Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(64)
- Merdan, Mehmet(47)
- Baltaci, Cemalettin(35)
- Kulakaç, Nurşen(28)
- Duran, Celal(27)
- Ozdes, Duygu(24)
- Turan, Ibrahim(24)
- Demir, Selim(23)
- Türkkan, Tuğba(22)
- Bayrakdaroglu, Serdar(21)
- Topal, Fevzi(21)
- Öztürk, Serkan(21)
- Ürkek, Bayram(21)
- Gücer, Mehmet Ali(20)
- Akar, Zeynep(19)
- Kaygusuz, Abdullah(19)
- Topal, Meryem(19)
- Anaç, Halil(18)
- Aydin, Aydanur(18)
- Batan, Nevzat(18)
- Erata, Hüseyin(18)
- Tuncer, Metin(18)
- Akyürek, Suat(17)
- Baltacı, Cemalettin(17)
- Karimullah, Suud Sarim(17)
- Acet, Tuba(16)
- Akar, Bülent(16)
- Ashyralyyev, Charyyar(16)
- Düzgün, Azer Özad(16)
- Hintistan, Sevilay(16)
- Yılmaz, Coşkun(16)
- Aliyazicioglu, Yuksel(15)
- Kaya, Hacer(15)
- Kurnaz, Muammer(15)
- Kurt, Kemal(15)
- Ozden, Talat(15)
- Yilmaz, Coskun(15)
- Yuksel, Ferhat(15)
- Yücel, Cem(15)
- Öz, Mehmet(15)
Yayınlar
- MakaleAçık Erişim2017Scopus SJRQ3Diversity and ecology of benthic diatoms in karagöl lake in karagöl-Sahara national park (Şavşat, Artvin, Turkey)
Akar, Bülent; Şahin, Bülent
The main goal of this study is to determine the composition, diversity and ecology of benthic diatoms in Karagöl Lake in Karagöl-Sahara National Park. Monthly sampling (from sediments, stones and aquatic plants in littoral zone of the lake) taken in three consecutive years revealed 57 diatom taxa with Gomphonema and Pinnularia being the most abundant species while other genera are represented with three or fewer species. Lindavia ocellata was the most dominant taxon in the samplings examined throughout the whole study. The values of diversity and evenness indices are high during the spring and early summer. Based on cluster analysis for monthly samples of epipelic diatom, there are two different groups at the lowest similarity level. The associations between August 2010 and September 2010 months are the most significant with 86.02%. The organism number of epipelic diatoms showed positive correlation (P<0.01) with dissolved oxygen, while negative correlation (P<0.05) with temperature. Detailed floristic and ecological examination of the benthic diatom communities has not been carried out before this study in this lake. Therefore, this study is the first to our knowledge towards revealing aquatic benthic diatom biodiversity of Karagöl-Sahara National Park and provides basis for future investigations.
AtıfScopus7WoS9OpenAlex4
İncele - Kitap BölümüAçık Erişim2017Discontinuity controlled slope failure zoning for a granitoid complex: A fuzzy approach
Gurocak, Z.; Alemdag, S.; Bostanci, H.T.; Gokceoglu, C.
Kinematic analysis is one of the most used methods to evaluate potential failures such as planar, wedge and toppling in rock slopes. To analyze possible failure types, orientations of slope and discontinuity geometry with the friction angle of the discontinuities planes are used. In this study, kinematical analyses were evaluated to obtain discontinuity controlled potential failure types in the Gumushane Granitoid Complex which is exposed in Gumushane City and the surroundings. Unstable slope orientations for planar, wedge and toppling failure types were determined. The unstable orientations obtained from kinematic analyses were used to create Geographic Information System (GIS) based instability risk maps. The maps generated by the GIS were evaluated using the Fuzzy Interference System (FIS) method to produce instability risk maps for the study area.
AtıfScopus6OpenAlex5İncele - MakaleAçık Erişim2017Scopus SJRQ3Influence of Duplex Treatment on Structural and Tribological Properties of Commercially Pure Titanium
Çelik, Ilhan
Titanium and its alloys are widely used in many fields, including aerospace and the chemical and biomedical industries. This is due to their mechanical properties, excellent corrosion resistance, and biocompatibility although they do have poor wear resistance. In this study, a duplex layer was successfully formed on the commercially pure titanium surface by duplex treatments (plasma nitriding and physical vapor deposition (PVD)). In the initial treatment, plasma nitriding was performed on the pure titanium samples and in the second treatment, the nitrided samples were coated with CrN by PVD. The friction and wear properties of the duplex-treated samples were investigated for tribological applications. Surface morphology and microstructure of the duplex-treated samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition, the tribological properties were investigated using pin-on-disc tribometer. A compound layer composed of ϵ-Ti2N and δ-TiN phases and a diffusion layer formed under the compound layer were obtained on the surface of pure titanium after the nitriding treatments. CrN coated on the nitrided surface provided an increase in the surface hardness and in the wear resistance.
