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Investigation of the compressibility and sinterabilty of AZ91 powder production and particle production by gas atomisation method

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Journal of Magnesium and Alloys 2019年第3期7卷 400-413页

作者： Mehmet Akkas mustafa Boz Faculty of Engineering and Architecture Department of Mechanical EngineeringKastamonu UniversityTurkey Faculty of Technology Department of Manufacturing EngineeringKarabiik UniversityKarabiikTurkey

This study intends to determine the pressability and sinterability of AZ91 powder production by gas atomisation method and that of the produced powder for partial ***,first,a gas atomisation unit has been designed and manufactured in the laboratories of the Karabiik University,Department of Manufacturing *** powder production has been achieved at a temperature of 795℃,with nozzle diameters of 2 and 4 mm and four different gas pressures(5,15,25,35 bars).Argon gas has been used for atomisation and as a protective gas *** electron microscope(SEM)is used to determine the shape of the produced AZ91 powder,and a laser particle size analyzer is used to analyze the powder ***,a microhardness(HV0.025)measurement has been conducted to determine the hardness of the produced *** achieve a homogeneous distribution,the produced powders are mixed in a three-dimensional moving turbulator for 30 *** powders have been pressed at 300,400,500 and 600 MPa and have been sintered at 500℃,550℃and 600℃.Additionally,the density values have been determined before and after sintering of the *** images have been obtained from the fractured surfaces of the samples before and after *** and EDX analyses have been performed to determine the chemical ***,microhardness(HV0.5)is obtained from the pressure surfaces of the samples to determine the effects of the pressing pressure and the sintering temperature on the *** a result of the experimental studies,it has been observed that the powder size decreases with the increase in gas pressure and that the powder shape generally changes from ligament and complex shape to droplet and spherical *** the XRD,XRF and EDX results,it has been determined that the structure comprises an a phase(Mg main matrix)and Mg17Al12 interphase,which isβphase,and very small amounts of MgO have been *** hardness of the produced powders increas

关键词： Gas atomisation AZ91 alloy powder Gas pressure Nozzle diameter Pressing Sintering

Efficient and stable perovskite-silicon two-terminal tandem solar cells

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Rare Metals 2020年第7期39卷 745-747页

作者： mustafa Haider Jun-Liang Yang State Key Laboratory of Powder Metallurgy School of Physics and ElectronicsCentral South UniversityChangsha 410083China

In the past several years, perovskite solar cells (PSCs)exhibited unexpected breakthrough and rapid evolution,and the power conversion efficiency (PCE) of singlejunction PSCs has been increased significantly from 3.81 to25.2%[1, 2], resulting from materials engineering, interface engineering, crystallization engineering, fabrication engineering, etc.[3-5]. In the case of silicon solar cells.

关键词： perovskite breakthrough crystallization

Conceptual framework for knowledge-based learning environments

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Journal of Harbin Institute of Technology(New Series) 2004年第1期11卷 71-76页

作者： mustafa Alshawi School of Construction and Property Management University of SalfordUK

The traditional concept of ”one-size-fits-all” educational and training programmes is no more fully adequate to meet the increasing demand worldwide. E-learning, as an alternative approach to traditional face-to-face education, is creating immense challenges for educational institutions to develop new approaches for the production and delivery of cost effective and efficient e-contents. Although, there have been many developments in web-based programmes, they have not fully attained their potential due to a variety of factors. These include: 1) lack of exchangeability between learning materials, 2) delivery mechanisms incompatible with the pedagogical design, 3) low student interaction and insensitive learning processes, 4) absence of intelligent online programme advice and guidance, 5) inflexibility in meeting diverse needs, and 6) institutionally centred ineffective implementation strategies. This paper addresses the critical elements for successful delivery of e-learning environments and then focuses on proposing a framework for the development of an integrated knowledge-based learning environment which has the potential to producer cost effective and personalised training programmes.

