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Study of the Geothermal Potential of the Locality of Kaladi and Its Surroundings (Adamawa-Cameroon) from the Frequency Processing of Magnetic Data

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International Journal of Geosciences 2022年第11期13卷 1024-1039页

作者： Ndam Njikam mohamed Moustapha Meying Arsène Zanga Amougou Alain abdou Raouf Nkemndem Agendia Demianus School of Geology and Mining Engineering University of Ngaoundere Ngaoundere Cameroon Department of Physics Faculty of Sciences University of Douala Douala Cameroon Research Center for Deep Ocean Science and Underwater Engineering School of Resources and Geosciences China University of Mining and Technology (CUMT) Xuzhou China Department of Geography University of Buea Buea Cameroon

The aim of this study is to estimate the variations in curie point depth, geothermal gradient and heat flux from the frequency analysis of magnetic data in order to evaluate the geothermal potential of the Kaladi locality and its surroundings. For this purpose, the magnetic field map was first reduced to equator (RTE). The centroid method was used to divide the RTE grid into a set of 40 blocks. The spectral analysis applied to each block allowed determining the depth to top (Zt), center (Z0) and bottom (Zb also called curie point depth or CPD) of the magnetic sources. Knowing the different CPD, the geothermal gradient associated with each block was calculated. The heat flow was then calculated from the geothermal gradient associated with the anomaly block considered. From the set of values obtained for each block, maps of geothermal gradient and heat flow variations were established. Analysis of these maps shows that the sectors that could be favourable for geothermal exploration are the north of Kaladi and the Goro-Bembara corridor, because they show variations in the geothermal gradient and heat flow between 0.4 and 0.8℃/m and between 1.2 and 2 mW/m2 respectively. In addition, the superposition of the different hot springs highlighted in previous studies with areas of high geothermal gradient and heat flow values supports this analysis. The proposed models can be used as background documents for any geothermal exploration project in the study area.

关键词： Spectral Analysis Curie Point Depth Heat Flow Geothermal Gradient

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Right Ventricular Mechanical Changes after Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy: Vector Velocity Imaging Study

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World Journal of Cardiovascular Diseases 2019年第7期9卷 467-488页

作者： Hala Mahfouz Badran Ghada Soltan Naglaa Faheem mohamed Ezzat Enait Magdi H. Yacoub Cardiology Department Menoufia University Al Minufya Egypt The BAHCM National Program Aswan Heart Center Egypt Imperial College London UK

Objectives: The impairment of right ventricular (RV) myocardial mechanics is evident in hypertrophic cardiomyopathy (HCM). It is independently influenced by LV mechanics and correlated to the severity of LV phenotype. We investigated the changes in RV global and regional deformation following surgical septal myectomy using vector velocity imaging (VVI). Methods: 25 HCM patients, 68% males with mean age (34.5 ± 12 years) were examined before and within two months after surgical myectomy using VVI. In addition to conventional echocardiographic parameters, peak systolic strain (εsys), strain rate (SR) and time to peak εsys (TTP) of regional RV free wall (RVFW) & septal walls were analyzed in longitudinal (long) directions from apical four-chamber view and their (Δ) changes were calculated. Similar parameters were quantified in LV from apical 2 & 4 CH views. Intra-V-delay was defined as SD of TTP and inter-V dyssynchrony was estimated from TTP difference between the most delayed LV segment & RVFW. Results: All study patients showed improvement of their functional class from NYHA class III to class I and reduction of LVOT gradient to below 20 mmHg except one patient who had 30 mmHg gradients at rest. There was significant reduction of septal thickness, left atrial diameter & volume, LVOT gradient, LVMI, severity of mitral regurgitation, tricuspid annular velocities (P < 0.0001), RV diameter (P < 0.02) and increase in LV internal dimensions(P < 0.001) post myectomy. However, there was significant reduction of RV and LV systolic mechanics;RV global εsys % (from -16.1% ± 4.4% to -12.9% ± 2.9%, P < 0.0001) and LV global εsys %: from -11.6% ± 2.8% to -9.4% ± 2.2%, P < 0.0001) respectively. The magnitude of reduction of RV strain (ΔRV εsys %, ΔSRsys) was directly correlated LV maximal wall thickness (r = 0.46, P < 0.01) and ΔRV dyssynchrony (TTP-SD) (r = 0.4, P < 0.05) and negatively correlated to age (r = -0.46, P sys (r = -0.52, P < 0.01) and pre-op LV EF % (r = -0.43, P , t

