239 research outputs found
Modeling of carbon credit prices using regime switching approach
No full textSemra Ağralı (MEF Author)In this study, we analyze the price dynamics of carbon certificates that are traded under the European Union's Emissions Trading System (EU-ETS). With the aim of investigating the joint relations among carbon, electricity, and fuel prices, we model historical prices using several methods and incorporating structural changes, such as econometric time series, regime switching, and multivariate vector autoregression models. We compare the results of the structural model with the results of traditional Markov switching and autoregressive models with breaks and present performance analysis based on the mean average percentage error, root mean squared error, and coefficient of determination. According to these performance tests, models with regimes outperform the approaches where breaks are defined using ex ante dummy variables. Moreover, we conclude that among regime switching models, univariate models are better than multivariate counterparts for modeling carbon price series for the analysis of both in-sample and out-of-samples. Published by AIP Publishing.WOS:0004372803000422-s2.0-85049234517Science Citation Index Expanded - Social Sciences Citation IndexArticleUluslararası işbirliği ile yapılmayan - HAYIRMayısYÖK - 2017-1
Nonlinear benefit-cost optimization-based selection of insulation material and window type: A case study in Turkey
No full textSemra Ağralı (MEF Author)In this study, we maximize the energy savings of a hypothetical household by choosing an optimal insulation material with its optimal thickness and also the optimal window type. We develop a nonlinear mixed integer optimization model that maximizes the net present value of the benefits obtained by insulation over the lifespan of the house. Savings are calculated based on the gains from the electricity usage for air conditioning during cooling-required days and the fuel usage for heaters in heating-required days. The heat transfer calculations consider conductive, convective, and radiative components simultaneously. The optimization model takes the climate conditions of the region where the house is located, the consumer's desired indoor temperature, and the properties of the insulation options; then, it returns a combination of selected insulation materials with its optimum thickness and window type as output. We applied the optimization model developed to hypothetical houses in four different climatic regions of Turkey for different lifespans. For all reasonable lifespans, the model choses stonewool as the ideal insulation material. For high interest rates, single windows or double-glazed windows are preferable, but as the interest rate decreases and the net present value of the energy-savings increases, the model prefers triple-glazed windows as the ideal material. Erzurum, a city in climatic region 4, characterized by very cold winters and cool summers, was found to require the highest optimum insulation thickness, and the economic return resulting from the above-mentioned energy-saving actions was also found to be the highest in the case of Erzurum. In all the regions, the energy-saving investments were found to be feasible via applying the feasibility assessment techniques of net present value and payback period. The model developed in this study is applicable to any household as long as the required input data are available. Published by AIP Publishing.WOS:0004190002000332-s2.0-85038567088Science Citation Index ExpandedArticleUluslararası işbirliği ile yapılmayan - HAYIRKasımYÖK - 2017-1
Energy Investment Planning at a Private Company: A Mathematical Programming-Based Model and Its Application in Turkey
No full textSemra Ağralı (MEF Author)We consider a mid-sized private electricity generating company that plans to enter the market that is partially regulated. There is a cap and trade system in operation in the industry. There are nine possible power plant types that the company considers to invest on through a planning horizon. Some of these plants may include a carbon capture and storage technology. We develop a stochastic mixed-integer linear program for this problem where the objective is to maximize the expected net present value of the profit obtained. We include restrictions on the maximum and minimum possible amount of investment for every type of investment option. We also enforce market share conditions such that the percentage of the total investments of the company over the total installed capacity of the country stay between upper and lower bounds. Moreover, in order to distribute the investment risk, the percentage of each type of power plant investment is restricted by some upper bound. We tested the model for a hypothetical company operating in Turkey. The results show that the model is suitable to be used for determining the investment strategy of the company.WOS:0004132478000032-s2.0-85037056874Science Citation Index Expanded - Social Sciences Citation IndexArticleUluslararası işbirliği ile yapılmayan - HAYIRKasımYÖK - 2017-1
