检索结果-南通市图书馆

Chinese Journal of Natural Medicines 2014年第12期12卷 901-910页

作者： ULUKANLI Zeynep KARABRKLü Salih BOZOK Fuat ATES Burhan erdogan selim CENET Menderes KARAASLAN Merve Gksin Smaniye Korkut Ata University Faculty of Science and Arts Department of Biology ?n?nü University Faculty of Science Department of Chemistry

Essential oils of the resins of Pinus brutia and Pinus pinea were evaluated for their biological potential. Essential oils were characterized using GC-MS and GC/FID. In vitro antimicrobial, phytotoxic, antioxidant, and insecticidal activities were carried out using the direct contact and the fumigant assays, respectively. The chemical profile of the essential oils of the resins of P. pinea and P. brutia included mainly α-pinene(21.39% and 25.40%), β-pinene(9.68% and 9.69%), and caryophyllene(9.12% and 4.81%). The essential oils of P. pinea and P. brutia exerted notable antimicrobial activities on Micrococcus luteus and Bacillus subtilis, insecticidal activities on Ephestia kuehniella eggs, phytotoxic activities on Lactuca sativa, Lepidium sativum, and Portulaca oleracea, as well as antioxidant potential. Indications of the biological activities of the essential oils suggest their use in the formulation of ecofriendly and biocompatible pharmaceuticals.

关键词： Essential oil Antimicrobial Insecticidal Phytotoxic Antioxidant Pinus brutia Pinus pinea

ON SPECTRAL PROPERTIES OF A NEW OPERATOR OVER SEQUENCE SPACES c AND c_0

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2014年第5期34卷 1481-1494页

作者： Ezgi erdogan Vatan KARAKAYA Department of Mathematics Marmara UniversityKad?ky Department of Mathematical Engineering Y?ld?z Technical University

In this work, we classify and calculate spectra such as point spectrum, continuous spectrum and residual spectrum over sequences spaces？∞, c and c0 according to a new matrix operator W which is obtained by matrix pr... 详细信息

关键词： spectrum of an operator matrix transformation sequence space

NOTES ON THE SPECTRAL PROPERTIES OF THE WEIGHTED MEAN DIFFERENCE OPERATOR G(u,v;?) OVER THE SEQUENCE SPACE ?_1

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2016年第2期36卷 477-486页

作者： Vatan KARAKAYA Ezgi erdogan Department of Mathematical Engineering Yzldiz Technical UniversityDavutpasaIstanbulTurkey Department of Mathematics Marmara UniversityKadikoyIstanbulTurkey

In the study by Baliarsingh and Dutta [Internat. ***., Vol.2014（2014）, Article ID 786437], the authors computed the spectrum and the fine spectrum of the product operator G （u, v; A） over the sequence space e1. The product operator G （u, v; △） over l1 is defined by （G（u,v;△）x）k=^k∑i=0ukvi（xi- xi-1） with xk = 0 for all k 〈 0, where x = （xk）∈e1,and u and v axe either constant or strictly decreasing sequences of positive real numbers satisfying certain conditions. In this article we give some improvements of the computation of the spectrum of the operator G （u, v; △） on the sequence space gl.

关键词： Spectrum of an operator weighted mean difference operator sequence space

A methodology for lining design of circular mine shafts in different rock masses

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2016年第5期26卷 761-768页

作者： Ozturk Hasan Guler erdogan Mining Engineering Department Middle East Technical University

In this study, the finite element numerical modelling of 2D shaft sections in a Hoek–Brown medium are carried out in a non-hydrostatic stress state in an attempt to predict pressures developing around mine shafts. An iterative process of applying support pressure until observing no failure zone around the shaft is used to simulate the required lining support pressure for different shaft models. Later, regression analysis is carried out to find a generic shaft pressure equation representing the rock mass and the stress state. Finally, the developed pressure equation which shows a good agreement with a case study is used in elastic ‘‘thick-walled cylinder" equation to calculate the lining thickness required to prevent the development of a failure zone around the shaft. At the end of the study, a user-friendly object-oriented computer program ‘‘Shaft 2D" is developed to simplify the rigorous shaft lining thickness calculation process.

关键词： Lining thickness Shaft support Shaft Non-hydrostatic stress

Physical and Mechanical Properties of PP Composites based on Different Types of Lignocellulosic Fillers

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2018年第6期33卷 1298-1307页

作者： Selcuk erdogan Umit HUNER Trakya University Faculty of Engineering Department of Mechanical Engineering

The presents preparation and characterization of different types of lignocellulosic fillers(pine wood sawdust/walnut shell flour/black rice husk powder) reinforced polypropylene composites were presented. The effect of MAPP as coupling agent(4 wt%) on the physical and mechanical properties was also investigated. Polypropylene composites were prepared at different rates of filler/matrix(wt%) by using extrusion(for melt blending) and hot compression molding process. Maximum values of tensile and flexural strength were obtained as 26.1 and 43.4 MPa, respectively, whereas the elongation at break value was 4.11% at 10% pine wood sawdust reinforced PP. Tensile and flexural modulus of composites reached the maximum values as 3855 and 3633 MPa with the composite of 30% walnut shell flour reinforced PP. Characterization of composites was carried out by using tensile test, flexural test, FT-IR, and SEM.

