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Soil Subgrade’s Characterization and Classification of Thies (Senegal, West Africa) on a Radius of 2.5 Kilometers along Five Roads  [PDF]
E.H.B.M. Niakhate, Séni Tamba, Makhaly Ba, Adama Dione, Issa Ndoye
Geomaterials (GM) , 2016, DOI: 10.4236/gm.2016.61001
Abstract: This article explains the results of a study conducted on the characterizations of subgrade soils in the region of Thies. The road platforms are mainly composed of a background soil, which is generally overlapped by a surface layer that plays two roles. Firstly, it protects the soil structure, ensures the leveling, and facilitates the movement of vehicles. Secondly, it brings harmony in the mechanistic characteristics of the materials that compose the soil while improving the long-term life force. The methodology consisted in taking samples of subgrade soil along the roads all over the region of Thies in a 5 km diameter span. The identification tests allowed the Thies-Tivaoune, Thies-Khombole and Thies-Noto axes are characterized by tight sands, poorly graded size. While Thies Pout-axis is characteristic of severe solid particle size and spread well graded and serious to spread and well graded particle size. Finally the Thies-Montrolland axis is characterized by severe to very tight particle size and graduated to spread and serious and well graded particle size. The specific gravity values found Proctor test shows the presence of sand, sandy laterite and laterite. In the target area, polished soils of the A-3 type according to the AASHTO classification system are the most represented with 60%, followed by the A-2-6 type 25%, and the A-2-4 type with 9%, which are typical of gravel, clay, and silty sands. Soils of the A-1-b type (2%) typical of roc fragments, sands and clay are also represented. Polished sands of the A-3 type have a better efficiency on road infrastructures than other types of soil listed above. Finally, we’ve also noted the presence of soils of the A-2-7 and A-4 types with the low percentage of 2%. Subgrade soils of class S4 are the most represented with 58%, followed by those of class S5 with 42%. Samples of the Thies-Montrolland road have a claylike plasticity (CL or CH group), while those of the Thies-Pout road belong to the ML or OL and CL or OL groups with a tendency mostly directed to the CL or OL group. All these results confirm the very nature of soils on the two roads and put the light on the presence of lateritic materials with certain plasticity.
Determination of Neutron Fluxes and Spectrum Shaping Factors in Irradiation Sites of Ghana’S Miniature Neutron Source Reactor (mnsr) by Activation Method After Compensation of Loss of Excess Reactivty  [PDF]
R.B.M. Sogbadji, B.J.B. Nyarko, E.H.K. Akaho, R. G. Abrefah
World Journal of Nuclear Science and Technology (WJNST) , 2011, DOI: 10.4236/wjnst.2011.12009
Abstract: Accurate neutron flux values in irradiation channels of research reactors are very essential to their usage. The total neutron flux of the Ghana Research Reactor-1(GHARR-1) was measured after a beryllium reflector was added to its shim to compensate for excess reactivity loss. The thermal, epithermal and fast neutron fluxes were determined by the method of foil activation. The experimental samples with and without a cadmium cover of 1-mm thickness were irradiated in the isotropic neutron field of the irradiation sites of Ghana Research Reactor-1 facility. The induced activities in the sample were measured by gamma ray spectrometry with a high purity germanium detector. The necessary correction for gamma attenuation, thermal neutrons and resonance neutron self-shielding effects were taken into account during the experimental analysis. By defining cadmium cutoff energy of 0.55eV, Al-0.1% Au wires of negligible thickness were irradiated at 3kW to determine the neutron fluxes of two irradiation channels, outer channel 7 and inner channel 2 whose Neutron Shaping Factor (α) were found to be (0.037 ± 0.001) and (–0.961 ± 0.034). The neutron flux ratios at the inner irradiation site 2 were found to be, (25.308 ± 3.201) for thermal to epithermal neutrons flux, (0.179 ± 0.021) for epithermal to fast neutrons flux and (4.528 ± 0.524) for thermal to fast neutrons flux, in the outer irradiation site 7, the neutron flux ratios were found to be, (40.865 ± 3.622) for thermal to epithermal neutrons flux, (0.286 ± 0.025) for epithermal to fast neutrons flux and (11.680 ± 1.030) for thermal to fast neutrons flux.
