Gümüşhane ÜniversitesiGümüşhane ÜniversitesiAçık Erişim Arşivi · RDL Open

Sürdürülebilir Kalkınma Amaçları

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Yeniden eskiyeEskiden yeniye
  • BildiriYalnız künye2017
    Statistical analysis of fundamental seismotectonic parameters for future Earthquake occurrences in tunceli province of Turkey

    Öztürk, S.

    An evaluation based on Gutenberg-Richter b-value, fractal dimension Dc-value, completeness magnitude Mc-value, annual probability and recurrence time of earthquakes is carried out for Tunceli province of Turkey. Earthquake catalog covers the years between 21 September 1970 and 30 December 2016, and contains 5462 earthquakes with magnitude equal to and greater than 1.1. Magnitude completeness is estimated as 2.8 and b-value is found as b=0.98+/-0.01. This b-value is smaller than average value of b=1.0 given for Gutenberg-Richter relation. So, this low b-value may be an indicator of stress to build up over time at the beginning of 2017. Dc-value is obtained as 1.63+/-0.04 with 95% confidence limits. This high Dc-value indicates that seismicity in Tunceli and vicinity is more clustered at larger scales or in smaller areas. Annual probability of the earthquakes between 4.5 and 5.5 magnitude levels exhibits a value between 1 and 10. Recurrence time of the earthquakes has a value between 10 and 30 years for magnitude levels between 5.5 and 6.0, and a value between 30 and 100 years for magnitude levels between 6.0 and 6.5. Consequently, this part of Turkey may have an earthquake potential for the possibility of intense earthquake occurrences in the next future.

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  • MakaleAçık Erişim2017
    Evolution of K-rich magmas derived from a net veined lithospheric mantle in an ongoing extensional setting: Geochronology and geochemistry of Eocene and Miocene volcanic rocks from Eastern Pontides (Turkey)

    Yücel, Cem; Arslan, Mehmet; Temizel, İrfan; Abdioğlu Yazar, Emel; Ruffet, Gilles

    The Eocene and Miocene volcanic rocks between the cities of Trabzon and Giresun in the Eastern Pontides (NE Turkey) erupted as mildly and moderately alkaline magmas ranging from silica-saturated to silica-undersaturated types. 40Ar-39Ar dating and petrochemical data reveal that the studied volcanic rocks are discriminated in two: Lutetian (Middle Eocene) mildly alkaline, (basaltic rocks: 45.31 ± 0.18 to 43.86 ± 0.19 Ma; trachytic rocks: 44.87 ± 0.22 to 41.32 ± 0.12 Ma), and Messinian (Late Miocene) moderately alkaline volcanic rocks (tephrytic rocks: 6.05 ± 0.06 and 5.65 ± 0.06 Ma). The trace and the rare earth element systematic, characterised by moderate light earth element (LREE)/heavy rare earth element (HREE) ratios in the Eocene basaltic and trachytic rocks, high LREE/HREE ratios in the Miocene tephrytic rocks, and different degrees of depletion in Nb, Ta, Ti coupled with high Th/Yb ratios, show that the parental magmas of the volcanic rocks were derived from mantle sources previously enriched by slab-derived fluids and subducted sediments. The Sr, Nd and Pb isotopic composition of the Eocene and Miocene volcanic rocks support the presence of subduction-modified subcontinental lithospheric mantle. During the magma ascent in the crust, parental magmas of both the Eocene and Miocene volcanic rocks were mostly affected by fractional crystallisation rather than assimilation coupled with fractional crystallisation and mixing. The silica-undersaturated character of the Miocene tephrytic rocks could be attributed to assimilation of carbonate rocks within shallow-level magma chambers. The parental magmas of the Eocene volcanic rocks resulted from a relatively high melting degree of a net veined mantle and surrounding peridotites in the spinel stability field due to an increase in temperature, resulting from asthenospheric upwelling related to the extension of lithosphere subsequent to delamination. The parental magmas for the Miocene volcanic rocks resulted from a relatively low melting degree of a net veined mantle domain previously modified by metasomatic melts derived from a garnet peridotite source after decompression due to extensional tectonics, combined with strike-slip movement at a regional scale related to ongoing delamination.

