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Sustainable Biocomposites Materials for Automotive Brake Pad Application:An Overview

Journal of Renewable Materials 2024年第3期12卷 485-511页

作者： Joseph O.dirisu Imhade P.Okokpujie Olufunmilayo O.Joseph Sunday O.Oyedepo Oluwasegun Falodun Lagouge K.Tartibu fird.ussi d.shehu department of Mechanical Engineering Covenant UniversityOtaOgunNigeria department of Mechanical and Mechatronics Engineering AFE Babalola UniversityAdoEkitiNigeria department of Mechanical and Industrial Engineering Technology University of JohannesburgJohannesburg2028South Africa School of Chemical and Metallurgical Engineering University of the WitwatersrandJohannesburgSouth Africa

Research into converting waste into viable eco-friendly products has gained global *** natural fibres and pulverized metallic waste becomes necessary to reduce noxious environmental emissions due to indiscriminately occupying the *** study reviews the literature in the broad area of green composites in search of materials that can be used in automotive brake *** made by biocomposite,rather than fossil fuels,will be favoured.A database containing the tribo-mechanical performance of numerous potential components for the future green composite was established using the technical details of bio-polymers and natural *** development of materials with diverse compositions and varying proportions is now conceivable,and these materials can be permanently connected in fully regulated *** explanation demonstrates that all of these variables affect friction coefficient,resistance to wear from friction and high temperatures,and the operating life of brake pads to varying *** this study,renewable materials for the matrix and reinforcement are screened to determine which have sufficient strength,coefficient of friction,wear resistance properties,and reasonable costs,making them a feasible option for a green *** most significant,intriguing,and unusual materials used in manufacturing brake pads are gathered in this review,which also analyzes how they affect the tribological characteristics of the pads.

关键词： Asbestos brake pad biocomposites green composite mechanical properties natural reinforcement waste

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New analytical modelling of fractional generalized Kuramoto-Sivashinky equation via Atangana-Baleanu operator and J-transform method

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Journal of Ocean Engineering and Science 2024年第1期9卷 66-88页

作者： Metonou Richard Weidong Zhao shehu Maitama School of Mathematics Shandong UniversityJinanShandongChina

In this paper,we propose a new analytical modelling of the well-known fractional generalized Kuramoto-Sivashinky equation(FGKSE)using fractional operator with non-singular kernel and the homotopy anal-ysis transform method via J-transform ***,using fixed-point theorem,we prove the existence and uniqueness of our proposed solution to the fractional Kuramoto-Sivashinky *** further val-idate the efficiency of the suggested technique,we proved the convergence analysis of the method and provide the error *** obtained solutions of the FGKSE,describing turbulence processes in the field of ocean engineering are analytically and numerically compared to show the behaviors of many parameters of the present model.

关键词： Homotopy analysis J-transform method J-transform method Fractional generalized Kuramoto-Sivashinky equation Fixed-point theorem Numeric-symbolic computation

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Genetics of carotenoids for provitamin A biofortification in tropical-adapted maize

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The Crop Journal 2016年第4期4卷 313-322页

作者： Alhassan d.Halilu shehu G.Ado daniel A.Aba Inuwa S.Usman department of Plant Science Institute for Agricultural Research Ahmadu Bello University

Yellow maize contains high levels of β-carotene(βC), making it an important crop for combating vitamin A deficiency through biofortification. In this study, nine maize inbred lines were selected at random from 31 provitamin A(PVA) maize inbred lines and crossed in a partial diallel mating design to develop 36 crosses. The crosses were evaluated in the field in two locations(Samaru and Kerawa) and their seed carotenoid content were determined by high-performance liquid chromatography. The modes of gene action, heritability, and correlations between agronomic traits and carotenoid content were estimated. Additive genetic variances(σ~2a) were lower than non-additive genetic variances(σ~2d) for all the carotenoids, plant height(PH), and grain yield(GY), suggesting a preponderance of non-additive gene action. Broad-sense heritability(H^2) was high(H^2> 60%) for zeaxanthin,days to anthesis, and PH, moderate(30% d GY, and low(H^2d PVA. Genetic advance as a percentage of mean, considered with H^2, also suggests a preponderance of non-additive gene action for PVA carotenoids. Hybrid variety development is thus an appropriate approach to improving grain yield and PVA. GY showed no significant genotypic correlations with carotenoid content, suggesting that these traits can be improved concurrently. Thus, there is ample scope for improvement of PVA and GY in the sample of tropical-adapted maize.

