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Additively manufactured Ti–Ta–Cu alloys for the next-generation load-bearing implants

International Journal of Extreme Manufacturing 2024年第1期6卷 353-374页

作者： Amit Bandyopadhyay Indranath Mitra Sushant Ciliveri Jose D Avila william Dernell Stuart B Goodman Susmita Bose W.M.Keck Biomedical Materials Research Laboratory School of Mechanical and Materials EngineeringWashington State UniversityPullmanWA 99164United States of America Veterinary Clinical Sciences College of Veterinary MedicineWashington State UniversityPullmanWA 99164United States of America Department of Orthopedic Surgery Stanford University Medical CenterRedwood CityCA 94063United States of America

Bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the most efficient defense against colonization, especially in the case of secondary infection, leading to surgical removal of implants and in some cases even limbs. In this study, laser powder bed fusion was implemented to fabricate Ti3Al2V alloy by a 1:1 weight mixture of CpTi and Ti6Al4V powders. Ti-Tantalum(Ta)–Copper(Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom alloy. The biological,mechanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta(10Ta) and 3 wt.% Cu(3Cu) were added to the Ti3Al2V alloy to enhance biocompatibility and impart inherent bacterial resistance. Additively manufactured implants were investigated for resistance against Pseudomonas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed improved antibacterial efficacy, i.e.78%–86% with respect to CpTi. Mechanical properties for Ti3Al2V–10Ta–3Cu alloy were evaluated, demonstrating excellent fatigue resistance, exceptional shear strength, and improved tribological and tribo-biocorrosion characteristics when compared to Ti6Al4V. In vivo studies using a rat distal femur model revealed improved early-stage osseointegration for alloys with10 wt.% Ta addition compared to CpTi and Ti6Al4V. The 3 wt.% Cu-added compositions displayed biocompatibility and no adverse infammatory response in vivo. Our results establish the Ti3Al2V–10Ta–3Cu alloy’s synergistic effect on improving both in vivo biocompatibility and microbial resistance for the next generation of load-bearing metallic implants.

关键词： Ti6Al4V load-bearing implants additive manufacturing 3D printing antibacterial performance

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Anatomic location of the first dorsal extensor compartment for surgical De-Quervain’s tenosynovitis release:A cadaveric study

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World Journal of Orthopedics 2024年第4期15卷 379-385页

作者： Aditya Thandoni william Nicholas Yetter Steven Michael Regal Department of Orthopaedic Surgery Allegheny Health NetworkPittsburghPA 15212United States

BACKGROUND De-Quervain’s tenosynovitis is a disorder arising from the compression and irritation of the first dorsal extensor compartment of the *** who fail conservative treatment modalities are candidates for surgical ***,risks with surgery include damage to the superficial radial nerve and an incomplete release due to inadequate ***,there is a paucity of literature demonstrating the exact anatomic location of the first dorsal extensor compartment in reference to surface ***,this cadaveric study was performed to determine the exact location of the first extensor compartment and to devise a reliable surgical incision to prevent *** To describe the location of the first dorsal compartment in relation to bony surface landmarks to create replicable surgical *** Six cadaveric forearms,including four left and two right forearm specimens were *** were performed by a single fellowship trained upper extremity orthopaedic *** of the first dorsal compartment from landmarks such as Lister’s tubercle,the wrist crease,and the radial styloid were *** variables studied included the presence of the superficial radial nerve overlying the first dorsal compartment,additional compartment subsheaths,number of abductor pollicis longus(APL)tendon slips,and the presence of a *** Distance from the radial most aspect of the wrist crease to the extensor retinaculum was 5.14 mm±0.80 *** distance from Lister’s tubercle to the distal aspect of the extensor retinaculum was 13.37 mm±2.94 ***’s tubercle to the start of the first dorsal compartment was 18.43 mm±2.01 *** radial styloid to the initial aspect of the extensor retinaculum measured 2.98 mm±0.99 *** retinaculum length longitudinally on average was 26.82 mm±3.34 *** cadaveric forearms had separate extensor pollicis brevis *** average number of APL tendon slips was th

关键词： De-Quervain’s tenosynovitis First extensor compartment Cadaveric study Superficial radial nerve Radial styloid Lister’s tubercle

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Isolating higher yielding and more stable rice genotypes in stress environments: fine-tuning a selection method using production and resilience score indices

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Frontiers of Agricultural Science and Engineering 2024年第1期11卷 169-185页

作者： Arnauld THIRY william J.DAVIES Ian C.DODD Lancaster Environment Centre Lancaster UniversityLancasterLancashire LA14YWUK