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  • BildiriYalnız künye2017
    Determination of the dynamic characteristics of the faculty building of engineering and natural science with hvsr method and fsr method

    Beker, Y.; Sayıl, N.

    Seismic response characteristics of structures can be estimated by spectral ratios of microtremors measured on structures and their foundation ground surface. The microtremor horizontal-to-vertical-spectral-ratio (HVSR) technique has received great attention from all over the world with its simplicity together with quick information about dynamic characteristics of ground and structures. The HVSR of microtremors gives a good estimation of natural building frequency. In this study, Nakamura (H/V) method and Floor Spectral Ratio Method (FSR) has been applied to microtremor records taken with three component broad band velocity seismometers in seven different locations inside the building (ground floor; east and west side for second, fourth and sixth floor) and one at outside with the aim of determining the dynamic characteristics of Faculty building of Engineering and Natural Science at Gumushane University, in NE Turkey. The average predominant frequency, period and amplification values for the Faculty building are calculated. The ratio of amplitude spectrum of the upper floors to amplitude spectrum of the ground floor for both of horizontal components (East-West, North-South) is determined using FSR Method. The vibration frequency and period is around 4.0 Hz and 0.332 s, respectively. Also, the damping ratio and vulnerability were calculated to the Faculty building.

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  • MakaleYayıncıda açık erişim2017
    Analysis of the changes in forest ecosystem functions, structure and composition in the Black Sea region of Turkey

    Keleş, Sedat; Durusoy, İdris; Çakir, Günay

    We used geographical information system to analyze changes in forest ecosystem functions, structure and composition in a typical department of forest management area consisting of four forest management planning units in Turkey. To assess these effects over a 25 year period we compiled data from three forest management plans that were made in 1986, 2001 and 2011. Temporal changes in forest ecosystem functions were estimated based on the three pillars of forest sustainability: economics, ecology and socio-culture. We assessed a few indicators such as land-use and forest cover, forest types, tree species, development stage, stand age classes, crown closure, growing stock and its increment, and timber biomass. The results of the case study suggested a shift in forest values away from economic values toward ecological and socio-cultural values over last two planning periods. Forest ecosystem structure improved, due mainly to increasing forest area, decreasing non-forest areas (especially in settlement and agricultural areas), forestation on forest openings, rehabilitation of degraded forests, conversion of even-aged forests to uneven-aged forests and conversion of coppice forests to high forests with greater growing stock increments. There were also favorable changes in forest management planning approaches.

    • SDG 15 · Karasal Yaşam
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  • MakaleAçık Erişim2017
    Long term outdoor performances of three different on-grid PV arrays in central Anatolia – An extended analysis

    Ozden, Talat; Akinoglu, Bulent G.; Turan, Rasit

    Long term outdoor testing of the PV systems at different climatic conditions or different systems under the same ambient conditions are extremely important in producing policies for the transition to renewables. The present research is the testing of three different PV systems under the same climatic conditions of central Anatolia, after four years of operation. The systems consist of a mono-Si, an a-Si thin film and a CdTe thin film arrays. Different calculation procedures of the input solar irradiation on tilted surface are used for comparison. Performances together with degradation rates are computed using different procedures and also using the measured solar data of 20 km away from the installed systems. The accuracy is verified using 4 months of simultaneous measurements. The results showed that the aforementioned different input calculation procedures of the performances are important and determinant. The 44-months-average efficiencies of these three systems are calculated to be 11.86%, 6.40% and 5.30%, respectively. The degradation rates of these systems are obtained as 0.40%, 1.88% and 10.60%, respectively. Although the degradation rates that are calculated for the first two systems are quite similar to those appeared in the literature, CdTe system is considerably higher than those given in the literature.

