Investigating approaches to continuous crystallisation using process-analytical technology: establishment of a steady-state cooling crystallisation process

In this work, two approaches to continuous crystallisation are investigated. The first approach is the mesoscale continuous oscillatory flow crystalliser which possesses a smooth periodic constriction design (herein known as the SPC mesoscale crystalliser) and is a tubular device operating at turbulent flow conditions. The second of these approaches is the popular mixed suspension mixed product removal (MSMPR) crystalliser based on stirred tank technology. The investigation of both approaches is aided by integrated process analytical technology (PAT), newly developed characterisation methods, and offline solid-state analytical tools. The SPC mesoscale crystalliser is a type of continuous oscillatory baffled crystalliser (COBC), which unlike the plug flow crystalliser (PFC), decouples mixing from net flow by combining oscillatory flow with steady flow. This enables significantly longer residence times to be achieved in practical lengths of the crystalliser for crystallisation purposes. In the past few years, COBCs have gained increasing attention as promising platforms for developing robust continuous crystallisation processes and transforming already existing commercial batch processes in industry. This small-diameter SPC mesoscale crystalliser, however, has had very little application to crystallisation despite possessing superior capabilities for efficient mixing and solids suspension, and small volume requirements for process development. The MSMPR crystalliser is an idealised crystalliser model that assumes steady-state operation of a well-mixed suspension with no product classification, and uniform supersaturation throughout, leading to constant nucleation and growth rates. The investigation of both approaches in this work involves the characterisation of the mixing and heat transfer performance, and the development of processes for the continuous cooling crystallisation of glycine (GLY) from water in both platforms. A characterisation of the mixing performance of the SPC mesoscale crystalliser is performed using a newly developed RTD measurement technique. The technique known as non-invasive dual backlit imaging involves the use of two high-definition (HD) cameras and light sources to simultaneously and precisely capture the concentration of a tracer in the crystalliser as a function of grayscale intensity. The new technique is benchmarked against the more traditional invasive conductivity measurements to determine the reliability of both techniques. Using the dual backlit imaging technique, the liquid and solid phase axial dispersion performance the SPC mesoscale crystalliser is determined, and the optimum conditions for solid-liquid plug flow are identified for crystallisation. A series of heat transfer experiments are performed to characterise the heat transfer performance of the SPC mesoscale crystalliser and its suitability for tight control of temperature and local supersaturation. Based on these experiments, an empirical correlation is developed to predict the tube-side Nusselt number and enable spatial temperature profile predictions in the SPC mesoscale crystalliser for cooling crystallisation. A seeded continuous cooling crystallisation process is then carried out based on metastable zone width (MSZW) measurements in a batch version of the SPC mesoscale crystalliser. A rapid intermittent vacuum transfer technique is applied to the single- and two-stage configurations of the MSMPR crystalliser to successfully mitigate transfer line blockage issues and obtain uninterrupted steady-state operation. The RTD performance of the MSMPR crystalliser is characterised and benchmarked against the SPC mesoscale crystalliser, confirming the contrasting RTD profiles offered by each platform. Solid suspension performance and determination of critical residence time for heat transfer is also carried out for the MSMPR platform to aid crystallisation process development. Subsequently, using a complete recycle operation, the unseeded cooling crystallisation of GLY from water is investigated systematically to understand the effect of mean residence time, MSMPR operating temperature, and number of MSMPR stages on the GLY product mean size, crystal size distribution (CSD), and yield. The systematic study of GLY-water seeded continuous cooling crystallisation in the SPC mesoscale crystalliser identified an operating strategy for obtaining desired product attributes. Specifically, seeding with small-sized seeds, running at longer mean residence times (by extending the crystalliser length), operating at near plug flow conditions, and implementing a spatial cubic temperature profile will lead to larger product mean sizes, with narrower CSDs, and higher yields. In the MSMPR crystalliser, experimental investigations showcased the higher degree of operational capability offered by cascade operation, whereby a two-stage MSMPR configuration enabled operation at much lower MSMPR temperature than possible in the single-stage MSMPR and provided higher yield. Results particularly highlighted the importance of controlling supersaturation distribution in the MSMPR system by manipulating operating variables such as mean residence time and MSMPR stage temperatures to achieve desired product quality. Overall, the investigations carried out in this body of work demonstrate the potential of the SPC mesoscale crystalliser for application to continuous crystallisation process development of small-volume active pharmaceutical ingredients (APIs). Both platforms are therefore equally feasible for process development and manufacturing

