research and a mixed research method which comprises the elements of the quantitative and qualitative research. It is important to know that the approach to the research is usually chosen on the basis of the main idea of the presupposed research. Basing on the main purposes and desired outcomes of the research, the researcher should choose one of the required methods. Therefore, it is impossible to say that one of the methods is better from another one. Only after consideration of the specific purposes, the method should be chosen.

The main purposes of the qualitative research are to comprise the information aimed at discussing and describing the research results. The researcher may be aware of the information he/she is looking for but he/she should not know for sure what kind of the information it is going to be. This kind of the research is recommended for the early stages of the research when a researcher is not really aware of the situation and the data which will be acquired. The instrument of the research is mainly the researcher who collects the data. Additionally, the data considered with this research method is usually displayed with words, pictures and objects (Creswell, 1998). The main methods of the qualitative research are interviews, observations, and documentation. One of the main purposes of the qualitative research is to evaluate the data and after close consideration to make a detailed description of the considered results. The researcher does not use any specific tools for data analysis.

Quantitative research is considered to be a more detailed point. It is aimed at classifying countable data and creating a statistical model explaining the observed data. The researcher should know in advance which data is going to be researched and particular tools should be used for gathering quantitative data. Qualitative research is usually planned on the basis of the recommendations and is never used on the early stages of the new research idea. Having a goal to test a specific hypothesis, numerical and statistical data is usually displayed that offer eliminated contextual details. Questionnaires, experiments and other specific methods may be considered as the quantitative research methods (Creswell, 2003). Quantitative research validity depends on the instrumentation of the research. Therefore, this type of research helps to generalize the results by means of making people answer of a limited set of questions (Patton, 2002).

It is obvious that each of the research methods considered above has advantages and disadvantages. Moreover, there are specific cases when one research type cannot offer the whole information and the results are going to be irrelative. In this case, the mixed method is used. The main idea of this method is to take the qualities of the quantitative and qualitative research and create a design which perfectly corresponds to the desired purpose. Setting the purposes, a researcher may use both numerical data and description analysis. The main peculiarity of this method is that he researcher can choose the best of two considered types of the research and provide the results which perfectly correspond to the set goals. Thus, it may be concluded that here are three types of the research (qualitative, quantitative and mixed) which should be considered depending on the research goals.

Reference List

Creswell, J. W. (1998). Qualitative inquiry and research design: choosing among five traditions. New York: Sage Publications.

Creswell, J. W. (2003). Research design: qualitative, quantitative, and mixed method approaches. New York: SAGE.

Patton, M. Q. (2002). Qualitative research and evaluation methods. New York: SAGE.

The two major types of statistical inference are hypothesis testing and confidential intervals. We use these two methods to make inferences. The difference between the use of the confidence intervals and hypothesis testing in inferential statistics is that the two have different goals. In hypothesis testing, we make some claim about a population based on the analysis of the evidence provided by our data. Where as in latter, an estimate of a population parameter is made. ¹

The concepts of the p-value and confidence intervals are related as measures of statistical significance in the sense that both confidence intervals and p values use probability to try to answer research questions using samples of a population. They can both help you decide whether to deny or accept a null hypothesis. They are both an approach to estimation and lastly, you can use confidence intervals or p values with most of the statistical tests.²

Writing a null and alternative hypothesis using 5- step approach to hypothesis testing

In an example of hypothesis testing using step 5  step approach to hypothesis testing, I conduct an investigation whether the IQs of RMIT Scholars are higher than the overall Australian population. ³

Random sample = 37 students.

Students IQ mean = 106.

The fact is that IQ = normal distribution. Mean (mµ) = 100. Sigma = 15.

1. State hypothesis (NULL and ALTERNATIVE)

Null hypothesis = presumed value of parameter (H₀)  statistical hypothesis that we test (strength of our sample data vs. the null hypothesis).

H₀ : µ = 100

Alternative hypothesis = contingent value if null rejected (H₁)  statement that specifies what we think is true (usually the opposite of the null hypothesis).

H₀ : µ ` 100 OR H₀ : µ > 100 OR H₀ : µ < 100. ⁴

2. State significance level (Level of rejecting a TRUE hypothesis)

The Z Statistic  n >30

Z = 2.76

3. Select test distribution to use

± = probability of denouncing (e.g., 2%)

1  ± = probability un-rejected (e.g. 99%) } ** Test distribution to be used**

4. Define area of rejection

I find the P- value. Z  score = 2.75. The probability of this result from the sample data set =.0029. I am using the 1  tailed test (> direction), therefore use the second half of the distribution ⁵.

i.e. P-value ; 1-.9971 =.0029

A-crit for alpha.05 = 1.64

The observation from the data result suggests that its highly unlikely that the hypothesis is true. Therefore we have rejected the hypothesis.

Also from the result of conducted calculation, the Z-score i.e. 2.76 is > the Z-crit i.e. 1.64, is another reason to reject the null hypothesis. ⁶

5. State decision rule (Conclusion)

RMITs students IQ is generally higher than the overall Australian population at the.05 level. I therefore have rejected the null hypothesis.

The Chi-Square goodness of is calculated using the below formula

References

Confidence intervals & hypothesis testing (1 of 5). (n.d.). HyperStat Online. Web.

Counts, t. s., & below:, a. s. (n.d.). Yale Statistics website. Web.

