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The main purpose of this study is to investigate the thermal efficiency of a Two-Phase Closed Thermosyphon (TPCT). For this purpose, initially, an experimental study was performed, then to predict the other experimental conditions ANN model which has used a wide range of thermal engineering systems was developed. A vertical copper pipe charged with different working fluids as pure water, ethanol, and ethylene glycol were used for TPCT. Impact of the various parameter such as heating power input, inclination angle, cooling water flow rate and working fluid type on the TPCT efficiency are examined. It is found that the increase in the inclination angle increased the TPCT efficiency while the increase in heating power input decreased efficiency. Regression analysis was applied to examine the performance of ANN between estimated and experimental data. The Mean Absolute Percentage Error (MAPE) was found to be less than 1.3 % for the training set and 3.1% for the test data set. The ANN predictions yield R2 in the range of 0.9998 for the training set and 0.9989 for the test data set. The obtained results from the experimental study and ANN were found in good agreement, and it is also concluded that from the study the ANN is a useful tool to estimate such thermal engineering problems. Keywords: Thermal efficiency Heat pipe Two-phase closed thermosyphon ANN

Karapınar-Karacadağ Volcanic Rocks (KKVR) have very complex magmatic history and outcropped the southwestern part of the Cappadocia Volcanic Province (Central Anatolia). Here we present the petrography and whole-rock chemistry of the enclave-bearing rocks to constrain their source and evolution history. These petrographic observation and geochemical data reveal that the enclaves in the Karapınar-Karacadağ volcanic rocks are magma mixing/mingling enclaves (MME), magma segregation enclaves (MSE), and xenoliths. Here we discriminated these enclaves into eight different types according to their mineral composition and textural features. The magma mixing/mingling enclaves (Type 1, 7, 8) are the mixing products of coeval more felsic and mafic magmas. They show hypocrystalline porphyritic, holocrystalline granular, and intergranular textures, and rich in mafic minerals, and have characteristic petrographic features such as quenched amphibole, bladed biotite, ocelli-quartz, sieved and cellular plagioclases. In andesites they range from basalt to andesite in composition. However, in basalts, they are in basaltic composition. The magma segregation enclaves (Type 2, 4, 5, 6), which are observed in almost all the KKVRs, are cognate xenolith because of plucking from the different parts of the magma chamber. They are holocrystalline and granular in texture. The magma segregation enclaves contained in the andesitic host rocks are hornblende gabbro and pyroxene gabbro in composition, whereas in the basaltic host rocks they are dunite, lherzolite, and basalt in composition. The xenolithic enclaves (Type 3) are observed in the basalts as quartz, plagioclase, biotite, and amphibole xenocrysts. Major oxides and trace element data of the studied rocks indicate that the MSEs are more primitive than their host rocks, and all of the enclaves (MME-MSE) are in accordance with their hosts. According to petrographic observations and geochemical data we propose that fractional crystallization, magma mixing and assimilation processes have a key role in the evolution of the KKVRs and their enclaves.

To determine the relationship between mean platelet volume (MPV) and treatment response of iron deficiency anaemia (IDA) with normal platelet count. Study further aimed to determine changing of platelet parameters treatment response of IDA.IDA patients (n = 124) and the control group (CG) (n = 124) who fulfilled the inclusion criteria were compared for MPV and platelet parameters. Patients with IDA were divided into two groups as partial and complete response. The partial response to treatment group (PRG) was accepted as haemoglobin level between 10 and 12 g/dL, mean corpuscular volume (MCV) below 80 fL, and ferritin below 15 ng/ml (n = 60). Complete response to treatment group (CRG) was the patients whose haemoglobin was above 12 g/dL, MCV is above 80 fL, and ferritin is above 15 ng/ml (n = 64).The MPV levels of CG (8.81 ± 0.99), PRG (8.80 ± 1.09), and CRG (8.96 ± 0.96) were similar at the beginning of the study. In addition, MPV levels of PRG (8.84 ± 1.08) and CRG (8.96 ± 1.11) with IDA therapy were similar at the end of the study (p 0.05). When IDA was treated, there was a decrease in plateletcrit, platelet distribution width (PDW), and platelet count from platelet parameters. There was a correlation between MPV level and platelet count in both PRG and CRG (r = - 0.506; p 0.001), (r = - 0.499; p 0.001).There is no change in MPV levels before and after treatment when normal platelet count IDA is treated, but there is a decrease in platelet count and an increase in PDW.