关键词： Right Ventricle Deformation Imaging Hypertrophic Cardiomyopathy

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Bias and Mean Square Error of Reliability Estimators under the One and Two Random Effects Models: The Effect of Non-Normality

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Open Journal of Statistics 2016年第2期6卷 254-273页

作者： mohamed M. Shoukri Tusneem Al-Hassan Michael DeNiro abdelmoneim El Dali Futwan Al-Mohanna Department of Cell Biology King Faisal Specialist Hospital and Research Center Riyadh Saudi Arabia Al-Faisal University College of Medicine Riyadh Saudi Arabia The Oncology Center King Faisal Specialist Hospital and Research Center Riyadh Saudi Arabia Department of Biostatistics Epidemiology and Scientific Computing King Faisal Specialist Hospital and Research Center Riyadh Saudi Arabia

The coefficient of reliability is often estimated from a sample that includes few subjects. It is therefore expected that the precision of this estimate would be low. Measures of precision such as bias and variance depend heavily on the assumption of normality, which may not be tenable in practice. Expressions for the bias and variance of the reliability coefficient in the one and two way random effects models using the multivariate Taylor’s expansion have been obtained under the assumption of normality of the score (Atenafu et al. [1]). In the present paper we derive analytic expressions for the bias and variance, hence the mean square error when the measured responses are not normal under the one-way data layout. Similar expressions are derived in the case of the two-way data layout. We assess the effect of departure from normality on the sample size requirements and on the power of Wald’s test on specified hypotheses. We analyze two data sets, and draw comparisons with results obtained via the Bootstrap methods. It was found that the estimated bias and variance based on the bootstrap method are quite close to those obtained by the first order approximation using the Taylor’s expansion. This is an indication that for the given data sets the approximations are quite adequate.

关键词： Rater’s Reliability Random Effects Models Multivariate Taylor’s Expansion Wald’s Confidence Interval Bootstrap Methods

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E-Health Information System： Ensuring a High Level of Availability by Implementing Replication, Backup ＆ Restoration Procedures

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通讯和计算机（中英文版） 2017年第1期14卷 13-21页

作者： abdelghani El malhi mohamed Ahd abdelrhani Mokhtari abdelmajid Soulaymani Adil Echchelh Rachida Soulaymani Bencheik Laboratory of Electrical Engineering and Energetic Systems Ibn Tofail University Faculty of Sciences Kenitra Morocco Laboratory of Genetics and Biometry Faculty of Sciences lbn Tofail University Faculty of Sciences Kenitra Morocco Moroccan Poison Control and Pharmacovigilance Center Rabat Morocco Faculty of Medicine and Pharmacy University Mohammed V Rabat Morocco

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Accumulation of Copper, Lead, Chrome, Cadmium in Some Tissues of <i>Procambarus clarkii</i>in Rharb Region in Morocco

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Journal of Geoscience and Environment Protection 2015年第8期3卷 74-81页

作者： Ikram El Qoraychy mohamed Fekhaoui abdellah El Abidi Rachid Benakame abdelkbir Bellaouchou Ahmed Yahyaoui Laboratory of Zoology and General Biology Faculty of Science Mohammed V University Rabat Morocco Scientific Institute Mohammed V University Rabat Morocco National Institute of Hygiene Rabat Morocco

