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Chinese Journal of Oceanology and Limnology 2011年第2期29卷 366-368页

作者： Aysel BEKLEYEN memet varol Bulent GOKOT Department of Biology Faculty of ScienceUniversity of Dicle-21280 DiyarbakirTurkey Ministry of Agriculture and Rural Affairs Province Control Laboratory-21010 DiyarbakirTurkey

We report the first record of the invasive freshwater jellyfish Craspedacusta sowerbii Lankester in Kralklzl Dam Lake, Southeastern Anatolia, Turkey. The medusa was found only in August, 2008 when average surface wate... 详细信息

关键词： freshwater jellyfish medusae Craspedacusta sowerbii Kralklzl Dam Lake Turkey new record

跨境电子商务与边境仓库建设推动边境贸易的路径研究——以新疆维吾尔自治区克州为例

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中国商论 2025年第1期34卷 56-59页

作者：麦麦提穆萨·麦麦提艾力中共克州党委党校新疆阿图什845350

跨境电子商务和边境仓库建设正日益成为推动边境贸易发展的重要力量。为了实现边境地区的发展,边境贸易跨境电商等外贸载体助力边境地区产品“走出去”,从而扩大贸易顺差,并吸引外资以推动当地经济发展。新疆维吾尔自治区克州作为边境地... 详细信息

跨境电子商务和边境仓库建设正日益成为推动边境贸易发展的重要力量。为了实现边境地区的发展,边境贸易跨境电商等外贸载体助力边境地区产品“走出去”,从而扩大贸易顺差,并吸引外资以推动当地经济发展。新疆维吾尔自治区克州作为边境地区,拥有独特的地理位置和资源优势,积极探索和发展跨境电子商务与边境仓库建设,对于促进边境贸易的繁荣具有重要意义。新疆克州与吉尔吉斯斯坦、塔吉克斯坦、乌兹别克斯坦等中亚国家保持着稳固战略伙伴关系,也是主要的贸易伙伴。克州需与时俱进、将传统的简单货物贸易方式转型升级。边境仓的建设正是为了促进跨境电子商务的发展,将其转化为新的生产力。本研究旨在探讨克州跨境电子商务与边境仓库建设对边境贸易的推动作用及可行路径,通过对克州的实际情况研究,指出克州跨境电商与边境仓库建设当前发展现状、面临的挑战,并提出了针对性的发展策略及建议,以供参考。

关键词：跨境电子商务边境仓库建设边境贸易国际贸易脱贫

Comparison of a commercial powder and a powder produced from Ti–6Al–4V chips and their effects on compacts sintered by the sinter-HIP method

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International Journal of Minerals,Metallurgy and Materials 2019年第7期26卷 878-888页

作者： Mustafa Ustundag Remzi varol Department of Mechanical Engineering Suleyman Demirel University

The present paper is related to the conversion of Ti–6Al–4V chips into powder and investigates the usability of the produced powder in powder metallurgy applications. In this regard, a disc-milling process was applied to Ti–6Al–4V chips and the obtained powder was subsequently compacted. The compacted samples were sintered by the sinter hot isostatic pressing (sinter-HIP) method at 1200°C under high vacuum, their mechanical properties and microstructure were investigated and compared with those of commercial powder compacts subjected to the same preparation processes. The results showed that the produced powder exhibits greater flowability and higher apparent density than the commercial powder. However, the sintered products prepared from the commercial powder exhibited a higher relative density, lower porosity, and, as a result, greater flexural strength compared with the sintered compacts prepared from the produced powder. In addition, transgranular fracture was greater in the sintered products of the commercial powder. The microstructural studies revealed that the sintered products made from both the commercial and the produced powders consisted of α- and β-phase but contained more α-phase. All of the examined properties were found to be substantially affected by the particle size of the powders.

关键词： Ti-6Al-4V chips sinter hot isostatic pressing flexural strength porosity

Predicting uniaxial compressive strength of tuff after accelerated freeze-thaw testing: Comparative analysis of regression models and artificial neural networks

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Journal of Mountain Science 2024年第10期21卷 3521-3535页

作者： Ogün Ozan varol Department of Mining Engineering Faculty of EngineeringVan Yuzuncu Yil UniversityVan 65080Türkiye