AtıfScopus4WoS4İncele - MakaleAçık Erişim2017Scopus SJRQ1Analysis of transcriptional profiles of Saccharomyces cerevisiae exposed to bisphenol A
Bereketoglu, Ceyhun; Arga, Kazim Yalcin; Eraslan, Serpil; Mertoglu, Bulent
Bisphenol A (BPA), an endocrine disrupting chemical, is used as a monomer in the production of epoxy resins and polycarbonates, and as a plasticizer in polyvinyl chloride. As such, it is produced in large quantities worldwide and continuously leaches into the environment. To capture the genome reprogramming in eukaryotic cells under BPA exposure, here, we used Saccharomyces cerevisiae as model organism and analyzed the genome-wide transcriptional profiles of S. cerevisiae BY4742 in response to BPA, focusing on two exposure scenarios: (1) exposure to a low inhibition concentration (50 mg/L; resulting in <10 % inhibition in cell number) and (2) a high inhibition concentration (300 mg/L; resulting in >70 % inhibition in cell number). Based on the transcriptional profiling analyses, 81 genes were repressed and 104 genes were induced in response to 50 mg/L BPA. Meanwhile, 378 genes were downregulated and 606 genes were significantly upregulated upon exposure to 300 mg/L BPA. While similar processes were affected by exposure to distinct BPA concentrations, including mitochondrial processes, nucleobase-containing small molecule metabolic processes, transcription from the RNA polymerase II promoter, and mitosis and associated processes, the number and magnitude of differentially expressed genes differ between low and high inhibition concentration treatments. For example, exposure to 300 mg/L BPA resulted in severe changes in the expression levels of several genes involved in oxidative phosphorylation, the tricarboxylic acid cycle, ribosomal activity, replication, and chemical responses. Conversely, only slight changes were observed in the expression of genes involved in these processes in cells exposed to 50 mg/L BPA. These results demonstrate that yeast cells respond to BPA in a concentration-dependent manner at the transcriptional level via different genes and provide insight into the molecular mechanisms underlying the modes of action of BPA.
AtıfScopus20WoS18OpenAlex21
İncele - BildiriAçık Erişim2017Scopus SJRQ3Fluoride levels in the Eastern Black Sea Basin streams, Turkey
Bayram, A.; Satilmiş, U.; Nas, S.S.; Kemer, B.
The aim of this study is to monitor the fluoride ion (F-), as well as chloride ion (Cl-), variation in the Eastern Black Sea Basin streams, and to evaluate drinking water quality of these streams, with reference to national and international directives and guidelines. The water samples (240) were semimonthly collected from three surface water resources, namely from the Degirmendere and Galyan streams in Trabzon Province, the biggest city on the Southeastern Black Sea Coast with a total population of 768 417, and the Harşit Stream in Gümüşhane and Giresun provinces. The monitoring results have revealed that the average F-concentration had varied between 0.154 and 0.200 mg/l in the Degirmendere Stream and between 0.156 and 0.163 mg/l in the Galyan Stream, respectively. However, the treated stream waters had lower F-concentrations, varying between 0.010 and 0.080 mg/l, than the untreated stream waters. In the Harşit Stream, the average F-concentrations were at relatively higher values, which ranged from 0.211 to 0.296 mg/l, in the uppermost stations, however showed a steadily decreasing trend throughout the lowermost stations and fell from 0.230 to 0.141 mg/l due to the hydropower dam reservoirs, namely Torul, Kürtün, and Akköy, operated in the watershed. The average Cl-concentrations have varied between 2.00 and 6.48 mg/l. On the one hand, the waters from the Degirmendere, Galyan, and Harşit streams are classified as high quality, considering the upper threshold values of 1.5 mg F-/l and 250 mg Cl-/l. On the other hand, these streams can be regarded as the fluoride-poor water resources.
- MakaleAçık Erişim2017Scopus SJRQ1Rice bran improve probiotic viability in yoghurt and provide added antioxidative benefits
Demirci, Talha; Aktaş, Kübra; Sözeri, Didem; Öztürk, Hale İnci; Akın, Nihat
Experimental yoghurts were made with 13% reconstituted skim milk supplemented with 1, 2, 3% rice bran (RB) and inoculated with probiotic culture of Lactobacillus casei 431. The products were stored at 4 °C for 3 weeks. During this period, the viability of the probiotic L. casei 431 strain and yoghurt starter cultures were evaluated. In addition to this, some physicochemical, antioxidative and sensory properties of yoghurts were also determined. L. casei 431 remained above the 8 log CFU/g throughout the storage period in yoghurts fortified with 2% and 3% RB. Addition of rice bran decreased the syneresis and viscosity values whereas it increased scavenging activities of DPPH radical. However, yoghurts with RB had less sensory scores compared to plain yoghurt.