The fact that the properties of thermoelectric materials are to be estimated with Artificial Neural Networks without production and measurement will help researchers in terms of time and cost. For this purpose, figure of merit, which is the performance value of thermoelectric materials, is estimated by Artificial Neural Networks without an experimental study. P-and n-type thermoelectric bulk samples were obtained in 19 different compositions by doping different elements into Ca2.7Ag0.3Co4O9- and Zn0.98Al0.02O-based oxide thermoelectric materials. The Seebeck coefficient, electrical resistivity and thermal diffusivity values of the bulk samples were measured from 200 degrees C to 800 degrees C with an increase rate of 100 degrees C, and figure of merit values were calculated. 7 different Artificial Neural Network models were created using 123 measured results of experimental data and the molar masses of the doping elements. In this system aiming to predict the electrical resistivity, thermal diffusivity and figure of merit values of thermoelectric materials, the average R value and accuracy rate of these values were estimated to be 94% and 80%, respectively. (c) 2020 Karabuk University. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [115M579]; Scientific Research Projects Coordinatorship of Karabuk UniversityKarabuk University [KBU-BAP-16/1-DR-078] This study was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under Grant No. 115M579 and by the Scientific Research Projects Coordinatorship of Karabuk University under Grant No. KBU-BAP-16/1-DR-078.

In this study, results of HTRI Xchanger software used in the analysis of shell and tube heat exchangers (STHE), and Kern and Bell-Delaware methods, which are the conventional methods used for calcu...

This study aimed to increase the energy efficiency of thermoelectric generators designed by considering the electrical properties of p- and n-type semiconductor materials for reducing the costs associated with the experiments, errors, and long production processes. Accordingly, the estimation of the energy amount to be produced by the thermoelectric materials was achieved by different doping elements using three different parameters such as skin-depth, electrical conductivity and dielectric constant. Additionally, the findings were supported by experimental results. In contrast to the conventionally used black-box type approach and estimation methods, an inference was obtained on the actual values of the materials.

In this paper, convective heat transfer and entropy generation of ZnO-EG nanofluid flow through a square microchannel are numerically investigated. Flow is modelled by using Eulerian-Eulerian two phase flow model. Nanoparticle volume fraction of ZnO-EG nanofluid ranged between %1.0 and %4.0. As a result, it is found that the convective heat transfer coefficient of flow increased from 9718.15 W/m2K to 23010.79 W/m2K when 4.0% ZnO nanoparticle addition to pure EG at Re=100. Total entropy generation of ZnO-EG nanofluid decreases with increase in nanoparticle volume fraction of ZnO-EG nanofluid. It is also observed that the Bejan number decreases with increase in nanoparticle volume fraction of ZnO-EG nanofluid.

In this study, steady-state thermal-electric analysis of a pi-shaped 8-pair TEG was performed by finite element method using thermal-electric module in Ansys Workbench for high temperature applications. TE powders of Ca2.7Ag0.3Co4O9 and Zn0.94Al0.04In0.02O were synthesized by sol-gel method followed by cold pressing (CP) to obtain bulk samples. High temperature thermoelectric properties of the bulk samples were used for p- and n-type legs, respectively. In the model, a Delta T temperature difference of 400 degrees C was applied to obtain a high temperature power output. As a result of the thermal-electric analysis, temperature distribution and total current density along the TEG were evaluated. (C) 2019 Elsevier Ltd. All rights reserved.

