检索结果-南通市图书馆

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Enumerating Pattern-avoiding Fishburn Permutations Subject to Seven Statistics

在线全文

学校读者我要写书评

暂无评论

Journal of Mathematical Research with Applications 2024年第4期44卷 427-436页

作者： Yujie DU Philip b.ZHANG College of Mathematical Science Tianjin Normal University

Fishburn permutations are in bijection with several important combinatorial structures including interval orders. In this paper, we use the method of generating trees to enumerate two classes of pattern-avoiding Fishburn permutations subject to 7 classical statistics simultaneously. The classes of our interest are(321,312)-avoiding and(321,4123)-avoiding Fishburn permutations. The statistics of our interest are ascents, descents, inversions, right-to-left maxima, right-to-left minima, left-to-right maxima and left-to-right minima. Our results generalize a result by Egge.

关键词： Fishburn permutation Fishburn number pattern avoidance generating tree

Clinical features of gastroesophageal reflux disease and erosive esophagitis:Insights from patients undergoing esophagogastroduodenoscopy in resource-limited Ethiopia

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第34期30卷 3883-3893页

作者： Firehiwot A Mengistie Abate b Shewaye Abel T Tasamma Zekarias S Ayalew Department of Internal Medicine Addis Ababa UniversityAddis Ababa 1176Addis AbabaEthiopia Department of Internal Medicine Rheum Rheumatology and Internal Medicine Specialty ClinicAddis Ababa 1000Addis AbabaEthiopia Division of Gastroenterology and Hepatology Department of Internal MedicineAdera Medical and Surgical CenterAddis Ababa 1000Addis AbabaEthiopia

bACKGROUND Gastroesophageal reflux disease(GERD)is a common disease worldwide with varying clinical presentations and risk *** data for Africa is lacking,but an increasing trend is expected due to demographic and epidemiological *** endoscopic studies for general gastrointestinal disorders have shown some patients with erosive esophagitis(EE),no studies in Ethiopia have investigated the clinical characteristics,risk factors,and severity of GERD using esophagogastroduodenoscopy(EGD).AIM To assess the clinical features of GERD in Ethiopian patients who underwent EGD and determine the severity and risk factors of *** We conducted a multicenter,retrospective cross-sectional study of 221 patients diagnosed with GERD and endoscopic findings of EE at Trauma Associated Severe Hemorrhage and Amniotic Membrane Stem Cell between January 2019 and August *** were collected from electronic medical records and phone call *** used descriptive statistics and binary logistic regression analysis with SPSS version 26 to identify the association between variables with a statistical significance set at P valueby heartburn(43%).Los Angeles(LA)-A EE was diagnosed in 71.1%of patients,followed by LA-b(14.9%),LA-C(7.7%),and LA-D(5.9%).Multivariate analysis showed that age 50 or above,presence of bleeding,and endoscopic findings of duodenitis/duodenopathy were significantly associated with severe EE(Pbarrett’s esophagus were observed in 4.5%and 1.36%of patients with EE,*** Most of the patients had milder EE with fewer ***,severe EE was more prevalent in older patients and those with duodenitis/duodenopathy.

关键词： Gastroesophageal reflux disease Erosive esophagitis Hiatal hernia Esophagogastroduodenoscopy Heart burn

Ab initio density response and local field factor of warm dense hydrogen

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Matter and Radiation at Extremes 2024年第5期9卷 48-67页

作者： Tobias Dornheim Sebastian Schwalbe Panagiotis Tolias Maximilian P.böhme Zhandos A.Moldabekov Jan Vorberger Center for Advanced Systems Understanding(CASUS) D-02826 GörlitzGermany Helmholtz-Zentrum Dresden-Rossendorf(HZDR) D-01328 DresdenGermany Space and Plasma Physics Royal Institute of Technology(KTH)Stockholm SE-10044Sweden Technische Universität Dresden D-01062 DresdenGermany

We present quasi-exact ab initio path integral Monte Carlo(PIMC)results for the partial static density responses and local field factors of hydrogen in the warm dense matter regime,from solid density conditions to the strongly compressed *** full dynamic treatment of electrons and protons on the same footing allows us to rigorously quantify both electronic and ionic exchange–correlation effects in the system,and to compare the results with those of earlier incomplete models such as the archetypal uniform electron gas or electrons in a fixed ion snapshot potential that do not take into account the interplay between the two *** full electronic density response is highly sensitive to electronic localization around the ions,and our results constitute unambiguous predictions for upcoming X-ray Thomson scattering experiments with hydrogen jets and fusion *** PIMC results are made freely available and can be used directly for a gamut of applications,including inertial confinement fusion calculations and the modeling of dense astrophysical ***,they constitute invaluable benchmark data for approximate but computationally less demanding approaches such as density functional theory or PIMC within the fixed-node approximation.

