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GENETIC POLYMORPHISMS ASSOCIATED WITH HYPERTENSION IN THE ETHNIC POPULATIONS OF CALABAR AND UYO, NIGERIA
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INSECTICIDE RESISTANCE ASSOCIATED WITH 2La INVERSION AND MICROSATELLITE LOCI POLYMORPHISM IN Anopheles gambiae s.s. POPULATIONS FROM LAGOS AND OYO STATES, NIGERIA
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CONTRIBUTIONS OF NATURAL RADIONUCLIDES IN CHEMICAL FERTILIZERS TO FARM SOIL RADIOACTIVITY AND COMMITTED EFFECTIVE DOSES TO HUMAN
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Page will reload when a filter is selected or excluded.- Mathematics 6 results 6
- Natural Sciences 6 results 6
- Natural Sciences — Mathematical Sciences 6 results 6
- Monte Carlo 4 results 4
- ASME 3 results 3
- FE Modeling 3 results 3
- FEM 3 results 3
- Polymorphism 3 results 3
- "This research work investigated the modeling of Von Mises stress in LNG Spherical Carbon Steel Storage tank using assumed displacement Finite Element analysis based on shallow shell triangular elements. Using equations of elasticity, constant thickness carbon steel spherical storage tanks were subjected to different loading conditions. This paper stresses the need for proper definition of shallow element using sector angles to obtain the shallowness. The shallow spherical triangular element has five degrees of freedom at each of its corner node, which are the essential external degrees of freedom. The assumed displacement fields of these shallow triangular elements satisfied the exact requirement of rigid body modes of motion. The FORTRAN 90 programming language was used for the programme coding to solve finite element equations resulting from the model while Von Mises stresses distribution within the spherical storage tank shell subjected to different internal pressures were determined. The results showed that the use of non-shallow elements due to improper sector angles resulted in unreliable results while real shallow elements produced results that tallied with ASME Section VIII Div 1, Part UG values. " 2 results 2
- ASCE 2 results 2
- Allele and genotype 2 results 2
- Autocorrelation 2 results 2
- Darcy flow 2 results 2
- Efiks and Ibibios 2 results 2
- Estimators 2 results 2
- Forcheimer equation 2 results 2
- Hypertension 2 results 2
- Hypertension is a public health challenge due to its high prevalence, and is a major risk factor for cardiovascular diseases. Hypertension is a complex disease resulting from an interaction of genes and environmental factors. Inconsistent association between polymorphisms of the renin angiotensin aldosterone, the atrial natriuretic peptide systems and hypertension has been reported among various ethnic groups, but not for the Efiks and Ibibios in south-south Nigeria. This study was designed to determine the frequency of gene polymorphisms of these two systems and their association with hypertension in Calabar and Uyo, Nigeria. A population-based case control design was used. A total of 1224 participants, 612 each of patients and controls were randomly recruited from hypertension clinics and the general population. Genotyping of the M235T allele of the angiotensinogen, Insertion/Deletion allele (I/D) of the angiotensinogen converting enzyme, A1166C allele of the angiotensin II type I receptor and C664G allele of the atrial natriuretic peptide genes to identify variants was performed using polymerase chain reaction and restriction enzyme digestion. The Hardy-Weinberg equation was used to calculate the allele and genotype frequencies. Plasma angiotensinogen levels were measured by Enzyme Linked Immunosorbent Assay. Hypertensinogenic factors such as age, familial history, physical exercise and drinking were assessed using questionnaires. Descriptive statistics, chi-square, multiple regression analysis and odds ratio were used to analyze the data. The frequency of the genotypes M235M, M235T, T235T of the M235T allele for the Efiks were 0.4, 7.7, 92 % in patients and 0, 6, 94 % in controls; for the Ibibios were 0.5, 1.2, 87 % in patients and 0, 7, 93 % in controls. The I/D genotypes II, ID, DD frequencies for the Efiks were 11, 44, 46 % in patients and 16, 45, 39 % in controls; for the Ibibios were 11, 40, 49 % in patients and 13, 49, 38 % in controls. The frequency of the A1166C carriers was 1 % while 99 % of the study population had the wild type A1166A genotype for the A1166C allele. Only the CC genotype was observed for the C664G allele. These frequencies did not conform to the Hardy-Weinberg assumptions. There were no significant differences between the genotype frequencies of patients and controls. Plasma angiotensinogen values were significantly higher in the patients with M235T allele than in the controls. Age was a positive predictor for systolic blood pressure (SBP, r = 0.60) in patients and diastolic blood pressure (DBP, r = 0.56) in controls. Other hypertensinogenic variables were not predictors for SBP and DBP in the population (p < 0.05). The Insertion/Deletion allele was a risk factor for hypertension, (O.R = 1.15). A high frequency was observed for the M235T allele and the Insertion/Deletion allele, which was associated with an increased risk for hypertension. The lack of association between the alleles of the M235T, A1166C and the C664G and hypertension suggests that other loci or environmental factors are involved in the disease outcome. 2 results 2