Population., o. d. (n.d.). HTCIP: Yale University. Web.

Preacher, K. J. (n.d.). Interactive Chi-square tests. Kristopher J. Preacher. Web.

What Is the relationship between confidence intervals and hypothesis testing. (n.d.). FTPRPEBROPP.com. Web.

Footnotes

1. Population., o. d. (n.d.). HTCIP: Yale University. Web.
2. Confidence intervals & hypothesis testing (1 of 5). (n.d.). HyperStat Online. Web.
3. population., o. d. (n.d.). HTCIP:. Yale University. Web.
4. Preacher, K. J. (n.d.). Interactive Chi-square tests. Kristopher J. Preacher. Web.
5. Counts, t. s., & below:, a. s. (n.d.). Yale Statistics website. Web.
6. What Is the relationship between confidence intervals and hypothesis testing. (n.d.). FTPRPEBROPP.com. Web.
7. Preacher, K. J. (n.d.). Interactive Chi-square tests. Kristopher J. Preacher. Web.

Abstract

Nitrogen is the mineral needed in most amounts by plants. Factors such as erosion leaching and biotic denitrification serve as a control mechanism to the amount of nitrogen absorbed by the plants. Plants in their inorganic forms take in nitrogen. Some plants also have the ability to assimilate nitrogen in form of urea. Optimal quantities of nitrogen are required for the growth.

Introduction

Invasive plant species can be described as introduced species (Cellot, Mouillot and Henry, 1998). This category of plants easily adapts to new environments in an aggressive manner with high reproduction rates. They lack natural enemies, which combined with their quick multiplication results into an outbreak population in most of their habitants (Luneva, 2009).

Research evidence strongly shows a relationship between the persistence of invasive plant species and the loss of native species with disturbance and fluctuations in soil fertility (DiTomaso and Healy, 2007). The addition of Nitrogen (N) to the soil in disturbed grazing land has been shown to increase the abundance of invasive species, while reduction in N availability has been shown to relatively increase the abundance of the native perennial species. A study showed that the seedling establishment of the medusahead increased with fertilization by NO3- (Thomas, Charles and Douglas, 2003).

The absorption of Nitrate is thought to vary with the type of soil in use due to the difference in water holding capacity. Evidence indicates that the water logging properties of the clay soil promote denitrification and nitrogen loss (Ling, 2010). However, other types of soils such as the sandy loam have a higher percentage of nutrient losses through leaching.

Myosotis scorpioides is a herbaceous perennial plant that belongs to the genus Myosotis, its commonly known as the European forget me not (Ling, 2010). The plant thrives in wet places, and is most commonly found near streams and rivers (Luneva, 2009). Myosotis scorpioides reproduces sexually through seeds and vegetative means by means of stolons that root at the nodes (Rose, 2007). No data is available to indicate the number of seeds that each Myosotis scorpioides plant produces. However, its close relative Myosotis alpestris has been documented to produce between 20 and 120 seeds per plant (DiTomaso, 2007). A study carried identified seedlings of Myosotis scorpioides scattered suggesting that grazing disturbances increases germination (Luneva, 2009). The plant is native in the temperate areas of Europe and Asia but grows exotically in the United States, Canada and other parts of the world. Studies show that the plant tends to escape from gardens to wet areas where it forms dense monocultures (Ling, 2010).

The goal of this study is to evaluate the influence of Nitrate concentrations on the growth and germination of Myosotis scorpioides seeds planted in either sandy loam, silt loam or clay loam (Morris, 2009).

The study hypothesizes that the increase in nitrate availability will increase the percentage of germination and the rate of growth of Myosotis scorpioides. Additionally, the study hypothesizes that change in the type of soil does not affect germination but may cause variation in the rates of growth (DiTomaso, 2007).

The study seeks to investigate the following specific objectives:

• The effect of increasing nitrite concentration and growth of Mysotosis scorpioides.
• The effect of soil variation in the uptake of nitrogen and growth of Mysotosis scopioides

Methods

To determine whether increasing the concentration of nitrates had an effect on the growth and germination of Myosotis scorpioides, seeds of Myosotis scorpioides L. were planted in sandy loam and gardening soil and treated with low, medium, and high concentrations of nitrate. Six 15-cell propagation trays were used in the experiment. The methodology described by Parera and Ruiz was also utilized. The approximate volume of one cell was 270 cm³ thus the amount of substrate required was determined by:

• 270 cm³ x 45(cells) ÷ 2 = 6075 cm³ of each substrate.
• Nitrate Concentrations (mg/L) 0mg/L 5mg/L 10mg/L
• Type of substrate Sandy loam n=15 n=15 n=15
• Gardening soil n=15 n=15 n=15

The preparation and distribution of nitrate was as described by Colman; solid potassium nitrate was mixed with deionized water and 20 mL (0.02 L) of the solutions added to each cell. 0 mg/L, 40 mL of deionized water was then added to the cell to be used for trial. Weighing was carried out using an electronic gram scale. The amount of deionized water needed per substrate batch was determined as follows:

• 2 (substrates) x 15 (cells) x 0.02 L of solution per cell, for a total of 0.6 L or 600 mL.

To ensure accuracy, 1000 mL beaker, and 50 mL graduated cylinder were used.

The substrates used in this experiment were chosen based on their characteristics, which make them much similar to the soil that is naturally found in riparian areas where Myosotis scorpioides L. grows (Márquez, 2005).

