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Yayın Thermal quenching of thermoluminescence in quartz samples of various origins(Univ Agean, Dept Mediterranean Stud, 2010) Subedi, Bhagawan; Afouxenidis, Dimitrios; Polymeris, George S.; Bakoglidis, Konstantinos D.; Raptis, Spyridoula; Tsirliganis, Nestor C.; Kitis, GeorgeThe effect of thermal quenching plays an important role in the thermoluminescence (TL) of quartz on which many applications of TL are based. In present work it is investigated that the thermal quenching parameters i.e. the activation energy W and the dimensionless parameter C, are more or less the same for every kind of quartzes or sample dependent on strong external treatment like a high temperature annealing. This preliminary investigation of seven quartz samples of different origin showed that the thermal quenching parameters W and C are common (universal) for most of the quartz samples.Yayın Preliminary TL and OSL investigations of obsidian samples(Univ Agean, Dept Mediterranean Stud, 2010) Polymeris, George S.; Gogou, D.; Afouxenidis, Dimitrios; Rapti, Sofia; Tsirliganis, Nestor C.; Kitis, GeorgeObsidian is a volcaniclastic mineral extremely hard to break, which was used in prehistoric Greece (and elsewhere in the World), in order to provide tools, weapons, knives and arrowheads. The present work aims to characterize this extremely precious tool stone by using both thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques and investigate its potential use for luminescence dating purposes. Basic TL and OSL properties, such as TL and OSL thermal and optical stability, repeatability, TL and LM-OSL glow curve shape and mainly the linearity of the TL and OSL signals as a function of beta dose were investigated. Artificially irradiated samples indicate all promising luminescence features, such as the 110 degrees C TL peak and dose response sub-linearity for intermediate doses, quick and effective bleaching all over the entire TL glow curve, along with quite linear CW-OSL dose response for doses larger than 5 Gy. The lack of predose sensitisation indicates the suitability of the material for single aliquot measurements. Furthermore, several features provide indications that the signal does not relate to quartz, but in fact to other silicates. Unfortunately, both lack of bleaching ability for NIL signal, along with a peculiar shape of NOSL, provide major difficulties in dating applications.Yayın Location and determinants of productivity: The case of the manufacturing industry in Turkey(M E Sharpe Inc, 2011-11-01) Falcıoğlu, PınarDiscussions in this paper are based on arguments from the geography, economic, and management literatures suggesting that exploring the spatial reasons for productivity in Turkey became significantly important after Turkey became a candidate country. The aim of this paper is to complement the findings of the studies on productivity differences in Turkey's manufacturing industry by exploring the spatial determinants of productivity at the regional level. The discussion is based on an econometric analysis for the years between 1980 and 2000. The results suggest that related variety, proximity to core areas, high wages, and capital intensity contribute to regional productivity.Yayın TL and OSL response of turquoise for dosimetric application(University of Aegean, 2010) Subedi, Bhagawan; Afouxenidis, Dimitrios; Polymeris, George S.; Tsirliganis, Nestor C.; Paraskevopoulos, Konstantinos M.; Kitis, GeorgeTurquoise is one of the amongst first gem stones used in jewelry and possessing cultural value since 2000 BC (at least). This work attempts characterize this stone scientifically using both thermally (TL) and optically stimulated luminescence (OSL) techniques. The experimental investigation included 1) the study of the natural TL and OSL signals, 2) the reproducibility of TL sensitivity over repeated irradiation and TL readout cycles, 3) dependence of sensitivity on annealing temperatures and 4) the TL and OSL dose response curves. The potential use of the TL and OSL techniques in determination of provenance, accidental dosimetry and probably to authenticity and dating purposes are then discussed.Yayın REITs, Growth Options and Beta(Springer New York LLC, 2016-11-08) Tırtıroğlu, Doğan; Nguyen, Thu Ha; Tırtıroǧlu, Ercan; Wee, TanchengAre REITs income stocks, only? Following Myers (1977) and Bernardo et al. (2007), we examine empirically REITs’ unlevered betas, betas of growth options, betas of assets-in-place and the difference between the latter two in detail for 1983–2012, and also for three sequential, distinct, and mutually-exclusive REIT sub-periods. We find that, (i) the betas of growth options are larger than those of assets-in-place, (ii) there are differences in these betas across Equity REITs’ sub-sectors and sub-periods, (iii) REITs with a high growth profile tend to employ more short-term debt and are mainly listed on NASDAQ, and (iv) the Global Financial Crisis has influenced considerably the beta estimates across all sub-sectors and REIT types. These findings raise a question mark about the ‘income stock, only’ description of REITs. Our findings have important implications for the cost of capital of REITs and their capital budgeting practices. We discuss them, when appropriate, with numerical examples.Yayın Luminescence dating of prehistoric site of smintheion (Gulpinar) in NW Turkey(Univ Agean, Dept Mediterranean Stud, 2010) Güneç Kıyak, Nafiye; Takaoğlu, Turan; Erginal, Ahmet Evren; Özcan, HalilThis study aims to place the prehistoric settlement of Smintheion in northwestern Turkey in its temporal setting on the basis of the dating of the quartz from pottery and sediments