WOS:000459408300003, In this study, a spark ignition (SI) engine performance is exergeticallyinvestigated for different crankshaft speeds. The test engine is VSG413SI type engine fueled with 95 octane gasoline. The test engine has 1.3 lvolume, four stroke, four cylinder, 45 kW maximum power capacity and98 Nm maximum torque capacity. The experiments are realized underfully loaded test conditions. The crankshaft speed is changed between1200 rpm and 5000 rpm. In the calculations, actual operating dataobtained by experiments are used. It is found that maximum energy andexergy efficiencies are obtained at crankshaft speed of 2500 rpm, whichare 29.78% and 27.77%, respectively. Entropy generation rateincreases with increase in crankshaft speed and ranged from 0.059kW/K to 0.253 kW/K for all study., Bu çalışmada, buji ateşlemeli bir motorun performansı farklı krank milihızları için ekserjetik olarak incelenmektedir. Test motoru 95 oktanbenzin yakıtlı VSG413 SI türü motordur. Test motoru 1.3 l hacim, dörtstrok, dört silindir, 45 kW’lık maksimum güç kapasitesi ve 98 Nm’likmaksimum tork kapasitesine sahiptir. Deneyler tam yük test koşullarıaltında gerçekleştirilmiştir. Krank mili hızı 1200 d/d ve 5000 d/daralığında değiştirilmiştir. Hesaplamalarda, deneylerden elde edilengerçek çalışma verileri kullanılmıştır. %29.78’lik maksimum enerjiverimi ve %27.77’lik maksimum ekserji veriminin 2500 rpm’lik krankmili hızında elde edildiği tespit edilmiştir. Entropi üretimi krank milihızının artmasıyla artmaktadır ve bütün çalışma boyunca 0.059 kW/Kile 0.253 kW/K aralığında değişmektedir.

Fluids can change their physical properties when they are exposed to magnetic fields. Magnetorheological (MR) fluids are classified as smart materials because their viscoelastic properties can increase by the application of the magnetic field. Accordingly, they are used in different engineering applications such as flow control and vibration damping. In this study, three different types of MR fluids flow in circular pipes with diameters of 10 and 15 mm and length of 300 mm were experimentally investigated with and without applying the magnetic field. An electromagnetic device was designed and manufactured in order to create a magnetic field induction for experiments. Throughout the experiments, the range of magnetic field induction value was B = 0-0.15 T, increased to 0.01 T. Based on the results obtained by the experimental study, it can be asserted that applying the magnetic field prompted an increase in the viscosity of MR fluids, leading to decreasing flow velocity. At B = 0.15 T, which is the highest value of the magnetic field, the flow velocity values dropped by 95%. Subsequently, the artificial neural networks algorithms are used in accordance with the obtained results to develop a correlation that clarifies the effect of the magnetic field on the flow velocity. The results show that the experimental and ANN models perform very similarly, and the ANN algorithm yields better results as a tool to predict the MR fluid flow behavior.

In this study, the effects of geometric properties such as baffle spacing, baffle cut, sealing strips, gaps between heat exchanger components, number of tubes and tube passes have been investigated...

Relations between effectiveness (e) and expense coefficients (ζ) were derived, and an economic simulation model was developed to simulate heat exchangers (HE) and HE networks (HEN) in all flow types for the first time. e values of parallel flow, counter flow, cross flow and all HEs under the condition of Cr = 0 were derived in terms of ζ, NTU (Number of Transfer Unit) and minimum heat capacities (Cmin). e values obtained from economic calculations were used for developing economic simulation model of HEs. Vectors including outlet temperatures and inlet temperatures of flows were obtained from static simulation to utilize in economic simulation model. Then, case studies were performed with counter flow HE and e values randomly determined in a sample HEN. Use (N), expense (P) and savings (E) of all HEs in a HEN were calculated easily by the way of linear equation systems without any complex processes, iterations, software and special hardware, in terms of both cold and hot flows properties by using economic simulation model.