An optimization model for carbon capture & storage/utilization vs. carbon trading: A case study of fossil-fired power plants in Turkey
Get PDFSemra Ağralı (MEF Author)We consider fossil-fired power plants that operate in an environment where a cap and trade system is in operation. These plants need to choose between carbon capture and storage (CCS), carbon capture and utilization (CCU), or carbon trading in order to obey emissions limits enforced by the government. We develop a mixed-integer programming model that decides on the capacities of carbon capture units, if it is optimal to install them, the transportation network that needs to be built for transporting the carbon captured, and the locations of storage sites, if they are decided to be built. Main restrictions on the system are the minimum and maximum capacities of the different parts of the pipeline network, the amount of carbon that can be sold to companies for utilization, and the capacities on the storage sites. Under these restrictions, the model aims to minimize the net present value of the sum of the costs associated with installation and operation of the carbon capture unit and the transportation of carbon, the storage cost in case of CCS, the cost (or revenue) that results from the emissions trading system, and finally the negative revenue of selling the carbon to other entities for utilization. We implement the model on General Algebraic Modeling System (GAMS) by using data associated with two coal-fired power plants located in different regions of Turkey. We choose enhanced oil recovery (EOR) as the process in which carbon would be utilized. The results show that CCU is preferable to CCS as long as there is sufficient demand in the EOR market. The distance between the location of emission and location of utilization/storage, and the capacity limits on the pipes are an important factor in deciding between carbon capture and carbon trading. At carbon prices over $15/ton, carbon capture becomes preferable to carbon trading. These results show that as far as Turkey is concerned, CCU should be prioritized as a means of reducing nationwide carbon emissions in an environmentally and economically rewarding manner. The model developed in this study is generic, and it can be applied to any industry at any location, as long as the required inputs are available. (C) 2018 Elsevier Ltd. All rights reserved.WOS:0004307847000312-s2.0-8504410277029574208Science Citation Index ExpandedArticleUluslararası işbirliği ile yapılmayan - HAYIRHaziranYÖK - 2017-1
Solution-focused therapy for self-handicapping behaviors among Turkish high school students
No full textPurpose: This randomized controlled trial examined solution-focused brief therapy (SFBT) effectiveness for reducing self-handicapping behaviors among Turkish high school students during the 2018-2019 academic year. Methods: Forty-five students (aged 14-16) scoring above 1 SD on the Self-Handicapping Scale were randomly assigned to SFBT intervention (n = 15), placebo control (n = 15), or waiting list groups (n = 15). The experimental group received 6 weekly 60-min SFBT sessions. Assessments occurred at pretest, posttest, and 6-week follow-up. Results: No significant between-group differences emerged at posttest (chi(2) = 3.588, p > .05). However, significant differences favoring experimental group appeared at follow-up (chi(2 )= 6.212, p < .05), particularly versus placebo (U = 34.50, p = .016, r = .46). Within-group analyses showed significant reductions for experimental group from pretest to follow-up (Z = -2.555, p < .05, r = .74). Discussion: SFBT effectively reduced self-handicapping with delayed benefits, supporting strength-based school approaches for at-risk adolescents
Semra Ertan - Word and Body as Instruments of Socio-Political Protest