    • SDG 7 · Erişilebilir ve Temiz Enerji
    • SDG 13 · İklim Eylemi
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  • MakaleAçık Erişim2017
    The importance of amount of settlement in determining the bearing capacity of soils

    Alemdaǧ, Selçuk; Cinoǧlu, Aslihan; Gacener, Elif

    In this study, it is aimed to determine safe bearing capacity of soils, which are out cropped around Tamzi and Akcakale villages located in Gumushane, providing allowable settlement conditions for an optimum foundation design. To define the geotechnical properties of soils, three trenches were dug and two seismic refraction with two Multichannel Spectral Analysis of Surface Waves (MASW) were carried out in each research area. Sieve analyses, shear box tests, triaxial compression tests were carried out on disturbed and undisturbed samples taken from the trenches. Seismic velocities of the soils are determined by seismic refraction and MASW methods. While determining the safe bearing capacity; the equations proposed by Terzaghi, Meyerhof, Kurtuluş, Tezcan and Özdemir, Türker, Keçeli were used and the obtained safe bearing capacity values were compared to each other. After, the soils were modeled numerically by using finite elements method and safe bearing capacities providing allowable settlement conditions were determined. According to the results, safe bearing capacity values obtained from empirical equations are not satisfactory to have an optimum foundation design. For the optimum foundation design, safe bearing capacity should be accepted as 190 kN/m2 for clayey soil (CL) and 485 kN/m2 for the clayey sand (SC).

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  • MakaleYalnız künye2017
    In situ gamma ray measurements for deciphering of radioactivity level in Sarıhan pluton area of northeastern Turkey

    Çınar, Hakan; Altundaş, Suna; Çelik, Necati; Maden, Nafız

    The present work utilizes in situ gamma ray spectrometric measurement data to map the surface geology of Sarıhan Granitoid and its surrounding area. The study area comprises three different lithological units, namely, Hozbirikyayla Formation (limestone and sandy limestones), Sarıhan Granitoid (consist of quartz monzodiorite, granodiorite and quartz diorite) and the Ophiolitic olistostromal melange (andesite, basalt, sandstone, gravelly sandstone). When lithological units are assessed according to the radioactivity characteristics, natural radionuclide contents (40K and radionuclides from 238U and 232Th series) of Hozbirikyayla limestones and ophiolitic melange rocks are lower than the Sarıhan pluton. The U, Th and K radionuclide contents were found to be 0.8–5.4 ppm, 10.1–33.6 ppm and 1.29–4.41% in the Sarıhan plutonic area and 0.9–5.3 ppm, 1.1–20.3 ppm and 0.04–2.71% in Horzbirikyayla formation, respectively. The element concentrations of 238U, 232Th and 40K of the Ophiolitic melange are 1.1–4.5 ppm, 1.6–25.3 ppm and 0.09–3.63%, respectively. Radioelement ratio maps are created for the studied area, because the parameters of radioelement ratios, eU/eTh, eU/K and eTh/K, reflect the radioactive characters of the rock and soil. The Hozbirikyayla Formation is characterized by the highest value of eU/eTh and lowest value of eTh/K. While the lowest eU/eTh and eU/K ratios were observed in the Sarıhan Granodiorite, the highest value of eU/K and eTh/K were obtained in the Ophiolitic olistostromal melange. By comparing these maps with the geology, it was found that the radioelement concentrations are in good agreement with the geological properties of the region. In addition to this, the radiation hazard parameters were evaluated to assess the radiation hazard for people living in this area. It has also been found that there is no significant radiologic hazard for humans and the environment in and around studied area.

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  • MakaleAçık Erişim2017
    Spatial and temporal analysis of recent seismicity in different parts of the vlora-lushnja-elbasani-dibra transversal fault zone, Albania

