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Lap-Shear Performance of Weld-Bonded Mg Alloy and Austenitic Stainless Steel in Three-Sheet Stack-Up

Chinese Journal of Mechanical Engineering 2024年第4期37卷 342-353页

作者： sunusi marwana manladan Mukhtar Fatihu Hamza Singh Ramesh Zhen Luo School of Materials Science and Engineering Tianjin UniversityTianjin 300350China Department of Mechanical Engineering Faculty of EngineeringBayero UniversityKano 3011Nigeria Department of Mechanical Engineering College of EngineeringPrince Sattam bin Abdulaziz University11942 AlkharjSaudi Arabia Department of Mechanical Engineering Faculty of EngineeringUniversity of Malaya50603 Kuala LumpurMalaysia

With the growing interest in utilizing Mg and austenitic stainless steel(ASS)in the automotive sector,joining them together in three-sheet configuration is ***,achieving this task presents considerable challenges due to the large differences in their physical,metallurgical and mechanical *** overcome these challenges,the feasibility of using weld-bonding to join Mg alloy/ASS/ASS was *** nugget formation,interface characteristics,microstructure and mechanical properties of the joints were *** results show that the connection between the Mg alloy and upper ASS was achieved through the combined effect of the cured adhesive and weld-brazing in the weld *** the other hand,a metallurgical bond was formed at the ASS/ASS *** Mg nugget microstructure exhibited fine columar grains composed predominantly of primaryα-Mg grains along with a eutectic mixture ofα-Mg andβ-*** nugget formed at the ASS/ASS interface consisted largely of columnar grains of austenite,with some equiaxed dendritic grains formed at the centerline of the *** weld-bonded joints exhibited an average peak load and energy absorption of about 8.5 kN and 17 J,respectively(the conventional RSW joints failed with minimal or no load application).The failure mode of the joints changed with increasing welding current from interfacial failure via the Mg nugget/upper ASS interface to partial interfacial failure(part of the Mg nugget was pulled out of the Mg sheet).Both failure modes were accompanied by cohesive failure in the adhesive zone.

关键词： Weld-bonding Resistance spot welding Austenitic stainless steel Mg alloy Failure mode

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Effect of Lüders Bands by Strain Ageing on Strain Distribution,Microstructure and Texture Evolution of High-Strength Pipe Steel

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Acta Metallurgica Sinica(English Letters) 2021年第5期34卷 657-667页

作者： Jian Han Jun Wang sunusi marwana manladan Yangchuan Cai Qian Wang Zhixiong Zhu Lisong Zhu Lianzhong Lu Zhengyi Jiang School of Materials Science and Engineering Tianjin University of TechnologyTianjin300384China School of Mechanical Materials and Mechatronic EngineeringUniversity of WollongongWollongongNSW2522Australia School of Materials Science and Engineering Tianjin UniversityTianjin300072China School of Materials Science and Engineering Hefei University of TechnologyHefei230009China

In this study,the high-strength pipe steel,i.e.X80,was heated at 260℃for half an hour followed by air cooling for thermal simulation of pipe coating *** the uniaxial loading of the specified tension samples,the migration behaviour of Lüders bands and the re-distribution of stress after strain ageing heat treatment were investigated using digital image *** image correlation was adopted to characterise the local axial and shear strain fields of samples that were extracted from different locations across the wall thickness of the high-strength pipe steel,and electron backscatter diffraction was used to compare the evolution of crystallographic texture among these *** characterisation methods regarding microstructure and mechanical properties were conducted meanwhile,including optical microscopy,scanning electron microscopy and X-ray diffraction to accurately define the detailed performances that strain ageing,*** heated to 260℃for half an hour,has led *** obtained results show that the Lüders band-related microstructure,dislocation density,lattice constant and texture vary at the different locations across the wall thickness and influence the fi nal mechanical properties of the selected high-strength pipe steel.

