3,307 research outputs found
Synthesis and Characterization of Starch-Graft-Acrylamide Hydrogel for Oral Drug Delivery
In this research, starch was extracted from fresh sweet potato and was used to prepare starch-g-acrylamide hydrogel using free radical polymerization method with potassium per sulphate and N’N-Methylene bisacrylamide as initiator and cross-linker, respectively. The swelling capacity and pH sensitivity of the synthesized hydrogel were investigated in solutions of various pH (1-12). The drug loading and release experiment was also carried out using promethazine (PMZ) as the model drug at 25oC and 37oC, respectively while the release study was carried out in an enzyme-free simulated gastric intestinal fluid (SGF) and simulated intestinal fluid (SIF). The result showed a 905% swelling at pH 11, suggesting increased swelling capacity at higher pH values. Drug loading result indicated 99% of the drug was entrapped by the hydrogel as confirmed by UV-visible spectrophotometry. SIF and SGF Simulation indicated a 24% and 9% drug release for the first ten hours. At the end of 48 hours the release was 96% and 89%, respectively indicating the hydrogel released more promethazine in SIF than in SGF. The results obtained in this work suggest that starch-graft-acrylamide hydrogel is a potential vehicle for oral drug delivery.
Keywords: Starch, Acrylamide, Hydrogel, Drug delivery
Islam and constitutionalism in Nigeria: 1999 constitution and the challenges of Islamic law and practices
Adherents of the two major religions, Islam and Christianity, sometimes relegate any state law that conflicts with their practice/faith. They would rather obey God than man1. In Geron Ali v. Emperor2, an Indian Muslim decapitated two persons and presented the heads to his religious instructor who asked for only one head. In Ashiruddin v. King3, the prisoner killed his son to secure a divine favour. Religious extremists will not have their religious teachings and practices ‘bow’ to any constitution. This paper, employs the analytical method, using journals, internet based materials, case law, historical records etc., to identify examine faith in the sharia law and the place of the Constitution of the Federal Republic of Nigeria, 1999 (henceforth referred to as CFRN) in the hearts of Islamic faithful. It concludes by recommending inter alia that patriotism and nationalism be inculcated into the citizenry right from childhood in our private and public schools.Keywords: Islam, Constitutionalism, 1999 Nigerian Constitution, Shari
Copper (I) oxide (Cu2) based solar cells - a review
Copper (I) oxide (Cu2O) is a potential material for the fabrication of low cost solar cells for terrestrial application. A detailed survey on the previous work so far carried out on Cu2O based solar cells has been presented. The aspects discussed include the fabrication of Schottky (metal/semiconductor) barrier Cu2O solar cells, where different low work function metals are used to form the Schottky barrier solar cells. The problems associated with the Cu2O Schottky barrier solar cells and efforts made at improving the performance of these solar cells are highlighted. Discussions on heterojunction solar cells with Cu2O have also been presented. Various transparent conducting oxides (TCOs) used in forming the heterojunction cells are mentioned, and successes and failures of using them highlighted. The technological developments of these cells are still in their infancy and the performance remains very poor. The root causes of this poor performance are analyzed and possible areas for future research in the field are outlined.
Keyword: Copper (I) oxide, Solar cells, Solar cells, Schottky barrier sola cell
Principal Components as a Tool in Statistical Quality Control: A Case Study of Sokoto Portland Cement
The principal components analysis and Hotelling’s T2 statistic are used in studying the clinker minerals of Portland Cement Company of Northern Nigeria (CCNN). The cement produced is considered to be a mixture of eight minerals, each being sensitive to the presence of fly ash. Effort was made in this paper to show that the dependence on only one mineral in detecting fault or diagnosing noise was not effective but rather using the entire components such that each component’s contribution to variation is measured thereby making a valid interpretation about fault.Keywords: Hotelling’s T2 approximated model, Fault detection, PCA, Components treatment
Influence of Sulphuric Acid on the Compressive Strength of Ternary Blended Geopolymer Mortar
The deteriorating effect of acid media on cement based constructions has become a worrying problem all over the world. These media generally occur as solutions in various branches of the industry, acid rains and mists, and acid ground-waters. A very popular form of acid attack on concrete that is usually referred to as biogenic sulphuric acid attack also occurs in both industrial and urban sewer systems. The emergence of new cementitious materials, like geopolymer cements, during the past decades necessitates detailed experimental work and research activities to investigate their durability in aggressive acid environments. The study therefore explored the development of alkali-activated CPA-SHA-MK ternary blended geopolymer mortar (GPM) using sodium silicate (Na2Si3) and sodium hydroxide (NAOH) solutions with 9M constant concentration as alkaline activators under both the aggressive and ambient-temperature curing media. The mass ratio of sodium silicate to sodium hydroxide (NS: NH) and as well as the binder to fine aggregate were fixed at 2.5 and 0.8 respectively. The durability of the ternary blended geopolymer mortar was examined through acid resistance test using 50 mm cubes after 28, 56 and 90 days of curing. The results revealed that the setting time prolonged as the replacement levels of RHA-MK increased at a decrease in the replacement levels of CPA. The results also showed that both the PCM and GPM samples studied suffered mass and strength losses in the acid solution and the loss increases at an increase in the hydration periods. The strength losses were observed to be higher in PCM mix (12.19 N/mm2 at 90 days) as compared to the GPMs (6.67 N/mm2 at 90 days) while the mix incorporated 50% CPA, 33% MK and 17% RHA (C50M33R17) was observed to be better compared to other mixes in durability behaviour. The study therefore recommends C50M33R17 mix proportion for good durability performance. 