- LNG 2 results 2
- Random deviates 2 results 2
- Root mean square error 2 results 2
- Spherical Storage Tank 2 results 2
- The effect of grain size on the mechanical properties of cold-drawn low carbon steel was investigated. Low carbonsteel specimen cold-drawn to 20%, 25%, 40% and 55% as applicable for the manufacture of 4 inches, 3 inches,21/2 inches and 2inches nail were obtained. The study was aimed at providing experimental result for the understanding of grain size effects which occur with increasing degree of cold-drawn deformation in low-carbon steel used for nail manufacture.The micrographs of steel were obtained using optical microscopy(OM) observation for 20%, 25%,40% and 55% degrees of drawn deformation. From the OM micrographs the counting method as stated in the ASTME E112 standard for grain size was used to determine the grain size of the steel on the micrograph at the different degrees of deformation. The tensile strength, yield strength, brinnel hardness, and toughness of the materials were obtained from mechanical tests. It was shown that the tensile strength, yield strength, toughness and hardness follow quite closely the hall-petch equation. 2 results 2
- Total absolute bias 2 results 2
- Von Mises Stress 2 results 2
- " Road tankers are the most used means of transporting petroleum product to end users due to its cost effectiveness and energy-efficiency. The cylindrical tank has been well designed for by ASME VIII divisions 1 and 2 using analytical equations. Petrol tankers are not circular but elliptical probably for stability during transportation. This paper has used the finite element method to investigate in-plane displacements and Von-Mises stresses in both circular and elliptical cylindrical tanks under full loading. An elliptical OANDO? tanker of 66.78 m3volume and shell thickness of0.2 mmand an equivalent volume circular cylindrical tank was used for the simulation. MATLAB? was used to generate geometrical mesh model of the petroleum tankers, extract element coordinates and conduct the finite element analysis. Plane strain condition was used in analyzing a section of the petroleum tanker. It was observed that an equivalent volume circular cylindrical tank was under a higher internal pressure (16,858 N/m2) compared to the elliptical cylinder (14,480 N/m2). Von-Mises stress and in-plane displacements showed direct linear relationships with internal fluid pressure. Von-Mises stress in the elliptical tank was found to be lower (5.7 × 106 N/m2) than for the circular tank (8 × 106 N/m2). In plane displacements was zero in the longitudinal direction for both tanks and of the order of 10-4 mm in the y-direction for both tanks with the circular larger by about 2.5 × 10-3 cm. So in addition to tank stability on the lorry, the Von-Mises stresses were lower as well for the elliptical tank. It was also observed that Von-Mises stresses were far below the yield stress of the steel plate. However, the effect of weldment area on lowering of yield stress was not studied. Stress values were validated using analytical method and found to be insignificantly different (P > 0.05). " 1 results 1
- "Darcy's law is an essential equation in determining the permeability of porous media which is vital tool in seepage and drainage control in soils. However, whenever the aggregate sizes of the porous media and hydraulic gradient are large, the flow in drains will be semi-turbulent to turbulent. This research aims at modifying the true Darcy's permeability determined under small hydraulic gradients that ensure laminar or nearly laminar flow to allow for reduced efficiency caused by turbulence at greater hydraulic gradient and provide a relation between the maximum gradient for laminar flow and porosity of the porous media. A modeled experiment was set up using sand samples of different porosities from riverbed as porous media, which were packed in a vertical transparent cylinder tube of diameter 1.85x102m and relative permeabilities were determined for gradient ranging from 1.15-15.00. The result of the experiment shows that relative permeability increases with increasing porosity but decreases with increasing gradient. The maximum (or limiting) hydraulic gradient for laminar flow decreases with increasing porosity. Also, the vertical fluid flow in any porous medium is laminar or nearly laminar as much as hydraulic gradient is less than or equal to 1.04. " 1 results 1