Ignimbrites have been widely used as building materials in many historical and touristic structures in the Kayseri region of Türkiye. Their diverse colours and textures make them a popular choice for modern construction as well. However, ignimbrites are particularly vulnerable to atmospheric conditions, such as freeze-thaw cycles, due to their high porosity, which is a result of their formation process. When water enters the pores of the ignimbrites, it can freeze during cold weather. As the water freezes and expands, it generates internal stress within the stone, causing micro-cracks to develop. Over time, repeated freeze-thaw (F-T) cycles lead to the growth of these micro-cracks into larger cracks, compromising the structural integrity of the ignimbrites and eventually making them unsuitable for use as building materials. The determination of the long-term F-T performance of ignimbrites can be established after long F-T experimental processes. Determining the long-term F-T performance of ignimbrites typically requires extensive experimental testing over prolonged freeze-thaw cycles. To streamline this process, developing accurate predictive equations becomes crucial. In this study, such equations were formulated using classical regression analyses and artificial neural networks (ANN) based on data obtained from these experiments, allowing for the prediction of the F-T performance of ignimbrites and other similar building stones without the need for lengthy testing. In this study, uniaxial compressive strength, ultrasonic propagation velocity, apparent porosity and mass loss of ignimbrites after long-term F-T were determined. Following the F-T cycles, the disintegration rate was evaluated using decay function approaches, while uniaxial compressive strength (UCS) values were predicted with minimal input parameters through both regression and ANN analyses. The ANN and regression models created for this purpose were first started with a single input value and then dev

关键词： Ignimbrite Uniaxial compressive strength Freeze-thaw Decay function Regression Artificial neural network

Analysis of the forest fires in the Antalya region of Turkey using the Keetch–Byram drought index

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Journal of Forestry Research 2016年第4期27卷 811-819页

作者： Tugrul varol Mertol Ertugrul Forest Engineering Department Faculty of Forestry Bart?n University

We investigated the correlation of large fires（[300 ha） from 1992 to 2013 within the borders of the Antalya Regional Directorate of Forestry using the Keetch–Byram drought index（KBDI）. Daily KBDI values were calculated for each year, and values for the period before the year 2000 differed significantly from those after2000. After 2000（large fires occurred in 2004, 2006, 2007,2008, 2010, and 2013）, when KBDI values increased, the KBDI, but not the number of fires, was inversely correlated with the natural log of the burned area（NLBA）. While there were both high and low KBDI values when the NLBA was small, only high KBDI values were associated with high NLBA values. Particularly for logarithmic values of 4 and higher, KBDI values increased in parallel with increases in NLBA values. On the basis of a Mann–Whitney U test done in addition to a Pearson correlation test, we found that when the burned areas were grouped according to small and large areas, the KBDI could be used to distinguish the two groups. Using a conditional probability analysis, we found that 4th, 5th and 6th class KBDI values may lead to large fires at the 60 % ***, the possibility of large fires greater than the median burned area in any given 6 years was found to be48 %. In addition, while the mean value of KBDI is 390.51 for the period from May to September for these 6 years, it is 359.93 for the other years. Consequently, the area burned also increased as the KBDI classes（Class 0： 0–99, Class 1：100–199, Class 2： 200–299, Class 3： 300–399, Class 4：400–499, Class 5： 500–599, Class 6： 600–699, and Class 7：700–800） increase.

关键词： drought grouped possibility distinguish median Turkey conditional explained moisture ranged

Comprehensive analysis of pulsed plasma nitriding preconditions on the fatigue behavior of AISI 304 austenitic stainless steel

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International Journal of Minerals,Metallurgy and Materials 2021年第4期28卷 657-664页

作者： Okan Unal Erfan Maleki Remzi varol Mechanical Engineering Department Karabuk UniversityKarabuk 78050Turkey Modern Surface Engineering Laboratory(MSELAB) Karabuk UniversityKarabuk 78050Turkey Mechanical Engineering Department Sharif University of Technology-International CampusKish Island 79417-76655Iran Mechanical Engineering Department Suleyman Demirel UniversityIsparta 32200Turkey

This study aims to draw an exact boundary for microstructural and mechanical behaviors in terms of pulsed plasma nitriding *** pulsed plasma nitriding treatment was applied to AISI 304 austenitic stainless steel at different temperatures and *** reveal that nitriding depth increased as process temperature and duration *** nitriding depth remarkably increased at 475℃for 8 h and at 550℃for 4 *** austenite structure was transformed into a metastable nitrogen-oversaturated body-centered tetragonal expanded austenite(S-phase)during low-temperature plasma *** S-phase was converted to CrN precipitation at 475℃for 8 h and at 550℃for 4 *** hardness and fatigue limit increased through plasma nitriding regardless of process *** best surface hardness and fatigue limit were obtained at 550℃for 4 h because of the occurrence of CrN precipitation.