Matrix-Norm Approach of Computing Levenberg-Marquardt Reg- ularization Parameter for Nonlinear Equations
In this paper, we present Levenberg-Marquardt method for solving nonlinear systems of equations. Here, both the objective function and the symmetric Jacobian matrix are assumed to be Lipchitz continuous. The regularization parameter is derived using Matrix-Norm approach. Numerical performance on some benchmark problems that demonstrates the effectiveness and efficiency of our approach are reported and have shown that the proposed algorithm is very promising.Mathematics Subject Classification: 65H10, 65K05, 65F22, 65F35.keywords: Nonlinear system of equations. Levenberg-Marquardt method. Regularization. Matrix-norm. Global convergence
Some religio-cultural practices against the property rights of women and children in Nigeria and specified African countries
Most African ethnic groups treat women as property to their husbands and could be inherited1 but without inheritance rights at all or with unequal rights tilted in favour of males2 especially in rural areas3. This inquiry sought the impediments to the realisation of the customary inheritance rights of African women and children and how to overcome them. Review of articles in journals, internet based materials consisting of reports of interviews of victims of inhuman customary practices, books, statutes and case law from some African countries was the analytical approach employed in this inquiry. Latest legislative and judicial attitudes were found to be intolerant of these practices but ignorance, poverty, etc. of victims is the setback. Sanctions on erring states members could secure compliance with charters/protocols that guarantee these rights; states and Human right groups’ interventions could provide the enlightenment and financial support needed by rural dwellers to assert their rights.Keywords: Property Rights, Women and Children, Religio-cultural Practices, Nigeria, Some other African Countrie
Poultry Litter Selection, Management and Utilization in the Tropics
In many places, poultry farms are sited and intensively managed in the residential areas with little welfare improvement and major concern of poultry waste disposal. The mean poultry litter generated per bird/day was estimated at 0.11 kg so that millions of metric tons of poultry manure are annually generated. Wastes generated from poultry farms constitute hazard to public health as well as potential source of conflict between neighbours. Beside environmental consequences, poultry waste impacts serious welfare and production effects on poultry. Suitable poultry droppings and moist absorbents referred to as litter materials were later discovered. Recently, conventional caging of birds is considered unethical, common litter materials are seasonally available, wood based litter materials are now being diverted for the manufacture of other wood products, the use of poultry litter as fertilizer and livestock feed supplement has increased, therefore, the demand and price for litter materials is now magnified. Adequate litter materials cannot be easily met by farmers and non-environmentally friendly alternative litter materials may be sought by farmers creating negative socio-economic impacts on poultry and the environment. Therefore, careful selection, adequate management and proper storage and utilization of poultry litter are here given due attention
Electroless deposition and electrical characterization of N- Cu2O layer
This work describes the preparation of n-Cu2O layer by the electroless methods of boiling and immersion of copper plates in 0.001M CuSO4Electron Microscopy (SEM) have been used to characterize the oxide films deposited. XRD studies show, for the first time, that cuprous oxide (Cu2O) and cupric oxide (CuO) were deposited by the two methods. The dissolution of the oxide layer for boiling above the 60 minutes time was found to be due to the turbulent nature of the boiling solution. There was no dissolution of the oxide layer in the case of the immersion method. The thickness of the films deposited for 60 minutes boiling andthat obtained by the immersion method at the solution pH of 9.83 are approximately 4.8 ìm and 3.8ìm, respectively. The resistivities of the oxide layers were found to be 75.64 Ùcm and 61.32 Ùcm, respectively. Annealing of the sample for 60 minutes by boiling, changes the mixed oxides(Cu2O-CuO) into the single phase Cu2O.Keywords: n-Cu2O deposition, boiling and immersion methods
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