    Ormeni, Rrapo; öZtürk, Serkan; Fundo, Akli; çElik, Kemal

    Spatial and temporal evaluation of current seismic activity throughout the Vlora- Lushnja-Elbasani-Dibra (VLED) transversal fault zone were carried out at the beginning of year 2016. The seismotectonic b-value, fractal dimension Dc-value and precursory seismic quiescence Z-value are considered for a detailed statistical analysis. Completeness magnitude Mc-value varies from 2.5 to 2.7 for different parts of the VLED fault zone. The b-value is calculated as 1.10±0.04 for the south western part and 1.13±0.05 for the middle part, whereas it is estimated as 0.94±0.07 for the north eastern part of the study region. These results reveal that b-values for all regions are well represented by a b-value typically close to 1.0. There are clear decreasing trends in temporal changes of b-values before the occurrences of some strong main shocks. On the contrary, no earthquakes are observed in some periods after decrease of b-value. Dc-values are computed as 2.66±0.04 for the south western part, 2.64±0.03 for the middle part and 2.15±0.02 for the north eastern part of the VLED fault zone. These rather large values show that earthquake activity is more clustered at larger scales or in smaller areas in the study area. Considering the phenomenon of seismic quiescence as a precursor of the main earthquakes gives successful outcomes in defining the potential anomalies and possible locations of future earthquakes. Quiescence analysis of current seismicity at the beginning of 2016 in the VLED fault zone is performed with the test of standard normal deviate Z-value. Distributions of resulting Z-values show six anomalous regions along the different parts of the VLED fault zone. These quiescence areas are detected at (i) 40.81°N- 19.86°E (including Kuc-Bubullim, southeast of Lushnja town), (ii) 41.00°N-20.01°E (in the Cerriku, south of Elbasani town), (iii) 41.31°N-20.13°E (around Bene-Qafe, northeast of Elbasani town), (iv) 41.43°N-20.21°E (Krasta-Batra, south of Bulqiza town), (v) 41.28°N-20.49°E (including Carrishta-Stebleve, northeast of Librazhdi town), (vi) 41.51°N-20.51°E (including Qerrenec-Gjorica, west of Dibra town). As an important result, analyses of spatial and temporal characteristics of the earthquake activity may supply significant clues for revealing the future seismic hazard along the VLED fault zone, and these anomaly regions may be interpreted as the locations of next possible earthquakes.

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  • MakaleAçık Erişim2017
    Detection of autoantibodies against carbonic anhydrase I and II in the plasma of patients with gastric cancer

    Mentese, Ahmet; Fidan, Evren; Alver, Ahmet; Demir, Selim; Yaman, Serap Ozer; Sumer, Aysegul; Fidan, Sami; Kavgaci, Halil; Turan, Ibrahim

    Cancer is the second leading cause of death and gastric cancer is the fourth most common cancer type worldwide. Investigation of autoantibodies in cancer patients has been a popular research area in recent years. The aim of the current study was to investigate carbonic anhydrase I and II (CA I and II) autoantibodies in the plasma of subjects with gastric cancer based on the information and considerations of autoimmune relation of gastric cancer. Anti-CA I and II antibody levels were investigated by ELISA in plasma samples of fifty two patients with gastric cancer and thirty five healthy peers. Anti-CA I and II antibody titers of the gastric cancer group were significantly higher compared with the control group (p = 0.004, p = 0.0001, respectively). Plasma anti-CA I levels of the metastatic group were lower than the non-metastatic group and this difference was found statistically significant (p < 0.05), but there was no statistical difference between plasma anti-CA II levels of the groups. CA I and II autoantibody titers in patients with gastric cancer were found higher compared to healthy subjects and the results suggest that these autoantibodies may be involved in the pathogenesis of gastric cancer.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
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  • MakaleAçık Erişim2017
    Determination of screw withdrawal resistance of some heat-treated wood species; [Određivanje otpora toplinski obrađenog drva izvlačenju vijaka]

    Perçın, Osman; Yasar, Şekip Şadiye; Altunok, Mustafa; Uzun, Oğuzhan

    In this study, the screw withdrawal resistance of heat-treated hornbeam (Carpinus betulus L.), black pine (Pinus nigra Arnold) and Uludag fir (Abies bornmuellerinana Mattf.) was determined according to the ASTM D 1761 standard. For this purpose, wood materials were heat treated at 150, 170, 190 and 210 °C for 3 h. After the heat treatment, the screw withdrawal resistance of the wood was determined in radial, tangential and transverse directions. As a result, the screw withdrawal resistance values decreased with increasing heat treatment temperature and the lowest resistance was obtained in the wood heat-treated at 210 °C. In terms of wood species, the highest screw withdrawal resistance was found in hornbeam (Carpinus betulus L.), while the lowest value was observed in black pine (Pinus nigra Arnold). Additionally, in terms of the cross-sectional direction, the highest screw withdrawal resistance was determined in the tangential direction, while the lowest resistance value was observed in the transverse direction.