In Asia, the rice crop sustains millions of people. However, growing demand for this crop needs to be met while simultaneously reducing its water consumption to cope with the effects of climate change. Lowland cropping systems are the most common and productive but have particularly high water requirements. High-yielding rice genotypes adapted to drier environments(such as rainfed or aerobic rice ecosystems) are needed to increase the water use efficiency of cropping. Identifying these genotypes requires fast and more accurate selection methods. It is hypothesized that applying a new quantitative selection method(the score index selection method), can usefully compare rice yield responses over different years and stress intensities to select genotypes more rapidly and efficiently. Applying the score index to previously published rice yield data for 39 genotypes grown in no-stress and two stress environments, identified three genotypes(ARB 8, IR55419-04 and ARB 7) with higher and stable yield under moderate to severe stress conditions. These genotypes are postulated to be better adapted to stress environment such as upland and aerobic environments. Importantly, the score index selection method offers improved precision than the conventional breeding selection method in identifying genotypes that are well-suited to a range of stress levels within the target environment.

关键词： Aerobic rice breeding selection drought resilience production capacity index resilience capacity index stress score index upland

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Spatio-Temporal Variability of Rainfall and Temperature and Their Effects on Pasture Variability over East Africa: Implication on the Cattle Grazing Areas

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Journal of Geoscience and Environment Protection 2024年第3期12卷 54-69页

作者： Natiko Peter Wang Wen Nyasulu matthews Raharivelo Sitraka Ny Aina Alupot Donnata School of Atmospheric Science Nanjing University of Information Science & Technology Nanjing China Uganda National Meteorological Authority Directorate of Station Networks Department of Instruments and Installations Kampala Uganda School of Ecology and Applied Meteorology Nanjing University of Information Science & Technology Nanjing China

Understanding the spatiotemporal variability of climatic parameters and their effects on pasture variability is vital for pasture management interventions over East Africa. The present study aims to assess the spatial-temporal variability of rainfall, temperature and Normalized Difference Vegetation Index (NDVI) (which is being used to assess pasture quality and productivity) over the region, between the period of 1982 and 2019. This study used annual mean values for rainfall, temperature and NDVI which were calculated for the period mentioned above. NDVI was derived from National Oceanic and Atmospheric Administration (NOAA) Global Area Cover (GAC) (NOAA-07-GAC) data. The rainfall data was acquired from the Climate Hazards Group Infrared Precipitation with Station (CHIRPS) while temperature is ERA5 reanalysis data sourced from the European Centre for Medium-Range Weather Forecasts (ECMWF). The study utilized the empirical orthogonal function (EOF) to identify patterns and dominant relationships between the climate variables. The correlation was calculated between rainfall, temperature and NDVI to assess the relationship among them. A non-parametric Mann-Kendall trends test was used to determine whether annual precipitation, temperature and NDVI had statistically increasing or decreasing trend. Results revealed a positive correlation between rainfall and NDVI while a negative correlation between NDVI and temperature. Positive correlation between rainfall and NDVI indicates that pasture health (quality and productivity), will improve accordingly. A negative correlation between temperature and NDVI indicates that pasture health will decrease with increase in temperature while improving with decreasing temperature. Outcome from this study suggests that changes in climatic variables influence the distribution of pasture in East Africa’s cattle grazing areas. The study hence recommends prioritisation of climatic (weather) information during pasture management over East A

关键词： NDVI Climatic Parameters EOF Pasture East Africa

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Thermodynamic analysis of metal segregation in dual phase high entropy ceramics

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Journal of Materiomics 2024年第4期10卷 889-895页

作者： Steven M.Smith II william G.Fahrenholtz Gregory E.Hilmas Stefano Curtarolo Missouri University of Science and Technology Materials Science and Engineering DepartmentRollaMO65409USA Duke University Department of Mechanical Engineering and Materials ScienceDurhamNC27708USA Duke University Center of Autonomous Materials DesignDurhamNC27708USA

Equilibrium Gibbs'free energy calculations were used to determine metal segregation trends between boride and carbide solid solutions containing two metals that are relevant to dual phase high entropy *** model predicted that Ti had the strongest tendency to segregate to the boride phase followed by Zr,Nb,Mo,V,Hf,and Ta,which matches experimental results of measured *** ratio of a metal in the carbide phase to the content of the same metal in the corresponding metal boride had a linear trend with the change in standard Gibbs'free energy of reaction for a metal carbide reacting with B_(4)C to produce its corresponding metal boride and *** proposed model was used to predict the changes in standard Gibbs'free energy for CrC→CrB_(2) to be−260 kJ and WC→WB_(2) to be 148 kJ,which indicates that Cr has the strongest segregation to the boride and W has the strongest segregation to the *** proposed model can be used to estimate the segregation of metals in dual phase high entropy boride-carbide ceramics of any boride/carbide ratio or metal content.