THE RELATIONSHIP BETWEEN IMPERIALISM AND FOOD INSECURITY IN AFRICA WITH SPECIAL EMPHASIS ON NIGERIA

Many African states have recently, hurriedly put together a number of measures aimed at cushioning the effects of the global food crisis. Most of these programs have been implemented in different forms since the era of independence and have had no significant impact on food and agricultural development. In this paper we used the historical materialism approach to critically evaluate Africa’s food crisis genesis. Our thesis, using the Nigerian, experiences is that Africa’s contact with metropolitan capital set the continent on the path to dependent economic and political development. The state structures in Africa emphasize economic programs which respond to Europe’s economic needs to the detriment of internal agricultural capacity building. To redress the situation, we have recommended an end to imperialism and capacity building among African peasants.Capital, Development, Poverty and Political

Medicalization of Female Genital Cutting in Sapele Local Government Area, Delta State, Nigeria: The Implication for Health Care Provision in Nigeria

Background: Female genital cutting (FGC) affects over 200 million girls and women globally. It is inimical to health and increasingly being performed by healthcare providers. Medicalization of FGC is proposed by its proponents to reduce and prevent the incidence of its complications and though perceived to be safer, it is unethical and unjustifiable. This study assessed medicalization of FGC in Sapele Local Government Area, Delta State and made recommendations geared towards ending its practice.Methods: A descriptive cross-sectional study was conducted among reproductive age women (15 – 44 years) selected using multi-stage sampling. Pre-tested structured questionnaire was used to obtain quantitative data from 502 women while a focus group discussion guide was used to obtain qualitative data. Data was analyzed using SPSS version 20.0 and by themes. Results were presented as tables and narratives.Results: Prevalence of FGC was 277 (55.2%), of which 223 (80.5%) were medicalized. The mean age of cutting was 16.8 ± 5.46 years and nurses performed majority 220 (79.4%) of them. Few 44 (8.8%) of the respondents were aware of possible complications of FGC. Qualitative findings indicated that FGC is still being practiced with nurses being reported as major practitioners.Conclusion: Despite concerted efforts to eliminate FGC, its practice is still propagated with increasing heath workers as practitioners. Advocacy and health education for women and girls as well as training and retraining of health care providers is imperative to check this trend

Utilization of conserved genic SSR markers for phylogenetic analysis of Nigerian Ipomoea species

Ipomoea, with enormous economic importance, is a large genus with species that are highly evolutionarily diverged. There is dearth of information regarding the phylogenetic relationships of the Nigerian species of the genus Ipomoea. It is therefore imperative to use contemporary taxonomic evidences to understand the diversity of its distribution in a region and provide enhanced delimitation of the taxa. In this study, 6 genic simple sequence repeat (SSR) markers whose cross transferability have been established among the plant species were selected to appraise their level of polymorphism and used to study the phylogenetic relationships among 11 indigenous Nigerian Ipomoea species. The 6 SSR loci showed varying levels of polymorphism among the genotypes of all 11 species assessed and demonstrated 100% polymorphism when examined across the 11 species. A total of 55 alleles were produced. The PIC of the primers ranged between 0.2223 and 0.874 with an average value of 0.71885. Phylogenetic analysis clustered species into 3 major and 6 sub clusters wherein the species were clearly separated. This study has shown the effectiveness of developed genic SSR markers for establishing phylogenetic relationship in Ipomoea species

Psychological Preparation for Peak Performance in Sports Competition

This paper attempt to make an overview of various techniques, sport psychologist adopt in psychological preparation of athletes for peak performance. To attain peak performance in sports competitions, coaches and athletes should not base their prospect on physical training on sport skills alone rather should integrate both the mental and physical aspects of performance. During sport competitions athlete should enter the competition with the proper mindset so as to achieve optimum performance. The importance of a sport psychologist to athletes or sports team in this respect cannot be overemphasized, therefore the sport psychologist is in a position to provide the needed therapy to athletes who have been psyched-out by personal, motivational and environmental factors. The paper therefore recommended among others that athletes should be advised for practice mental and psychological skill training and, faster rehabilitation of an injured athlete should be done as this would help to achieve success in peak performance. Keywords: Peak Performance, Sports Skills, Psychological Skills, Attention and Personality

Sequential Pathogenicity Study of Enteric Bacteria Isolated from Chicken Feeds on Broiler Chickens

This study was carried out to investigate the pathogenic potentials of enteric bacteria isolated from chicken feeds sold in Anambra State, Nigeria. A total of 1,536 of different chicken feed samples were collected and screened for the presence of enteric bacteria using pour plate technique. The isolates obtained were characterized and identified. The pathogenic potentials of the isolates on broiler chickens were investigated by challenging the chickens orally using 0.5 ml of the inoculum (108cells/ml). All chickens were kept under complete observation for 4 weeks for pathological signs and symptoms, mortalities and gross morphological lesions of the internal organs. Escherichia coli O157:H7 SS52 (EC), Salmonella ser. Typhimurium U288 (ST), Escherichia coli SEC470 (ES), Salmonella ser. Enteritidis YU39 (SY) and Salmonella ser. Enteritidis FM366 (SE) were isolated from the feed samples. There were significant pathological lesions among the infected chickens, and these decreased significantly (P<0.05) as the age of the chickens increased.The histopathological examination of infected organs revealed congestion, mononuclear infiltration, hemorrhage, necrosis and significant destruction of the organs. The mean plate counts of EC was highest followed by SE, and ST was the least among the plated organs. The isolates showed obvious pathological features among the infected chickens, and these obvious pathological features were pronounced among the chicks mostly the day old chicks