The fluid flow and heat transfer characteristics and entropy generation of zirconia, ZrO2-water, nanofluid flow through a rectangular micro-channel are numerically investigated. The flow is considered under single-phase 3-D steady-state incompressible laminar flow conditions. The constant heat flux is applied to the bottom surface of micro-channel. The finite volume method is used to discretize the governing equations. As a result, the average Nusselt number decreases with increasing nanoparticle volume fraction, while the average Darcy friction factor is not affected. Moreover, the total entropy generation decreases with increase in nanoparticle volume fraction, while the Bejan number is almost not affected.

Exergetic and thermoeconomic analyses of a coal-fired power plant with 160 MW capacity where located in Turkey were performed. Specific Exergy Costing (SPECO) and Modified Productive Structure Analysis (MOPSA) methods were separately applied to the system to determine the unit exergy cost of electricity generated by the coal-fired plant. The differences of these methods were discussed. As a result, the exergy efficiency of coal-fired power plant is found to be 39.89%. The equipment having the highest improvement potential is determined as boiler. The unit specific exergy cost of electricity generated by the system obtained for SPECO and MOPSA thermoeconomic analysis methods are 12.14 US$/GJ and 14.06 US$/GJ, respectively. The unit specific exergy cost of electricity obtained by using MOPSA thermoeconomic method is the same as the one obtained by the overall cost-balance equation for the coal-fired power plant.

Faz değişim malzemeleri (FDM) enerji üretimi ve talebi arasındaki uyumsuzluğu azaltmak amacıyla ısıtma ve soğutma uygulamalarında yaygın olarak kullanılmaktadır. FDM’ler ayrıca ısıl sistemler içerisine uygulanarak sabit sıcaklık sağlar ve ısıl konforun artmasına vesile olurlar. İnsanoğlu tarafından üretilen tüm sistemlerden farklı olarak olası bir hasarın geri dönüşünün mümkün olmaması nedeniyle, insan vücudunun ısıl konfor koşulları çok daha önemlidir. Bu çalışmada itfaiyecinin ısıl konfor koşullarının arttırılması ve aşırı ısınma kaynaklı deri hasarlarının engellenmesi amacıyla tekstil kumaşı tabakaları içerisine faz değişim malzemesi yerleştirilmiştir. ANSYS-FLUENT paket programında zamana bağlı 1-boyutlu bir sayısal model geliştirilmiştir. Deri katmanları içerisindeki kan dolaşımından kaynaklı ısı transferi etkisini programda tanımlamak için kullanıcı-tanımlı-fonksiyon (UDF) oluşturulmuş ve programa aktarılmıştır. ANSYS-FLUENT paket programı içerisine tanımlanan kaynak terimlerinin uygunluğunu test etmek için öncelikle literatürden alınan basitleştirilmiş bir problem tekrarlanmıştır. Deri katmanları içerisindeki zamana bağlı sıcaklık değişimleri literatürden alınan sonuçlarla karşılaştırılmıştır. Modelin doğrulanmasından sonra ise itfaiyeci kıyafeti içerisinde FDM kullanımı farklı ısıl sınır koşulları için sayısal olarak incelenmiştir. En uzun süreli yangın etki durumunda 1. Derece ve 3. Derece yanık derinlikleri sırasıyla 5,29 mm ve 2,57 mm olarak belirlenmiştir. FDM’nin kumaş içerisine yerleştirilmesi malzemenin ısı depolama kapasitesini arttırmakta ve deri katmanlarının sıcaklık artışını engellemektedir. Mevcut tasarım ve çalışma koşullarında, 1 mm kalınlığında FDM içeren itfaiyeci kıyafetinin en uzun yangın etki senaryosunda dahi deri hasarını engellediği saptanmıştır., Phase change materials (PCMs) are widely used in heating and cooling applications to reduce the mismatch between the energy production and the demand. PCMs can also be incorporated into the thermal systems to maintain a constant temperature and conduce to increase the thermal comfort. Unlike any human-made thermal system, the thermal comfort of the human body is more crucial since a possible damage may not be recovered. In this study, PCM layers are incorporated into the textile fabric to increase the thermal comfort of a firefighter and protect the skin layers from the thermal burn due to overheating. A transient one-dimensional numerical model is developed in the ANSYS-FLUENT software. The effect of blood perfusion inside skin layers is simulated as an energy source term and defined into the software using user-defined-function (UDF). The validatity of the source term implentation into ANSYS-FLUENT is proven by repoducing a reduced model fom the literature. The predicted time-wise variations of the temperature of the body layers are compared with the ones which are taken from the literature. After the validation procedure, the usage of PCM inside a firefighter protective clothing is numerically investigated by varying the thermal boundary conditions acting on the coating. Results depict that, for the longest fire exposure duration the 1st-degree burn is effective for a depth of 5.29 mm and the 3rd-degree burn is observed for a depth of 2.57 mm. Implementing the PCM inside the clothing inhibits the temperature rise in skin layers and improves the heat storage capacity of the fabric. In the current design and working conditions, firefighter protective clothing with 1 mm of PCM layer prevents the skin burn, even for the longest fire exposure scenario.