AtıfScopus115WoS91İncele - MakaleAçık Erişim2017Scopus SJRQ2Sexual health literacy as a predictor of reproductive health and family planning attitudes among university students: a cross-sectional study
Karaahmet, Aysu Yıldız; Bilgiç, Fatma Şule; Karakaş, Sevda
Introduction: This study was conducted to investigate the relationship between sexual health literacy (SHL) and reproductive health and family planning (RHFP) attitudes among university students and to identify the sociodemographic and informational predictors influencing these variables. Methods: A descriptive, cross-sectional design was employed with a sample of 867 university students aged 18-35 in Türkiye between May and September 2024. Data were collected using a Sociodemographic Questionnaire, the Sexual Health Literacy Scale (SHLS), and the Reproductive Health and Family Planning Attitude Scale (RHFPAS). Data analysis included Pearson correlation and multiple linear regression models to determine predictors and relationships. Results: The findings revealed a strong positive correlation between SHL and RHFP attitudes (r = 0.880, P < .05). Multiple linear regression analysis showed that total SHLS scores and students’ conceptual definitions of sexual health were significant predictors of RHFP attitudes. In particular, the knowledge and attitude subscales of the SHLS were identified as key determinants. Furthermore, residence type, sexual activity status, and information sources were found to significantly influence both SHL levels and RHFP attitudes. Discussion: SHL is a critical determinant in shaping the RHFP attitudes of young adults. Higher literacy levels directly correlate with more positive attitudes toward reproductive health services, suggesting that targeted educational interventions are necessary to improve health outcomes in this population.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2017Scopus SJRQ2Bounds for the radii of univalence of some special functions
Aktaş, Ibrahim; Baricz, Árpád; Yaǧmur, Nihat
Tight lower and upper bounds for the radii of univalence (and starlikeness) of some normalized Bessel, Struve and Lommel functions of the first kind are obtained via Euler-Rayleigh inequalities. It is shown also that the radius of univalence of the Struve functions is greater than the corresponding radius of univalence of Bessel functions. Moreover, by using the idea of Kreyszig and Todd, and Wilf it is proved that the radii of univalence of some normalized Struve and Lommel functions are exactly the radii of starlikeness of the same functions, and they are actually solutions of some functional equations. The Laguerre-Pólya class of entire functions plays an important role in our study.
AtıfScopus35WoS34OpenAlex22İncele - Kitap BölümüAçık Erişim2017The role of financial ratios on evaluation of stock values: An application in Bist
Cam, Alper Veli; Tosunoglu, Busra; Gurtay, Enes
Financial ratios obtained from past data are used in estimations of the future, which is financially uncertain, in many studies and analyses. In this regard, financial ratios can be used to determine stock values and therefore the value of the company. The objective of this study is to determine the relationship between the financial ratios of companies and stock values. Accordingly, ten year and quarterly data of16 cement factories whose stocks are traded on the Istanbul Stock Market (BIST) between years 2005-2014 are studied. In the study, current ratio, acid test ratio, liability ratio, accounts receivable turnover rate, inventory turnover rate, market value/book value are used as independent variables. Financial leverage and size of assets are used as control variables and stock value is used as the dependent variable. In accordance with the results of panel data analysis, it is seen that there is a meaningful relationship between acid-test ratio, liability ratio, market value/book value and financial leverage and between stock values.
AtıfScopus1OpenAlex198İncele - MakaleAçık Erişim2017Scopus SJRQ2Bounds for Radii of Starlikeness of Some q -Bessel Functions
Aktaş, İbrahim; Baricz, Árpád
In this paper the radii of starlikeness of Jackson’s second and third q-Bessel functions are considered and for each of them three different normalization are applied. By applying Euler–Rayleigh inequalities for the first positive zeros of these functions tight lower and upper bounds for the radii of starlikeness of these functions are obtained. The Laguerre–Pólya class of real entire functions plays an important role in this study. In particular, we obtain some new bounds for the first positive zero of the derivative of the classical Bessel function of the first kind.
AtıfScopus38WoS38OpenAlex38İncele - MakaleAçık Erişim2017Scopus SJRQ1Evolution 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.
AtıfScopus77WoS74OpenAlex86İncele - MakaleAçık Erişim2017Scopus SJRQ1Long 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.