关键词： High-strength pipe steel Lüders band Strain ageing Stress distribution Texture Mechanical property

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Malaria and Climate Variability in Two Northern Stations of Nigeria

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American Journal of Climate Change 2022年第2期11卷 59-78页

作者： Ademola Akinbobola sunusi Hamisu Department of Meteorology and Climate Science Federal University of Technology Akure Nigeria Nigeria Meteorological Agency Abuja Nigeria

Malaria is a significant public health problem in Nigeria. The prevalence of malaria incidence across regions in Nigeria can be linked to climatic and environmental factors. This study explored what and how local weather/climate variability impact on malaria prevalence in Jos, North central and Kano, North western Nigeria. Data on monthly malaria cases from 1997 to 2018 were obtained from the hospital archives and consulting room record books. The Kano hospital is the Abdullahi Wase Specialist Hospital, a standard state government hospital that is situated in the Centre of the city. Also, same data were collected from the Plateau state general hospital, Jos. Local weather factors including rainfall, relative humidity, minimum and maximum temperature were considered in the analyses. Time series analyses were applied to evaluate the associations of malaria incidence with weather/climate factors. The results showed that malaria incidence was associated with local weather factors in Jos and Kano but at different lag times and in directions. The results reveal local weather factors strongly affect malaria occurrence in Jos than Kano. The location-specific approaches seem to be one of the keys to minimizing the potential impacts of climate change and maximizing the effects of control and prevention programs in these stations. Therefore, for effective malaria control, interventions could be synchronized with some important climatic predictors of the disease for greater impact and reduce the prevalence of the disease especially in Jos.

关键词： Malaria Weather Climate Plasmodium Time Series

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Growth and nitrogen productivity of drip-irrigated winter wheat under different nitrogen fertigation strategies in the North China Plain

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Journal of Integrative Agriculture 2023年第3期22卷 908-922页

作者： sunusi Amin ABUBAKAR Abdoul Kader Mounkaila HAMANI WANG Guang-shuai LIU Hao Faisal MEHMOOD Abubakar Sadiq ABDULLAHI GAO Yang DUAN Ai-wang Key Laboratory of Crop Water Use and Regulation Ministry of Agriculture and Rural Affairs/Farmland Irrigation Research InstituteChinese Academy of Agricultural SciencesXinxiang 453002P.R.China Graduate School of Chinese Academy of Agricultural Sciences Beijing 100081P.R.China Department of Agricultural and Bioresource Engineering Abubakar Tafawa Balewa UniversityBauchi 740272Nigeria

Excessive application of nitrogen (N) fertilizer is the main cause of N loss and poor use efficiency in winter wheat (Triticum aestivum L.) production in the North China Plain (NCP).Drip fertigation is considered to be an effective method for improving N use efficiency and reducing losses,while the performance of drip fertigation in winter wheat is limited by poor N scheduling.A two-year field experiment was conducted to evaluate the growth,development and yield of drip-fertigated winter wheat under different split urea (46%N,240 kg ha^(-1)) *** six treatments consisted of five fertigation N application scheduling programs and one slow-release fertilizer (SRF) *** five N scheduling treatments were N0–100 (0%at sowing and 100%at jointing/booting),N25–75 (25%at sowing and 75%at jointing and booting),N50–50(50%at sowing and 50%at jointing/booting),N75–25 (75%at sowing and 25 at jointing/booting),and N100–0 (100%at sowing and 0%at jointing/booting).The SRF (43%N,240 kg ha^(-1)) was only used as fertilizer at *** N application significantly (P<0.05) affected wheat grain yield,yield components,aboveground biomass (ABM),water use efficiency(WUE) and nitrogen partial factor productivity (NPFP).The N50–50 and SRF treatments respectively had the highest yield(8.84 and 8.85 t ha^(-1)),ABM (20.67 and 20.83 t ha^(-1)),WUE (2.28 and 2.17 kg m^(-3)) and NPFP (36.82 and 36.88 kg kg^(-1)).This work provided substantial evidence that urea-N applied in equal splits between basal and topdressing doses compete economically with the highly expensive SRF for fertilization of winter wheat *** the single-dose SRF could reduce labor costs involved with the traditional method of manual spreading,the drip fertigation system used in this study with the N50–50 treatment provides an option for farmers to maintain wheat production in the NCP.