Bimodal volcanic suites occur in both orogenic and anorogenic geotectonic settings. Although their formation can be attributed to either fractional crystallization from basaltic parents to felsic derivatives or partial melting of different sources, the origin of bimodal suites is still unclear. By reporting mineral chemistry, 40Ar/39Ar geochronology, elemental and Sr-Nd-Pb isotope geochemistry data, this study aims to investigate the genesis of bimodal basalt-dacite association from the Yukselen area located on the northern end of the Sulutas Volcanic Complex (Konya, Central Anatolia). The Yukselen area volcanic rocks are represented by basaltic lava flows, and dacitic dome with enclaves and pyroclastics. Basaltic flows and pyroclastic rocks are interlayered with the Neogene fluvio-lacustrine sedimentary units, while dacitic rocks cut the pre-Neogene basement in the area. A biotite separation from dacites yielded 40Ar/39Ar plateau age of 16.11 ± 0.18 Ma. On the other hand, a whole rock sample from basalts gave two plateau ages of 16.45 ± 0.76 Ma and 22.37 ± 0.65 Ma for the first steps and next steps, respectively. The investigated basalts are sodic alkaline, and characterized by ocean island basalt (OIB)-like anorogenic geochemical signatures. However, dacites are calc-alkaline and metaluminous, and carry geochemical signatures of orogenic adakites. Sr-Nd-Pb isotopic systematics suggest that the basalts were derived from an asthenospheric mantle source enriched by recycled crustal rocks. The dacites show more enriched Sr and Pb ratios and more depleted Nd ones relative to the basalts, which at the first glance might be attributed to crustal contamination of the associated basalts. However, trace element features of the dacites rule out cogenetic relationship between the two rock types, and point to an origin by melting of lower crust. On the other hand, enclaves share several elemental and isotopic characteristics with the dacites, and appear to be fragments of sub-volcanic intrusions closely related to the dacitic host magma. Based on the obtained geochemical data combined with the published geological and geophysical data, the investigated bimodal volcanic activity can be explained by slab break-off process in the convergence system between the African and Anatolian plates.