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  • MakaleYalnız künye2017
    How does corporate social responsibility create customer loyalty? the role of corporate image

    Gürlek, Mert; Düzgün, Ertugrul; Uygur, Selma Meydan

    Purpose - This paper aims to investigate whether corporate image has a mediating effect on the influence of corporate social responsibility (CSR) on customer loyalty in independent hotels. Design/methodology/approach - Data were collected from customers of five-star hotels located in Istanbul in Turkey. The theoretical model was tested with 404 usable data. The results were analyzed by using structural equation modeling (SEM). Findings - Findings show that CSR creates customer loyalty partially through corporate image in the independent hotels. In addition, it was found that the hotels included in the study carried out moderate level of CSR activities. Research limitations/implications - The research model was tested in independent five-star hotels. Further studies could be carried out using different independent hospitality companies. In addition, the research was conducted on a limited sample, as hotel managers were not willing to allow direct contact with customers. Further studies could be carried out on larger samples. Practical implications - This study recommends that independent hotels carry out more CSR activities on social and environmental issues. In addition, direct effect of CSR on customer loyalty is lower than its indirect effect via corporate image. Therefore, if companies desire to create customer loyalty through CSR, they should introduce their CSR activities to customers via communication tools (website, media etc.) Originality/value - This study examines CSR in terms of sustainable development in the independent hotels. Furthermore, it explains relationships between CSR and corporate image and customer loyalty through the principle of generalized reciprocity specified in the theory of social change.

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  • MakaleYalnız künye2017
    Formation of the Eğrikar (Gümüşhane) Fe–Cu skarn type mineralization in NE Turkey: U–Pb zircon age, lithogeochemistry, mineral chemistry, fluid inclusion, and O-H-C-S isotopic compositions

    Sipahi, Ferkan; Akpınar, İbrahim; Eker, Çiğdem Saydam; Kaygusuz, Abdullah; Vural, Alaaddin; Yılmaz, Meltem

    The Eğrikar Fe–Cu skarn type mineralization is located approximately 100 km NW of Gümüşhane in NE Turkey. Geochemical analyses of diorite, which is thought to cause skarn, indicate medium K calc-alkaline (1.3 to ~ 2.3 wt% K2O), metaluminous to peraluminous (A/CNK = 0.76 to 1.13) and resembles a continental arc granite. The age of U–Pb zircon obtained from diorite is 42.3 ± 1.0 Ma, which reflects the age of skarn metasomatism after intrusion into Late Cretaceous sandy carbonates. Skarn formation zones are recognized as endo- and exoskarn. The endoskarn zone mainly consists of pyroxene with hedenbergite (Di4.31–28.14Hd59.29–80.82Jo5.0–35.55) at prograde stage. Mn content of pyroxene increases a slight from endo to exoskarn. Pyroxene is replaced by epidote and hornblende at the retrograde stage. The exoskarn zone comprises garnet with andradite (Ad91-99Gr01–07) and grossular-andradite (Ad44-95Gr05–54), epidote and quartz as silicate minerals, and magnetite and hematite as ore minerals. Magnetite is the abundant ore mineral and is accompanied by chalcopyrite and minor pyrite at retrograde stage. On the basis of fluid inclusion values of minerals, the temperature range for hedenbergite in endo-exoskarn is 350 °C–425 °C, for epidote in exoskarn is 365 °C–376 °C, and for quartz in exoskarn 200 °C–380 °C. NaCl equivalent salinity for hedenbergite 6.88–10.73 wt% and for quartz is 3.9–15.38 wt. The δ18O values of hedenbergite is 4.1 to 4.7‰ and for garnet 3.4‰ at prograde stage, for epidote 7.9–9.2‰, for magnetite 1 to 4.4‰, for hematite − 2.9 to − 1.6‰ and for quartz range between 8.5‰ and 15.2‰. The δ18O value of epidote suggests that oxygen is a magmatic fluid whereas hedenbergite, garnet, quartz and magnetite show the mixing of magmatic and meteoric fluids. In addition, the C isotope values (− 3.2 to 2.8‰) of calcite and marble in Eğrikar Fe–Cu skarn reflect those of metamorphic, and skarns. Based on oxygen isotope data from mineral pairs, the retrograde skarn formation is characterized by epidote–magnetite assemblage formed at 255 °C–438 °C. Fluid oxygen isotope compositions of magnetite and epidote pairs of the exoskarn skarn zone indicate a mixing of magmatic and meteoric fluids with narrow δ18O values between 7.17‰ and 8.9‰. The δ34S values of the pyrites exhibit a narrow range of 3‰ and 4.4‰, thereby indicating that sulfur were probably leached from magmatic rocks. Based on the field and laboratory observation, mineral chemistries, fluid inclusion studies and isotope composition analysis, it is suggested that the Eğrikar Fe–Cu skarn mineralization occurs in a magmatic origin fluids being initially under reduced conditions, subsequently under oxidized conditions, and at shallow depth.