关键词： split nitrogen strategies wheat yield drip fertigation water use efficiency nitrogen use efficiency

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An Evaluation of the Effect of Credit Risk Management （CRM） on the Profitability of Nigerian Banks

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Journal of Modern Accounting and Auditing 2014年第1期10卷 104-115页

作者： Junaidu Muhammad Kurawa sunusi Garba Bayero University Kano Nigeria Federal University Dutse Jigawa Nigeria

This paper assesses the effect of credit risk management （CRM） on the profitability of Nigerian banks with a view to discovering the extent to which default rate （DR）, cost per loan asset （CLA）, and capital adequacy ratio （CAR） influence return on asset （ROA） as a measure of banks＇ profitability. Data were generated from secondary sources, specifically, the annual reports and accounts of quoted banks from 2002 to 2011. Descriptive statistics, correlation, as well as random-effect generalized least square （GLS） regression techniques were utilized as tools of analysis in the study. The findings establish that CRM as measured by three independent variables has a significant positive effect on the profitability of Nigerian banks as indicated by the coefficient of determinations ＂R2 value＂ which shows the within and between values of 40.89% and 58.35% （which are impressive） while the overall R2 iS 43.91%, indicating that the variables considered in the model account for about 44% change in the dependent variable, that is, profitability. The study recommends that banks＇ management should be more scientific （application of risk evaluation techniques） in their credit risk assessment and management of loan portfolios in order to minimize the high incidence of non-performing loans and their negative effect on profitability.

关键词： credit risk default rate (DR) cost per asset capital adequacy return on asset (ROA)

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不同施氮量对麦田土壤水稳性团聚体和N_(2)O排放的影响

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应用生态学报 2021年第11期32卷 3961-3968页

作者：陈津赛孙玮皓王广帅 Abubakar sunusi Amin 高阳中国农业科学院农田灌溉研究所/农业农村部作物需水与调控重点实验室河南新乡453002 中国农业科学院研究生院北京100081

过量施氮可破坏农田土壤结构,增加温室气体排放量。为揭示不同施氮量对土壤团聚体和N_(2)O排放的影响,于2018—2020年基于氮肥定位试验,设置秸秆原位还田条件下施氮0(N_(0))、120(N_(120))、180(N_(180))、240(N_(2)40)、300(N_(300))、... 详细信息

过量施氮可破坏农田土壤结构,增加温室气体排放量。为揭示不同施氮量对土壤团聚体和N_(2)O排放的影响,于2018—2020年基于氮肥定位试验,设置秸秆原位还田条件下施氮0(N_(0))、120(N_(120))、180(N_(180))、240(N_(2)40)、300(N_(300))、360 kg·hm^(-2)(N_(360))6个处理,研究不同施氮量对麦田土壤N_(2)O排放、土壤充水孔隙度(WFPS)、土壤温度、硝态氮、铵态氮含量、水稳性团聚体的组成及稳定性的影响。结果表明:土壤N_(2)O排放量与氮肥用量之间呈显著正相关关系,WFPS与施氮量之间无显著相关关系,0~10 cm土壤温度随氮肥施用量的增加而显著降低,土壤硝态氮、铵态氮含量与氮肥施用量间存在显著正相关关系。随氮肥施用量的增加,直径>2 mm的水稳性团聚体含量降低,直径<0.5 mm的水稳性团聚体含量增加,土壤水稳性团聚体的粒径也逐渐减小。氮肥施用量与团聚体平均重量直径(MWD)、几何平均直径之间呈显著负相关关系,但与分形维数之间并无显著相关性。MWD(x)与N_(2)O排放通量(y)之间的拟合方程为:y=3928.3e^(-2.171x)(R^(2)=0.55,P<0.001),表明当MWD减小时,N_(2)O排放量将会剧烈升高。可见,麦田施氮量的增加会降低0~10 cm土壤温度,增加土壤硝态氮和铵态氮含量,减小耕层土壤水稳性团聚体的平均粒径,降低团聚体的稳定性,增加N_(2)O的排放量。

关键词：冬小麦施氮土壤理化性质 N_(2)O 水稳性团聚体

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Characterisation for <i>Radioelements</i>over an Escarpment Feature(S): A Case Study of the Duku-Tarasa Gwandu Ridge Area of Birnin Kebbi NW Nigeria