After planting, the propagation trays was transferred to the greenhouse at West Virginia University, where they were observed in accordance to universal greenhouse practices. Each cell was watered with 40 mL of deionized water three times a weekMondays, Wednesdays and Fridays. The weekly amount of deionized water needed is determined by:

• 20 mL x 4 (weeks) x 6 (trays) x 15 (cells per tray) x 3 (times a week) = 21600mL.

If this is added to the amount of deionized water needed to make the nitrate concentration:

• 21600 mL + 3000 mL = 24600 mL (24.6 L)

Watering was carried out at 10:00 AM and 4:00 PM, during that time the trays are examined for growth presence and progress.

This analysis showed the effect of substrate and nitrate concentration on the growth and germination of Myosotis scorpioides L. Results was considered significant if p < 0.05 representing a confidence interval of 95%.

Results

Increased nitrate concentration resulted to increased growth followed by no germination at all for all the three substrates i.e. nitrate concentration caused a significant (p < 0.05) reduction on the germination in the long-run.

Discussions

The nitrate uptake is versatile and robust in plants because plants have to transport sufficient nitrate to compensate for its total demand. External nitrate concentrations usually vary by five orders of magnitude. In order to function optimally in environmental variation, the energy driving nitrate uptake is found from the proton gradient and kept constant in the plasma membrane by the H+-ATPase.

Nitrate Concentration, Plant Growth and Germination

References

Cellot, B., F. Mouillot, and C. Henry. (1998). Flood Drift And Propagule Bank Of Aquatic Macrophytes In The Riverine Wetland. Journal Of Vegetation Science. 9(5).631-640

DiTomaso, J., and E. Healy. ( 2007). Weeds of California and other Western States.

University of California Agriculture and Natural Resources Communication Services. Oakland, CA. 834 p.

Ling, C. (2010). Myosotis scorpioides. USGS Nomindigeneous Aquatic Species Database, Gainesville, FL. Web.

Luneva, N. (2009). Weeds, Myosotis arvensis L.  Common (field) Forget-me not. AgroAtlas. Interactive agricultural ecological atlas of Russia and neighboring countries: Economic plants and their diseases, pests, and weeds. Web.

Márquez A. J. (2005). Lotus Japonicus Handbook. New York, NY: Springer.

Morris P. (2009). Methods Of Environmental Impact Assessment. London: Taylor & Francis.

Rose N. L. (2007). Lochnagar: The Natural History of a Mountain Lake. New York, NY: Springer.

Thomas A., T. Charles, and A Douglas. (2003). Nitrogen effects on seed germination and seedling growth. J Range Manage. 56: 646-654 p.

A paramecium is a singled celled living organism that belongs to the kingdom Protista. The organisms size is about 0.02 inches in length. They have an oval shape and are rounded on the front and tapered at the end. The organism has a pellicle which gives shape to the organism and allows for small body changes which is an important thing in as far as the movement of the organism is concerned. The pellicle is covered by cilia which are smaller locomotory structures. An oral groove is located near the front end and is usually used in feeding and in excretion. The contractile vacuole also found on the outer of the paramecium aid in locomotion. Enclosed within the cell are other structures including trychocysts, cytoplasm, gullet, macronucleus, food vacuole and micronucleus (Foissner 364).

The pellicle has a protective function just like the skin will protect large organisms. The cilia apart from helping in locomotion, they also assist the organism in bringing food to the oral groove. The oral groove collects food from the surrounding and directs it into the interior of the cell. The cell mouth is what acts as the opening to the digestive system. The anal pore functions in dispelling waste materials from the cell. Extra water from the cell is dispelled from the cell through the contractile vacuole. Contractile vacuole is fitted with radiating canals that act as paths to and from the vacuole. Cytoplasm contains other vital cell components including the nucleus. The trichocysts are more important in defense of the paramecium. There is also a food vacuole which acts as a food store forms from the gullet. The large nucleus called macronucleus is important in performing cell functions while the smaller nucleus (micronucleus) is important during cell division (Foissner 364).

Complete taxonomy

• Super kingdom&&&&&Eukaryote
• Kingdom&&&&&&&&Animalia (Protista/Protozoa)
• Phylum&&&&&&&&..Ciliophora
• Class&&&&&&&&&&Ciliatea
• Subclass&&&&&&&&&Rhabdophorina
• Order&&&&&&&&&&..Hymenostomatida
• Suborder&&&&&&&&&Peniculina
• Family&&&&&&&&&&.Parameciidae
• Genus&&&&&&&&&&.Paramecium
• Species&&&&&&&&Aurelia

Paramecium Aurelia has been described as a complex species consisting of 15 entities. Despite the fact that this group of free living ciliates show a lot of morphological similarities, the 15 groups or species show distinct variations in terms of their genetic composition. It has also been shown that each of these different species is composed of two kinds of mating members (Beale 17). The mating types are designated as even represented as (E) or odd represented as (O). These mating types are what represent intraspecific reproduction among members of each species through conjugation. Interspecific reproduction has been shown not to occur and this has been proved by placing clones of different species together and later observing that no conjugation occurs. Also, it is worth noting that conjugation does not occur between the same mating types. Members of mating type E cannot conjugate and the same case applies to member of mating type O (Aufderheide 135). However it has reportedly been said that weak cross-reactions may occur between different mating types from different species but the conjugated cells usually die after sometime or if the cells survive, their F1 generation cells show sterility. This phenomenon has been reported among member species of Paramecium tetraurelia and Paramecium octaurelia and also between Paramecium primaurelia and Paramecium pentaurelia (Haggard 153).

