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Öğe An experimental investigation of the effect of thermophysical properties on time lag and decrement factor for building elements(Gazi University, 2020-06-01) Oktay, Hasan; Yumrutaş, Recep; Argunhan, ZekiThe time lag (TL) and decrement factor (DF) are essential for the heat storage capabilities of building elements, which strictly depend on the thermophysical properties of the elements. Many investigations are presented in literature arguing to find the influence of each thermophysical property on TL and DF by keeping the other properties constant. This study aims to investigate the effect of each property on TL and DF, utilizing relationships between the measurement values of the thermophysical properties of wall materials. Therefore, first, 132 new concrete wall samples were produced, and their thermophysical properties were tested. Secondly, TL and DF values for each building element are computed from the solution of the problem by Complex Finite Fourier Transform (CFFT) technique. Finally, a multivariate regression analysis has been performed, and the variations of each thermophysical property versus TL and DF are presented, and also the findings are compared with literature. The results show that each property alone (keeping the other properties constant) is not adequate to identify the thermal inertia and thermal performance of a wall element. Besides, 87.3 % decrease in thermal diffusivity corresponds to 6.03 h increase in the value of TL and 88.8 % decrease in value of DF; respectively, for W1 wall assembly.Öğe Assessment of heavy metal pollution of urban soils of Batman by multiple pollution indices(Taylor & Francis, 2021-03-28) Baran, Hacı Alim; Gümüş Kıral, NurcanHeavy metal accumulation is observed in urban soils, sometimes due to anthropological effects and sometimes due to natural geological units. In order to determine the heavy metal content of the Upper MioceneLower Pliocene Selmo Formation, which is observed in the whole study area and consists of conglomerate, sandstone and silt stone, soil and river sediment samples were taken. Within the scope of pollution assessment, geo-accumulation index (Igeo), enrichment factor (EF) and pollution index (PI) calculations of Batman urban soil samples were made and different degrees of pollution values were determined. High pollution values were obtained for As, Mo and Sb elements in all pollution indices calculated. The pollution levels of the three elements were determined as strongly to extremely contaminated according to Igeo values, the others except As (very severe enrichment) according to EF values were determined as severe enrichment, and according to PI, all three were determined as strong polluted. Pollution and element distribution maps were created with a geographical information system software. According to the results of correlation analysis and cluster analysis, the elements found to be contaminated are divided into two groups, whose locations and sources of contamination are different. The first group (Sn, Zn and Pb) is observed in the approximate centre of the study area and developed due to traffic emissions. The elements belonging to the second group (especially As, Mo and Sb) show high pollution values in the south-southeast of the study area. These pollutions are thought to be caused by the inadequate storage of mineral oils and batteries that are changed in the industrial site and from leaks in the oil production, storage, refining and transmission phase in TPAO, TÜPRAŞ and BOTAŞ. The analysed samples were compared with the Soil Pollution Control Regulation and WHO standards, and Co, Ni and As element values were found to exceed the permissible values for healthÖğe “Balcı” aspir (Carthamus tinctorius l.) çeşidinin in vitro sürgün uçlarının mikroçoğaltımı ve köklendirilmesi üzerine oksin ve sitokininlerin etkisi(Yüzüncü Yıl Üniversitesi, 2018-12-31) Akbaş, Filiz; Hamidi Birecikli, AtikeBu çalışmada, linoleik tipte olan Balcı aspir çeşidinin, mikroçoğaltımı ve köklendirilmesi üzerine bazı sitokinin (BAP ve Kin) ve oksinlerin (NAA ve IAA) etkisi incelenerek in vitro çoğaltım protokolünün geliştirilmesi amaçlanmıştır. Başlangıç materyali olarak, in vitro koşullarda çimlendirilen olgun tohumlardan elde edilen steril fidelerin sürgün uçları kullanılmıştır. Sürgün uçları mikroçoğaltım için, BAP ve Kin’in farklı konsantrasyonlarının (0.0, 0.5, 1.0, 2.0 ve 4.0 mg/L) bulunduğu MS besi ortamında kültüre alınmıştır. Elde edilen sürgünler köklendirme aşamasında farklı NAA ve IAA (0.0, 0.5, 1.0 ve 2.0 mg/L) konsantrasyonlarını içeren MS besi ortamına transfer edilmiştir. BAP konsantrasyonları arasında en iyi sürgün çoğaltımı, eksplant başına 5.33 adet sürgün ile 0.5 mg/L BAP’lı ortamdan elde edilirken, Kin uygulamalarında ise 3.75 adet sürgün ile 0.5 mg/L Kin ve 3.33 adet sürgün ile 4.0 mg/L Kin içeren ortamdan elde edilmiştir. Ancak BAP uygulamalarının genelinde ve 4.0 mg/L Kin uygulamasında oluşan sürgünlerde vitrifikasyon olduğu belirlenmiştir. Bu nedenle, 0.5 mg/L Kin ile desteklenmiş MS besi ortamının Balcı aspir çeşidinin in vitro sürgün çoğaltımı için en ideal ortam olduğu tespit edilmiştir. En iyi kök oluşumunun, eksplant başına 20 adet ile 2.0 mg/L NAA içeren ortamda kültüre alınan sürgünlerde olduğu saptanmıştır. Elde edilen köklü fideler torf – perlit karışımı içeren saksılara dikilerek toprağa adaptasyonu sağlanmıştır.