AtıfScopus77WoS63OpenAlex76İncele - MakaleAçık Erişim2017Scopus SJRQ3The 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).
AtıfScopus1OpenAlex4İncele - MakaleAçık Erişim2017Scopus SJRQ2Spatial 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.
AtıfScopus11WoS6OpenAlex11İncele - MakaleAçık Erişim2017Scopus SJRQ3Detection 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.
AtıfScopus8WoS7OpenAlex7İncele - MakaleAçık Erişim2017Scopus SJRQ3Determination 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.
AtıfScopus7WoS7OpenAlex7İncele - MakaleAçık Erişim2017Scopus SJRQ3Space-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.
AtıfScopus25WoS20OpenAlex24İncele - MakaleAçık Erişim2017Scopus SJRQ2Developing web based decision support system for evaluation occupational risks at shipyards
Cebi, Selcuk; Akyuz, Emre; Sahin, Yasin
In this study, a web based decision support system (WBDSS) has been developed to provide decision aid for risk analysis on occupational health and safety at shipyards. The system has been constructed as a modular structure to make its application easy for all kind of firms. The WBDSS is rule based and its database includes safety measures and risks for each tool and machine used in shipbuilding process. In addition, probability and hazard values have been involved in the case of violated measures. The frequencies of the violations that occurred in the work environment are entered to the system by the user. Hence, the system provides a decision support about the risks related to facilities and the cautions to be taken in the workplace. The developed WBDSS has the capability of determining accident, almost accident, and threat formation factors at workplace according to the changing parameters. In this aspect, it enables one to constantly monitor, check and evaluate risk preventive measures. Then, the capabilities of the suggested decision support system have been tested with different scenarios for shipyard processes. When the developed WBDSS is applied to all workplaces, it is aimed at providing a decrease in the number of accidents which cause death, occupational illness, injury, and temporary incapability.
AtıfScopus11WoS11OpenAlex12İncele - MakaleAçık Erişim2017Scopus SJRQ1ZnO and ZnO1−x based thin film memristors: The effects of oxygen deficiency and thickness in resistive switching behavior
Gul, Fatih; Efeoglu, Hasan
In this study, direct-current reactive sputtered ZnO and ZnO1−x based thin film (30 nm and 300 nm in thickness) memristor devices were produced and the effects of oxygen vacancies and thickness on the memristive characteristics were investigated. The oxygen deficiency of the ZnO1−x structure was confirmed by SIMS analyses. The memristive characteristics of both the ZnO and ZnO1−x devices were determined by time dependent current–voltage (I-V-t) measurements. The distinctive pinched hysteresis I-V loops of memristors were observed in all the fabricated devices. The typical homogeneous interface and filamentary types of memristive behaviors were compared. In addition, conduction mechanisms, on/off ratios and the compliance current were analyzed. The 30 nm ZnO based devices with native oxygen vacancies showed the best on/off ratio. All of the devices exhibited dominant Schottky emissions and weaker Poole-Frenkel conduction mechanisms. Results suggested that the oxygen deficiency was responsible for the Schottky emission mechanism. Moreover, the compliance currents of the devices were related to the decreasing power consumption as the oxygen vacancies increased.
AtıfScopus68WoS63OpenAlex71İncele - BildiriAçık Erişim2017Scopus SJRQ3K-Ar dating for determining the age of mineralization as alteration product: A case study of antimony mineralization vein type in granitic rocks of Gümüşhane area, Turkey
Vural, A.
Is it feasible to use K-Ar dating method in determination of the age of mineralization by utilizing alteration minerals? The purpose of this study was to examine the utility of the K-Ar dating method to accurately determine the age of mineralization. In ideal circumstances, dating of alteration products, such as illite and serisite minerals, gives the age of alteration event, which is indirectly associated with mineralization. In the study site, referred to as Avliyana, antimony mineralization (Gümüşhane, Turkey), stibnite (antimony) mineralizations of hydrothermal vein type were observed in granitic young intrusive rocks and the host rocks. In the study area, alteration was observed in the form of a small amount of weak silicification, argillitization (sericitization and illitization), hematitization, limonitization close to the mineralization and of epidotization and chloritization far from the mineralization. In order to determine the limits of the age of antimony mineralizations of the area, the K-Ar method was used to date illite and serisite minerals, which are alteration products related to mineralization. Two samples containing sericite and illite were collected from Avliyana antimonite mineralization. The alteration origin of these minerals was confirmed by supporting petrographic, XRD and scanning electron microscope studies. These samples were analysed for K-Ar dating.
AtıfScopus6WoS5OpenAlex11İncele