Get PDFThe bachelor thesis is dedicated to Semra Ertan, a poet and activist of Turkish origin, who lived since the 1970s with her parents in Germany, who worked there as guest workers (Gastarbeiter). In 1982, Ertan publicly set herself on fire in Hamburg. Although the publication of her poetry collection in 2020 aroused interest in both Germany and Turkey in her work and life's destiny, academic research is still lacking. The thesis aims to present the person and work of Semra Ertan as a topic that has not yet been researched. The student will first outline the development of the situation of the Turkish guest workers in Germany since the bilateral agreement between Germany and Turkey, introduce the author herself, and in the main part of the thesis will analyze her poems as such and the relationship between Semra Ertan's poems and her self-immolation. Thesis will try to answer the question of whether and how aspects of the author's life can be seen in her poems. To answer this question, in addition to the thematic analysis of the poems the approaches of the social contextual studies of literature as outlined by Josef Šebek will be used.Bakalářská práce je věnována Semře Ertan, básnířce a aktivistce tureckého původu, která žila od sedmdesátých let 20. století s rodiči v Německu, kteří zde pracovali jako hostující dělníci (Gastarbeiter). V roce 1982 se Ertan v Hamburku veřejně upálila. Přestože vydání její básnické sbírky v roce 2020 vzbudilo v Německu i v Turecku zájem o její tvorbu i životní osudy, odborné zpracování dosud chybí. Práce si klade za cíl představit osobu a dílo Semry Ertan jakožto téma v akademickém prostředí doposud nezpracované. Studentka nejprve nastíní vývoj situace tureckých pracovních sil v Německu od uzavření bilaterální smlouvy mezi SRN a Tureckem, představí samotnou autorku a v hlavní části práce pak bude analyzovat její básně jako takové a také vztah mezi básněmi Semry Ertan a jejím sebeupálením. Pokusí se odpovědět na otázku, zda a jakým způsobem lze v básních spatřovat aspekty autorčina života. K zodpovězení této otázky bude vedle tematické analýzy básní využívat přístupy sociálně kontextového studia literatury, jak je nastiňuje Josef Šebek.Department of Middle Eastern StudiesKatedra Blízkého východuFilozofická fakultaFaculty of Art
Non-legal savings in protection of public receivables and cancellation of savings
Get PDFKamu alacaklarının tahsilinde egemenlik gücünü kullanan devlet, kamu alacaklarını
hızlı ve etkin bir şekilde tahsil etmek için bir takım önlemler almaktadır. Bu
önlemlerden birisi de 6183 Sayılı AATUHK kanunda da açıklandığı gibi bazı
tasarrufların hükümsüz sayılmasını içermektedir. Kamu alacağının koruma
yöntemlerinden biri olan bu yöntem, kamu alacağının tahsilinde cebren
uygulanabileceği gibi yine alacağın tahsilinde bu alacağı müşkül kılabilecek özelliği
bulunan bazı tasarruf edinişlerini de göz önüne alarak geçersiz sayabilmektedir.
Kamu alacakları tahsil edilirken bir koruma metodu olarak kullanılan bu yöntem, diğer
koruma yöntemlerinde olduğu gibi ortak amaca hizmet etmekte; borçluların
alacaklılardan mal kaçırmasını engellemek ve kötü niyetli olarak yapmış oldukları
hukuki işlemlerin hükümsüz sayılarak, alacağın temin edilmesini sağlamaktır.
Bu çalışma üç bölümden oluşmaktadır. Birinci bölümde kamu alacakları ile ilgili genel
açıklamalara yer verilmiştir. İkinci bölümde kamu alacaklarını korumaya yönelik
metotlar incelenmiştir. Üçüncü bölümde tasarrufun iptali davası ele alınmış olup iptal
davasında taraf sıfatı, kanun yolları, yargılama harç ve giderleri tasarrufun iptali
davasının sonuçları incelenip mahkeme kararları örnekleri ile sonuçlandırılmıştır.The state, which uses sovereign power in the collection of public receivables, takes
some measures for the rapid and effective collection of public receivables. One of these
measures includes the deprivation of certain savings as explained in the Law No. 6183
of the AATUHK. This method, which is one of the protection methods of the public
receivable, may be applied by force in the collection of the public receivable, and may
also be deemed invalid by taking into account some of the savings acquisitions that may
make this receivable in the collection of the receivable.
This method, which is used as a protection method when collecting public receivables,
serves the same purpose as other protection methods; to prevent the borrowers from
smuggling goods and to ensure that the receivables are deemed null and void.