Effect of Retrenchment on Employees’ Service Delivery: A Study of Ten Districts of Enugu Electricity Distribution Company (EEDC) in Southeast Nigeria

This study examines the effect of retrenchment on employees’ service delivery: a study of ten districts of Enugu Electricity Distribution Company (EEDC) in Southeast Nigeria. The study was necessitated by the alarming rate of retrenchment across various industries in Nigeria particularly the energy sector that is a major driver of economic growth and development in the country. The poor service delivery of the sector has been a teething problem to both the citizens and organizations that need their services. With the recent restructuring of the sector and emergence of Enugu Electricity Distribution Company (EEDC) with its attendant retrenchment, it becomes more constricting what the service delivery of the retrenchment survivors will be. This study therefore, modelled variables like employee work load, longer working hours, pay cut, depression and anxiety and restructuring of work to ascertain how they have influenced on employees’ service delivery in Enugu Electricity Distribution Company (EEDC) using an econometric regression model of the Ordinary Least Square (OLS). Findings revealed that with the exception of longer working hours that were not significant, all other variables (employee work load, pay cut, depression and anxiety; and restructuring of work) had significant effect on employees’ service delivery. Based on the findings, the study recommends that electricity distribution companies should adequately adjust employees work load, increase survivors pay, restore confidence on the survivors and ensure work place harmony during restructuring of work to enable them improve their service delivery

Production of Periwinkle Shell Reinforced Grindstone

The study involves the use of periwinkle shell particles as reinforcement in the production of grindstone to meliorate its physical and mechanical properties. The assessment of the properties of the periwinkle shell reinforced concrete grindstone showed that reinforcement yielded several promising results. The compressive strength was higher for samples with lower water/cement ratio (7%) than those with higher water/cement ratio (10%). The introduction of concrete that contains periwinkle shells as fine aggregates resulted in the loss of smooth like appearance and reduction in weight. The loss of its smooth like nature introduces the rough nature which improved its functionality. The reinforced sample had the lowest hardness test and in hardness test the lower the number the higher the hardness. There was an increase in the density after absorption test was carried out on specimens. There was also reduction in production cost with periwinkle shells partial replacement of cement and gravel as fine aggregate. The composite was adequate for grindstone production since its sample has a compressive of 18.15Mpa and thus satisfied MOR requirements of 11.5 MPa for general purpose boards

Comparison of Reinforcement Loading on the Mechanical and Physical Properties of Palm Trunk Ash and Polyethene Composites

A comparison experiment of reinforcement loading on the physical and mechanical properties of palm trunk ash and polyethene composites was carried out. The effect of physical and mechanical properties of reinforced low density polyethylene of both virgin and recycled with palm trunk ash was compared using tensile test, hardness test, flexural test and micro structural test determination. The equipment used in determining physical and mechanical properties of the composites materials  include metal mould, sieves, digital weighing balance, hack saw, grinding machine, tensometer, universal material tester, digital Rockwell hardness tester and optical micro structural microscope. The matrix materials used for the formation of the composites are the virgin and recycled low density polyethene and palm trunk ash was used as filler material. The composites were prepared using percentage weight of 0%,10%, 20%, 30%, 40% and 50% of palm trunk ash. The conversion of waste materials to a valuable product was the major target of the author and the results showed that palm trunk ash (PTA) can be used as a reinforcing material on polymeric matrices of both virgin and recycled polyethene. The results of the RLDPE-PTA and VDPE-PTA showed that the virgin material was more effective than the recycled material and the quality of the recycled composites can be increased with an increase in the PTA. The Palm trunk ash at 50% increases the tensile strength thereby increasing the brittleness of the material and reducing the ductility. The tensile strength of VDPE-PTA and RLDPE-PTA obtained showed that proper mixture of palm trunk ash and low density polyethene composite are good engineering materials for reinforcement loading. The increase in PTA also decreases the flexural strength of the composite materials which shows that the 0% PTA composite materials have the highest flexural strength. It was also observed that the melting point of the composite materials increase with increase in palm trunk ash of both VDPE-PTA and RLDPE-PTA. Keywords: Comparison, Reinforcement, Properties, Palm Trunk Ash, Polyethene, Composite