关键词： e-learning knowledge-based learning environment flexible learning critical success factors for e-learning

Wear Resistance and Non-Magnetic Layer Formation on 316L Implant Material with Plasma Nitriding

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Journal of Bionic Engineering 2014年第4期11卷 620-629页

作者： Ali Fatih Yetim mustafa Yazici Department of Mechanical Engineering Faculty of Engineering and Architecture Erzurum Technical University Erzurum 25700 Turkey Department of Nanoscience and Nanoengineering Ataturk University Erzurum 25240 Turkey

In this study, the applicability of plasma nitriding treatment in the production of non-magnetic and corrosion resistant layer on 316L stainless steel implant material was investigated. 316L stainless steel substrates were plasma nitrided at temperatures of 350 ℃, 375 ℃, 400 ℃, 425 ℃ and 450 ℃ for 2 h in a gas mixture of 50% N2-50% H2, respectively. It was determined that the treatment temperature is the most important factor on the properties of the corrosion resistant layer of 316L stainless steel. The results show that s-phase formed at the temperatures under 400 ℃, and at the temperatures above 400 ℃, instead of s-phase, CrN and y＇-Fe4N phases were observed in the modified layer. The electrical resistivity and surface roughness of the modified layer increase with treatment temperature. Under 400 ℃ the corrosion resistance increased with the temperature, above 400 ℃ it decreased with the increase in treatment temperature. It was analyzed that the electrical resistivity and the soft （ideal） ferro- magnetic properties of 316L stainless steel increased with treatment temperature during nitriding treatment. Also, plasma ni- triding at low temperatures provided magnetic behavior close to the ideal untreated 316L stainless steel.

关键词： 316L stainless steel biomaterials plasma nitriding magnetic properties wear electrical resistivity

Which factors determine exocrine pancreatic dysfunction in diabetes mellitus?

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World Journal of Gastroenterology 2019年第22期25卷 2699-2705页

作者： mustafa Altay Department of Endocrinology and Metabolism University of Health SciencesKe?i?ren Health Administration and Research Center

The exocrine structure is significantly affected by diabetes because of endocrine structure-function disorder within the pancreas. Exocrine pancreatic dysfunction (EPD) is the general name of the malabsorption process resulting from inadequate production, release, decreased activation, and/or insufficient degradation of enzymes required for digestion from pancreatic acinar cells. It is important to diagnose patients early and correctly, since there may be both macro- and micro-nutrient deficiency in EPD. In this paper, EPD, the diabetes- EPD relationship, and the predictive, effective factors affecting the emergence of EPD are briefly explained and summarized with contemporary literature and our experienced based on clinical, lab, and radiological findings.

关键词： Exocrine pancreas Diabetes mellitus Fecal elastase Malabsorption Chronic complication

Research on Narrative Design of Creative Products Based on Regional Cultural Elements

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Journal of Contemporary Educational Research 2024年第1期8卷 65-73页

作者： Qiqiong Huang Mohd mustafa Mohd Ghazali City Graduate School City University Malaysia46100 Petaling JayaSelangorMalaysia Faculty of Creative Industries City University Malaysia46100 Petaling JayaSelangorMalaysia

The research explored the ways and means of narrative design in which regional cultural elements are integrated into cultural and creative *** also researched a new way of thinking and methods of creative product design based on regional cultural elements in order to satisfy consumers’emotional and cultural *** theory takes the perspective of narrative expression in the design of cultural and creative *** regional cultural elements were used for better interactive communication with consumers in the form of cultural and creative *** the narrative of cultural and creative product design,intervening in the development of regional cultural and creative design from the perspective of narratology can better exert and create the cultural value of the region itself,with cultural and creative products playing an important role in“local cultural stories.”This research adopted a qualitative approach and provided ideas and guidance for the narrative design and expression of regional cultural elements in creative products through comparative analysis of case *** research highlighted the role of narrative design in creating multi-layered experiences,weaving regional cultural stories into products,and the importance of deep understanding and effective use of regional cultural elements in design.