In the Central Pontides, Late Cretaceous-Eocene volcanic rocks prominently outcrop around Sinop-Samsun. The Late Cretaceous volcanites are represented by the Hamsaros volcanites near Sinop in the north and volcanic units in the Yemişliçay Formation around Alaçam-Dikmen-Durağan in the south. The Eocene volcanites are represented by the Tekkeköy Formation outcropping in a large area from Bafra to the East. 40Ar/39Ar geochronology, mineral- and whole-rock geochemistry of the (sub)volcanic units in the Yemişliçay Formation will be presented in this study. The Yemişliçay Formation volcanites include plagioclase (An50-70), clinopyroxene (augite-diopside), amphibole (mainly magnesio-hastingsite, rarely tschermakite) phenocrysts and opaque minerals. 40Ar/39Ar ages from the volcanites show that volcanic activity occurred two different time as Late Cretaceous (~71 Ma, inverse isochron age) and Eocene (~48 Ma, plateau age). The Late Cretaceous volcanites were considered as products of the volcanism contemporaneous with the deposition of the Yemişliçay Formation, but as shallow intrusions in this formation, the Eocene volcanites were interpreted to be continuation of volcanites of the Tekkeköy Formation. The Late Cretaceous volcanites are andesite/basaltic andesite and calc-alkaline, but the Eocene volcanites basalt/trachyandesite and shoshonitic in character. N-MORB-normalized trace element patterns of all the volcanites are characterized by strong enrichments in LILE (Rb, Ba, K and Sr), Th and LREE (La, Ce), prominent negative Nb-Ta-Ti and positive Pb anomalies, all characteristic for subduction-related volcanites. The shoshonitic samples possess relatively high Ndi (εNd: +4) and low Sri (0.704634) isotopes whereas calc-alkaline rocks have low Ndi (εNd: down to -3) and high Sri (0.705203-0.706956) isotopes. The obtained geochronological and geochemical data together with the published geological information reveal that the Yemişliçay Formation volcanites formed in a fore-arc setting in the Pontide magmatic arc., Orta Pontidlerde, Sinop-Samsun çevresinde Geç Kretase-Eosen yaşlı volkanik kayaçlar belirgin yüzlekler vermektedir. Geç Kretase volkanitleri, kuzeyde Sinop yakın civarında Hamsaros Volkanitleri, güneyde ise Alaçam-Dikmen-Durağan çevrelerinde Yemişliçay Formasyonu içindeki volkanik birimler ile temsil edilmektedir. Eosen volkanitleri, Bafra’dan başlayıp doğuya doğru geniş bir alanda yüzeyleyen Tekkeköy Formasyonu volkanitleri ile temsil edilir. Bu çalışmada, Yemişliçay Formasyonu içindeki (sub)volkanik birimlerin 40Ar/39Ar jeokronolojisi, mineral- ve tüm-kayaç jeokimyası sunulacaktır. Yemişliçay Formasyonu volkanitleri plajiyoklas (An50-70), klinopiroksen (ojit-diyopsit), amfibol (magnezyo-hastingsit, nadiren çermakit) fenokristalleri ve opak mineraller içermektedir. Volkanitlerden elde edilen 40Ar/39Ar yaşları, volkanik faaliyetin Geç Kretase (~71 Myıl, ters izokron yaşı) ve Eosen (~48 Myıl, plato yaşı) olmak üzere iki ayrı dönemde etkili olduğunu göstermektedir. Geç Kretase volkanitlerinin Yemişliçay Formasyonuyla eş yaşlı bir volkanizmanın ürünü olduğu düşünülürken, bu formasyonu sığ intrüzyonlar olarak kesen Eosen yaşlı volkanitler Tekkeköy Formasyonu volkanitlerinin bir eşleniği olarak yorumlanmıştır. Geç Kretase volkanitleri andezit/bazaltik andezit bileşiminde ve kalk-alkalen, Eosen volkanitleri bazalt/trakiandezit bileşiminde ve şoşonitik karakterlidir. İncelenen tüm örneklerin N-MORB’a göre normalleştirilmiş iz element desenleri, yitimle ilişkili volkanitler için tipik olan, BİYE (Rb, Ba, K, Sr), Th ve HNTE (La, Ce) zenginleşmesi, belirgin negatif Nb-Ta-Ti ve pozitif Pb anomalileri göstermektedir. Şoşonitik kayaçlar göreceli olarak yüksek Ndi (εNd: +4) ve düşük Sri (0.704634) izotopları ile temsil edilirken, kalk-alkalen kayaçlar tersine düşük Ndi (εNd: -3’e kadar) ve yüksek Sri (0.705203-0.706956) değerlerine sahiptir. Elde edilen jeokronolojik ve jeokimyasal veriler, yayınlanmış jeolojik bilgiler ile beraber değerlendirildiğinde, Yemişliçay Formasyonu volkanitlerinin Pontid magmatik yayında bir yay-önü ortamda oluştuğuna işaret etmektedir.