关键词： Biofortification Tropical-adapted maize Provitamin A Carotenoids Gene actions Correlations

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drugs Supply and Laboratory Services in dots System of Kaduna State: A Health Care Worker Perspective

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Journal of Tuberculosis Research 2018年第1期6卷 19-35页

作者： shehu Usman Adamu d. McGill Biological Sciences Kaduna State University Kaduna Nigeria University of Liverpool Liverpool UK

A study was conducted in Kaduna State Nigeria to ascertain the impact of drug Supply and laboratory services towards effective functioning of dOTS system. Six dOTS providing centres were identified for the study and in each centre, three respondents were selected based on their profession, the Medical Officer, the Pharmacist and the Laboratory Technician totaling 18. The officers were interviewed for the purpose of the research. Semi structured Interviews were conducted in this research as a means of obtaining Health workers perspective. The Interview which was conducted in their respective work station was open ended and all questions are same for all respondents. during the course of the study, all respondents agreed that the sources of drugs supply to their respective centres was the Kaduna State Tuberculosis and leprosy control Program office from the state capital and that drugs are been supplied quarterly and are adequate with slight interruption due to Logistic while for Laboratory services the respondents were of the view that there is the need to improve on it as there are cases of shortage of reagents and erratic supply of Electricity for effective Laboratory functioning.

关键词： drug Supply and Laboratory Services Workers Perspective

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Minor Pressure differences within the Fontan-Anastomosis in Patients with Total Cavopulmonary Connection by 4d-Flow Magnetic Resonance Imaging

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Congenital Heart disease 2023年第4期18卷 461-474页

作者： Nerejda shehu Christian Meierhofer Anja Hennemuth Markus Hüllebrand Pavlo Yevtushenko Peter Ewert Stefan Martinoff Heiko Stern department of Congenital Heart disease and Pediatric Cardiology German Heart Center MunichTechnical University of MunichMunichGermany Fraunhofer Institute for digital Medicine—MEVIS BerlinGermany Institute for Cardiovascular Computer-Assisted Medicine CharitéUniversitätsmedizinBerlinGermany department of Radiology German Heart Center MunichTechnical University of MunichMunichGermany

Background: Pressure measurement in total cavopulmonary connection (TCPC) patients is a domain of cardiaccatheterization. 4d velocity encoded cardiovascular magnetic resonance (4d–flow MRI) offers an alternative forassessment of even minor pressure differences. The scope of this study was to measure even minor pressure differencesin the anastomosis of TCPC patients, who are clinically uncompromised. Methods: Twenty-four patients(median 15 years [8;34]) with TCPC were studied prospectively by 4d-flow MRI. Pressure differences betweensuperior vena cava (SVC) and extracardiac conduit (C) to both right pulmonary artery (RPA) and left pulmonaryartery (LPA) were assessed. Small fluid obstructions as vortices within the anastomosis were detected by flowpathlines from 4d-flow MRI. In two patients pressure differences were calculated also by computational flowdynamics (CFd) as a plausibility check for the order of magnitude. Results: Median values of pressure differencesin the anastomosis between SVC and RPA were 0.63 (0.21–2.1) mmHg, between C and RPA 0.67 (0.3–2.2)mmHg, between SVC and LPA 0.8 (0.3–2.4) mmHg and between C and LPA 0.7 (0.2–1.9) mmHg. Patients withpotential flow obstruction (stents, occluder, vortices) had significantly higher gradients at the anastomosis (p d- and measurement-based pressure difference showed good agreement. Conclusion: 4d-flow MRI is able to detect minor pressuredifferences within the Fontan circuit even in patients with apparently satisfactory TCPC. Slightly higherpressure differences are due to the presence of small flow obstruction.