Recent studies concerning molecular phylogeny and speciation in species complex of Paramecium aurelia has in a greater extent supported phylogenetic relationships among those species that have been described to have diverged in recent times. Experiments that have been conducted to study the reliability and existence of such phylogenetic relationships has shown that there exists a tendency of members or recently diverged species to cross-react and actually produce viable cell at the end of the conjugation process (Sonneborn 156). This has been proven in members of P. primaurelia and P. pentaurelia. These studies have shown that during the conjugation process, there is close pairing of gene genealogies in all aspects. It is therefore important here to consider the effect of divergence and the phylogenetic impact it has on species (Sonneborn 156).

My choice of this organism is rather personal because am interested in microbiology and am actually focusing on becoming a specialist in this field. Paramecium is a very dynamic genus consisting of free living species. Most importantly, despite the fact that many micro-organism are associated with diseases, most of the paramecium species have not been associated with any. As a matter of fact, many of these species have been of significant importance by the fact that they feed on bacteria and other protists and considering that some most bacteria are associated with human and animal disease (Coleman 23).

The economic importances to humans that can be attached to paramecium are incredible. Some paramecium has been associated with degrading of pollutants in water and therefore helping in the creation of a healthier environment. Also their feeding on some pathogenic microorganism helps to reduce these disease-causing microbes from the environment and therefore saving on the resources that could have been used in the treatment of these diseases. These importances led me to choosing paramecium as my organism of choice.

Works Cited

Aufderheide K, J. Daggett PM, Nerad TA. Paramecium sonneborni N-Sp, a new member of the Paramecium aurelia species-complex. J Protozool. 30 (1983):128131.

Beale G, Preer J, R. Paramecium: Genetics and Epigenetics. Boca Raton (FL): CRC, 2008. Press.

Coleman A, W. Paramecium aurelia revisited. J Eukaryot Microbiol. 52 (2005):6877.

Foissner W. Protist diversity: estimates of the near imponderable. Protist. 150 (1999):363368

Haggard B, W. Interspecies crosses in Paramecium Aurelia (syngen 4 by syngen 8). J Protozool. 21 (1974):152159.

Sonneborn T, M. The Paramecium-aurelia complex of 14 sibling species. Trans Am Microsc Soc. 94 (1975):155178.

Introduction

The problem of creating an effective vacuum in many studies is important because different vacuum systems operate under different principles and can achieve the evacuation goal because of different evacuation abilities. Among the system to consider include the condensation systems, mechanical pumps, the ion and penning pumps that have different operating principles. On the other hand, during the evacuation process, it is possible to integrate a cryostat into the vacuum system because it provides a suitable environment to create a vacuum using existing pressure regions to achieve low cryogenic temperatures.

However, cryostats provide different evacuating capabilities because of they belong to different classes that include the continuous-flow cryostats, multistage cryostats, closed-cycle cryostats, and bath cryostats. The entire system can be set up using good light current and light sources and systems such as the exciton to study how vacuum systems can be created and used.

Vacuum System

The pressure reduction in a vacuum system is achieved by decreasing the gas pressure, the density, and volume of the gas in the system. Two techniques have been proposed as effective in reducing the density and volume of gas in an enclosure that leads to the reduction in the gas pressure to create a vacuum. The methods include ejecting the gas particles from the system into the atmosphere by use of different stages of gas particles compressions. The other technique involves removing the gas particles by condensing and making them to adhere to the surface of a body before being removed from the original container.

Some of the methods belong to the category that uses pressure reduction and the others belong to the category that relies on condensation of gas molecules to create a vacuum. One of the methods that are used to remove gas particles from a system to create a vacuum that was proposed by Benson (2008) uses a pulse or a mechanical pump.

Condensation system

The condensation systems are also known as ejector systems. Ejector systems rely on different ejector stages that consist of condensers arranged in series to reduce the pressure of the gas in the container to create a partial vacuum. The vacuum system works by allowing the fluid or gas to come into contact with the surface of the body as the fluid moves through a series of stages to the extent that the pressure and temperature permit. Typically, the ejector has a fixed capacity that uses devices that are arranged in series and parallel to enable the system to control the pressure and other loads in the pressure reduction process. It is possible to use a single or a multistage non-condensing ejector to create the vacuum. In both cases, condensation is achieved at different levels of efficiency because the effectiveness of the system depends on the condensation stages that are used in each stage.

Many pumps have been designed and developed that belong to the category of high vacuum pumps and one of them is the diffusion pump. The diffusion pumps works by directing a jet of condensed of vapors at the air molecules to sweep them to the point where the fore pump forces them to the outside system. The only disadvantage with the system is that it cannot work at high pressures.

Mechanical Pump

Mechanical pumps work on the principle of removing gas molecules by reducing the pressure of a sealed container to create a partial vacuum. The mechanical vacuum pump works by use of a positive displacement of the gas molecules from a sealed container to deliver the gas molecules into the external system or the environment. Different pumps have different pumping capabilities that depend on the compression ratio of the pump (Wang & Hartnett, 2010).