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International Journal of Geosciences 2020年第8期11卷 529-543页

作者： A. Adamu O. Ologe A. L. Ahmed A. Y. sunusi Department of Applied Geophysics Federal University Birnin Kebbi Birnin Kebbi Nigeria Department of Physics Ahmadu Bello University Zaria Nigeria Department of Physics Usmanu Danfodio University Sokoto Nigeria

The paper presents results of radiometric investigations of an area (Duku-Tarasa) near the capital city of the State of Birnin Kebbi, NW Nigeria. The area of study is about 440 m × 420 m and encloses an Escarpment Feature/Structure on a sedimentary rock generally referred to as the Gwandu Formation. The Gwandu Formation (though not described in the paper) consists of continental lacustrine sediments and is the youngest Palaeogene Formation present in the Sokoto sector of the larger Iullemmeden Basin. The study measured, along some selected profiles across this escarpment feature, radiometric signatures using a Sim-Max G411 portable field gamma-ray spectrometer (giving counts for U, Th and K relative to the background values over the area), the ground total-field magnetic data (using the proton precession magnetometer) along those profiles and collected some (5) rock samples for flame photometry and AAS analyses towards the target proposition. Activity concentration levels due to potassium (K), uranium (U) and thorium (Th) were measured in the area along the five established profiles spaced at 50 metres. The results from these measurements and analyses were displayed (in Tables/histograms and gray level maps/images of concentrations of Uranium, Thorium and Potassium prospects) and interpreted (dismissing the magnetic data as seemingly passive as no filter was applied to the mapped data).

关键词： Gwandu Ridge Iso-Radiometric Contour Map Gamma Activity Gamma-Ray Spectrometry and Radioelements

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盐胁迫下棉花幼苗叶片K^(+)、Na^(+)含量与光合参数的关系

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生态学杂志 2021年第6期40卷 1716-1722页

作者：付媛媛江晓慧申孝军孙文君张俊鹏 Abubakar sunusi Amin 高阳农业农村部作物需水与调控重点实验室/中国农业科学院农田灌溉研究所河南新乡453002 塔里木大学植物科学学院新疆阿拉尔843300 山东农业大学水利土木工程学院山东泰安271018

为了解盐分胁迫下棉花叶片的K^(+)、Na^(+)含量与光合参数(净光合速率、最大羧化速率、最大电子传递速率、叶肉导度)之间的关系,设置4个盐分水平(50、100、150和200mmol·L^(-1))和对照处理,测定叶片的K^(+)、Na^(+)含量及光合参数。结... 详细信息

为了解盐分胁迫下棉花叶片的K^(+)、Na^(+)含量与光合参数(净光合速率、最大羧化速率、最大电子传递速率、叶肉导度)之间的关系,设置4个盐分水平(50、100、150和200mmol·L^(-1))和对照处理,测定叶片的K^(+)、Na^(+)含量及光合参数。结果表明:棉花幼苗叶片的Na^(+)含量与盐分水平呈显著正相关,决定系数R^(2)为0.958,叶片K^(+)含量随盐分水平增加而降低,决定系数R2为0.871。此外,Na^(+)/K^(+)与盐分水平呈显著正相关。棉花叶片的K^(+)与Na^(+)含量表现为极显著负相关。叶片的Na^(+)含量与净光合速率、叶肉导度、最大羧化速率、暗呼吸速率、最大电子传递速率呈极显著负相关,相关系数分别为-0.878、-0.861、-0.835、-0.837和-0.813;叶片的K^(+)含量与净光合速率、叶肉导度、最大羧化速率、暗呼吸速率、最大电子传递速率呈极显著正相关,相关系数分别为0.718、0.735、0.645、0.856和0.603。当盐分水平为150 mmol·L^(-1)时,棉花叶片的K^(+)和Na^(+)含量分别为11.54和3.32 mg·g^(-1),是K^(+)、Na^(+)含量影响光合参数的临界值。研究结果为缓解盐分胁迫对植物造成的离子伤害提供重要参考。

关键词： K^(+)含量 Na^(+)含量最大羧化速率最大电子传递速率叶肉导度暗呼吸速率

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