关键词： 4d-flow MRI pressure differences TCPC Fontan

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Media Appraisal for Somatic Embryogenesis of Elite Inbred Lines of Maize

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Journal of Life Sciences 2011年第5期5卷 360-363页

作者： Inuwa shehu Usman shehu Garki Ado Ng Shou Yong department of Plant Science Ahmadu Bello University PMB 1044 Zaria Nigeria 525/96 （Apt. C20） Rattanakosin View Mansion Bangkok Thailand

Several protocols have been published for somatic embryogenesis in maize. It is essential to compare different protocols on selected germplasm at initial stages of tissue culture to identify a protocol that would yield optimum results. The ultimate goal is to use in vitro system for selecting and generating stress tolerant maize germplasm. Immature embryos of the elite inbred lines of maize （87014 ×Z28-11 and POP43SRS5-57） were cultured on three different semi-solid media （0.5% agar） and the effectiveness of the media for somatic embryogenesis assessed over a period two weeks of sub-culturing. A significant difference was observed among the media in proportion of potentially embryogenic calli and callus cluster size at 1 and 2 weeks after culturing. N6 medium supplemented with casaminoacid （100 mg/L）, 2, 4-dichlorophenoxy acetic acid （1 mg/L）, L-proline （25 mM） and sucrose （2%）, and Murashige and Skoog （MS） medium supplemented with 2, 4-d （2 mg/L） and sucrose （3%） gave higher proportion of potentially embryogenic calli and callus size than MS medium supplemented with casaminoacids （100 mg/L）, 2, 4-d （2 mg/L）, abscissic acid （3.3μM）, and silver nitrate （195 μM） and sucrose （3%）. The difference between genotypes is not significant

关键词： Somatic embryogenesis maize inbreds media silver nitrate

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In Vitro Regeneration of Commercial Sugarcane （Saccharum spp.） Cultivars in Nigeria

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Journal of Life Sciences 2012年第7期6卷 721-725页

作者： Sani Lawan Abdu Mustapha Yahaya Usman Inuwa shehu College of Engeneering Science Technology Federal Polytechnic Kazaure PMB 5004 Kazuare Nigeria department of Biological Sciences Bayero University Kano PMB 3011 Kano Nigeria department of Plant Science Institute for Agricultural Research Ahmadu Bello University PMB 1044 Zaria Nigeria

The effect of different concentrations of 6-benzylaminopurine （BA） with or without 0.2 mg/L NAA on in vitro regeneration of sugarcane （Saccharum spp.） cultivars SP726180, B47419, M1176/77 and M2119/88 were evaluated. Leaf base explants were cultured on Murashige and Skoog （MS） basal medium supplemented with 3.0 mg/L 2,4-dichlorophenoxyacetic acid （2,4-d） for 4 weeks. Thereafter, induction of somatic embryogenesis was observed following the transfer of resulting calli to 2,4-d-free medium for another 4 weeks. Regeneration was achieved by transfer of the embryogenic calli to regeneration media fortified with different concentrations of BA ＋ tt-naphthylacetic acid （NAA）. The number, length and vigor of shoots produced in all the genotypes were highest on media supplemented with 1.0 and 1.5 mg/L BA with and without 0.2 mg/L NAA. Among the genotypes tested, B47419 and M1176/77 recorded highest number of shoots, while maximum shoot length and crop vigor was obtained with M1176/77. Induction of callus with 3.0 mg/L 2,4-d and its subsequent incubation on 2,4-d-free media, followed by regeneration on media supplemented with 1.0 or 1.5 mg/L BA with 0.2 mg/L NAA was found to be efficient for in vitro regeneration of the sugarcane genotypes used in this study. This protocol could be applied for micropropagation of other elite genotypes.

关键词： Saccharum spp. leaf explant 2 4-d callus BA NAA regeneration.

