339 research outputs found
Influence of Steel and Bamboo Fibres on Mechanical Properties of High Strength Concrete
This paper evaluated the influence of steel and bamboo fibres on high strength concrete. Samples of concrete cubes, beams and cylinders cast with varying proportions of steel and bamboo fibres were subjected to compression, flexural and splitting tensile strength tests respectively. A total of sixty three cubes of 100mm x 100mm x 100mm, fourteen beams of 100mm x 100mm x 500mm, and cylinders of diameter 100 mm and length of 150 mm were tested. The results revealed that concrete containing 1.0% bamboo fibre produced the greatest effect on flexural strength (81% increase in strength), and also on splitting tensile strength (101% increase). However, it was discovered that bamboo fibre has little or no impact on the compressive strength of high strength concrete. Steel fibre-reinforced concrete generally produced an appreciable increase in compressive, flexural and splitting tensile strengths than the bamboo fibre-reinforced concrete
Influence of spark plasma sintering temperature on the densification and micro-hardness behaviour of Ni-Cr-Al alloy
Abstract : Sintering temperature is essential towards attaining desired densification and formation of phases which in turn influences the microstructure and properties of a material. In this study, the densification and microhardness behaviour of Ni-Cr-Al alloy prepared by spark plasma sintering (SPS) at different sintering temperatures were investigated. After sintering operation, the density, hardness, phase analysis, and microstructural evolution were investigated using the Archimedeâs principle, hardness tester, X-ray diffraction (XRD), and scanning electron microscopy (SEM) respectively. The nickel based alloy was sintered at temperatures of 600, 750, 950 and 1100 ÂșC. The results indicated that the densification, microstructure, and hardness values were influenced by changes in the sintering temperature. The relative density increased from 73.89 % at 600 ÂșC to 99.89 % at 1100 ÂșC, while the hardness value was enhanced from 131.9 ± 2.8 HV to 404 ± 1.2 HV respectively
Maize rhizosphere modulates the microbiome diversity and community structure to enhance plant health
Metagenomic has been explored in investigating microbiome diversity. However, there is limited available information on its application towards securing plant health. Hence, this study adopts the metagenomic approach to unravel the microbiome diversity associated with healthy (LI and MA) and Northern corn leaf blight (NCLB) infected (LID and MAD) maize rhizosphere in the maize growing field at Lichtenburg and Mafikeng, North-West province of South Africa. The extraction of whole DNA from the respective healthy and diseased rhizosphere soils was conducted and sequenced using shotgun metagenomics. A total of 12 bacteria, 4 archaea and 2 fungal phyla were found as predominant across the fields with the use of the SEED subsystem database. The most predominant bacteria phyla included Proteobacteria, Dienococcus-Thermus, Gemmatimonadetes, Chlorobi, Cyanobacteria, Planctomycetes, Verrucomicrobia, Acidobacteria, Firmicutes, Chloroflexi and Bacteroidetes. Archaea consisted of Euryarchaeota, Thaumarchaeota, Crenarchaeota and Korachaeota, while Ascomycota and Basidiomycota were the dominant fungal phyla. Microbial abundance and diversity were higher in the rhizosphere of healthy maize (LI and MA) rhizosphere as compared to the NCLB diseased (LID and MAD), in the order LI > MA > LID > MAD. At phylum and genus level, alpha diversity index showed no significant (p > 0.05) difference in the abundance of the microbial community of healthy and NCLB infected maize rhizosphere, while beta analysis produced a significant (p = 0.01) difference in the microbial diversity in the soil. Taken together, the study revealed that the abundance of microbial diversity in the maize rhizosphere influences the efficacy of the rhizosphere microbiome to modulate microbial functions towards managing and sustaining plant health
Pedagogic Integration of Cultural Art-knowledge Contents into Architecture curriculum: Teachersâ Gestalt Acculturation Experience
Most communities of the world acculturate their own identity by
the inculcation of art cultures into the spines of citizenry education. Right
from the pre-school stage to higher level education, it has been observed
that the Art knowledge contents have skewed away from the gate keepersâ
(Accreditation bodies) expectations and requirements in most schools today.
The aim of this study is to evaluate the current art knowledge contents in
the selected Universitiesâ curricula in order to integrate the relevant artknowledge
ingredients into the architecture curricula in southwest Nigeria.
