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Enhancement of galena-potassium ethyl xanthate flotation system by low power ultrasound

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Transactions of Nonferrous Metals Society of China 2020年第4期30卷 1102-1110页

作者： Can GUNGOREN Yasin BAKTARHAN Ismail demir Safak Gokhan OZKAN Department of Mining Engineering Engineering FacultyIstanbul University-CerrahpasaBuyukcekmeceIstanbul 34500Turkey Department of Robotics and Intelligent Systems The Institute of the Graduate Studies in Science and EngineeringTurkish-German UniversityBeykozIstanbul 34820Turkey

The objective of this study is to investigate the improvement possibilities of the floatability of galena with ultrasonic application in the presence of potassium ethyl xanthate(KEX). For this purpose, micro-flotation experiments were carried out in addition to surface chemistry studies including zeta potential, contact angle, and bubble-particle attachment time measurements at various ultrasonic power levels and conditioning time. The results showed that, the maximum micro-flotation recovery of 77.5% was obtained with 30 W ultrasound power and 2 min conditioning time. In addition, more negative zeta potential values were obtained with ultrasound as well as higher contact angle and lower bubble-particle attachment time, which indicated the increased hydrophobicity of galena with ultrasound.

关键词： galena potassium ethyl xanthate flotation ultrasound bubble-particle attachment time

An Examination ofthe Impact of Game-Based Geometric Shapes Education Software Usage on the Education of Students With Intellectual Disabilities

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ECNU Review of Education 2022年第4期5卷 761-783页

作者： Umit demir Department of Computer Technologies Canakkale Onsekiz Mart UniversityCanakkale 17020Turkey

Purpose:This study aims to research the impact of the e-learning environment,in which gamebased education software was used,on the learning of students with intellectual ***/Approach/Methods:The study group consisted of 34 students with intellectual disabilities studying at a special education vocational school in Canakkale,*** this study,the true experimental method was *** 5 weeks,the experimental group received blended learning that was supported by the usage of a game-based education software designed by the researcher,which includes interactive educational game *** the same time,control group students only received the teaching process in the classroom with the traditional teaching *** attitude scale and an achievement test were used fordata ***:The analysis of the findings showed that there was a significant increase between precourse and post-course attitudes and academic achievement scores of the *** wasn't a significant difference between pre-course and post-course attitudes and academic achievement scores according to the gender and academic achievement ***'academic achievement and attitude post-test scores were higher than females'*** having upper daily mobile devices usage experience had higher post-test and academic achievement scores than students havinglowerdaily mobile devices usage experience.

关键词： Game-based education geometry education special education

Identifying disaster-related tweets and their semantic,spatial and temporal context using deep learning,natural language processing and spatial analysis:a case study of Hurricane Irma

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International Journal of Digital Earth 2019年第11期12卷 1205-1229页

作者： Muhammed Ali Sit Caglar Koylu Ibrahim demir Department of Computer Science University of IowaIowa CityIAUSA Department of Geographical and Sustainability Sciences University of IowaIowa CityIAUSA Department of Civil and Environmental Engineering University of IowaIowa CityIAUSA

We introduce an analytical framework for analyzing tweets to(1)identify and categorize fine-grained details about a disaster such as affected individuals,damaged infrastructure and disrupted services;(2)distinguish impact areas and time periods,and relative prominence of each category of disaster-related information across space and *** first identify disaster-related tweets by generating a human-labeled training dataset and experimenting a series of deep learning and machine learning methods for a binary classification of *** employ LSTM(Long Short-Term Memory)networks for the classification task because LSTM networks outperform other methods by considering the whole text structure using long-term semantic word and feature ***,we employ an unsupervised multi-label classification of tweets using Latent Dirichlet Allocation(LDA),and identify latent categories of tweets such as affected individuals and disrupted ***,we employ spatiallyadaptive kernel smoothing and density-based spatial clustering to identify the relative prominence and impact areas for each information category,*** Hurricane Irma as a case study,we analyze over 500 million keyword-based and geo-located collection of tweets before,during and after the *** results highlight potential areas with high density of affected individuals and infrastructure damage throughout the temporal progression of the disaster.