关键词： local incomplete rigorous

Progression of e-ticketing implementation for state transportation agencies for asphalt materials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Road Engineering 2024年第1期4卷 80-92页

作者： Joshua Withrow Gabriel b.Dadi Hala Nassereddine Department of Civil Engineering University of KentuckyLexingtonKY 40506USA Kentucky Transportation Cabinet FrankfortKY 40622USA

E-ticketing,which has been promoted by the Federal Highway Administration(FHWA)“every day counts”(EDC)initiative,utilizes software applications to digitally track and store information regarding highway construction materials paid by state transportation agencies(STAs)by weight in unit bid contract *** often face implementation barriers such as institutional inertia,or the resistance by stakeholders to adopt changes from the status quo,including new *** purpose of this paper is to determine the progression of STA e-ticketing policy adoption,specifically with a focus on asphalt paving operations,due to the COVID-19 *** accomplish this research effort,previous FHWA data,National Cooperative Highway Research Program(NCHRP)data,and other literatures are reviewed to determine an implementation *** data is collected from the American Association of State Highway and Transportation Officials Committee on Con-struction to gain current feedback from STAs and their highway contractor partners after the COVID-19 ***,a case study featuring the Kentucky Transportation Cabinet(KYTC),the Kentucky Association of Highway Contractors(KAHC),and the Plantmix Asphalt Industry of Kentucky(PAIKY)is performed to provide more in-depth *** major finding includes a statistically significant result indicating increased imple-mentation of e-ticketing for asphalt operations within the last two years,along with noting benefits including employee safety,task loading,and project documentation along with concerns regarding cellular connectivity and procurement *** findings indicate the importance of STAs investing in partnership with con-tractors to improve stakeholder buy-in before proceeding towards e-ticketing adoption.

关键词： Asphalt paving Construction inspection E-ticketing COVID-19

Measures of Relative and Absolute Convergence and Pro-poor Growth with an Illustration based on China(2010–2018)

在线全文

学校读者我要写书评

暂无评论

China & World Economy 2024年第2期32卷 1-41页

作者： Elena bárcena-Martin Jacques Silber Yuan Zhang Facultad de Ciencias Económicas y Empresariales Universidad de MálagaSpain Department of Economics Bar-Ilan UniversityIsrael China Center for Economic Studies Fudan UniversityChina

Income mobility is a key issue for understanding the process of economic growth and distributional *** economists have used the concept of“pro-poor growth”to examine,with individual-level panel data,whether the poor benefit more than the rich from economic growth by tracking the extent of income mobility among different population *** is also literature in macroeconomics on the measurement of *** paper introduces population-weighted relative and absolute indices of mobility,convergence,and pro-poor growth;it also distinguishes between anonymous and nonanonymous approaches to these *** empirical analysis is based on Chinese panel data for the period 2010–*** both absolute and relative terms,income growth in China was greater for individuals with an initially lower income but only for lower income deciles in relative *** was also an overall increase in individual welfare from anonymous and nonanonymous perspectives,which was higher among younger *** welfare of the poor did not increase more than that of the *** results shed light on the evolution of income distribution in China during the past decade's rapid economic growth.

关键词： anonymous and nonanonymous approach convergence exchange and structural mobility pro-poor growth

Excellent photoluminescence and electrochemical properties of Sm^(3+) doped Ca_(2)MgSi_(2)O_(7) nanophosphor:Display and electrochemical sensor applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第6期42卷 1046-1055,I0002页

作者： R.b.basavaraj K.Sureshkumar D.P.Aarti M.b.Madhusudana Reddy G.Nagaraju T.Ramakrishnappa G.R.Navyashree K.R.Venkatesha babu K.S.Hemalatha Department of Physics BMS Institute of Technology and ManagementBangalore560064India Department of Chemistry BMS Institute of Technology and ManagementBangalore560064India Department of Chemistry School of Applied SciencesREVA UniversityBangalore560064India Energy Materials ResearchLaboratory Department of ChemistrySiddaganga Institute of TechnologyTumakuru57203KarnatakaIndia School of Physical Sciences REVA UniversityBangalore560057Indi Department of Physics Govt.Science CollegeBengaluru560001India Department of Physics Maharani Science College for WomenMaharani Cluster UniversityBengaluru560001India