collected from the site employing Optically Stimulated Luminescence and Thermoluminescence techniques. The site belongs to the problematic Middle Chalcolithic period in western Anatolia. This period represents a cultural upheaval in western Anatolia as it has a completely different material culture when compared to that of the preceding Early Chalcolithic period. The pottery and sediment samples were collected from two different locations of the Middle Chalcolithic settlement at Smintheion for dating study. The fact that this examined settlement is represented by a single cultural level provides an opportunity to obtain secure and reliable dates for the settlement. Results of this study show that the site can be dated to a period between 4800 and 4500 B.C.Yayın Investigation of the OSL signal from very deep traps in natural quartz(Univ Agean, Dept Mediterranean Stud, 2010) Kitis, George; Güneç Kıyak, Nafiye; Polymeris, George S.; Pagonis, VasilisIt has been recently reported by several studies that a thermally transferred optically stimulated luminescence (TT-OSL) signal from quartz grains can be used to extend the dating range for quartz samples. The TT-OSL signals are believed to consist of a recuperated OSL (ReOSL) component and a basic-transferred OSL (BT-OSL) component. In the present work the TT-OSL signals from several types of unfired quartz samples were studied. A special protocol was used, which allowed the measure the OSL from very deep traps (VDT) as a function of the OSL stimulation temperature. It was found that all quartz samples exhibit TT-OSL signals, which are depended on sample and on the OSL stimulation temperature. The activation energy of the process was evaluated and the influences of the TT-OSL on the ReOSL dating protocol are discussed.Yayın Turkey and Eurasia: Frontiers of a new geographic imagination(Omer Academic Publ House, 2009-03) Aras, Bülent; Fidan, HakanTurkey has adopted a new course in foreign policy toward Eurasia. This article employs the notion of geographic imagination to analyze how Turkish policy-makers have developed a new political rhetoric and foreign policy towards the Eurasian region, specifically Central Asia, the Caucasus and Russia. Turkish policy-makers aim to further Turkey's interests ranging from security, over regional trade, to energy issues in this geography, in addition to creating an environment of cooperation and eliminating regional power constellations. We conclude that Turkey's renewed activism has opened new horizons for its relations in this region and that this new foreign policy orientation is linked to reform and change in Turkey's domestic landscape.Yayın Regional specialization and industrial concentration patterns in the Turkish manufacturing industry: An assessment for the 1980-2000 period(Routledge Journals, Taylor & Francis Ltd, 2008-02) Falcıoğlu, Pınar; Akgüngör, Emine SedefPrevious studies on geographical distribution of economic activity in Turkey demonstrate that firms are localized in major metropolitan areas as well as a set of emerging regions. The aim of the paper is to complement the findings of the studies on regional and industrial concentration in Turkey's manufacturing industry by exploring whether regional specialization and industrial concentration patterns changed during the 1980-2000 period. The paper further aims to explore the driving forces of industrial concentration in Turkey's manufacturing industry, particularly during Turkey's economic integration process that started with trade liberalization after 1980 and further developed with the Customs Union in 1996. Regional specialization and industrial concentration are measured by GINI indices Turkey's NUTS-2 regions at the four-digit level for the years between 1980 and 2000. To investigate which variables determine industry concentration, systematic relation between the characteristics of the industry and industrial concentration is tested. Following the method proposed by Paluzie, Pons and Tirado, a panel regression equation is estimated, where the dependent variable is the Gini concentration index and the independent variables are the variables that represent the characteristics of the sectors that follow the predictions of classical trade theory, new trade theory and new economic geography. The major finding of the study is that during 1980-2000, Turkey's regions became more specialized and industry became more concentrated. Increases in the average values of regional specialization and industrial concentration support the prediction developed by Krugman hypothesis that regions become more specialized and industries become more concentrated with economic integration. In exploring the driving forces of industrial concentration, the findings demonstrate that firms tend to cluster in regions where there are economies of scale.Yayın National industry clusters and regional specializations in Turkey(Carfax Publishing, 2003-09) Akgüngör, Emine Sedef; Kumral, Neşe; Lenger, AykutThe article aims to identify industry clusters in Turkey by examining inter-industry selling and purchasing relationships. The 1990 Turkish input-output table is used to identify similarities between selling and purchasing patterns of the 60 manufacturing industries and derive a matrix that describes relative linkages between them. The article also investigates the regional specializations by using the identified national clusters as templates for an analysis of local patterns. Principle component factor analysis reveals the presence of six identfiable industry clusters. The firms within the identified clusters provide a potential to share technical information and knowledge transfer through formal or informal interactions.