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  • MakaleYalnız künye2017
    Selection application of material to be used in hip prosthesis production with analytic hierarchy process: Anwendungsselektion des zu verwendenden Materials in der Hüftprothesenproduktion mit dem analytischen Hierarchieverfahren

    Çelik, İ.; Eroğlu, H.

    Metallic biomaterials used in making hip prosthesis are required to meet expectations in terms of fatigue strength, corrosion resistance, wear resistance, cost and biocompatibility. It is also desirable that the modulus of elasticity they possess is close to the level of the possible bone. Metallic biomaterials face the problem of ion release even though they meet the criteria mentioned above. As a result, the choice of metallic material to be preferred in the manufacture of hip prosthesis can be made by evaluating all these criteria among themselves and by the performances of biomaterials to be compared according to these criteria. In this study, firstly the criteria expected from the metals to be used as biomaterials have been determined. Expert opinions about the subject and criteria determined in accordance with the studies in the literature by using analytical hierarchy process have been graded according to each other. Afterwards, selection of the most appropriate material was ensured by making the order of importance according to the criteria of the candidate materials.

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  • MakaleYalnız künye2017
    Effects of certain drugs on dihydropyrimidine dehydrogenase enzyme purified from bovine liver

    Aygul, Imdat; Ozdemir, Hasan; Ciftci, Mehmet

    The inhibitory effects of certain drugs on dihydropyrimidine dehydrogenase from the bovine liver have been investigated. Dihydropyrimidine dehydrogenase [5, 6-dihydrouracil: NADP+ oxidoreductase, EC 1.3.1.2; DPD] enzyme was purified from the bovine liver. The purification was performed by preparation of homogenate, ammonium sulphate precipitation, and affinity chromatography. Moreover, some important modifications were made in the purification procedure. Purification of bovine liver DPD enzyme was obtained with a yield of 12.5%. SDS polyacrylamide gel electrophoresis was performed after the purification of the enzyme, and the electrophoretic pattern is discussed in this article. In addition, the effects of certain drugs on bovine liver dihydropyrimidine dehydrogenase enzyme activity were investigated. Oxytetracycline, ciprofloxacin, ceftazidime, cefoperazone, amikacin, ornidazole, metronidazole, cefuroxime, cefepime, ampicillin, and amoxicillin, were used as drugs. All the drugs indicated the inhibitory effects on the enzyme. IC50 values of the drugs were determined by plotting activity % vs [I]. IC50 values of oxytetracycline, ciprofloxacin, ceftazidime, cefoperazone, amikacin, ornidazole, metronidazole, cefuroxime, cefepime, ampicillin, and amoxicillin 0.030, 0.046, 0.140, 0.610,1.820, 2.500, 3.600, 4.330, 4.370, 4.920, and 6.300, mM; the Ki constants were 0.050±0.01,0.090± 0.06, 0.130±0.045, 0.185±0.057, 2.010±0.55, 2.096±1.06, 2.115±1.00, 2.700±0.56, 3.730±1.48, 5.240±1.04, and 9.570±2.84, mM for bovine liver DPD, respectively. Ki constants for dihydropyrimidine dehydrogenase were determined by Lineweaver-Burk graphs. All drugs showed non-competitive inhibition patterns.

