48 research outputs found

    Synthesis of zeolite-A using kaolin samples from Darazo, Bauchi state and Ajebo, Ogun state in Nigeria

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    Kaolin samples from Ajebo and Darazo in Nigeria were characterized and used to produce zeolite - A crystals. The thermal analysis indicates that both samples under gode-hydroxylation from 450oC to about 700oC and are converted to metakaolin with a weight lo ss of about 11.39 and 10.43% for the Ajebo and Darazo samples respectively. Characteristic OH, Al-OH, Si-OH and Si-O-Albands were confirmed in both samples with Infra-red spectroscopy studies. The X - ray diffraction patterns clearly show the presence of the characteristic peaks (12.35 and 24.88o ) of kaolinite with little quartz impurities. X - ray diffraction measurements (2Ɵ peaks at 7 – 18o and 21 – 35o ) and scanning electron micro graphs clearly show that zeolite - A crystals are produced. The microstructures of kaolin, metakaolin and zeolite - A crystals reveal the presence of platy crystals, amorphous spherical aggregates and cubic - shaped crystals with some amorphous gel respectively . The results show that both Ajebo and Darazo kaolin are suitable for zeolite - A synthesis. Keywords: Kaolin, Metakaolin, Thermal analysis, X - ray Diffraction, Zeolite -

    Evaluation of sesamum gum as an excipient in matrix tablets

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    In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated

    Nanoscale Visualization of Elastic Inhomogeneities at TiN Coatings Using Ultrasonic Force Microscopy

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    Ultrasonic force microscopy has been applied to the characterization of titanium nitride coatings deposited by physical vapor deposition dc magnetron sputtering on stainless steel substrates. The titanium nitride layers exhibit a rich variety of elastic contrast in the ultrasonic force microscopy images. Nanoscale inhomogeneities in stiffness on the titanium nitride films have been attributed to softer substoichiometric titanium nitride species and/or trapped subsurface gas. The results show that increasing the sputtering power at the Ti cathode increases the elastic homogeneity of the titanium nitride layers on the nanometer scale. Ultrasonic force microscopy elastic mapping on titanium nitride layers demonstrates the capability of the technique to provide information of high value for the engineering of improved coatings

    Reduced Cortisol and Metabolic Responses of Thin Ewes to an Acute Cold Challenge in Mid-Pregnancy: Implications for Animal Physiology and Welfare

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    Background: Low food availability leading to reductions in Body Condition Score (BCS; 0 indicates emaciation and 5 obesity) in sheep often coincides with low temperatures associated with the onset of winter in New Zealand. The ability to adapt to reductions in environmental temperature may be impaired in animals with low BCS, in particular during pregnancy when metabolic demand is higher. Here we assess whether BCS affects a pregnant animal’s ability to cope with cold challenges. Methods: Eighteen pregnant ewes with a BCS of 2.760.1 were fed to attain low (LBC: BCS2.360.1), medium (MBC: BCS3.260.2) or high BCS (HBC: BCS3.660.2). Shorn ewes were exposed to a 6-h acute cold challenge in a climate-controlled room (wet and windy conditions, 4.460.1uC) in mid-pregnancy. Blood samples were collected during the BCS change phase, acute cold challenge and recovery phase. Results: During the BCS change phase, plasma glucose and leptin concentrations declined while free fatty acids (FFA) increased in LBC compared to MBC (P,0.01, P,0.01 and P,0.05, respectively) and HBC ewes (P,0.05, P,0.01 and P,0.01, respectively). During the cold challenge, plasma cortisol concentrations were lower in LBC than MBC (P,0.05) and HBC ewes (P,0.05), and FFA and insulin concentrations were lower in LBC than HBC ewes (P,0.05 and P,0.001, respectively). Leptin concentrations declined in MBC and HBC ewes while remaining unchanged in LBC ewes (P,0.01). Glucose concentrations and internal body temperature (Tcore) increased in all treatments, although peak Tcore tended to be higher in HBC ewes (P,0.1). During the recovery phase, T4 concentrations were lower in LBC ewes (P,0.05). Conclusion: Even though all ewes were able to increase Tcore and mobilize glucose, low BCS animals had considerably reduced cortisol and metabolic responses to a cold challenge in mid-pregnancy, suggesting that their ability to adapt to cold challenges through some of the expected pathways was reduced

    Prevalence, awareness, treatment, and control of hypertension in Nigeria in 1995 and 2020: A systematic analysis of current evidence