WOS: 000504526900001 Subduction-related environments are complex geological sites where various magmas occur in close spatial and temporal association. To better understand geological processes led to the generation of compositionally distinct magmas, we need to know the origin and evolution of magmas formed in these settings. Our purpose here is to determine the genesis of the Sulutas Volcanic Complex (SVC), located near Konya (Central Anatolia, Turkey) and to understand its relation to the subduction-related processes. Based on a detailed field study of the SVC, we present here Ar-Ar geochronology, mineral chemistry, whole-rock major, trace element and Sr-Nd-Pb isotope data. The SVC can be subdivided into three distinct chemical groups. The oldest group (similar to 16 Ma) characterized by bimodal association is composed of Na-alkaline basaltic rocks and adakitic dacite. The Na-alkaline basaltic rocks were derived from an OIB-like enriched asthenospheric mantle source, but the adakitic dacites from a mafic lower crust. Geochemistry of potassic lamprophyres (similar to 13.5 to 12.5 Ma), the second group, can be best explained by melting of a depleted lithospheric mantle source that was metasomatized by slab-derived sediment melts. This metasomatic component generated phlogopite-rich veins in their source. The youngest group (similar to 13 to 11 Ma), high-K calc-alkaline rocks (HKCA) is composed of basalt, andesite and mafic enclave-bearing dacite. Parental magmas to the HKCA are consistent with the derivation from a lithospheric mantle source metasomatized by fluid-like subduction components. Geochemical variations in the HKCA can be explained by magmatic processes (e.g. assimilation-fractional crystallization for basalt and dacite, fractional crystallization for andesite) from a common parental magma similar to the mafic enclave. The SVC composed of orogenic and anorogenic rocks occurred in a graben-like extensional basin in the Central Anatolia, and this extensional tectonics is related to the retreating subduction zone along the Cyprus arc within the convergence system of the African-Eurasian plates during Miocene. Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [113Y415]; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under Grant No. 113Y415. The authors gratefully thank to the TUBITAK for financial support.

The Plio-Quaternary associated with the Karapinar-Karacadag Volcanic Complex (Konya-Central Anatolia) involves dacitic-andesitic domes/flows and basaltic lava flows, and their pyroclastic equivalents (e.g., base surges, ash-block flows, scoria and ash falls). The present study deals with examining the new mineral chemistry and textural investigations concerning the Karapinar mildly alkaline to calc-alkaline basalts and Karacadag calc-alkaline intermediate rocks predominant in Central Anatolia. Application of amphibole thermobarometry and clinopyroxene-liquid thermobarometry to the Karacadag andesites has yielded temperature estimates in the range of 855–1198 °C and pressure estimates of a range of 1.34–5.95 kbar, indicating the presence of a magma chamber lying at the middle-upper crust for intermediate unit. Temperature and pressure estimate’s as drawn from pyroxene, related to the Karapinar basalts are in the range of 1173–1251 °C and 8.9–12.2 kbar, highlighting persistence of crystallization at the crust base level. Some of the andesites, particularly the enclave bearing andesites, enclose spongy cellular, fine-coarse sieved, oscillatory and inverse zoned plagioclase, standing as the evidence of open system process. Besides, the Karapinar basalts include abundant quartz and biotite xenocrysts. There is no physical contact between the Karacadag andesites and the Karapinar basalts surrounding the area, but the relating geochemical and textural properties appear to indicate that the Quaternary Karapinar basalts prove to be evidently assimilated from Pliocene associated with the Karacadag andesites.

This paper presents the comparison of specific exergy costing (SPECO) and modified productive structure analysis (MOPSA) method to test their abilities on costing of exergy destruction. MOPSA method is applied to a combined supercritical CO2 regenerative cycle and organic Rankine cycle using zeotropic mixtures for gas turbine waste heat recovery system. The results obtained with applying SPECO method to the system are taken from literature. The exergy destruction cost rate of overall system is obtained to be $86.08/h and $1,113.13/h for MOPSA and SPECO methods, respectively. The exergoeconomic factor of overall system is found to be 31.88% for SPECO method, while this value is found to be 85.82% for MOPSA method. The obtained results with applying MOPSA method for exergy destruction cost rate are significantly lower and more consistent compared to the results obtained by SPECO method.