A series of orange-red light emitting Ca_(2)MgSi_(2)O_(7):Sm^(3+)nanopowders were fabricated via low-cost ecofriendly green combustion technique using Aloe vera gel as *** phase purity of the samples were confirmed by the powder X-ray diffraction(PXRD)*** single-phase tetragonal structure is observed from the PXRD results with no additional impurity *** band gap energy of the fabricated powders was estimated by diffuse reflectance spectra(DRS)and is found to be in the range of 4.01-5.98 eV.A high resolution scanning electron microscope(SEM)was used to study the morphological behaviour of the ***-like structures are observed from the SEM *** particle size was evaluated by transmission electron microscopy(TEM)and is found to be~50 *** interplanar distance is found to be 0.53 *** properties were systematically studied in *** phosphors are successfully excited at 403 nm NUV light,producing reddish-orange characteristic *** emission peaks are centered at 558(^(4)G_(5/2)→^(6)H_(5/2)),607(^(4)G_(5/2)→^(6)H_(7/2))and 645 nm(^(4)G_(5/2)→^(6)H_(9/2)),*** the observed peaks the red emanation(^(4)G_(5/2)→^(6)H_(7/2))is stronger than the orange emission(^(4)G_(5/2)→^(6)H_(5/2))in the current *** photoluminescent concentration quenching is noticed above 5 mol%Sm^(3+)ion doping *** dipole-dipole interaction resulting in cross relaxation is found to be the principal cause of concentration quenching *** color features such as Commission Internationale de I’Eclairage(CIE)and correlated color temperature(CCT)were studied in *** optimized chromaticity coordinates were estimated to be(0.6363,0.3632),which fall in the reddish-orange *** average CCT value obtained is 3362 *** average color purity is found to be~82%.Sm^(3+)incorporated Ca_(2)MgSi_(2)O_(7) samples are possible contender for single white light generation commercial candidates owing to

关键词： Green combustion Photoluminescence Orange-red emission Color purity Sensors Rare earths

Effect of Al_(2)O_(3)on the Mechanical Properties of(b_(4)C+Al_(2)O_(3))/Al Neutron Absorbing Materials

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1411-1420页

作者： J.X.Cai b.M.Shi N.Li Y.Liu Z.G.Zhang Y.N.Zan Q.Z.Wang b.L.Xiao Z.Y.Ma Shi‑Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Nuclear Equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.Ltd.Beijing 100840China Department of Materials Science School of Mechanical EngineeringShenyang UniversityShenyang 110044China

b_(4)C/Al composites are widely utilized as neutron absorbing materials for the storage and transportation of spent nuclear *** order to improve the high-temperature mechanical properties of b_(4)C/Al composites,in-situ nano-Al_(2)O_(3)was introduced utilizing oxide on Al powder *** this study,the Al_(2)O_(3)content was adjusted by utilizing spheroid Al powder with varying diameters,thereby investigating the impact of Al_(2)O_(3)content on the tensile properties of(b_(4)C+Al_(2)O_(3))/Al *** was found that the pinning effect of Al_(2)O_(3)on the grain boundaries could hinder the recovery of dislocations and lead to dislocation accumulation at high *** the result,with the increase in Al_(2)O_(3)content and the decrease in grain size,the high-temperature strength of the composites increased *** finest Al powder used in this investigation had a diameter of 1.4μm,whereas the resultant composite exhibited a maximum strength of 251 MPa at room temperature and 133 MPa at 350℃,surpassing that of traditional b_(4)C/Al composites.

关键词： Al matrix composites Neutron absorbing materials (b_(4)C+Al_(2)O_(3))/Al composites High-temperature strength

Direct microwave leaching conditions of rare earth elements in fluorescent wastes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第6期42卷 1165-1174,I0007页

作者： A.bilen b.birol M.N.Saridede S.S.Kaplan M.S.Sonmez Department of Metallurgical and Materials Engineering Yildiz Technical UniversityIstanbulTurkey Department of Chemical Engineering and Materials Science Stevens Institute of TechnologyNew JereyUSA Department of Metallurgical and Materials Engineering Istanbul Technical UniversityIstanbulTurkey

The luminescent phosphor powder in the fluorescent lamp constitutes 2%of the lamp’s *** can be mentioned that fluorescent wastes are a crucial raw material to produce rare earth *** the present study,microwave leaching process was conducted to dissolve rare earth elements yttrium(Y),europium(Eu),and remaining rare earth elements(REEs)present in the phosphor powder of the fluorescent *** the yields were *** the microwave leaching process,the effects of the temperature(80-160℃),acid type(hydrochloric acid(HCl),nitric acid(HNO_(3)),sulphuric acid(H_(2)SO_(4))),acid concentration(0.5-6 mol/L),solid to liquid ratio(0.1:10-0.5:10)and reaction time(5-90 min)parameters on leaching efficiencies of varying rare earth elements and calcium were *** highest yield was obtained in the direct microwave leaching of fluorescent waste with the experimental conditions of 6 mol/L HCl,160℃,0.1:10 solid-to-liquid ratio(S:L),and 90 *** energy calculations were made,and kinetic models of the reactions were obtained,and it is observed that Y and Eu dissolution is diffusion-controlled,on the other hand,lanthanum(La),cerium(Ce),and terbium(Tb)were examined to be chemical reaction ***,calcium(Ca)and gadolinium(Gd)seem coherent with the mixed ***,mathematical models of all experimental studies are created with the response surface box-behnken method and the correlation coefficients of all the models are over 90%.

关键词： Rare earth elements(REEs) Direct microwave leaching Fluorescent waste Kinetic models Response surface method