关键词： Social sensing Twitter deep learning natural language processing spatial analysis hurricane

Analyzing dynamic curve widening on forest roads

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Journal of Forestry Research 2017年第2期28卷 411-417页

作者： Mustafa Akgul Murat demir Abdullah E.Akay Forest Engineering Division Faculty of ForestryForest Construction and TransportationIstanbul UniversitySariyerIstanbulTurkey Forest Engineering Department Faculty of ForestryBursa Technical UniversityOsmangazi16200 BursaTurkey

Forest roads require important design specifications to ensure all-season access for various vehicles. Long and heavy log trucks can face serious maneuvering problems on forest roads due to insufficient amount of area to the left for road widening on horizontal curves. In order to provide safe and continuous shipment and transportation,appropriate curve widening areas should be provided for long vehicles along horizontal curves. In this study, a statistical model was developed to provide curve-widening solutions for long trucks（e.g., those with 18 wheels） considering various curve radius and deflection angles. The dynamic curve widening feature of Plateia 2013 program was employed to calculate curve widening for the specified vehicle. During the solution process, nine different horizontal curve diameters from 10 to 50 m（by 5 m intervals）and 17 different deflection angles from 90° to 170°（by 5°intervals） were evaluated to run horizontal curve-widening analysis. Using a multiple regression model, we made suitable predictions about curve widening. The curvewidening areas decrease as the horizontal curve radius increases, while increasing the deflection angle on horizontal curves increases curve widening areas. Clearly, the computer-based dynamic curve widening model developed in this study can be effectively used in determining optimum widening for horizontal curves by evaluating the number of alternatives that fit geometrical specifications and vehicle types.

关键词： deflection diameters radius specifications transportation alternatives determining evaluating insufficient season

Automated integration of real-time and non-real-time defense systems

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Defence Technology（防务技术） 2021年第2期17卷 657-670页

作者： Emre Dalkıran Tolga Onel Okan Topçu Kadir Alpaslan demir Barbaros Naval Science and Engineering Institute Turkish Naval AcademyNational Defense UniversityTuzlaIstanbul34942Turkey Department of Computer Engineering Turkish Naval AcademyNational Defense UniversityTuzlaIstanbul34942Turkey Department of Computer Engineering Middle East Technical University Northern Cyprus CampusKalkanliGuzelyurtMersin 1099738Turkey Institute of Social Sciences Gebze Technical UniversityGebzeKocaeli41400Turkey

Various application domains require the integration of distributed real-time or near-real-time systems with non-real-time *** cities,smart homes,ambient intelligent systems,or network-centric defense systems are among these application *** Distribution Service(DDS)is a communication mechanism based on Data-Centric Publish-Subscribe(DCPS)*** is used for distributed systems with real-time operational *** Message Service(JMS)is a messaging standard for enterprise systems using Service Oriented Architecture(SOA)for non-real-time *** allows Java programs to exchange messages in a loosely coupled *** also supports sending and receiving messages using a messaging queue and a publish-subscribe *** this article,we propose an architecture enabling the automated integration of distributed real-time and non-real-time *** test our proposed architecture using a distributed Command,Control,Communications,Computers,and Intelligence(C4I)*** system has DDS-based real-time Combat Management System components deployed to naval warships,and SOA-based non-real-time Command and Control components used at *** proposed solution enables the exchange of data between these two systems *** compare the proposed solution with a similar *** solution is superior in terms of automation support,ease of implementation,scalability,and performance.

关键词： Systems integration System of systems Systems engineering Software engineering C4I systems Defense systems Data distribution service DDS integration Java message service JMS

A novel paradigm for feedback control in LPBF:layer-wise correction for overhang structures

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Advances in Manufacturing 2022年第2期10卷 326-344页

作者： Ema Vasileska Ali Gokhan demir Bianca Maria Colosimo Barbara Previtali Department of Mechanical Engineering Polytechnic University of MilanVia La Masa 120156 MilanItaly

In laser powder bed fusion(LPBF),it is common practice to select process parameters to achieve high density parts starting from simple geometries such as cubes or ***,additive manufacturing is usually adopted to producevery complex geometries,where parameters should be tuned locally,depending on the local features to be *** fact,geometrical features,such as overhangs,acute corners,and thin walls may lead to over-or under-heating conditions,which may result in geometrical inaccuracy,high roughness,volumetric errors(i.e.,porosity)oreven job failure due to *** work proposes a layer-wise control strategy to improve the geometrical precision of overhanging regions using a coaxial melt pool monitoring *** meltpool images acquired at each layer are used in a controlloop toadapt theprocess parameters locally at the next layer in order to minimize surface *** particular,the laser duty cycle is used as a controllable parameterto correct the energy *** work presents the main architecture of the proposed approach,the control strategy and the experimental procedure that need to be applied to design the control *** layer-wise control strategy was tested on AISI 316L stainless steel using an open LPFB *** results showed that the proposed layer-wise control solution results in a constant melt pool observed via the laser heated area size starting from the second layer onward,leading to a significant improvement in the geometrical accuracy of 5 mm-long bridge geometries.