关键词： natural filler water absorption FTIR polypropylene MAPP

Single endoscopist-performed percutaneous endoscopic gastrostomy tube placement

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2013年第26期19卷 4172-4176页

作者： Askin erdogan Department of Gastroenterology Baskent University Alanya Research and Teaching Center

AIM: To investigate whether single endoscopist-performed percutaneous endoscopic gastrostomy (PEG) is safe and to compare the complications of PEG with those reported in the literature. METHODS: Patients who underwent PEG placement between June 2001 and August 2011 at the Baskent University Alanya Teaching and Research Center were evaluated retrospectively. Patients whose PEG was placed for the first time by a single endoscopist were enrolled in the study. PEG was performed using the pull method. All of the patients were evaluated for their indications for PEG, major and minor complications resulting from PEG, nutritional status, C-reactive protein (CRP) levels and the use of antibiotic treatment or antibiotic prophylaxis prior to PEG. Comorbidities, rates, time and reasons for mortality were also evaluated. The reasons for PEG removal and PEG duration were also investigated. RESULTS: Sixty-two patients underwent the PEG procedure for the first time during this study. Eight patients who underwent PEG placement by 2 endoscopists were not enrolled in the study. A total of 54 patients were investigated. The patients' mean age was 69.9 years. The most common indication for PEG was cerebral infarct, which occurred in approximately two-thirds of the patients. The mean albumin level was 3.04 ± 0.7 g/dL, and 76.2% of the patients' albumin levels were below the normal values. The mean CRP level was high in 90.6% of patients prior to the procedure. Approximately two-thirds of the patients received antibiotics for either prophylaxis or treatment for infections prior to the PEG procedure. Mortality was not related to the procedure in any of the patients. Buried bumper syndrome was the only major complication, and it occurred in the third year. In such case, the PEG was removed and a new PEG tube was placed via surgery. Eight patients (15.1%) experienced minor complications, 6 (11.1%) of which were wound infections. All wound infections except one recovered with antibiotic treat

关键词： Gastrostomy Gastric feeding tube Enteral nutrition Enteral feeding Endoscopy Gastrointestinal

Microtextural Characteristics and Origin of Dolomites in the Tepearasi Formation, SW of Beysehir-Konya, Turkey

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2002年第1期76卷 100-109页

作者： erdogan TEKIN Ali SARI Department of Geological Engineering Faculty of Engineering Ankara UniversityTandogan Ankara 06100 TurkeyDepartment of Geological Engineering Faculty of Engineering Ankara UniversityTandogan Ankara 06100 Turkey

The Tepearasi Formation of the autochthonous Geyikdagi Group in the CentralTauride Belt, SE of Beysehir, is Dogger in age and consists dominantly of massive limestones andgreyish dolomites occurring within the middle to upper sections. The total thickness of thedolomitic levels ranges from 100-300 m and laterally extends 500-700 m. Three types of dolomite weredistinguished through petrographic analyses: homogeneous, mottled (saddle-crystalline) andjoint-filling dolomite, which were interpreted to have formed in two different stages, earlydiagenetic and late diagenetic. The homogeneous dolomite of the early diagenetic stage islight-coloured and monotonous-textured and shows the form of a dolosparite mosaic. The mottleddolomite formed in the late diagenetic stage is light- to dark-coloured and coarsely granularidiomorphic. The other type of late diagenetic dolomite, described as the joint-filling type,presents a crystal growth pattern from the joint walls towards the centre of the joint space. It isassociated with coarse calcite crystals as well as primary dolomite crystal clasts which were formedin the early diagenetic stage. In addition to these characteristics, cataclastic texture indicatingthe influence of tectonism is also observed. Microtexture-oriented scanning electron microscopy(SEM) studies indicate that mottled dolomites show zonal structures and contain secondarydissolution vugs. SEM studies also revealed the existence of some remains (calcite, clay etc.) injoint-filling dolomites. Analyses by energy dispersive spectrometry (EDS) indicate the existence ofclay minerals (likely to be illite) in the pores of dolomite. Isotope studies conducted to shedlight onto the origin of the dolomites of the Tepearasi Formation yielded the results of delta^18O=-2.48 to - 3.87 per thousand and delta^13C=0.93 to l.12 per thousand for the early diagenetichomogeneous dolomites. Mottled and joint-filling type dolomites of the late diagenetic stage, on theother hand, gave the r

关键词： Tepearasi dolomites microtextural characteristics dolomitization models

Digital Identification of Ecosystem Structure in the FIrtIna Valley of the Kakar Mountains in the Rize City of Turkey