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  • MakaleYalnız künye2017
    Low-complexity early termination method for rateless soft decoder

    Albayrak, Cenk; Simsek, Cemaleddin; Turk, Kadir

    We propose a new early termination method (ETM) with low computational complexity for Luby transform belief propagation (BP) decoder. The proposed method, which we call least reliable messages (LRM) ETM, observes only sign alterations of a small cluster in log-likelihood ratio messages passing between nodes in BP decoder. Simulation results and complexity analyzes show that LRM ETM has quite low computational complexity and small average iteration amounts without any performance degradation compared with conventional ETMs in literature. The method can be applied to code families which can be decoded by BP such as low density parity check codes, polar codes, and Raptor codes.

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  • MakaleAçık Erişim2017
    Space-time assessing of the earthquake potential in recent years in the Eastern Anatolia region of Turkey; [Evaluación espacio-temporal del potencial de terremotos en los años recientes para la región de Anatolia, en el este de Turquía]

    Öztürk, S.

    In this study, a statistical analysis is carried out to reveal the current earthquake potential in the Eastern Anatolia region of Turkey. For this purpose, a space-time assessing based on the recent changes in Gutenberg-Richter b-value, seismic quiescence Z-value, cumulative moment, annual probability and recurrence time of earthquakes is achieved. Temporal variation of b-value indicates that average b-value decreased from 1.25±0.02 between 2002 and 2010 to 1.08±0.02 between 2011 and 2015. A clear quiescence in the seismic moment in recent years may be a clue foretelling the occurrence of an intense event. Annual probability of the earthquakes between 3.5 and 4.0 magnitude levels exhibits a value equal to and larger than 30. Recurrence time of the earthquakes has a value between 2.0 and 3.0 years for magnitude level of 6.0, and a value between 6.0 and 7.0 years for magnitude level of 7.0. A significant decrease in b-value and clear quiescence anomalies in Z-value at the beginning of 2015 are observed in the several same regions. These areas cover the Central Anatolia Fault Zone, Malatya and Ovacık faults, the southeastern part of the Eastern Anatolia Fault Zone, and the junction of the Eastern Anatolia and Dead Sea Fault Zones. In these anomaly regions, a decreasing trend in b-value may be an indicator of stress increases and an increasing trend in Z-value may show the quiescence areas before the next earthquake occurrences. As a remarkable fact, these areas in the Eastern Anatolia region may be interpreted as one of the most likely locations for the major earthquakes in the future.

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  • MakaleYalnız künye2017
    An Investigation of Corrosion Resistance and Antibacterial Sensitivity Properties of Nano-Ag-Doped TiO 2 Coating and TiO 2 Coating Grown on NiTi Alloy with the Micro-Arc Oxidation Process

    Karabudak, Filiz; Yeşildal, Ruhi; Şüküroğlu, Ebru Emine; Şüküroğlu, Süleyman; Zamanlou, Hamid; Dikbaş, Neslihan; Bayındır, Funda; Şen, Sadri; Totik, Yaşar

    In this study, TiO 2 coatings were grown with nano-Ag doped and micro-arc oxidation technique on NiTi shape memory alloy. The antibacterial sensitivity and corrosion resistance characteristics of both coatings were investigated. The microstructure and composition analyses of the coatings were performed with scanning electron microscope, energy dispersive X-ray spectrometry, and X-Ray diffraction (XRD). The XRD results showed that there were only TiO 2 crystal phases (anatase and rutile) on the coating. The results showed that a clean and dense oxide layer was grown on the surface successfully. The surface of nano-Ag-doped TiO 2-coated samples appear to be smoother than the surface of the coatings without Ag. The corrosion tests of the coated and uncoated samples were carried out in three different environments (simulated body fluid, synthetic saliva, and cola) at 37 ∘ which is human body temperature. The corrosion tests showed that the corrosion resistance of TiO 2-coated and nano-Ag-doped TiO 2-coated samples was much higher than the corrosion resistance of the NiTi substrate. Seven different bacteria including (S. aureus, L. monocytogenes, Bacillus subtilis, Salmonella enteritidis, Yersinia enterocolitica, and E. coli, P.aeruginosa) which have the human pathogen feature were used in the antibacterial susceptibility tests. The process was conducted based on the disk diffusion method to test the susceptibility of bacterial strains on the selected coated and uncoated samples, and antimicrobial activity was evaluated in the nano-Ag-doped TiO 2-coated material; P.aeruginosa, Y. enterocolitica, and E. coli (zone diameter of 8–14 mm) were found to be moderately susceptible; S. aureus, L. monocytogenes, B. subtilis, and S. enteritidis (zone diameters of 8–14 mm) were found to be resistant. The antimicrobial activity of the coating material NiTi was found to be sensitive for all antibacterial tests. According to the TiO 2-coated material results, S. aureus, P.aeruginosa, L. monocytogenes, E. coli were found to be moderately sensitive and Y. enterocolitica, S. enteritidis, and B. subtilis were found to be resistant.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
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  • MakaleYalnız künye2017
    Remote sensing technique for capturing and exploration of mineral deposit sites in Gumushane metallogenic province, NE Turkey