Different concentrations of four metals namely copper, lead, chrome and cadmium were evaluated in crayfish Procambarus clarkii tissues (carapace, flesh) for a six-month period, from March to August 2013 in the Rharb of Morocco (Lagoon Merja Zerga and Nador canal). The determination of heavy metals was carried using atomic absorption spectroscopy Varian VV20. The results obtained revealed a metal’s contamination of Procambarus clarkii in both sites. Concentrations of heavy metals examined Procambarus clarkii carapace ranged as follows: Merja Zerga (Pb 2.07 - 6.7 μg/g;Cu 2.9 - 9.97 μg/g;Cr 0.89 - 14.22 μg/g dry weight) and Nador canal: (Pb 0.08 - 7.8 μg/g;Cu 3.40 - 9.3 μg/g;Cr 0.87 - 3.5 μg/g dry weight). Concentrations of heavy metals found in flesh were as follows: Merja Zerga (Pb 0.02 - 5.25 μg/g;Cu 9.58 - 23.59 μg/g;Cr 0 - 2.71 μg/g dry weight) and Nador canal (Pb 0.06 - 6.81 μg/g;Cu 9.5 - 37.20 μg/g;Cr 0 - 3.23 μg/g dry weight). The distribution of those metals in Procambarus clarkii shows high levels of contamination for lead, copper and chrome with an absence of cadmium in both sites (Merja Zerga and Nador canal). The concentrations differed in carapace and flesh.

关键词： Procambarus clarkii Heavy Metals Merja Zerga Nador Canal Morocco

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Correlation between Serum CD36 Level and Lipid Profile in Patients with Type 2 Diabetes Mellitus, Khartoum State, Sudan

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Journal of Diabetes Mellitus 2023年第1期13卷 68-75页

作者： Eglal Elamein Mohammed Ali Abuagla M. Dafalla Yousif abdelhameed Mohammed Bakri Yousif mohamed Nour Faculty of Medical Laboratory Sciences University of Gezira Wad Medani Sudan

Background: Diabetes mellitus (DM) is a chronic metabolic disorder characterized by hyperglycemia. DM-related dyslipidemia are associated with complications resulting from progressive damage of various organs. CD36 is 88-kD, class B scavenger receptor, expressed on different types of cells. In diabetic patients, LDL particles are glycated with strong level;this increases CD36 expression, initiates foam cell formation and accelerates atherosclerosis. Objective: This study aimed to determine the correlation between serum CD36 level and lipid profile among patients with type 2 diabetes mellitus in Zeenam Specialized center, Khartoum State, Sudan, in a period between 2019 and 2022. Methodology: Hundred participants at different ages were included in this study;70 were type 2 diabetic patients (cases) and 30 apparently healthy individual (control). 3 ml of venous blood were collected from the participants by using a sterile needle and syringe into a labeled plain container. Each sample was stood until complete clot occurs. Clotted blood sample was then centrifuged to obtain the serum. Then they were used for measurement of total cholesterol, LDL cholesterol, HDL cholesterol, triglyceride and soluble CD36 levels. Total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides were measured using Biosystem chemistry analyzer BTS-302. Serum CD36 was measured using Microplate Reader (URIT-660). Results: The results revealed that serum total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride levels were significantly higher in patients with type 2 diabetes mellitus compared with control (P = 0.03, P = 0.031, P = 0.000, P = 0.000) respectively, while there is no statistically significant differences in serum CD36 level between cases and control (P = 0.129). Also this study showed that there is no statistically significant correlation between serum CD36 level and total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, age and body mass index. Conc

关键词： Type 2 Diabetes Mellitus Serum CD36 Lipid Profile Sudan

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Fabrication and Characterization of Tungsten Heavy Alloys Using Chemical Reduction and Mechanical Alloying Methods

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Open Journal of Applied Sciences 2013年第1期3卷 15-27页

作者： Zeinab abdel Hamid Sayed Farag Moustafa Walid mohamed Daoush Fatema.abdel Mouez Mona Hassan Corrosion Control and Surface Protection Department Central Metallurgical R&D Institute Helwan Cairo Egypt Powder Technology Department Central Metallurgical R&D Institute Helwan Cairo Egypt