To enhance energy absorption of photovoltaics, several etching experiments with various parameters were performed. In addition, an Artificial Neural Network (ANN) simulation was utilized to predict chemical nano etching parameters such as masking and etching durations for Silicon (Si) solar cell applications to reach minimum surface reflectance in an optimum etching duration. Experiments were performed with different masking and etching durations to determine the characteristics of surface reflectance of micro textured n-type single crystalline Si wafers in 25mmx25mm width and 300 µm thickness to provide training data for ANN. For this purpose, solutions with identic properties including Ag nanoparticles were applied with different application durations on the surfaces of n-type single crystalline Si wafers to cover partially the Si surfaces with Ag nano-particles at masking step. After, partially masked Si surfaces were exposed to chemical nano etching to develop nano-sized porous structures under different etching durations in an identic acidic etching solution. For the etching of Si wafers, 32 masking and etching processes were performed. Reflectance measurements and SEM images were evaluated to determine the optimum etching duration resulting the best surface quality with minimum reflectance. In addition, reflectance values were utilized as input data for training, testing and validation steps of developed ANN. In the ANN simulation, 70% of reflectance values were used as training, 15% of reflectance values were used as validation and 15% of reflectance values were used to test data in the ANN. Consequently, surface reflectance values under different masking and etching durations were predicted with the new parameter set by using the trained ANN with a success level above 99%. © 2018 Elsevier B.V.

Motivation to learn English plays a curial role in students’ performance, achievement and attendance. This indicates that instructors should put effort to motivate their students. The aim of this article is to find out the instructional practices that motivate students to learn English most. For that reason, ARCS motivational model (Keller, 2010) was applied throughout ten weeks. By means of this model several motivational tactics and strategies were inserted to the classroom instruction and students were asked to write weekly comments about them at the end of each week. Using a qualitative research design, comments from 30 students were collected and analyzed. As a result, we have reached the conclusion that students’ comments can be evaluated under two headings. The first heading includes comments related to classroom instruction and the second one is related to instructor behavior and we tried to explain it in detail in this article.

An artificial neural network (ANN) simulation was utilized to determine the lapping parameters such as rotation speed, lapping duration and lapping pressure under a constant slurry supply for n-type crystalline Silicon (c-Si) wafers. Experiments were done with a Logitech PM5 lapping and polishing machine to obtain input data and target data for training, testing and validation of ANN. Lapping operation had five main parameters affecting surface quality: rotation speed, lapping duration, lapping pressure, flowrate of abrasive slurry and particle size in abrasive slurry. However, in this study slurry flowrate was assumed constant due the researches performed before. 218 lapping operations were performed with different values of the selected parameters and new lapping parameters were derived for different lapping conditions to achieve the best surface quality by using an ANN. In this study, wafers in 400 µm thickness cut under identical conditions from n-type single c-Si ingot in a STX 1202 DWS cutting machine were employed. Surface roughness (R a ) values were measured three times from different points of the wafers after lapping with a contact type surface roughness measurement tool using a microscopic scale stylus profiler (SP). In ANN simulation 70% of R a values were utilized for training, 15% of R a values were utilized for validation and 15% of R a values were utilized for test data. Results obtained from ANN simulation validated with a success above 99%.

Currently, cooling of photovoltaic (PV) panels, a significant issue due the negative effect on panel efficiency, is subjected to intensive researches. For this purpose, numerous researches on cooling methods are performed to keep the panel efficiencies around the design values. In this study, a comprehensive literature review was presented to give the status of the technological improvement in cooling options. In addition, strong and weak aspects of the studies were discussed, and advantageous methods were emphasized for the further application of PV panels. Finally, future perspective of PV panel cooling studies was explored with proper cooling options in lower operating temperatures for higher operation efficiencies.