The rotary vane pump is one of the many different types of mechanical pumps have been used to create vacuums. The rotary vane pump is driven by the use of an electric driven motor that has several sliding vanes that are used to create partial pressure as the vanes move. Typically, partial pressure is achieved by reducing the amount of gas molecules in a chamber without increasing the size of the chamber.

However, the system is not always perfect because of some leaks that occur at the points of contacts the pumping devices make with each other. In addition, leaks can occur or a reduction in pressure can occur if the pump has materials that can easily evaporate, that creates a virtual pressure that making effective leaks to occur in the system (Regier, Pieper & Matias, 2010).

Ion Pump

The ion pump was developed using plural cells that make it very efficient for gaseous evacuation. It has been shown that ionic pumps utilise highly efficient magnetic circuits that enables them to work efficiently in creating vacuums and when working under ideal conditions, the pump can reach a pressure of 10^11 mbar.

Penning trap

The penning pump works based on the penning effects where a penning trap is made to work by storing charged particles using homogeneous quadrupole electric and homogeneous axial magnetic fields that work effectively when used in precision instruments. A magnetic field is used to propagate the electrons under the strong magnetic field towards the anode. In the process of the movement of the ions towards the anode, the gaseous molecules and atoms in the chamber get ionized.

The ions that are generated from this process are accelerated towards the cathode because of the potential difference between the anode and the cathode and strike the cathode making it to be chemically active when the charges fall on them (Capatina, Islam, Trakhtenberg, Nojiri & Narumi, 2011). As the ions come into contact with cathode, they become embedded into the cathode or get embedded into the walls of the ion pump. The new ions pump the molecules through the chemisorption and physisorption processes (Chen et al., 2010).

Cryostat

Studies show that the cryostat can be used to create a confinement barrier to reduce thermal heat transfers from warm to less warm components to maintain low cryogenic temperatures. The engineering design of the cryostat is based on the minimization of the cost function to ensure that the best results are achieved when using the component (Chen, Bai, Bird, Bole, Cantrell, Toth & Zhai, 2010).

It is important when using the cryostat to ensure that the external pressure of the cryostat is made to be lower than internal pressure of the cryostat. That enables the cryostat to force the gas to flow from the high pressure region into the low pressure region. In practice, the gas cannot flow into the cryostat but will always flow away from the cryostat because of the pressure differences (Cosier & Glazer, 1986).

Pressure regions

On the other hand, when using the cryostat to pump the gas from the high to the low pressure region, it is important to pump until an adequate internal pressure is achieved. Once the cryostat pump is removed, the internal pressure has to be made equivalent with the maximum number of molecules in the cryostat to ensure that the acceptable pressure prevails in the system (Cosier & Glazer, 1986).

The structure consists of the penetration cover plates and system covers. In addition, the system consists of the neutral beam ducts, primary heat transfer systems, coolant penetration systems, thermal shields, gravity support systems, and vacuum pump penetrations.

Classifications

Cryostats are classified into continuous-flow cryostats, closed-cycle cryostats, bath cryostats, and multistage cryostats. The multistage cryostat is used to achieve temperatures that are lower than those achieved with the use of helium gas (Cosier & Glazer, 1986). By connecting the He-4 isotope attached to the cold plate of the 1-K pot, it is possible to reach temperatures lower than of 1K (Cosier & Glazer, 1986). A cold plate is used reduce the temperature of the system by using helium gas that is continuously replenished and that depends on the volume of the cryostat. To ensure that the temperature of the system is maintained as low as required, a vacuum shield is positioned around the system with a continuous replenishment of helium gas and helium vapor.

The continuous-flow cryostat uses liquid cryogens to keep the temperature of the system as low as possible. The system is designed to keep the temperature requirements by the use of steady replenishment of cryogen. The nature of cryostat makes them applicable in Magnetic Resonance Imaging (MRI) machines.

Pump

Different techniques have been applied to achieve the low temperatures desired for experimental purposes. When conducting an experiment using the cryostat to create an ultrahigh vacuum (UHV) pressure difference, the appropriate setup to use is shown below.

A sample chamber and a mixing chamber are setup as shown in the diagram below. The chambers are made of stainless steel and molecular turbo pumps that are used to create the required vacuum. Rotary pumps are used to create a vacuum so that the background pressure of 10^6 and 10^8 are achieved (Nataf & Ciuti, 2010). The mixing chamber for the samples and the high pressure bottles with pure gases are connected through the pressure reduction valves.

Both the closed cycle cryostat and the flow cryostat are used to cool the sample to the required temperature. In addition, thermal insulation is assured for each sample used in the experiment by use of insulating materials. The flow cryostat enables the samples to be moved using the x-y-z manipulator and the setup allows for movements to occur between the flow and closed cycle cryostats to be made possible (Chou, De Rouffignac, Stegmeier, & Vinegar, 1993).

To be able to control the continuous flow cryostat, liquid helium must be made available from helium Dewar, effective circulation of helium, a high vacuum pump to generate the required vacuum, and a temperature controller.

Types of pumps

Different types of pumps exist that can be used to pump and create the required vacuum. One of them includes the two stage rotary pumps that can use a cold trap to achieve a very low temperatures and pressures. However, the pressure achieved by use of the two stage rotary pumps cannot be used for such experiments. One of the most reliable pumps is the Cryopump. It is a single shot pump and it is very clean and appropriate for such experiments.