A novel reduction technique has been developed to synthesize nano-sized tungsten heavy alloys powders and compared with the same powders processed by mechanical alloying technique. In the first method, nano-sized tungsten heavy alloys powders have been obtained by reduction of precursors obtained by spray drying of several appropriate aqueous solutions, which were made from salts containing tungsten, cobalt, and nickel. By adjusting the stoichiometry of the component of the solutions, it is possible to obtain the desired chemical composition of the tungsten heavy alloys powders. In the second method, highly pure elemental powders of tungsten heavy alloys have been mechanically alloyed in a tumbler ball mill for different milling time. The investigated tungsten heavy alloy powders with the composition (95%W-3.5%Ni-1.5%Fe), (93%W-4.5%Ni-1.0%Fe-1.5%Co), and (90%W-6%Ni-4%Cu) have been prepared using both methods. The prepared powders have been compacted at 70 bar (200 MPa) and sintered in vacuum furnace at 1400℃. Vacuum sintering was carried out to achieve full densification of the produced tungsten heavy alloys. The investigated materials were going to be evaluated the physical and mechanical properties of the sintered parts such as density;electrical conductivity, hardness, and transverse rupture strength. The results reveal that, the grain size of alloys fabricated by chemical reduction technique (53.1 - 63.8 nm) is smaller than that fabricated by mechanical alloying technique (56.4 - 71.4 nm).

关键词： Tungsten Heavy Alloys Mechanical Alloying Chemical Reduction Powder Metallurgy Hardness Transverse Rupture Strength Conductivity

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Bio-assembled MgO-coated tea waste biochar efficiently decontaminates phosphate from water and kitchen waste fermentation liquid

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Biochar 2023年第1期5卷 391-408页

作者： Chuchu Feng Lan Zhang Xiu Zhang Jingyu Li Yimeng Li Yaru Peng Yuan Luo Ronghua Li Bin Gao mohamed A.Hamouda Ken Smith Esmat F.Ali Sang Soo Lee Zengqiang Zhang Jörg Rinklebe Sabry M.Shaheen College of Natural Resources and Environment Northwest A&F UniversityYangling 712100ShaanxiChina Ningxia Key Laboratory for the Development and Application of Microbial Resources in Extreme Environments North Minzu UniversityYinchuan 750021Ningxia Hui Autonomous RegionChina Department of Agricultural and Biological Engineering University of FloridaGainesvilleFL 32611USA Department of Civil and Environmental Engineering Faculty of EngineeringUnited Arab Emirates UniversityAl AinAbu DhabiUnited Arab Emirates The Department of Environmental Science The University of ArizonaShantz Building Rm 4291177 E 4th St.TucsonAZ 85721USA Department of Biology College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Environmental and Energy Engineering Yonsei UniversityWonju 26493Republic of Korea School of Architecture and Civil Engineering Laboratory of Soil and Groundwater ManagementInstitute of Foundation EngineeringWater-and Waste-ManagementUniversity of WuppertalPauluskirchstraße 742285 WuppertalGermany Department of Arid Land Agriculture Faculty of MeteorologyEnvironmentand Arid Land AgricultureKing Abdulaziz UniversityJeddah 21589Saudi Arabia Department of Soil and Water Sciences Faculty of AgricultureUniversity of KafrelsheikhKafr El-Sheikh 33516Egypt