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    Improved understanding of the current burden of hypertension, including awareness, treatment, and control, is needed to guide relevant preventative measures in Nigeria. A systematic search of studies on the epidemiology of hypertension in Nigeria, published on or after January 1990, was conducted. The authors employed randomeffects meta-analysis on extracted crude hypertension prevalence, and awareness, treatment, and control rates. Using a meta-regression model, overall hypertension cases in Nigeria in 1995 and 2020 were estimated. Fifty-three studies (n = 78 949) met our selection criteria. Estimated crude prevalence of pre-hypertension (120-139/80-89 mmHg) in Nigeria was 30.9% (95% confidence interval [CI]: 22.0%-39.7%), and the crude prevalence of hypertension (≥140/90 mmHg) was 30.6% (95% CI: 27.3%-34.0%). When adjusted for age, study period, and sample, absolute cases of hypertension increased by 540% among individuals aged ≥20 years from approximately 4.3 million individuals in 1995 (age-adjusted prevalence 8.6%, 95% CI: 6.5-10.7) to 27.5 million individuals with hypertension in 2020 (age-adjusted prevalence 32.5%, 95% CI: 29.8-35.3). The age-adjusted prevalence was only significantly higher among men in 1995, with the gap between both sexes considerably narrowed in 2020. Only 29.0% of cases (95% CI: 19.7-38.3) were aware of their hypertension, 12.0% (95% CI: 2.7-21.2) were on treatment, and 2.8% (95% CI: 0.1-5.7) had at-goal blood pressure in 2020. Our study suggests that hypertension prevalence has substantially increased in Nigeria over the last two decades. Although more persons are aware of their hypertension status, clinical treatment and control rates, however, remain low. These estimates are relevant for clinical care, population, and policy response in Nigeria and across Africa

    Available phosphorus levels in diets for 30 to 60 kg female pigs selected for meat deposition by maintaining calcium and available phosphorus ratio

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    With the objective to evaluate levels of available phosphorus (aP) in diets for pigs selected for meat deposition by maintaining the calcium and available phosphorus ratio, it was used 50 commercial hybrid female pigs with initial weight of 30.32 ± 0.29 kg, distributed in a complete randomized experimental design, with five treatments, five replicates, and two animals per experimental unit. Treatments were composed of a corn-soybean meal basal diet and four diets obtained by supplementation of basal diet with dicalcium phosphate, resulting in diets with 0.144; 0.224; 0.304; 0.384 and 0.464% of aP. Calcium levels were adjusted by varying the quantities of limestone in the diets. There was no effect of aP on both daily feed intake and feed conversion. Levels of aP affected daily weight gain which increased quadratically up to the estimated level of 0.372%. There was no effect of aP on quantity of phosphorus in the bones. The quantity of calcium in the bones and percentage of ash in the bones were influenced in an increasing linear way by the aP in the rations. The best result of weight gain of swine females, from 30 to 60 kg, genetically selected for meat deposition, is provided by the level of available phosphorus of 0.372%, which corresponds to a relationship with calcium of 2.06:1 and to a daily intake of 8.20 g of available phosphorus.Com o objetivo de avaliar níveis de fósforo disponível (Pd) em rações para suínos selecionados para deposição de carne, mantendo-se a relação entre o cálcio e o fósforo disponível, foram utilizadas 50 fêmeas suínas, híbridas comerciais, com peso inicial de 30,32 ± 0,29 kg, distribuídas em delineamento experimental inteiramente casualizado, com cinco tratamentos, cinco repetições e dois animais por unidade experimental. Os tratamentos foram constituídos por uma ração basal formulada a base de milho e farelo de soja e quatro rações obtidas pela suplementação da ração basal com fosfato bicálcico resultando em rações com 0,144; 0,224; 0,304; 0,384 e 0,464% de Pd. Os níveis de cálcio foram ajustados variando-se a quantidade de calcário das rações. Não houve efeito dos níveis de Pd das rações sobre o consumo de ração diário e sobre a conversão alimentar. Os níveis de Pd influenciaram o ganho de peso diário que aumentou de forma quadrática até o nível estimado de 0,372%. Não houve efeito dos níveis de Pd sobre a quantidade de fósforo nos ossos. A quantidade de cálcio nos ossos e a porcentagem de cinza óssea foram influenciadas de forma linear crescente pelos níveis de Pd das rações. O melhor resultado de ganho de peso de fêmeas suínas, dos 30 aos 60 kg, selecionadas geneticamente para deposição de carne, é proporcionado pelo nível de fósforo disponível de 0,372%, correspondente a uma relação com o cálcio de 2,06:1 e a um consumo diário de 8,20 g de fósforo disponível

    Influence of cutting frequencies andN-Rate on percent water content of herbage in three grass species

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    No Abstract. Global Journal of Pure and Applied Sciences Vol. 12(3) 2006: 2301-30
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