Temperature Controller

During the exchange of heat, a temperature controller is used to measure the temperature of the sample to ensure that the power supply is adequate for the experiment. The temperature is controlled by the use of the regulated heat injection techniques that uses a current carrying coil. Care is taken to ensure the thermal insulation of the system is adequately maintained because the system has been proved that it can hold the temperature to within a few millikelvins for several weeks. To achieve that efficiency the electronic temperature controls system must be designed and placed in a temperature controlled environment as shown below.

In practice, one can use the computer to interface between the system and the temperature controlling device. When setting up the system, one should ensure that the temperature controlling device is properly connected to the circuit as shown above (Isaksson, Kjäll, Nilsson, Robinson, Berggren & Richter-Dahlfors, 2007).

Light Source

Light is crucial in the experiment and collimated light enters through the spectrometer into the chamber where the study is taking place. The light source is also important because it enables the movement of the cryostat to be controlled effectively.

Light bulb

The light bulb is used to supply light to enable the movement of the particles to be recorded.

Power Supply

The source of power for use is the Micro regulator PID temperature control system that can be used to ensure that the temperature of the system is controlled to maintain it at the required level. The source of current is controlled by the use of a current amplifier and energy limiter circuits that is integrated into the system. An operational amplifier is used to increase the output current and has a configuration of the class AB push-pull and the circuit for the operational power supply and control sis shown below.

Monochromator

It is possible to use a high resolution trochoidal electron monochromator that can be housed in the UHV chambers and rotated freely while ensuring that the temperature of the system can be reduced to 15 K. Electrons from the monochromator gain sufficient energy to undergo the injection curve by entering into the multi-layered film on the substrate substance.

Chopper and Chopper Controller

The Chopper and Chopper Controller is used to provide the most appropriate source of light for the experiment based on an electric current chopper with a superconductor material. The niobium carbo-nitride is used to make the resistance component that is used to regulate the flow of current. On the other hand, resistance means are achieved by the insulating plate and the resistance component is supported on the front side of the insulation plate and wherein a thermal mass is located within the cryostat against the reverse side of the insulating plate facing the resistance component to accelerate its cooling (Medo, 1999).

Detector

It is possible to install the system with two detectors. However, the detectors can be used to measure the emissions that come from the sample that is used in the study. Studies show that the accuracy of the recommended DTGS detector for the study lies between 6,000 and 350 cm^-1 or (1.7 to 28 µm). The diagram below shows how the detector can be optimized for use in the detection of the particles released in the experiment.

Limitation

The system is limited in the acquisition the particles that are used for the experiment.

Lock-in Amplifier

The amplifier can be used to collect signals that correspond to known wavelengths from the experimental environment that has a lot of noise. The noise level is increased by the presence and movement of different particles within the system that generates the particles under investigations (Nataf & Ciuti, 2010). In addition, the amplifier uses demodulation techniques to filter the incoming sine and cosine waves to remove noise and create a clean signal. The device measures any changes that occur in each signal phase, that are known as phase shift changes to recover signals that are hidden in the noise environment.

Function Generator + Amplifier (DC + AC)

The diagram below shows the setup of the function generator

Table of the specifications of the power supply for the experiment

Exciton

The femtosecond vacuum pump is one of the typical examples where the exciton is applied. Experimental studies with pumpprobe experiments require one to understand the behavior of excitons on different materials including semiconductors that depend on the coherence of excited electron states. Excitons are formed when semiconductors absorb photons because electrons are excited from the valence into the conduction band of a material (Nataf & Ciuti, 2010).

The concept of excitons that was established by Yakov Frenkel in 1931 classifies excitons into Surface excitons, Atomic, Wannier excitons, molecular, Frenkel excitons. For each category of the excitons, research studies show that long conjugated molecules have the ability to act as microwave conductors by use of conjugated molecules to enhance the conductivity of the molecules in organic semiconductors.

Exciton is a state that is achieved by the action of the electrostatic Coulomb force that binds electrons to each other in semiconductor materials, insulators, and in some liquids. It has been demonstrated that boosting the number of electrons and holes increases the pressure. However, excitons behave differently from metal conductors because it is possible to achieve elementary excitation states of condensed matter to allow for energy to be transported without any net effects on electric charges.

Semiconductor materials and exciton categories

There exists a structural difference between organic and inorganic molecules because organic molecules are bounded by van de Waals force that makes the material to have the unique electrical conduction properties. Results show that intermolecular forces between the molecules of the organic material commonly referred to as covalent bonds makes the dielectric constants usually low compared with the dielectric constant of inorganic materials as shown in the diagram below.

Frenkel excitons are usually based on strong and high Coulomb interactions between the hole and an electron leading to a low excitation state for materials with low dielectric constants. Studies show that excitation is possible within the molecules such as is evident with fullerene. Fullerene is a carbon molecule that exists in tube, sphere or ellipsoidal form. The binding energy of the Frenkel excitons in alkali crystals fall between 0.1 and 1 eV.

Another category of excitons is the Wannier-Mott excitons. The Wannier-Mott excitons occur when the electric field strength reduces because of the interaction between electrons and the semiconductor holes.

The results from the experiment show how different particles are bound within orbits of the atoms because the particles energy is much lower than that of a hydrogen atom because of the screened coulomb effect and the lower masses of the particles as illustrated in the diagram below (Nataf & Ciuti, 2010).