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Conjugate Heat Transfer Predictions of Gas Turbine Hot Walls Jets Cooling: Influence of Short Hole Grid Resolutions Using Computational Fluid dynamics*

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Journal of Power and Energy Engineering 2023年第10期11卷 1-16页

作者： Abubakar M. El-Jummah shehu A. Abdulrahman Alhaji S. Grema department of Mechanical Engineering University of Maiduguri Maiduguri Nigeria department of Mechanical Engineering Nigerian Army University Biu Borno Nigeria department of Chemical Engineering University of Maiduguri Maiduguri Nigeria

Short hole investigations relevant to gas turbine (GT) hot walls cooling heat transfer techniques, were carried out using computational fluid dynamics (CFd) combined with conjugate heat transfer (CHT) code. The CFd software are commercial ones: ICEM for grid modelling and ANSYS Fluent for the numerical calculation, where symmetrical application prevails. The CFd CHT predictions were undertaken for Nimonic-75 metal walls with square (152.4 mm) arrays of 10 holes, whereby the lumped heat capacitance method was applied in order to determine the surface average heat transfer coefficient (HTC), h (W/m2 K) and the dimensionless Nusselt number, Nu. The major parameters considered for the short hole geometries are the pitch to diameter, X/d and length to diameter, L/d ratios and both were varied with range of d values, but X of 15.24 mm and L of 6.35 mm kept constant. Also applied, are variable mass flux, G (kg/s∙m2) and were used in predicting the flow aerodynamics in the short holes. The predictions were for classic thermal entry length into a round hole, as vena contracta, flow separation and reattachment dominates the holes, hence the development of thermal profile through the depth of the GT hot walls. Additionally, the acceleration of the flow along the wall surfaces as it approaches the holes, was a significant part of the overall heat transfer. This was shown to be independent of the hole length, even though the L/d parameter is a critical component to enhanced heat transfer. The CFd CHT predictions showed that validation of the HTC h, Nu and pressure loss, ∆P are in better agreement with measured data and within reasonable acceptance. The ∆P agreement signifies that the aerodynamics were predicted correctly, which is also the reason why the HTC expressed per wall hole approach surface area and Nu were better predicted. This illustrates how effective and efficient the wall internal heat transfer cooling is for gas turbine hot wall heat transfer

关键词： Lumped Heat Capacitance Thermal Entry Length Symmetrical Application Flow Separation Flow Reattachment

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Mathematical modeling and analysis of schistosomiasis transmission dynamics

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第4期12卷 58-76页

作者： Umar T.Mustapha Salihu S.Musa Muhammad A.Lawan Aliyu Abba Evren Hincal Musa d.Mohammed Bashir d.Garba Rabiu B.Yunus shehu A.Adamu daihai He department of Mathematics Near East University TRNC Mersin 10 Turkey department of Mathematics Federal University dutse Nigeria department of Applied Mathematics The Hong Kong Polytechnic University Hong Kong department of Mathematics Kano University of Science and Technology Wudil Nigeria department of Statistics Jigawa State Polytechnic DutseNigeria department of Computer Engineering Institute of Continuing Education Kano University of Science and Technology Wudil Nigeria department of Mathematics and Statistics Kano State Polytechnic Nigeria

Schistosomiasis is a parasitic disease from the family of Schistosomatidae and genus Schistosoma,which is caused by blood *** disease is endemic in many countries and still a serious threat to global public health and *** this paper,a new deterministic model is designed and analyzed qualitatively to explore the dynamics of schistosomiasis transmission in human,cattle and snail *** from our mathematical analysis show that the model has a disease-free equilibrium(dFE)which is locally asymptotically stable(LAS)whenever a particular epidemiological threshold quantity,also known as basic reproduction number(R0)is less than *** analysis shows that the model has a unique endemic equilibrium(EE)which is globally asymptotically stable whenever R0>1 and unstable when R0dopt partial rank correlation coefficient for sensitivity analysis to reveal the most important parameters for effective control and mitigation of schistosomiasis disease in a ***,we obtain some numerical results by simulating the entire dynamics of the model,which show that the infections in the compartments of each population decrease with respect to *** further indicates that avoiding contact with infected human,cattle or infested water is vital to prevent the spread of schistosomiasis disease infection.

关键词： Schistosomiasis disease basic reproduction number stability analysis sensitivity analysis

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