关键词： Dual phase High entropy ceramic Boride Carbide Thermodynamics

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Efficiency and effectiveness of systems for the treatment of domestic wastewater based on subsurface flow constructed wetlands in Jarabacoa, Dominican Republic

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Water Science and Engineering 2024年第2期17卷 118-128页

作者： Yvelisse Pérez Enmanuel Vargas Daniel Garcia-Cortes william Hernandez Humberto Checo Ulises Jauregui-Haza Area de Ciencias Basicas y Ambientales Instituto Tecnologico de Santo Domingo(INTEC)Avenida de Los Proceres 49Los Jardines del NorteSanto Domingo 10602Dominican Republic Ministry of Environment and Natural Resources Calle Cayetano Germosen esq.Ave.LuperonEl PedregalSanto Domingo 11107Dominican Republic Plan Yaque Calle Estela Geraldino 14 AltosJarabacoa 41000Dominican Republic Institute of Technologies and Applied Sciences University of HavanaHavana 10400Cuba

Constructed wetlands(CwW)are well known nature-based systems for water *** study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jarabacoa,the Dominican *** results showed that the CWs were efficient in reducing the degree of contamination of wastewater to levels below the Dominican wastewater discharge standards for parameters such as the 5-day biochemical oxygen demand(BOD5)and chemical oxygen demand,but not for the removal of phosphorus and fecal *** addition,a horizontal flow subsurface wetland in the peri-urban area El Dorado was evaluated in terms of the performance of wastewater treatment in tropical climatic *** concentrations of heavy metals,such as zinc,copper,chromium,and iron,were found to decrease in the effluent of the wetland,and the concentrations for nickel and manganese tended to *** levels of heavy metals in the effluent were lower than the limit values of the Dominican wastewater discharge *** construction cost of these facilities was around 200 USD per population equivalent,similar to the cost in other countries in the same *** study suggested some solutions to the improved performance of CWs:selection of a microbial flora that guarantees the reduction of nitrates and nitrites to molecular nitrogen,use of endemic plants that bioaccumulate heavy metals,combination of constructed wetlands with filtration on activated carbon,and inclusion of water purification processes that allow to evaluate the reuse of treated water.

关键词： Domestic wastewater Constructed wetland BOD COD Pathogens Heavy metals

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Effect of stress-dependent microannulus aperture on well leakage

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 1967-1976页

作者： Meng Meng Luke P.Frash J.william Carey Mohamed Mehana Wenfeng Li Bailian Chen Earth and Environmental Sciences Los Alamos National LaboratoryLos AlamosNMUSA

Debonding at the cement-casing interface is recognized as a principal failure mechanism leading to CO_(2) leakage in *** detachment gives rise to a microannulus,which notably possesses greater permeability than undamaged cement,undermining its sealing ***,the permeability of the microannulus is regarded as a uniform value throughout the ***,fundamentally,a microannulus is one type of fracture,and its gap or aperture size is affected by the effective *** this work,we developed a unique experimental *** equipment facilitates the curing of cement inside a steel casing,the formation of a microannulus between the casing and the cement,and the investigation of the fluid flow dynamics along the microannulus under laboratory-replicated in situ *** microannulus was formed by injecting fluid from one end of the setup,and receiving similar amount of fluid on the other end signified the development of the leakage ***,strain gauges affixed to the casing’s external surface yielded key information on the microannulus’s opening and *** observed a noticeable decline in microannulus hydraulic aperture(or permeability)in relation to effective stress and an exponential equation fits their *** findings also indicate a distinct behavior when comparing liquid CO_(2) with ***,it is easier for liquid CO_(2) to create the ***,the hydraulic aperture range for this microannulus(0.7-6 mm)is considerably smaller than that created by water flow(2-17 mm).Finally,we integrated the stressdependent microannulus aperture size into the combined analysis of well mechanical integrity and well *** outcomes consistently demonstrated that when factoring in the stress-dependent aperture sizes,the leakage rates are 3e5 times compared to a fixed aperture *** traditional assumption of a constant aperture significantly underestimates fluid leakage risks.