关键词： pulsed plasma nitriding S-phase fatigue nitrided layer

Modeling of the Prediction of Densification Behavior of Powder Metallurgy Al–Cu–Mg/B_4C Composites Using Artificial Neural Networks

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Acta Metallurgica Sinica(English Letters) 2015年第2期28卷 182-195页

作者： Temel varol Aykut Canakci Sukru Ozsahin Department of Metallurgical and Materials Engineering Engineering Faculty Karadeniz Technical University Department of Industrial Engineering Engineering FacultyKaradeniz Technical University

Al-Cu-Mg/B4Cp metal matrix composites with reinforcement of up to 20 wt% were produced using the powder metallurgy technique. The effects of reinforcement ratio, reinforcement size, milling time, and compact pressure on the density and porosity of the composites reinforced with 0, 5, 10, and 20 wt% B4C particles were studied. Moreover, an artificial neural network model has been developed for the prediction of the effects of the manufacturing parameters on the density and porosity of powder metallurgy Al-Cu-Mg/B4Cp composites. This model can be used for predicting the densification behavior of Al-Cu-Mg/B4Cp composites produced under reinforcement of different sizes and amounts with various milling times and compact pressures. The mean absolute percentage error for the predicted values did not exceed 1.6%.

关键词： Al alloys Composite Mechanical milling Metal matrix composite Artificial neural network

Monte Carlo forecasting of time series data using Polynomial-Fourier series model

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第3期12卷 112-124页

作者： Salim Jibrin Danbatta Asaf varol Software Engineering Department Firat University Elazig CenterElazigTurkey Computer Engineering Department Maltepe University College of Engineering and Natural Sciences Maltepe University34857 Maltepe/IstanbulTurkey

The perishable nature of tourism products and services makes forecasting an important tool for tourism planning,especially in the current COVID-19 pandemic *** forecast assists tourism organizations in decision-making regarding resource allocations to avoid *** study is motivated by the need to model periodic time series with linear and nonlinear trends.A hybrid Polynomial-Fourier series model that uses the combination of polynomial and Fourier fittings to capture and forecast time series data was *** proposed model is applied to monthly foreign visitors to Turkey from January 2014 to August 2020 dataset and diagnostic checks show that the proposed model produces a statistically good *** improve the model forecast,a Monte Carlo simulation scheme with 100 simulation paths is applied to the model *** mean of the 100 simulation paths within±2σbounds from the model curve was taken and found to give statistically acceptable results.

关键词： Time series forecasting Monte Carlo Fourier series polynomial COVID-19.

A Comparative Study of Metaheuristic Optimization Algorithms for Solving Real-World Engineering Design Problems

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 1039-1094页

作者： Elif varol Altay Osman Altay Yusuf Ovik Department of Software Engineering Manisa Celal Bayar UniversityManisa45400Turkey

Real-world engineering design problems with complex objective functions under some constraints are relatively difficult problems to *** design problems are widely experienced in many engineering fields,such as industry,automotive,construction,machinery,and interdisciplinary ***,there are established optimization techniques that have shown effectiveness in addressing these types of *** research paper gives a comparative study of the implementation of seventeen new metaheuristic methods in order to optimize twelve distinct engineering design *** algorithms used in the study are listed as:transient search optimization(TSO),equilibrium optimizer(EO),grey wolf optimizer(GWO),moth-flame optimization(MFO),whale optimization algorithm(WOA),slimemould algorithm(SMA),harris hawks optimization(HHO),chimp optimization algorithm(COA),coot optimization algorithm(COOT),multi-verse optimization(MVO),arithmetic optimization algorithm(AOA),aquila optimizer(AO),sine cosine algorithm(SCA),smell agent optimization(SAO),and seagull optimization algorithm(SOA),pelican optimization algorithm(POA),and coati optimization algorithm(CA).As far as we know,there is no comparative analysis of recent and popular methods against the concrete conditions of real-world engineering ***,a remarkable research guideline is presented in the study for researchersworking in the fields of engineering and artificial intelligence,especiallywhen applying the optimization methods that have emerged *** research can rely on this work for a literature search on comparisons of metaheuristic optimization methods in real-world problems under similar conditions.

关键词： Metaheuristic optimization algorithms real-world engineering design problems multidisciplinary design optimization problems

Brightness of Blue/Violet Luminescent Nano-Crystalline AZO and IZO Thin Films with Effect of Layer Number:For High Optical Performance

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Chinese Physics Letters 2016年第5期33卷 80-83页

作者： Panagiota KORAL Songül FAT varol Michael KOMPITSAS Mihaela GIRTAN School of Mechanical Engineering National Technical University of Athens National Hellenic Research Foundation Theoretical and Physical Chemistry Institute Giresun University Faculty of EngineeringEnergy Systems Engineering Photonics Laboratory Angers University

From different reports, it （AZO） and indium-doped including usage areas. We nanocrystalline films with is realized that there is a need to consider all sides of aluminum-doped zinc oxide zinc oxide （IZO） thin films with their optical, luminescence and surface properties establish an assessment to carry out further information to summarize AZO and IZO impact of the layer number.

关键词： of in is AZO ZnO Brightness of Blue/Violet Luminescent Nano-Crystalline AZO and IZO Thin Films with Effect of Layer Number:For High Optical Performance for that with