关键词： Closed-loop control Melt pool monitoring:Defect correction Pulsed-wave emission

Gastroprotective activity of Nigella sativa L oil and its constituent, thymoquinone against acute alcohol-induced gastric mucosal injury in rats

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World Journal of Gastroenterology 2005年第42期11卷 6662-6666页

作者： Mehmet Kanter Halit demir Cengiz Karakaya Hanefi Ozbek Department of Histology and Embryology Faculty of Medicine Trakya University Edirne Turkey Department of Chemistry Faculty of Art and Science Yuzuncu Yil University Van Turkey Department of Biochemistry Faculty of Medicine Yuzuncu Yil University VanTurkey Department of Pharmacology Faculty of Medicine Yuzuncu Yil University Van Turkey

AIM: To evaluate the role of reactive oxygen species in the pathogenesis of acute ethanol-induced gastric mucosal lesions and the effect of Nigella sativa L oil (NS) and its constituent thymoquinone (TQ) in an experimental ***: Male Wistar albino rats were assigned into 4groups. Control group was given physiologic saline orally (10 mL/kg body weight) as the vehicle (gavage); ethanol group was administrated 1 mL (per rat) absolute alcohol by gavage; the third and fourth groups were given NS (10 mL/kg body weight) and TQ (10 mg/kg body weight p.o) respectively 1 h prior to alcohol intake. One hour after ethanol administration, stomach tissues were excised for macroscopic examination and biochemical ***: NS and TQ could protect gastric mucosa against the injurious effect of absolute alcohol and promote ulcer healing as evidenced from the ulcer index (UI) values. NS prevented alcohol-induced increase in thiobarbituric acid-reactive substances (TBARS), an index of lipid peroxidation. NS also increased gastric glutathione content (GSH), enzymatic activities of gastric superoxide dismutase (SOD) and glutathione-S-transferase (GST). Likewise, TQ protected against the ulcerating effect of alcohol and mitigated most of the biochemical adverse effects induced by alcohol in gastric mucosa, but to a lesser extent than NS. Neither NS nor TQ affected catalase activity in gastric ***: Both NS and TQ, particularly NS can partly protect gastric mucosa from acute alcohol-induced mucosal injury, and these gastroprotective effects might be induced, at least partly by their radical scavenging activity.

关键词： Nigella sativa Thymoquinone Ulcer Antioxidant Rat

Evaluation of mixed mode-Ⅰ/Ⅱ criteria for fatigue crack propagation using experiments and modeling

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Chinese Journal of Aeronautics 2018年第7期31卷 1525-1534页

作者： Oguzhan demir Ali O.AYHAN Sedat IRIC Hüseyin LEKESIZ Department of Mechanical Engineering Sakarya University Department of Mechanical Engineering Bilecik S?eyh Edebali University Department of Mechanical Engineering Bursa Technical University

In this study, in-plane mixed mode-Ⅰ/Ⅱ fatigue crack growth simulations and experiments are performed for the Al 7075-T651 aluminum alloy which is widely used in the aerospace industry. Tests are carried out under different mode mixity ratios to evaluate the applicability of a fracture criterion developed in a previous study to mixed mode-Ⅰ/Ⅱ fatigue crack growth *** obtained from the analyses and experiments are compared with existing and developed criteria in terms of crack growth lives. Compact Tension Shear（CTS） specimens, which enable mixed mode loading with loading devices under different loading angles, are used in the simulations and experiments. In an effort to model and simulate the actual conditions in the experiments, crack surfaces of fractured specimens are scanned, crack paths are modeled exactly, and contacts are defined between the contact surfaces of a specimen and the loading device for each crack propagation step in the analyses. Having computed the mixed mode stress intensity factors from the numerical analyses, propagation life cycles are predicted by existing and the developed mixed mode-Ⅰ/Ⅱ criteria and then compared with experimental results.

关键词： Crack propagation Fatigue crack growth simulation Fatigue crack growth test Fracture mechanics Mixed mode-Ⅰ/Ⅱ

Tracheobronchopathia osteochondroplastica： four cases

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Chinese Medical Journal 2012年第16期125卷 2942-2944页

作者： Dursun Tatar Gunes Senol Atike demir Gulru Polat Department of Chest Diseases and Tuberculosis lzmir Dr. Suat Seren Chest Diseases and Surgery Training Hospital Yenisehir lzmir Turkey Department of Clinical Microbiology and Infectious Diseases lzmir Dr. Suat Seren Chest Diseases and Surgery Training Hospital Yenisehir lzmir Turkey

Tracheobronchopathia osteochondroplastica （TO） is a rare and benign disorder of unknown cause affecting the large airways. It is characterized by the presence of multiple osseous and cartilaginous nodules in the submucosa of the trachea and main bronchi that is characterized by the progression of submucosal bone and/or cartilage including nodules through the lumen of trachea and bronchus, We present four cases that were diagnosed TO while investigating for the causes of hemoptysis and chronic cough. We plan to emphasize TO in differential diaqnosis in proper patients.

关键词： airway obstruction chronic cough," fiberoptic bronchoscopy," hemoptysis," respiratory metaplasia tracheobronchopathia osteochondroplastica