Analytical Solution of the Point Reactor Kinetics Equations for One-Group of Delayed Neutrons for a Discontinuous Linear Reactivity Insertion
S. Yamoah,E.H.K. Akaho,B.J.B. Nyarko,M. Asamoah
Research Journal of Applied Sciences, Engineering and Technology , 2012,
Abstract: The understanding of the time-dependent behaviour of the neutron population in a nuclear reactor in response to either a planned or unplanned change in the reactor conditions is of great importance to the safe and reliable operation of the reactor. It is therefore important to understand the response of the neutron density and how it relates to the speed of lifting control rods. In this study, an analytical solution of point reactor kinetic equations for one-group of delayed neutrons is developed to calculate the change in neutron density when reactivity is linearly introduced discontinuously. The formulation presented in this study is validated with numerical solution using the Euler method. It is observed that for higher speed, r = 0.0005 the Euler method predicted higher values than the method presented in this study. However with r = 0.0001, the Euler method predicted lower values than the method presented in this study except for t = 1.0 s and 5.0 s. The results obtained have shown to be compatible with the numerical method.
Analysis of Thermal-hydraulic Transients for the Miniature Neutron Source Reactor (MNSR) in Ghana
S. Yamoah,E.H.K. Akaho,B.J.B. Nyarko,M. Asamoah
Research Journal of Applied Sciences, Engineering and Technology , 2011,
Abstract: A mathematical model is presented that permits to simulate the effect of the cooling coils of the pool upper section on the reactor thermal-hydraulic behaviour of Ghana research reactor-1. The model is based on a lumped parameter description solved numerically using Matlab/Simulink tool which is a commercial software package with the capability of modelling dynamical and control systems. The model incorporates fuel grids and cooling coil models as well as radiating energy from the clad. In this model, the reactor tank and the pool is divided into three sections. The model predictions are qualified by comparing the results with experimental data. The effect of cooling the upper section of the pool on reactor thermal-hydraulic parameters using the cooling coil is presented and discussed. It was observed that all maximum values of the reactor thermalhydraulic parameters decrease when the cooling coil power is increased. Good agreement is found between the model predictions and the experimental results.
Temporomandibular joint ankylosis and salivary mucocele in a cat: case report
Rahal, S.C.;Mamprim, M.J.;Caporali, E.H.;Ciani, R.B.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2007, DOI: 10.1590/S0102-09352007000100023
Abstract: an approximately 1.5-year-old, not neutered mixed breed cat was referred for evaluation of inability to open its mouth, and soft tissue swelling around the intermandibular region. both signs were present since the cat was adopted, 1 year before presentation. the cause of the signs was not determined prior to referral. based on the physical and radiographic examinations, left temporomandibular joint ankylosis and salivary mucocele were diagnosed. the lateral aspect of the condyloid process of the left mandible was removed and the salivary mucocele was treated by right mandibular and sublingual gland resection and drainage of the mucocele. after surgery, the cat showed good functional use of the mandible without discomfort.
定向结晶时高温合金组织控制的工艺前景
卡布洛夫E.H.,格拉西莫夫B.B.,杜布罗夫斯基B.A.,瓦希克E.M.