This study consists of three parts. In the first part, general explanations about public
receivables are given. In the second part, methods for protecting public receivables are
examined. In the third section, the cancellation of the case was discussed and in the case
of cancellation, the title of party, the remedies, the court fees and expenses were
examined and the results of the cancellation of the case were examined and finalized
with examples of court decisions
In vitro evaluation of antileishmanial activity of some endemic and non-endemic plants (extracts) against leishmania tropica promastigotes
No full textSağlık Bilimleri Enstitüsü, Parazitoloji Ana Bilim DalıÖZET Bu araştırmada, halen kullanımda olan antileishmanial ilaçlara daha etkili alternatifler bulmak için, in vitro koşullarda 30 bitki ekstraktının aktivitesi araştırılmıştır. Çalışmamızda Şanlıurfa ve Adana yörelerinden elde edilen 8 farklı Leishmania tropica susu kullanılmıştır. Bitki ekstraktlannın L. tropica promastigotlan üzerine dördüncü gün sonunda olan inhibitor etkilerinin araştırıldığı çalışmamızda, promastigot proliferasyon düzeyi hemositometri yöntemiyle sayılmıştır. Bitki ekstraktlannın L. tropica suşlarına olan aktivitelerinde önemli bir fark bulunamamıştır. Sivas yöresinden toplanmış 26 bitkiden elde edilen 30 metil alkol ekstraktı, 8 farklı L. tropica susuna karşı çalışılmıştır. Bu ekstraklardan 16'sınm IC50 konsantrasyonları, Glukantim®'le kıyaslandığında antileishmanial aktivite yönünden etkin bulunmuştur. Çalıştığımız bitki ekstraktlan ile aynı konsantrasyondaki Glukantim® deneylerinin sonucunda, Glukantim®'in IC50 değeri 2 mg/ml olarak saptanmıştır. Farklı 6 familyadan 26 bitkinin çalışıldığı bu araştırmada en etkili türler sırası ile, Allium scorodoprasum ssp.' rotundum (IC50 0,1 mg/ml), Allium nevsehirense - soğanı (IC50 0,3 mg/ml), Tanacetum balsamita ssp. balsamita (IC50 0,4 mg/ml), Tanacetum parthenium -çiçekleri (IC50 0,4 mg/ml), Pimpinella anicetum (IC50 0,4 mg/ml), Tanacetum densum ssp. amani (IC50 0,4 mg/ml), Origanum acutidens (IC50 0,4 mg/ml), Thymus pectinatus var. pectinatus (IC50 0,5 mg/ml), Tanacetum densum ssp. sivasicum (IC50 0,7 mg/ml), Tanacetum parthenium -yaprak ve dallan (IC50 0,7 mg/ml), Allium sivasicum -soğanı (IC50 0,9 mg/ml), Salvia ruselli (IC50 0,9 mg/ml), Allium nevsehirense -toprak üstü kısımları (IC50 1 mg/ml), Allium sivasicum -toprak üstü kısımlan (IC50 1 mg/ml), Salvia cryptantha (IC50 1 mg/ml), Allium dictyoprasum (IC50 2 mg/ml) olmuştur. Glukantim®' le kıyaslandığında antileishmanial aktivite saptanamayanlar ise, Salvia virgata (IC50 2 mg/ml), Achillea teretifolia (IC50 3 mg/ml), Salvia candidissima (IC50 3 mg/ml), Helichrysum chionophylum -yaprak ve dalları (IC50 3 mg/ml), Helichrysum arenarum ssp. aucheri (IC50 4 mg/ml), Helichrysum chionophylum - 92çiçekleri (IC50 4 mg/ml), Astragalus densifolius (IC50 5 mg/ml), Helichrysum plicatum ssp. plicatum (IC50 5 mg/ml), Pelargonium endlicherianum (IC50 5 mg/ml), Astragalus melanophourius (IC50 6 mg/ml), Thymus sipyleus ssp. sipyleus (IC50 6 mg/ml), Helichrysum noeanum (IC50 6 mg/ml), Thymus sipyleus ssp. rosulens (IC50 7 mg/ml), Salvia syriaca (IC50 7 mg/ml) olarak bulunmuştur. 93SUMMARY The present work was designed to study the in vitro susceptibility of exctracts of 30 plants in order to determine more effective alternatives to antileishmanial drugs which currently being used for treatment. Eight different Leishmania tropica strains were used in this study and they were collected from the region of Adana and Şanlıurfa. The inhibitor effects of plant exctracts on proliferation of L. tropica promastigotes on day fourth was evaluated by using of haemocytometer tecnique. There was no significant different effects of plant exctracts on activities among L. tropica strains. Thirty methil alcohol exctracts which obtained from 26 different plants that were harvested in the region of