- "Runge-Kutta scheme is one of the versatile numerical tools for the simulation of engineering systems. Despite its wide and acceptable engineering use, there is dearth of relevant literature bordering on visual impression possibility among different schemes coefficients which is the strong motivation for the present investigation of the third and fourth order schemes. The present study capitalise on results of tedious computation involving Taylor series expansion equivalent supplemented with Butcher assumptions and constraint equations of well-known works which captures the essential relationship between the coefficients. The simulation proceeds from random but valid specification of two out of the total coefficients possible per scheme. However the remaining coefficients are evaluated with application of appropriate function relationship. Eight and thirteen unknown coefficients were simulated respectively for third and fourth schemes over a total of five thousand cases each for relevant distribution statistics and scatter plots analysis for the purpose of scheme comparison and visual import. The respective three and four coefficients of the slope estimate for the third and fourth schemes have mix sign for large number of simulated cases. However, none of the two schemes have above three of these coefficients lesser than zero. The percentages of simulation results with two coefficients lesser than zero dominate and are respectively 56.88 and 77.10 for third and fourth schemes. It was observed that both popular third and fourth schemes belong to none of the coefficients being zero classification with respective percentage of 0.72 and 3.28 in total simulated cases. The comparisons of corresponding scatter plots are visually exciting. The overall difference 'between corresponding scatter plots and distribution results can be used to justify the accuracy of fourth scheme over its counterpart third scheme. " 1 results 1
- "Search for alternative materials required for shielding ionizing radiation has being on the increase for some period of time. Lead which is widely used is expensive, therefore researches has to be carried out on other materials. Clay has been suggested but it is not as effective as lead in shielding ionizing radiation. This work therefore studies the compression of clay samples at different pressures and thicknesses, so as to improve its shielding ability in the attenuation of ionizing radiations. The research work was on pure clay material and studied their effectiveness as radiation shielding material. The samples were made in bricks and their linear attenuation coefficients were measured at two different X-ray energies of 60keV, 10 mA and 120 keV, 15 mA. The samples were compressed at a pressure of 875Nm-2, 1750 Nm-2, 2625 Nm-2, 3500 Nm-2, and 4375 Nm-2, for thicknesses of 1.0cm, 1.5cm, 2.0cm, 2.5cm,and 3.0cm. The result obtained shows that as the thicknesses increases, the linear attenuation increases which is in conformity with Lambert beer’s equation. The attenuation coefficient obtained shows increase in value when compared to ordinary clay samples that were irradiated without compression. " 1 results 1
- "The bouncing ball problem has proved to be an important phenomenon in engineering applications involving vibro-transportation and vibratory feeder systems. In this paper, the dynamics of a bouncing ball falling consecutively on an accelerating lift tabletop is studied. Using simulation, it is established that the dynamic interaction of accelerating lift tabletop constrained to one-dimensional motion on which the ball is bouncing is fractal. The acceleration of the lift table top was varied gradually as a percentage of acceleration due to gravity over one thousand steps while the number of bounces-off made by the bouncing ball before the lift table top covered a fall distance of 10.000 m was recorded graphically. Similarly, every lift tabletop acceleration has the set of bounce-off height of the bouncing ball recorded graphically, and taken to be one third of height of fall. The number of bounce off drastically dropped to about zero when the acceleration of the lift tabletop was 40% of acceleration due to gravity. The graphical presentation of the ball bounce off height has normal distribution shape with fractal detail. This study showed that two objects, initially at different heights, falling under gravity, maintain separating heights for the period of their fall. The equation governing the dynamics of the bouncing ball and the lift tabletop are of quadratic type but the ball bounce off height graphical results contain fractal details. " 1 results 1
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