Öğe Morphological, structural and optical characteristics of graphene oxide layers and metal/interlayer/semiconductor photovoltaic diode application(National Institute of Research and Development for Optoelectronics, 2018) Güllü, Ömer; Çankaya, MuratThis work describes the optical, morphological and structural characterizations of graphene oxide (GO) layers grown by drop casting and annealing process. UV-vis optical measurement shows that the values of direct and indirect optical gap energy of the GO film are 3.89 eV and 3.21 eV, respectively. The graphene oxide (GO) layer has been placed in the metal/ interlayer /semiconductor (MIS) diodes (total 17 devices) on p-Si wafers. The graphene oxide diodes give a better barrier height enhancement as compared with the conventional diodes. The value of homogeneous barrier height for Al/GO/p-Si MIS junctions was extracted as 0.74 eV. The diodes were also investigated under 300 watt light illumination for photovoltaic applications. Additionally, interfacial properties of the MIS diode with GO interlayer were determined. It has been seen that the capacitance of the device changes as a function of gate voltage and signal frequency from the capacitance-frequency measurements. It has also been reported that the interfacial trap charges reduce the capacitance with increasing frequency values.Öğe Ahmet Mithat Efendi’nin ilk romanlarında Mısır ve Mısırlılar(Atatürk Üniversitesi, 2011-06) Korkmaz, FerhatAhmet Mithat Efendi, Şemsettin Sami’den sonra ikinci telif romanı yazan Türk romancısıdır. Osmanlı Devleti açısından 18. Yüzyıldan itibaren başlayan Mısır sorunu, 19. Yüzyılda özellikle Kavalalı Mehmet Ali Paşa döneminde en karmaşık halini alır. 1517’de fethedilen; ancak 1882’de Osmanlı Devleti’nin elinden çıkan Mısır bu ilk romancılarımızın ilgisini çekmiş ve Tanzimat dönemi romanlarında bu ülkeye ait kimi konular işlenmiştir. Tanzimat romanında Mısır coğrafyası mekân olarak kullanılmış, roman yazarları ise romanlarının kimi bölümlerini Mısır, Mısırlılar veyahut Mısır’daki meselelere ayırmıştır. Ahmet Mithat Efendi de bir Tanzimat romancısı olarak Mısır konusuna bîgâne kalmamıştır. Onun romanlarını Osmanlı ülkesinin yaşayan halklarının siyasi, ekonomik, coğrafi, sosyal, psikolojik ve kültürel tarihi olarak değerlendirdiğimizden makalemizde, Ahmet Mithat Efendi’nin romanlarında Mısır coğrafyası ve Mısırlılar ele alınmıştırÖğe Novel bis(aminoalcohol)oxalamide organogelators and their diglycolylamide analogs: evaluation of gelation efficiency in various organic fluids(TÜBİTAK, 2017-11-10) Çolak, Mehmet; Pirinççioğlu, Necmettin; Hoşgören, Halil; Barış Cebe, DenizThree modular types of bis(aminoalcohol)oxalamides (1, 4, and 7) and bis(aminoalcohol)diglycolylamide (8) gelators have been prepared by the reaction of the respective aminoalcohols with oxalyl and digycolyl methylesters as potential low-molecular-weight organogelators. The gelation properties of these amides have been evaluated in various aromatic organic solvents (xylene, toluene, isopropyl benzene, and aromatic ether type organic fluids such as anisole or α-phenylethylmethylether) as well as the long-chain aliphatic alcohols (1-hexanol, 1-octanol, 2-octanol, and aromatic 1- phenylethanol). The compounds with sec-butyl and ethyl side chains produce good gelation properties in both aromatic and other organic fluids. Furthermore, the common oxalamide linker present in the gelators was replaced by an extended diglycolylamide linker (8) and its behaviors were compared with the benzylic oxalamide analog (3). The gelator (8) gives the best results with aromatic fluid and lauric acid ethyl ester. 1 H NMR studies reveal the existence of temperaturedependent network assembly/dissolution equilibrium and produce Kgel . FTIR was employed to see the effect of hydrogen bonding in the formation of gel network. Thermodynamic parameters regarding gel-to-sol transition were collected with van’t Hoff relationships.