Correlation between maximum dry density and cohesion of remoulded Nsukka clays

Due to the ever increasing cost of laboratory equipment to determine soil parameters such as cohesion and maximum dry density and the enormous time and energy dissipated in such experiment, this research work was attempted in order to investigate the possi ble correlation between cohesion and maximum dry density. Thirty remoulded clay samples obtained from Nsukka were used for this investigation. The clay samples were categorized into clay of low plasticity (CL), medium plasticity (CI) and high plasticity (C H) after preliminary tests have been carried out on them. To determine the correlation between cohesion and maximum dry density, unconsolidated undrained triaxial test and compaction tests were conducted on all samples and their cohesion and maximum dry de nsity values determined appropriately. Using regression analysis, correlations were developed for the various categories of clay soils. The correlation coefficient, R, obtained for the CL, CI and CH soils were 57.8%, 67.9% and 93% respectively. Based on th is correlation coefficient, it is safe to suggest that for preliminary estimates of soils, the correlations obtained for these soils will suffice. Keywords : Cohesion, Compaction, Correlation, Maximum dry density, Nsukka Clays, Triaxial compression tes

South Sudan: The dilemma of a protracted social conflict

Abstract. This study examined the conflict in South Sudan, which started in December 2013 due to political dissatisfaction between President Salva Kiir and his then Vice President Riek Machar. When South Sudan got independence in 2011 through a referendum where more-than 98 percent of the population supported secession from Sudan, the country became a case study for potential secessions in Africa. However, the euphoria of independence quickly evaporated, and immediately replaced by violent conflict. Thus, the study explored the major causes of the conflict and concluded that political discontent resulting from power struggle among the elites fuelled the conflict. Furthermore, the study argues that citing ethnicity as the fundamental cause of the conflict is misleading and ill-conceived. Rather than being the catalyst of the conflict, the present conflict in South Sudan has rekindled ethnic identities and ideologies to a record height. The new wave of ethnic sentiment in South Sudan is as a result of irrational quest for political power and control among the top echelons in the country. Although ethnicity is not considered as the main cause of the conflict, however, given that the present situation has invigorated ethnic identities and sentiments in the country, the study concludes that any viable solution to the conflict must give incentives to fair ethnic and inter-ethnic representation and coalitions. Keywords. South Sudan, Power struggle, Ethnicity, Violence conflict, Peace-building.JEL. A13, A14, A30

Structural development of HDPE in injection molding

This study investigated some relevant structure/properties relationships in shear-controlled orientation in injection molding (SCORIM) of high-density polyethylene (HDPE). SCORIM was used to deliberately induce a strong anisotropic character in the HDPE microstructure. Three grades with different molecular weight characteristics were molded into tensile test bars, which were subsequently characterized in terms of the mechanical behavior by tensile tests and microhardness measurements. The structure developed upon processing was also characterized by polarized light microscopy (PLM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and wide-angle X-ray diffraction (WAXD). SCORIM allows the production of very stiff molded parts, exhibiting a very well-defined laminated morphology. This morphology is associated with both an M-shaped microhardness profile and a pronounced mechanical anisotropy. These characteristics are supported by an analogous variation in the crystallinity and a high level of molecular orientation, as indicated, respectively, by calorimetric measurements and X-ray diffraction resultsSubprograma Ciência e Tecnologia do 2° Quadro Comunitário de Apoio, Ministério da Ciência e Tecnologia (Portugal)

Formulation and characterization of artemether-loaded sodium alginate microcapsules

Purpose: To increase the solubility of artemether (ART) in Transcutol® HP through microencapsulation in sodium alginate polymer to achieve  sustained in vivo release.Method: Graded concentrations of ART (0.00, 0.25, 0.50, 0.75, and 1.00 g) microcapsules were produced using Tween® 80 by the cold  homogenization method at 24 x 1000 rpm for 15 min. Characterization based on yield, encapsulation efficiency (EE), particle size, pH stability,  differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and in vivo release using Peter’s four-day suppressive protocol in Wistar mice infected with Plasmodium berghei, were determined.Results: The results obtained indicate that 0.5 g ART-loaded microcapsules (AMC) showed the highest yield of 96.85 %. The EE of 88.3 %  corresponded to 0.75 g ART-loaded microcapsules. DSC results revealed that there was a significant reduction in enthalpy in all the formulations compared to the crystalline drug, but no strong bond interaction occurred except for the blank microcapsules. The AMC1.0 showed high dose-dependent plasmodial growth inhibition of 88.75 % while AMC0.25 had the least (68.13 %).Conclusion: The artemether microcapsules showed sustained release characteristics for oral delivery of artemether and therefore may reduce some of the adverse effects associated with high dose artemether therapy in conventional oral tablets. Keywords: Malaria, Artemether, Transcutol® HP, Sustained-release, RBC count, Antiplasmodial activit

