Microbial physiology and culture (Practical Oxygen Transfer in a Essay

Microbial physiology and culture (Practical Oxygen Transfer in a Stirred Tank Reactor) - Essay Example In this experiment, this method is used in the determination of KLa. This process is important since it is applied in many fermentation processes which undergo aerobic reactions. This allows meeting the necessary metabolic demands of aerobic microorganisms. In this process, air is passed through a reactor at a constant flow rate at given speed in revolutions per minute. From the data, CL and time, it’s able to calculate KLa using the formula. Drawing a graph of  against time produces a straight line whose gradient is KLa (Karimi, 2013). Question 1 RPM = 200 From the graph, Thus M=0.0594 KLa=3.564 RPM at 400 From the graph, Thus Therefore the slope, m=0.0146 Thus, KLa = 0.0146*60 = 0.876 h-1 RPM at 600 From the graph, Thus Therefore the slope, m=0.0343 Thus, KLa = 0.0343*60 = 2.058 h-1 RPM at 800 From the graph, Thus Therefore the slope, m=0.0344 Thus, KLa = 0.0344*60 = 2.064h-1 Second practical Flow rate 0.5 Rpm 500 From the graph, Thus Therefore the slope, m=0.0114 Thus, KLa = 0.0114*60 = 0.684h-1 Flow rate 1.50 Rpm 500 Start air concentration 5.7 From the graph, Thus Therefore the slope, m= Thus, KLa = *60 = 2.07h-1 Flow rate 2.0 Rpm 500 Start air concentration 5.7 From the graph, Thus Therefore the slope, m= 0.0594 Thus, KLa = 0.0594*60 = 3.564h-1 Question 2 KLa F N Log KLa Log N 3.564 1 200 0.551938 2.30103 2.058 1 600 0.313445 2.778151 2.064 1 800 0.31471 2.90309 Since Log KLa= y log N + constant From the graph, The equation y=-0.4234X + 1.5199 Therefore the constant y=0.4234 KLa F N Log KLa Log F 0.684 0.5 500 -0.16494 -0.30103 2.07 1 500 0.31597 0 3.564 1.5 500 0.551938 0.176091 Since Log KLa= X log F + constant From the graph, The equation y=-1.5127X + 0.2973 Therefore the constant x=1.5127 Question 3 Factors affecting KLa in STR: 1. Culture Conditions 2. Operation of the fermenter 3. Impeller Design Question 4 Increase in the values of the above stated factors reduces the time for the dissolved oxygen concentration. Question 5 Why KLa ra ther than KL It is extremely impossible to measure KL alone. Therefore, to make KL measurable it has to be combined with a to form KLa (Volumetric mass – transfer coefficient) which is easier to determine Question 6 Polarographic oxygen electrode measure Polarographic system is used to measure dissolved oxygen. In this system, the measurement device known as a transducer is the Clark oxygen electrode. An oxygen monitor is the processing (coupling Device) and the recording device is a computer aided data system. Question 7 Importance of KLa KLa is important since it facilitates establishment of efficiency and also it helps in quantifying effects of operating variables that has to be applied on the provision of oxygen. Question 8 Techniques of determining KLa Sulfite oxidation technique In this process, the Oxygen transfer rate is determined by the oxidation of sulfite solution. Gassing-out techniques In this process, the estimation of KLa is done by monitoring the increase of dissolved oxygen in during the process of aeration and agitation. Question 9 From the graphing and the trend of the graph, it can be determined that as the agitation speed increases, the time taken for the dissolved oxygen to reach dissolved oxygen concentration is shortened. Bibliography Karimi, A., 2013. Oxygen mass transfer in a stirred tank bioreactor using different

Are Black Afro Caribbean boys underachieving within the Education Dissertation - 1

Are Black Afro Caribbean boys underachieving within the Education system that are born in the UK - Dissertation Example However, it is also important to understand that success is about opportunity. In the case of Black Afro Caribbean boys, the opportunity for them may also rely on the level of encouragement given to them for success. These children are mostly encouraged to participate in sports, dance or music, but not on professions such as in line with politics and law. The sole purpose is to make them role models in arts and entertainment (BBC News, 2011). Thus, these children are given less substantial background on politics and law but they are rather given much exposure in areas such as sports, dance or music. Certainly, there are different perceptions or ideas about achieving and under achieving. In short, the perception about success may vary. This means that Black Afro Caribbean boys can become successful when it comes to the opportunity given to them but not on areas where they are not given much exposure or encouragement. Prior to the understanding of underachieving among Black Afro Caribb ean boys within the UK’s education system, it is important to understand the derivation of acknowledgement of achievement. Achievement in the academe is given greater weight in the measurement of one’s level of attainment in life. Education particularly in the UK is given with great importance. That is why performing better in the academe has become a good measure of one’s success. There is only secondary evaluation given to areas which pertain to talents and skills. In line with this, Black Afro Caribbean boys are usually secluded from academic evaluation due to the fact that they are much exposed to sports, dance, music and other skill and talent related areas. However, the issue of racial discrimination especially among teachers on black Caribbean pupils exists in the education system (Thomas et al., 2009). In this way, the entire evaluation system may not be having enough solid foundation for concise evaluative process. Thus, more relevant bases are necessar y in order to find out how exactly black Caribbean pupils are performing in school. Objectives It is in line with this that the proponent of this paper tries to evaluate and find out if Black Afro Caribbean boys are really underachieving in the academe provided that they are much exposed to sports, dance, and music and even susceptible to racial discrimination. On the other hand, it is also part of this paper to define what exactly are the bases or standards used in evaluating under achievement among Black Afro Caribbean boys. The proponent will particularly answer the following questions at the end of the study. 1. What are the reasons why children underachieve in education? 2. Are black Afro Caribbean boys especially under achieving within the education system in the UK? 3. What are the reasons and effects of different education system in the UK on black afro Caribbean’s boys lerning? 4. What are the prevailing perception and acknowledgement of achieving and under achieving ? 5. How and where does the acknowledgement of achievement derive? 6. Do black afro Caribbean boys have the same opportunities or expectations to achieve? 7. Are black afro Caribbean boys affected by the lack of male role models? 8. Do teachers have low expectations of social groups such as looked after children, asylum seekers, single parented families and the disabled etc? Methodology The proponent in general would therefore investigate the reasons why