关键词： Regional cultural elements Creative products Narrative design

A Comparison between Premortem and Postmortem Diagnosis in Trauma Cases

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Forensic Medicine and Anatomy Research 2015年第4期3卷 89-94页

作者： Dua Sumeyra Demirkiran Ibrahim Ortanca mustafa Sahan adnan Celikel Muhammet mustafa Arslan Department of Forensic Medicine Medical Faculty of Mustafa Kemal University Serinyol Hatay Turkey Department of Emergency Medicine Medical Faculty of Mustafa Kemal University Serinyol Hatay Turkey

This study evaluated the comparison of premortem and postmortem diagnoses of trauma cases that died during treatment and then autopsied. We had analyzed the autopsy reports of forensic deaths retrospectively which occurred between 2013 and 2014. The cases that died because of trauma and which had complete medical reports were included the study. Totally 626 cases were autopsied and 307 cases records were examined from them. The mean age was found to be 28.11. According the treatment period, it was detected that 116 (37.8%) cases died within the first 24 hours. Discrepancies between premortem and postmortem diagnoses were determined in 20.6% of cases. 5.9% had a main diagnostic discrepancy and 14.7% were of second lethal diagnoses. The discrepancies were observed mostly in the multiple injury cases. In our study, diagnostic discrepancy rate was higher in multiple injury cases especially who died by explosion. When clinicians focus on the treatment according to their main diagnosis, they overlook the fatal injuries in other parts of the body. This study shows that autopsy is the most reliable method for the confirmation of the clinical diagnosis in trauma patients. Therefore, particularly surgery physicians should compare the results of the autopsy diagnoses to their own diagnosis.

关键词： Clinical Diagnosis Autopsies Trauma

Hepatitis B virus genotypes:Global distribution and clinical importance

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World Journal of Gastroenterology 2014年第18期20卷 5427-5434页

作者： mustafa Sunbul Department of Infectious Diseases School of MedicineOndokuz Mayis University55139 SamsunTurkey

At least 600000 individuals worldwide annually die of hepatitis B virus(HBV)-related diseases,such as chronic hepatitis B(CHB),liver cirrhosis(LC),and hepatocellular carcinoma(HCC).Many viral factors,such as viral load,genotype,and specific viral mutations,are known to affect disease *** reverse transcriptase does not have a proofreading function,therefore,many HBV genotypes,sub-genotypes,mutants,and recombinants *** between genotypes in response to antiviral treatment have been *** date,10 HBV genotypes,scattered across different geographical regions,have been *** example,genotype A has a tendency for chronicity,whereas viral mutations are frequently encountered in genotype *** chronicity and mutation frequency are common in genotype *** and progression to HCC are more commonly encountered with genotypes C and D than the other *** differences between HBV genotypes explain disease intensity,progression to LC,and *** conclusion,genotype determination in CHB infection is important in estimating disease progression and planning optimal antiviral treatment.

关键词： Hepatitis B virus Genotypes Chronic hepatitis B Anti-viral therapy Viral mutation

Utilization of psychoacoustic parameters for occupancy-based acoustic evaluation in eating establishments

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Building Simulation 2022年第5期15卷 729-739页

作者： Onurcan Cakir mustafa Emre ilal izmir Institute of Technology Faculty of ArchitectureIzmirTurkey

Psychoacoustic parameters are mostly used for determining the sound quality of mechanical *** have also started to be used for evaluating soundscapes of open areas and enclosed *** research aims to find out the relationship between the psychoacoustic parameters and acoustic comfort in non-acoustic enclosed public spaces,specifically in eating *** on-site measurements and laboratory listening tests were conducted for five eating *** on-site measurements,a simultaneous questionnaire study was also carried *** and objective data were comparatively *** tests were based on auralizations with calibrated simulation *** provided a research model,that allows control over the acoustic environment without having to make real changes in the physical elements of the eating *** auralization sound files were presented to listening test participants with headphones and they evaluated soundscapes with different psychoacoustic *** results,better acoustic comfort was found to be related with higher sharpness,lower reverberation time,lower loudness and lower roughness values for the examined parameter ranges.

关键词： psychoacoustic parameters eating establishments acoustic comfort soundscape