Crystal morphology of metal oxides in engineered metal-biochar composites governs the removal of phosphorus(P)from aqueous *** to our best knowledge,preparation of bio-assembled MgO-coated biochar and its application for the removal of P from solutions and kitchen waste fermentation liquids have not yet been ***,in this study,a needle-like MgO particle coated tea waste biochar composite(MTC)was prepared through a novel biological assembly and template elimination *** produced MTC was used as an adsorbent for removing P from a synthetic solution and real kitchen waste fermentation *** maximum P sorption capacities of the MTC,deduced from the Langmuir model,were 58.80 mg g^(−1) from the solution at pH 7 and 192.8 mg g^(−1) from the fermentation liquid at pH *** increase of ionic strength(0-0.1 mol L^(−1) NaNO_(3))reduced P removal efficiency from 98.53%to 93.01%in the synthetic solution but had no significant impact on P removal from the fermentation *** of MgHPO4 and Mg(H2PO4)2(76.5%),ligand exchange(18.0%),and electrostatic attraction(5.5%)were the potential mechanisms for P sorption from the synthetic solution,while struvite formation(57.6%)and ligand exchange(42.2%)governed the sorption of P from the kitchen waste fermentation *** to previously reported MgO-biochar composites,MTC had a lower P sorption capacity in phosphate solution but a higher P sorption capacity in fermentation ***,the studied MTC could be used as an effective candidate for the removal of P from aqueous environments,and especially from the fermentation *** the future,it will be necessary to systematically compare the performance of metal-biochar composites with different metal oxide crystal morphology for P removal from different types of wastewater.

关键词： MgO carbon composite Biowaste-derived biochar Phosphorus sorption Fermentation liquid Dephosphorization

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PI and RST Control Design and Comparison for Matrix Converters Using Venturini Modulation Strategy

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Journal of Power and Energy Engineering 2015年第8期3卷 36-54页

作者： Bekhada Hamane Mamadou Lamine Doumbia Hicham Chaoui mohamed Bouhamida Ahmed Chériti Mustapha Benghanem Department of Electrical and Computer Engineering UQTR Trois-Rivières Canada Center for Energy Systems Research Department of Electrical and Computer Engineering Tennessee Technological University Cookeville USA Department of Electrical Engineering University Mohamed Boudiaf Oran Algeria

This paper presents a thorough design and comparative study of two popular control techniques, i.e., classical Proportional Integral (PI) and RST, for Matrix Converters (MCs) in terms of tracking the reference and robustness. The output signal of MCs is directly affected by unbalanced grid voltage. Some research works have attempted to overcome this problem with PI control. However, this technique is known to offer lower performance when it is used in complex and nonlinear systems. On the other hand, RST control offers better performance, even in case of highly nonlinear systems. Therefore, the RST can achieve better performance to overcome the limitation of PI control of nonlinear systems. In this paper, a RST control method is proposed as output current controller to improve the performance of the MC powered by unbalanced grid voltage. The overall operating principle, Venturini modulation strategy of MC, PI control and characteristics of RST are presented.

关键词： Matrix Converter Unbalanced Grid Venturini Modulation Strategy PI Control RST Control

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Enthalpy of Dissolution and Dehydration of Two Moroccan Clays

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World Journal of Engineering and Technology 2018年第1期6卷 119-127页

作者： Jabrane Maissara Halima Karym Mohammed El Mahi Chbihi Mohammed Moutaabbid mohamed Abatal Said Benmokhtar Department of Chemistry Faculty of Sciences Laboratory of Chemistry and Physics of Materials LCPM Faculty of Sciences Ben M’Sik University of Casablanca Casablanca Morocco Laboratory of Investigation of Advanced Materials Faculty of Engineering in Autonomous University El Carmen Mexico

This work aims to characterize and determine the dehydroxylation enthalpy variations of two natural Moroccan clays from the Nador region (denoted K1) and the Settat region (denoted by K2). The variations of dissolution enthalpies were determined by dissolving clays in hydrofluoric acid. They have a minimum value for dehydroxylation of clays made between 600°C and 700°C. The analysis of the two clays shows that they consist of kaolinite in significant proportion. The optimum calcination parameters, for which dehydroxylation is total, are 700°C with a heating time of 6 H. The conversion of the kaolinite to metakaolinite was confirmed by IR analyses of the starting and thermally treated kaolin samples. The result confirms previous observations about obtaining metakaolinite with optimum reactivity when hydrated with calcium hydroxide as chemical activator.

关键词： Clay Characterization Dissolution Calorimetry IR

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