材料工程 , 1996,
Abstract: 报道了俄国航空材料研究院(ВИАМ)在定向单晶高温合金组织控制方面的最新研究成果,例如,利用高速定向结晶工艺创造具有单晶组织的宽弦叶片,以及制造前后缘为规定位相的单晶,而在叶身中部为细柱状定向结晶组织的复合组织叶片。这些新工艺提高了材料的工作能力和发动机寿命。
Serum protein and enzyme levels in rats following administration of ethanolic leaf extract of Ageratum conyzoides (goat weed)
A.B Antai, E.U Eyong, M.U Eteng, E.H Itam, M.E Eko, S.O Ita
Nigerian Journal of Physiological Sciences , 2009,
Abstract: The potential hepatotoxic effects following oral administration of ethanolic leaf extract of Ageratum conyzoides (goat weed) was investigated in albino Wistar rats. Twenty eight (28) adult male Wistar rats were uniformly divided into four groups of seven rats each. Group 1 served as control while groups 2, 3 and 4 were respectively gavaged with 200mg/kg body weight, 400mg/kg body weight and 600mg/kg body weight of the extract daily for 21 days. At the end of treatments, animals were sacrificed, serum and liver tissues obtained for assay of total protein concentration and levels of ALT, AST and ALP. Results showed that treatment of rats with the respective doses of the extract did not significantly alter the serum and liver levels of total protein, ALT, AST and ALP in all test groups. This result suggests that ingestion of the extract may not be toxic at the doses investigated.
Immobilization of Penicillium citrinum Lipase on Ferromagnetic Azide-Dacron
M.C.B. Pimentel,A.B.F. Le？o,E.H.M. Melo,W.M. Ledingham
Biotechnology , 2006,
Abstract: The immobilization of Penicillium citrinum lipase by covalent bond onto ferromagnetic azide-Dacron showed 73% of specific lipase activity retention with 7.3 mg protein/g support. There was no change in either optimal temperature (37°C) or pH (8.0-8.5) after immobilization. The thermal stability of ferromagnetic azide-Dacron-Penicillium citrinum lipase derivative was significant, retaining 86.8% of lipolytic activity while the soluble enzyme retained only 34.2% after 1 h at 45°C, this represented an improvement of 154% in the thermal stability. This lipase did not show inhibition by isopropanol. Both soluble and immobilized Penicillium citrinum lipases showed a kinetic of Michaellis-Menten to hydrolysis of 4-nitrophenyl palmitate of (4NPP) at 37°C and pH 8.0. The values of KM were for soluble enzyme of 233 μM and immobilized derivative of 276 μM. This immobilized derivative showed a good operational stability keeping about 75% of initial activity after its reuse for 5 times. Also, it was stable to storage at 4°C in Tris-HCl buffer pH 7.2 with a half-life of 25 days. Immobilized Penicillium citrinum lipase was able to catalyse the synthesis of triolein using glycerol and olive oil as substrates free of organic solvent, with 80% of conversion after 20 h at 40°C.
Carbapenem-resistant Acinetobacter baumannii outbreak at university hospital
Takagi, E.H.;Lincopan, N.;Cassettari, V.C.;Passadore, L.F.;Mamizuka, E.M.;Martinez, M.B.;
Brazilian Journal of Microbiology , 2009, DOI: 10.1590/S1517-83822009000200024
Abstract: nineteen clonally related imipenem-resistant acinetobacter baumannii isolates were recovered from eight intensive care unit patients. all isolates harboured blaoxa-51-like β-lactamase genes and showed the absence of 22 kda fraction in outer membrane porin profile analysis. it suggests a combination of two mechanisms as responsible for carbapenemresistant phenotypes.
Lipopolysaccharide Extracellular Emulsifier Produced by Penicillium citrinum
M.M. Camargo de Morais,S.A.F. Ramos,M.C.B. Pimentel,E.H.M. Melo
Journal of Biological Sciences , 2006,
Abstract: A Brazilian strain of Penicillium citrinum produced a lipopolysaccharide with emulsifier properties during cultivation on mineral medium, containing ammonium sulfate as nitrogen source, with 1% (v/v) olive oil as the carbon source. The maximal emulsifier production (1.6 U mL-1) was obtained after 60 h of cultivation and the biomass reached 7.5 g L-1 at the end of fermentation. The production yield i.e. the amount the carbon source utilized for product synthesis was 54% and the best emulsifying activity was observed for xylene and diesel oil when compared to other carbohydrates tested. The emulsifier was shown to be stable to a wide range of pH and temperature values and was shown to contain D-galactose, D-glucose and D-xylose (8.2:1.0:5.3) with a total carbohydrate content of 43%. The presence of salts stimulated the emulsification activity, suggesting potential for its application in industrial waste or marine remediation.
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