关键词： Microannulus Leakage assessment Aperture size Triaxial experiment Carbon sequestration

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Comparative Study of the Socioeconomic Characteristics and Digital Literacy Level of Agricultural Extension Personnel in Imo and Ebonyi States, South-East, Nigeria

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Agricultural Sciences 2024年第2期15卷 230-245页

作者： Ogbonnaya Okoro Aja Cyril Chigozie Asiabaka Anthony Okorie Ani Edna Chioma.matthews-Njoku Department of Agricultural Extension Federal University of Technology Owerri Nigeria

The study comparatively analysed the socioeconomic characteristics and digital literacy level of Agricultural Extension personnel (AEP) in Ebonyi and Imo States, South-East, Nigeria. The specific objectives were to describe the socioeconomic characteristics of agricultural extension personnel in Ebonyi and Imo States, and to ascertain the digital literacy level of AEP in the studied states. Purposive sampling technique was used to select 312 Agricultural Extension personnel (132 from Ebonyi State Agricultural Development Program and 180 from Imo State Agricultural Development Program) for the study. Data were collected through the use of validated and structured questionnaire, and administered through the help of well-trained enumerators. Data were analysed using simple descriptive statistical tools such as percentages mean score, standard deviation and weighted mean. Findings indicated that they were more male in the both States (55.3% and 57.8%) for Ebonyi and Imo State respectively and that the average age of AEP in Ebonyi and Imo States were 44.7 years and 49.2 years respectively. It was further revealed that the majority (77.3% and 82.8%) had ***./HND as their highest academic qualifications, belonged to professional organisations (62.1% and 75%), and were earning an average monthly income of N58,798 and N62,648 for Ebonyi and Imo State respectively. Also, it was revealed that their mean years of service were 12.4 years and 13.4 years for Ebonyi and Imo State respectively. Almost all of them (87.9% and 95.0%) own a smartphone, had access to the internet (80.3% and 90.0%), but do not own a laptop/ipad (82.6% and 72.8%) for Ebon-yi and Imo State respectively. Results further revealed that Agricultural extension personnel in both Ebonyi and Imo State respectively had low digital literacy level ( = 2.41 and 2.32). The study concluded that AEP in Ebonyi and Imo State respectively had similar socioeconomic characteristics and low level of digital literacy. The study

关键词： Agricultural Extension Personnel Digital Literacy Ebonyi State Imo State Socioeconomic Characteristics

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Promoting green transformation by ensuring food security while reducing the environmental footprint of food and farming with agriculture green development

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Frontiers of Agricultural Science and Engineering 2024年第1期11卷 1-4,I0005页

作者： william J.DAVIES Jianbo SHEN Lancaster Environment Centre Lancaster UniversityLancaster LA14YQUK State Key Laboratory of Nutrient Use and Management National Academy of Agriculture Green DevelopmentCollege of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China

Reconciling the challenges of producing adequate amounts of nutritious food for the increasing global population while limiting environmental damage that can result from operations of our food systems is an enormous *** many parts of the world,agriculture is undergoing major transformations and this has been and still is particularly the case in China.

关键词： operations agriculture transformation

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Analysis of the Digital Skill Gap of Agricultural Extension Personnel in South-East, Nigeria

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Agricultural Sciences 2024年第9期15卷 1057-1070页

作者： Ogbonnaya Okoro Aja Chigozie Cyril Asiabaka Anthony Okorie Ani Edna Chioma.matthews-Njoku Department of Agricultural Extension Federal University of Technology Owerri Nigeria

The study analysed the digital skill gap of agricultural extension personnel on the use of digital technologies for extension services delivery in South-East, Nigeria. The specific objectives were to describe the socioeconomic characteristics of agricultural extension personnel in South-East Nigeria and identify the digital skill gaps among agricultural extension personnel in the area of study. Purposive sampling technique was used to select 364 Agricultural Extension personnel for the study. Data were collected through the use of structured questionnaire and were analysed using simple descriptive statistical tools such as percentages, mean score, and standard deviation. Findings indicated that most of the personnel were male (57.8%), within the age bracket of 38 - 47 years (62.9%), had ***./HND as their highest educational qualification (74.7%), married (86.3%), and had a household size of 6 - 10 Persons (57.7%). It was further revealed that the majority (70.1%) were members of professional organization, earned a monthly income of N50,001.00 - N100,000.00 (65.7%), had a work experience of 11 - 15 years (51.1%), and owned a smartphone/ iPad/laptop (91.5%). Findings further indicated that they had moderate skill gap in Basic Computer skills (Mean = 4.32), and digital communication and collaboration skills (Mean = 4.26). Findings also showed that they had a high skill gap in digital technical skills (Mean = 2.46), digital data analysis skills (Mean = 2.09), digital content creation skills (Mean = 2.43), digital ethical skills (Mean = 2.79), multimedia production skills (Mean = 2.81), and video library management skills (Mean = 2.39). The study concluded that though there exists a high digital skill gap among agricultural extension personnel in South-East, Nigeria, their socioeconomic characteristics are capable of supporting the implementation of digital extension services in the area. The study recommended that the management of Agricultural Development Programs in

关键词： Agricultural Extension Personnel Socioeconomic Characteristics Digital Skill Gap South-East Nigeria

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