The methodology employed qualitative-content analysis on the secondary
data retrieved from the curriculum of schools, Community Charrette
guidelines and art-oriented pedagogic activities. The results yielded
pedagogic indices from Art-based curriculum integration, Tenets from
hidden curriculum, Gestalt Acculturation experiences and architectural
design studio exhibitions of works. The study recommended that relevant
pedagogic knowledge Art-culture content (PKC) should be integrated
pragmatically into the curricula of schools to preserve the art cultures in
architectural Identity and design practices of the future professionals
Physicochemical Properties of Palm Kernel Oil
Abstract: Physicochemical analyses were carried out on palm kernel oil (Adin) and the following results were obtained: Saponification value; 280.5±56.1 mgKOH/g, acid value; 2.7±0.3 mg KOH/g, Free Fatty Acid (FFA); 1.35±0.15 KOH/g, ester value; 277.8±56.4 mgKOH/g, peroxide value; 14.3±0.8 mEq/kg; iodine value; 15.86±4.02 mgKOH/g, Specific Gravity (S.G) value; 0.904, refractive index; 1.412 and inorganic materials; 1.05%. Its odour and colour were heavy burnt smell and burnt brown, respectively. These values were compared with those obtained for groundnut and coconut oils. It was found that the physico-chemical properties of palm kernel oil are comparable to those of groundnut and coconut oils except for the peroxide value (i.e., 14.3±0.8 mEq) which was not detectable in groundnut and coconut oils. Also the odour of both groundnut and coconut oils were pleasant while that of the palm kernel oil was not as pleasant (i.e., heavy burnt smell)
Phenotyping and genotyping of CYP2C19 using comparative metabolism of proguanil in sickleâcell disease patients and healthy controls in Nigeria
Polymorphic expression of metabolic enzymes have been identified as one of the key factors responsible for the interindividual/ethnic/racial variability in drug metabolism and effect. In Nigeria, there is a disproportionately high incidence of sickleâcell disease (SCD), a condition characterized by painful crisis frequently triggered by malaria. Proguanil, a substrate of the polymorphic CYP2C19, is a chemoprophylactic antimalarial drug widely used among SCD patients in Nigeria. This study aimed to conduct a comparative CYP2C19 phenotyping among SCD patients and healthy controls and to compare the results with those previously reported. One hundred seventyâseven unrelated subjects comprising 131 SCD patients and 46 nonâSCD volunteers were phenotyped. This was carried out by collecting pooled urine samples over 8Â h following PG administration. Proguanil and its major CYP2C19âdependent metabolites were measured by highâperformance liquid chromatography. Metabolic ratios (MRs) were computed and employed in classifying subjects into poor or extensive metabolizers. Among SCD group, 130 (99.2%) were extensive metabolizers (EMs) and 1 (0.8%) was poor metabolizer (PM) of PG, while 95.7 and 4.3% nonâSCDs were EMs and PMs, respectively. MRs ranged from 0.02 to 8.70 for SCD EMs and from 0.22 to 8.33 for nonâSCD EMs. Two nonâSCDs with MRs of 18.18 and 25.76 and the SCD with MR of 16.77 regarded as PMs had earlier been genotyped as CYP2C19*2/*2. Poor metabolizers of proguanil in SCD patients are reported for the first time. Regardless of clinical significance, a difference in metabolic disposition of proguanil and CYP2C19 by SCDs and nonâSCDs was established
Comparative study of spark plasma sintering features on the densification of Ni-Cr binary alloys
Abstract: Spark plasma sintering (SPS) has been widely regarded as an advanced powder consolidation technique which helps in the development of array of engineering materials. Many have been reported in the literature about sintering parameters such as temperature, pressure, heating rate and holding time. However, little or no reports has been made on some of the intricate features such as process time(s), power SPS (KW), pressing speed (mm/min), and average pressing force (KN) on which sintering parameters are directly related to. This study aims to investigate the behaviour of spark plasma sintered Ni-17Cr binary alloys with emphasis on the densification, hardness value and spark plasma sintering features such as process time (s), power SPS (KW), pressing speed (mm/min), and the average pressing force (KN). Nickel and chromium powders were milled individually using High energy ball milling for durations of 5hr, 10 hr prior to mixing and subsequent sintering. The sintered 5 hr and 10 hr milled Ni-17Cr binary alloys attained relative densities of 98.72 % and 99.1 % respectively. The Microstructural morphology was examined using Scanning electron microscopy (SEM). The sintered 10 hr milled Ni-17Cr binary alloy revealed the higher hardness
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