Sivas, were studied against to 8 different L. tropica strains. Sixteen of those exctracts in the IC50 concentrations were found that they have an antileishmanial activity compared to Glucantime®. Glucantime® IC50 value was found as 2 mg/ml when it was compared to same concentration of plant excracts. In this study, 26 plants were studied in the 6 different family and the most effectives strains were as follow: Allium scorodoprasum ssp. rotundum (IC50 0,1 mg/ml), Allium nevsehirense -bulb (IC50 0,3 mg/ml), Tanacetum balsamita ssp. balsamita (IC50 0,4 mg/ml), Tanacetum parthenium -flowers (IC50 0,4 mg/ml), Pimpinella anicetum (IC50 0,4 mg/ml), Tanacetum densum ssp. amani (IC50 0,4 mg/ml), Origanum acutidens (IC50 0,4 mg/ml), Thymus pectinatus var. pectinatus (IC50 0,5 mg/ml), Tanacetum densum ssp. sivasicum (IC50 0,7 mg/ml), Tanacetum parthenium -aqueous and chloroform parts (IC50 0,7 mg/ml), Allium sivasicum -bulb (IC50 0,9 mg/ml), Salvia ruselli (IC50 0,9 mg/ml), Allium nevsehirense -aerial (IC50 1 mg/ml), Allium sivasicum -aerial (IC50 1 mg/ml), Salvia cryptantha (IC50 1 mg/ml), Allium dictyoprasum (IC50 2 mg/ml), respectively. Those plants did not show antileihmanial activity when they were compared to Glukantim® were as follow: Salvia virgata (IC50 2 mg/ml), Achillea teretifolia (IC50 3 mg/ml), Salvia candidissima (IC50 3 mg/ml), Helichrysum chionophylum - aqueous and chloroform parts (IC50 3 mg/ml), Helichrysum arenarum ssp. aucheri (IC50 4 mg/ml), Helichrysum chionophylum -flowers (IC50 4 mg/ml), Astragalus densifolius (IC50 5 94mg/ml), Helichrysum plicatum ssp. plicatum (IC50 5 mg/ml), Pelargonium endlicherianum (IC50 5 mg/ml), Astragalus melanophourius (IC50 6 mg/ml), Thymus sipyleus ssp. sipyleus (IC50 6 mg/ml), Helichrysum noeanum (IC50 6 mg/ml), Thymus sipyleus ssp. rosulens (IC50 7 mg/ml), Sa/v/a syriaca (IC50 7 mg/ml). 9
Okul Öncesi Öğretmenlerinin Mesleki Etik Davranışları Algılama Düzeylerinin ve Etik İkilemleri Çözümlemelerinin İncelenmesi
No full textThis study aimed at determining pre-school teachers perception levels regarding professional ethical conducts and examining how they could generate solutions for ethical dilemmas. In this context, the research group consisted of 205 pre-school teachers working in 8 central districts of Ankara Province (Çankaya, Yenimahalle, Etimesgut, Keçiören, Sincan, Mamak, Altındağ, and Gölbaşı) in the spring semester of the 2013-2014 academic year.A mixed design involving quantitative and qualitative methods together was employed. A 6-question Personal Information Form prepared by the researcher was used for determining the demographic characteristics of the research participants. Quantitative data of the study were collected via the Scale for Pre-School Teacher s Ethical Conducts (SPTEC) developed by Sakin (2007) in order to measure the pre-school teachers ethical conducts.Bu araştırma, okul öncesi öğretmenlerinin mesleki etik davranışları algılama düzeylerini belirlemek ve etik ikilemlere nasıl çözümler üreteceklerini incelemek amacıyla yapılmıştır. Bu kapsamda araştırmanın çalışma grubunu, 2013-2014 eğitim-öğretim yılı bahar döneminde Ankara nın merkez 8 ilçesinde (Çankaya, Yenimahalle, Etimesgut, Keçiören, Sincan, Mamak, Altındağ ve Gölbaşı) görev yapan 205 okul öncesi öğretmeni oluşturmuştur.Araştırmanın deseni nicel ve nitel yöntemlerin bir arada kullanıldığı, karma desendir. Örnekleme ait demografik özellikleri belirlemek amacıyla, araştırmacı tarafından hazırlanan 6 soruluk Kişisel Bilgi Formu kullanılmıştır. Okul öncesi öğretmeninin etik davranışlarının ölçülmesinde, Sakin (2007) tarafından geliştirilen, Okul Öncesi Öğretmeninin Etik Davranışları Ölçeği (OÖEDÖ) kullanılarak araştırmanın nicel verileri toplanmıştır. Bu sonuçlara göre öğretmenlerden etik algıları yüksek olan grup üst grup, düşük olan grup ise alt grup olarak belirlenmiştir
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