The above diagram shows the effects of the Columbic interactions and the effects that occur because of the interactions between the particles and the resulting changes. In addition, it shows the amount of energy that is required to cause excitations of the particles into other energy states. It is possible to have single wall excitations because of the way the holes and charges interact between themselves.

Interactions

It is important to understand how the interactions occur in semiconductor materials that allow for the emission of light at low temperatures. It has been shown that polariton are formed when interactions occur among the excitons (dressed excitons). Biexciton are formed when dressed excitons combine with other dressed excitons and as the density of the dressed excitons increases, electron holes are formed and that allows for the behavior observed with excitons to occur. It is also possible to achieve atomic and molecular excitons among molecules, ions, or atoms by enabling the particle to acquire a quantum of energy that excites and electron to move from one energy state to the other.

The state transition allows an electron to move into the electron hole from its lower energy state that exists in the highest occupied molecular orbit. However, such states are transitional and when the electron moves back into its normal state, it undergoes photon or phonon emission. The transient states and behavior of the molecules and electrons are important in energy transfer mechanisms that occur among different materials.

Conclusion

The study shows that vacuum pumps exist in different forms and have different pressure reduction abilities. Vacuum are created by the use of pressure reduction methods such as the condensation system that works by gaseous molecules through ejections, mechanical pumps that work through the creation of partial pressures, and the cryostat that works by ionizing gas molecules to create ions that pus the gas molecules from a high pressure to a low pressure region.

In addition, different pups are used to achieve the pressure reductions and to set up an experiment to study how to create vacuums, different elements have to be combined with different properties to create the desire environment. The elements include monochromator that uses a high resolution trochoidal electron, the Chopper and Chopper Controller that controls the flow of current, a detector, lock amplifier and other elements in the system. However, it is also important to conduct a detailed study in another area of special interest that uses excitons to create a vacuum.

References

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Capatina, D., Islam, Z., Trakhtenberg, E., Nojiri, H., & Narumi, Y. (2011). Mechanical design of a dual-cryostat instrument for a high-field pulsed magnet. Diamond Light Source Proceedings, 1(MEDSI-6), e42.

Chen, J., Bai, H., Bird, M. D., Bole, S., Cantrell, K., Toth, J., & Zhai, Y. (2010). Cryostat design for the HZB and NHMFL series-connected hybrids. Applied Superconductivity, IEEE Transactions on, 20(3), 644-647.

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Medo, E. M. (1999). U.S. Patent No. 5,902,267. Washington, DC: U.S. Patent and Trademark Office.

Nataf, P., & Ciuti, C. (2010). Vacuum degeneracy of a circuit QED system in the ultrastrong coupling regime. Physical review letters, 104(2), 023601.

Regier, C., Pieper, J., & Matias, E. (2010). Dynamic modeling of a liquid helium cryostat at the Canadian Light Source. Cryogenics, 50(2), 118-125.

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Appendix

The dimension of the sample that is used in the experiment is the decision of the owner of the experiment. The diagram below shows the sample DCS that is 440 mm to achieve a 10% scatterer that implies that of those neutrons that are released, about 10% of them are scattered and the setup can achieve multiple scattered, which implies that the particles can be scattered more than once when they have been released.

Blood circulation in a double circulatory system is divided into the pulmonary circuit and the systemic circuit (Starr, 126). The pulmonary circuit creates a link between the heart and the lungs. It is through the pulmonary circuit that blood absorbs oxygen and carbon dioxide diffuses from blood in the lungs (Starr, 126). The pulmonary circuit is composed of the right atrium, the atrioventricular valve, the right ventricle, the semilunar valve, the pulmonary artery, the lungs, the pulmonary vein, and the left atrium. The pulmonary vein carries blood highly concentrated in oxygen and lowly concentrated in carbon dioxide from the alveoli to the heart (Starr, 126). The blood flow in the pulmonary circuit starts with deoxygenated blood getting in to the right atrium of the heart via the vena cava. Blood in the vena cava is then drained to the right ventricle via the atrioventricular valve. The atrioventricular valve is located between the ventricle and the atrium. When the right ventricle is filled with blood, the ventricle muscles contract closing the atrioventricular valve. This prevents blood from flowing back into the atrium (Starr, 126). During the contraction of the right ventricle, blood in the right ventricle is pushed to the pulmonary artery via the semilunar valve (Starr, 126). The semilunar valve stops blood flowing backwards from the pulmonary artery to the right ventricle (Starr, 126). The pulmonary artery then carries blood into the lungs. From the lungs, blood is transported to the heart via the pulmonary vein (Starr, 126). This cycle ends with blood being drained into the left atrium.

Chronic pulmonary heart disease is a disease that causes the right ventricle to enlarge (Starr, 134). The disease can take place in two phases: a short time phase or built up over a long period. The chronic type of this disease, which builds up over a period, is caused by cigarette smoking (Starr, 134). The disease is initiated with inability of the lungs to supply enough oxygen to the blood. This disease results due to the lack of enough oxygen in the body forcing the heart to pump the blood faster in order to supply the body with enough oxygen. This results in an enlarged right ventricle. A person suffering from this disease has breathing problems, irregular heartbeat, pain in the chest, discolored fingertips, and swollen feet. Prolonged exposure to this disease causes the right ventricle of the heart to fail hence resulting in a heart failure (Starr, 135).