Substance Use: Prevalence, Pattern and Risk Factors among Undergraduate Students in a Tertiary Institution in Southwest Nigeria

Background: Substance use is a global public health problem with increasing burden among university students. This study assessed the prevalence, pattern and risk factors of substance use among undergraduate students of Afe Babalola University, Ado-Ekiti, Nigeria.Methods: This was a cross-sectional study of undergraduate students of Afe Babalola University, Ado-Ekiti. A multi-stage sampling technique was used to select respondents. Data collection tool was a structured self-administered questionnaire. Data analysis was done using Statistical Package for the Social Sciences (SPSS) version 23. Statistical significance was set at p value <0.05Results: The respondents’ mean age was 19.5 ± 2.0 years and all 416 (100.0%) were aware of substance abuse. The prevalence of substance use was 299 (71.9%). Alcohol 133 (32.0%) and over-the-counter drugs (29.9%) were the two most commonly used substance. Being male (p=0.017) and in 400 level (p=0.047) were associated with substance use while curiosity 112 (37.5%), peer pressure 95 (31.8%) and school stress 85 (28.4%) were reasons given. Predictors of substance use were being a female (aOR: 2.54; 95% CI=1.89-3.66; p=0.011), civil servant mother (aOR: 5.75; 95% CI=1.90-17.4; p=0.002) and mother with secondary education (aOR: 5.27; 95% CI= 2.20- 12.65; p<0.001).Conclusion: There was high prevalence of substance use with curiosity, peer pressure and school stress being influencers of substance use among the study population. Predictors of substance use were being a female, civil servant mother and mother with secondary education. The University authority should institute measures to prevent access to alcohol and other substances by the students

Validation of the Organizational Culture Assessment Instrument

Organizational culture is a commonly studied area in industrial/organizational psychology due to its important role in workplace behaviour, cognitions, and outcomes. Jung et al.'s [1] review of the psychometric properties of organizational culture measurement instruments noted many instruments have limited validation data despite frequent use in both theoretical and applied situations. The Organizational Culture Assessment Instrument (OCAI) has had conflicting data regarding its psychometric properties, particularly regarding its factor structure. Our study examined the factor structure and criterion validity of the OCAI using robust analysis methods on data gathered from 328 (females = 226, males = 102) Australian employees. Confirmatory factor analysis supported a four factor structure of the OCAI for both ideal and current organizational culture perspectives. Current organizational culture data demonstrated expected reciprocally-opposed relationships between three of the four OCAI factors and the outcome variable of job satisfaction but ideal culture data did not, thus indicating possible weak criterion validity when the OCAI is used to assess ideal culture. Based on the mixed evidence regarding the measure's properties, further examination of the factor structure and broad validity of the measure is encouraged

Effect of Supplementation with Zinc and Other Micronutrients on Malaria in Tanzanian Children: A Randomised Trial

Hans Verhoef and colleagues report findings from a randomized trial conducted among Tanzanian children at high risk for malaria. Children in the trial received either daily oral supplementation with either zinc alone, multi-nutrients without zinc, multi-nutrients with zinc, or placebo. The investigators did not find evidence from this study that zinc or multi-nutrients protected against malaria episodes

Best practices in heterotrophic high-cell-density microalgal processes: achievements, potential and possible limitations

Microalgae of numerous heterotrophic genera (obligate or facultative) exhibit considerable metabolic versatility and flexibility but are currently underexploited in the biotechnological manufacturing of known plant-derived compounds, novel high-value biomolecules or enriched biomass. Highly efficient production of microalgal biomass without the need for light is now feasible in inexpensive, well-defined mineral medium, typically supplemented with glucose. Cell densities of more than 100 g l−1 cell dry weight have been achieved with Chlorella, Crypthecodinium and Galdieria species while controlling the addition of organic sources of carbon and energy in fedbatch mode. The ability of microalgae to adapt their metabolism to varying culture conditions provides opportunities to modify, control and thereby maximise the formation of targeted compounds with non-recombinant microalgae. This review outlines the critical aspects of cultivation technology and current best practices in the heterotrophic high-cell-density cultivation of microalgae. The primary topics include (1) the characteristics of microalgae that make them suitable for heterotrophic cultivation, (2) the appropriate chemical composition of mineral growth media, (3) the different strategies for fedbatch cultivations and (4) the principles behind the customisation of biomass composition. The review confirms that, although fundamental knowledge is now available, the development of efficient, economically feasible large-scale bioprocesses remains an obstacle to the commercialisation of this promising technology