    Vural, Alaaddin; Corumluoglu, Özsen; Asri, Ibrahim

    This study examines the determination and confirmation of mineral deposits in the Gumushane Province,Turkey. Rather than using classical techniques, Remote Sensing (RS) and Geographic Information System GIS technologies are applied for this purpose. Mineral alteration traces on the ground are characteristic indicators of ore below the surface. These traces can be determined using RS techniques. The Crosta technique is one of the most important RS image analysis methods used for the determination of mineral alterations. The technique has shown particular usefulness around mine areas, which are rich in ore deposits and show hydrothermal alterations. Therefore, four separate mine fields covering a total area of 718 km2 in the southern part of Gumushane, which is rich in iron oxides, hydroxides and hydrothermal alteration, were chosen. The Crosta technique was applied to the satellite image of each area to explore the regional alterations. The determined locations could be confirmed as alteration areas. Within these four regions, some other locations showing similar alteration patterns were also determined using the Crosta technique. These locations represent good candidates for mineral exploration.

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  • MakaleYalnız künye2017
    Effect of dc field on ac-loss peak in a commercial Bi:2223/Ag tape

    Öztürk, Ali; Düzgün, Ibrahim; Çelebi, Selahattin

    Measurements of the ac susceptibility in a commercial Bi:2223/Ag tape for some different ac magnetic field amplitudes, Hac, in the presence of bias magnetic field Hdc directed along Hac are reported. It is found that the peak values of the imaginary component of ac susceptibility χ″max versus Hac trace a valley for the orientation where applied field Ha perpendicular to wide face of the tape total. We note that the observation of the valley depends on various parameters such as field dependence parameter n in the critical current density, in the simple power law expression jc = α(T)/Bn, choice of the bias field Hdc together with selected ac field amplitudes Hac, and dimension and geometry of sample studied. Our calculations based on critical state model with jc = α(1 - T/Tcm)p/Bn using the fitting parameters of n = 0.25, p = 2.2, Tcm = 108 K gives quite good results to compare the experimental and calculated curves.

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  • MakaleYayıncıda açık erişim2017
    Evaluation of the contraceptive effects of carprofen, flunixin meglumine and meloxicam in rats

    Paksoy, Z.; Kirbas, A.

    The objective of this study was to determine the suitability of carprofen, flunixin meglumine and meloxicam for use in emergency contraception. Forty-eight pregnant Sprague-Dawley rats were used as material. Five groups were subjected to treatments while one group served as a control. The numbers of animals in each group were equal (n = 8). Treatment groups were administered carprofen (10 mg/kg, single or double dose, s.c.), flunixin meglumine (5 mg/kg, single or double dose, i.m.) and meloxicam (2 mg/kg, a single dose, s.c.) on the third day after mating. The control group received saline. The rats were sacrificed on Day 7 of gestation. Luteal spots and implantation sites were recorded. Pre-implantation loss was calculated by subtracting the number of luteal spots from the number of implantation sites. Compared with the control, the administration of flunixin meglumine (double dose), carprofen (double dose) and meloxicam highly significantly decreased the implantation rate (P < 0.001). Single dose administration of flunixin meglumine and carprofen led to significant decreases (P < 0.01). In conclusion, this study indicates that carprofen, flunixin meglumine and meloxicam treatment cause a decline in implantation rate in rats.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
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