Arteries are large blood vessels that are hose-like. The walls of the arteries are masculine and thick. Arteries are elastic to allow the blood to flow through it during systole and diastole without difficulties (Starr, 130). Arteries lack valves because they carry blood at high pressure. Arteries transport blood away from the heart. All arteries accept pulmonary arteries carry oxygenated blood that is low in carbon dioxide concentrations. Blood pressure is increased in the arteries through vasoconstriction, where the walls contract to reduce the internal diameter of the blood artery (Starr, 130). The reverse of this process is called vasodilation, this lowers the blood pressure.

Arterioles are small and narrow branches of the arteries (Starr, 130). They have thinner walls compared to the arteries. Arterioles are less masculine than arteries. They are found in between the arteries and the capillaries. They are therefore wider than the capillaries but narrower compared to arteries. The narrow lumen of the arterioles causes blood to flow through the arterioles with a higher pressure compared to the arteries. The blood pressure is controlled by vasodilation and vasoconstriction processes (Starr, 130). The pressure in the arterioles is lowered through vasodilation. Vasoconstriction increases blood pressure in the arterioles.

Introduction

According to Skoog, Holler and Crouch (2007, p.23) chromatography refers to the process of separating constituents of different chemicals that are in a sample for purposes of detection or individual use. There are different types of chromatography techniques. For example, the gas chromatography commonly referred to as the GC involves the separation of volatile compounds if found in a mixture of complex other chemicals (Henderson 2003, p.234). In this type of chromatography, the separation occurs based on vapor pressure differences as well as how the compounds behave while in the GC. According to Kurganov (2007, p.101) there are a different techniques in gas chromatography. Laghari, Khuhawar and Zardari (2007, p.2727) assert that in the formation of metal chelates, several analytical methods in the ultra-trace of such metals have evolved. Such techniques, which are responsible for precision, accuracy, and sensitivity of the metals, always find the use in a number of areas (Poole 2012, p.24). Some of the areas include water as well as in the analysis of wastewater. This paper will present a proposal on gas chromatography of volatile metal chelates: application of a new technique for metal analysis in natural waters.

Research Project Proposal

The process of forming metal chelates from a solution in an aqueous state is not something to go by in the event of determining how successful a given analytical method is (Stuart 2003, p.100). Usually, research has showed that not all ions in the aqueous metallic form react into an organic phase extraction. The primary reason for such is attributable to diketone hydrate formation. In order to overcome such limitations, this proposal aims at the adoption of a gas chromatography technique that incorporates a derivative of monothio (HFAS). The study will form the metal chelates directly from aqueous solutions whose concentration is 0.001M. The choice of this compound is because it has potential uses in such areas. In addition, there have been notable improvements in the system used in GC detection. Such developments call for a better method to trace the analysis of metals.

Methodology

The research will make use of analytical techniques in collecting as well as analyzing data for the gas chromatography. As such, analysis will be contacted in the lab through gas chromatographic methods as well as atomic absorption. For this reason, the study will make use of an absorption spectrometer as well as a gas chromatograph. In addition, an atomizer will be utilized in the detection of samples that have low concentrations and of small volumes. The study will make use of ACS grade reagents in the reactions along with subsequent gas chromatography studies. For this proposal, the specific chelating agents are the tetra methyl pentanone and the monothiohexafluoroacetylacetone (HFAS). The data collected from the study will be analyzed by the use of Excel spreadsheet. Excel is chosen since it will be easy to draw any curves or graphs required using excel. However, representation of data from the study will be by curves and graphs.

Conclusion

The study, therefore, will show that gas chromatography on a number of metal chelates such as the HFAS and the tetramethylpentane-3,5-dionate is possible (Henderson 2003, p.234). From the previously stated, according to Bayer et al. (2000, p.34) the success of an analytical technique cannot be based on the ability of the metal to form chelates from its aqueous solution. Usually, gas chromatography techniques, especially in the analysis of volatile metals, are hindered by the formation of diketone hydrate. Based on previous studies on the application of gas chromatography of volatile metal chelates, it is evident that the use of a better technique to metal analysis in natural waters is required (Grob 2000, p.21). As such, the adoption of the HFAS proved to be a significant alternative to other methods that were in use previously.

References

Bayer, O., Bulchel, K., Houben, J., Kropf, H., Muller, E. and Weyl, T. (2000). Methods of organic chemistry. Stuttgart [u.a.]: Thieme, pp.12-243.

Grob, R. (2000). Modern practice of gas chromatography. New York: Wiley, pp.20-21.

Henderson, D. (2003). The analytical application of tetradentate [beta]-ketoamine chelating agents in the gas chromatography of divalent transition metals. p.234.

Kurganov, A. (2007). A mass-balanced definition of corrected retention volume in gas chromatography. Journal of Chromatography A, 1150(1-2), pp.100-104.

Laghari, A., Khuhawar, M. and Zardari, L. (2007). Capillary gas chromatographic analysis of pyrrolidine dithiocarbamate metal chelates. J. Sep. Sci., 30(16), pp.2727-2732.

Poole, C. (2012). Gas chromatography. Amsterdam: Elsevier, p.24.

Skoog, D., Holler, F. and Crouch, S. (2007). Principles of instrumental analysis. pp.1-300.

Stuart, B. (2003). Gas chromatography. Cambridge: Royal Society of Chemistry, p.100.