Öğe Chemical constituents and biological activities of cirsium leucopsis, c. sipyleum, and c. eriophorum(Walter de Gruyter, 2015-03-19) Boğa, Mehmet; Köseoğlu Yılmaz, Pelin; Barış Cebe, Deniz; Fatima, Mashhad; Siddiqui, Bina S.; Kolak, UfukTwo endemicCirsiumspecies,C. leucopsisDC. andC. sipyleumO. Schwarz, andC. eriophorum(L.) Scop. growing in Turkey were investigated to establish their secondary metabolites, fatty acidcompositions, and antioxidant and anticholinesterase potentials. Spectroscopic methods were usedto elucidate the structures of thirteen known compounds (p-hydroxy-benzoic acid, vanillic acid,cis-epoxyconiferyl alcohol, syringin, balanophonin, 1′-O-methyl-balanophonin, apigenin, kaempferol-3-O-β-D-glucopyranoside, kaempferol-3-O-α-L-rhamnopyranoside, taraxasterol, taraxasterol acetate,β-sitosterol,β-sitosterol-3-O-β-D-glucopyranoside).cis-Epoxyconiferyl alcohol and 1′-O-methyl-balanophonin were isolated for the first time fromCirsiumspecies. Palmitic acid (47.1 %) was foundto be the main fatty acid ofC. leucopsis, linoleic acid in bothC. sipyleum(42.1 %) andC. eriophorum(37.8 %). Assays ofβ-carotene bleaching, scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) freeradicals, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium (ABTS) cation radicals,and superoxide anion radicals, as well as cupric reducing antioxidant capacity (CUPRAC) were usedto determine the antioxidant activities of the extracts and isolated compounds. Vanillic acid, balano-phonin, and kaempferol-3-O-α-L-rhamnopyranoside exhibited strong antioxidant activity. Taraxa-sterol was a potent inhibitor of acetyl- and butyrylcholinesterase activity, respectively.Öğe Enantioselevtive compexation of chiral lariat crown ethers and chiral primary alkylamonum perchlorates(Turkish Journal Chemistry, 2011-02-01) Aral, Tarık; Köylü, Mehmet Zafer; Kocakaya, Şafak Özhan; Karakaplan, Mehmet; Hoşgören, HalilIn order to investigate the enantiomeric recognition abilities toward 2 chiral alkylammonium perchlorates (AmI, AmII) by 1 H-NMR titration method in CDCl 3, 4 chiral lariat ethers 8-11 with a (p-methoxyphenoxy) methyl flexible side arm were used. The most effective enantiomeric recognition was obtained by LCEs 9 and 11 toward AmII, by KR /KS 6.58 and KS /KR 6.63, respectively. The effect of macroring size, subunit of macroring, and side arm appeared to have strong influence on the binding ability of these alkylammonium ions.Öğe Application of a pencil graphite electrode for voltammetric simultaneous determination of ascorbic acid, norepinephrine, and uric acid in real samples(TÜBİTAK, 2018-04-27) Levent, Abdulkadir; Önal, GünayA pencil graphite electrode (PGE) was used for the simultaneous detection of ascorbic acid (AA), norepinephrine (NE), and uric acid (UA) by differential pulse voltammetry and cyclic voltammetry. The anodic peaks of AA, NE, and UA in their mixture can be well separated in 0.1 M Britton–Robinson buffer solution at pH 4.0. The effects of various experimental parameters such as pH, scan rate, and voltammetric parameters on the voltammetric response of these compounds were investigated. Under optimum conditions, linear calibration graphs were obtained from the AA, NE, and UA concentration ranges, which were 100–800 nM, 20–170 nM, and 40–175 nM, respectively. The detection limits for AA, NE, and UA were 27 nM, 4 nM, and 10 nM in the form of a mixture at the PGE. This electrode shows great analytical performance characteristics, corresponding repeatability and recovery for the simultaneous determination of these compounds. PGE, which was used for the first time in this method, has been successfully applied for the assay of UA in human urine samples with the aim of determining AA and NE in pharmaceutical drugs.Öğe Application and comparative performance analysis of PSO and ABC algorithms for optimal design of multimachine power system stabilizers(Gazi Üniversitesi, 2016-06-20) Ekinci, SerdarThis paper presents the application and performance comparison of PSO and ABC optimization techniques, for multi-objective design of power system stabilizers (PSSs) in the multi-machine power system. The design objective is to improve the power system stability. The PSSs parameters tuning problem is converted to an optimization problem with the time domain-based objective function and both PSO and ABC optimization techniques are used to search for optimal stabilizers parameters. The optimized stabilizers are tested on multi-machine electric power system subjected to different disturbances. The performance of both optimization techniques in terms of computational time, convergence rate and solution quality is compared. The eigenvalue analysis, nonlinear timedomain simulation results, critical clearing times and some performance indices studies are introduced and compared in order to demonstrate the effectiveness of both optimization techniques in designing stabilizers, to enhance the dynamic stability of the system. What is more, the potential and superiority of the ABC algorithm over the PSO algorithm are verified.