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2014年第2期11卷 421-428页

作者： Cagasan KARACAOGLU selim Sualp CAGLAR Department of Biology Faculty of Science Biology Department Ecology Section EBAL Laboratories Hacettepe University

Identifying the structure of protected mountain ecosystems is an important task for understanding conservation sustainability. The study area, the Firtina Valley, located in the Rize City on the Eastern Blacksea Coast, is one of the biological hotspots and a National Park of Turkey. In order to identify the structure of mountain ecosystems, we generated a GIS database for the main environmental parameters of the study area, including elevation,slope and aspect layers for topographic structure, 10year mean values of Normalized Difference Vegetation Index(NDVI), data for vegetation structure, annual mean temperature and precipitation layers for climatic structure, main soil groups for soil structure and stream flow accumulation, stream flow length and stream order layers for hydrological *** identify the complex relations among environmental factors in the study area a data reduction method is applied with Principal Component Analysis(PCA). PCA is performed using data of 16 layers from Geographical Information Systems(GIS). PCA analysis reduced 16 dimensions into 5 dimensions containing 75% of the variation in all data. It is also revealed that the topographic structure, mainly altitude, dominates the ecosystems of the Firtina Valley, but it should be considered that the interactions of environmental factors in an ecosystem dynamics are very complex. The ecosystem structure is determined by the environmental factors direct or indirect effects on energy regulation of an ecosystem. Therefore the relationship between topographic elements and other abiotic-biotic elements in the Firtina Valley are important for environmental assessment and sustainability of a protected area, and these effects are explained in this study.

关键词： PCA GIS Firtina Valley Ecosystem structure Protected areas

Strength properties of xanthan gum and guar gum treated kaolin at different water contents

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2021年第5期13卷 1160-1172页

作者： Irem Bozyigit Akbar Javadi selim Altun Department of Civil Engineering Ege UniversityBornova-IzmirTurkey College of Engineering Mathematics and Physical SciencesUniversity of ExeterExeterUK

Nowadays,using biopolymer as a ground improvement method has become very ***,since biopolymers are organic and degradable,their long-term effect is not fully *** this study,the effects of biopolymers on the mechanical behavior of kaolin clay were investigated through a comprehensive program of *** types of biopolymer,*** gum and guar gum were chosen to investigate the effect of biopolymer *** this purpose,specimens were prepared using standard Proctor energy at four different water contents(25%,30%35%and 40%)with 0.5%,1%,1.5%and 2%biopolymer *** specimens were cured for 1 d,7 d,28 d and 90 ***,some of the specimens were kept in the curing room for 3 years to observe the long-term effect of the *** the end of the curing periods,the specimens were subjected to unconfined compression test,and scanning electron microscopy(SEM)analysis was performed to observe the mechanism of strength *** results revealed that the unconfined compressive strength(UCS)of the specimens treated with biopolymers increased in all biopolymer inclusion levels and water contents up to a 90-d curing *** specimens containing xanthan gum,the maximum strength increase was observed at 25%water content and 2%xanthan gum with 90-d *** strength increased 5.23 times induced by xanthan gum addition when compared to the pure ***,the increase in strength reached 8.53 times in specimens treated with guar ***,increasing water content caused more ductile behavior,thus increasing the axial deformation.

关键词： Biopolymer Clay Unconfined compressive strength(UCS) Xanthan gum Guar gum Strength properties

A fast and efficient coordinated vehicle-to-grid discharging control scheme for peak shaving in power distribution system

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2018年第3期6卷 555-566页

作者： Nuh erdogan Fatih ERDEN Mithat KISACIKOGLU Department of Electrical Engineering University of Texas at Arlington Department of Electrical and Electronics Engineering Bilkent University Department of Electrical and Computer Engineering University of Alabama

This study focuses on the potential role of plugin electric vehicles(PEVs) as a distributed energy storage unit to provide peak demand minimization in power distribution systems. Vehicle-to-grid(V2 G) power and currently available information transfer technology enables utility companies to use this stored energy. The V2 G process is first formulated as an optimal control ***, a two-stage V2 G discharging control scheme is proposed. In the first stage, a desired level for peak shaving and duration for V2 G service are determined off-line based on forecasted loading profile and PEV mobility model. In the second stage, the discharging rates of PEVs are dynamically adjusted in real time by considering the actual grid load and the characteristics of PEVs connected to the grid. The optimal and proposed V2 G algorithms are tested using a real residential distribution transformer and PEV mobility data collected from field with different battery and charger ratings for heuristic user case scenarios. The peak shaving performance is assessed in terms of peak shaving index and peak load reduction. Proposed solution is shown to be competitive with the optimal solution while avoiding high computational loads. The impact of the V2 G management strategy on the system loading at night is also analyzed by implementing an off-line charging scheduling algorithm.

关键词： Distribution transformer Optimal discharging control Peak shaving Plug-in electric vehicles Vehicle-togrid