Koleksiyon/r/gumushane/10001

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Koleksiyondaki öğeler

  • MakaleYalnız künye2020Scopus SJRQ2
    Comparison of sandstone and mudstone with different methods for assessing toxic element contamination in the Early–Middle Jurassic sediments of Gümüşhane (NE Turkey)

    Saydam Eker, Çiğdem; Arı, Uğur Volkan

    To investigate the vertical changes of toxic elements in Jurassic sediments, sampling was performed in four sites. Samples were collected from sandstones and mudstones/marls and analyzed for some toxic elements (Cu, Pb, Zn, As, Ni and V). Results exhibited that the sediment grain size played a significant role in controlling the concentrations of the toxic elements in the sediments. The mean toxic element contents of mudstones/marls were higher than those of sandstones (except Cu). The contamination level of toxic elements was detected by enrichment factor (EF), geo-accumulation index (Igeo), potential ecological risk index (Eir), pollution index (Pi) and united pollution index (PIn). The low EF, Igeo, Eir, Pi and PIn for Cu, Pb, Zn, Ni, V in the sandstones and Cu, Zn, Ni in the mudstones/marls exhibited an absence of clear these elements pollution. The high EF, Eir, Pi and PIn for As (9.7, 73, 7 and 29, respectively, as mean values) in the sandstones and for As (49.3, 222, 22 and 75, respectively, as mean values) Pb (8.8, 24, 5 and 19, respectively, as mean values), V (8.3, 15, 7 and 39, respectively, as mean values) in the mudstones/marls indicated significant contamination. Additionally, according to the potential ecological risk (RI) values, the sandstones had low potential ecological risk for the toxic elements (RI < 150) and the mudstones/marls had moderate potential ecological risk (150 ≤ RI ≤ 300). The potential ecological risk As, Pb, V (especially As) were higher in urban areas than in agricultural activities. Therefore, the source of As, Pb, V could be gasoline combustion, burning coal and vehicle exhausts. The contents of these elements generally increased from bottom to top of the measured stratigraphic sections, which indicated transported by atmospheric conditions.

    • SDG 6 · Temiz Su ve Sanitasyon
    AtıfScopus9WoS8OpenAlex11
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  • MakaleYalnız künye2021Scopus SJRQ1
    Simultaneous separation and preliminary purification of anthocyanins from Rosa pimpinellifolia L. fruits by microwave assisted aqueous two-phase extraction

    Odabaş, Halil İbrahim; Koca, Ilkay

    Rosa pimpinellifolia L. fruits (RPF) have great industrial potential due to the high presence of anthocyanins. In this work, microwave-assisted aqueous two-phase extraction (MA-ATPE) was applied to simultaneous extraction and purification of anthocyanins from RPF with ethanol/ammonium sulfate aqueous two-phase system (ATPS). MA-ATPE process was optimized by single-factor experiments and response surface methodology. The optimal anthocyanin yields were achieved in conditions of 0% HCl (w:w), 26.85% ethanol (w:w), 19.15% ammonium sulfate (w:w), liquid to solid ratio 40, 17.29 min, 60 °C and 400 W. Predicted anthocyanin yield of MA-ATPE at optimum conditions were determined as 1373.04 mg cyanidin 3-glucoside equivalent/g dry RPF. The purity of anthocyanin rich extract obtained by MA-ATPE was 1.65-fold greater than microwave assisted extraction using 80% ethanol (MAE). The compositional characterization of anthocyanins were carried out with HPLC-QTOF-MS. MA-ATPE had no obvious changes on anthocyanin composition when compared to MAE. Results indicated that the MA-ATPE could be a promising method for the extraction and preliminary purification of anthocyanins from different plant materials.

    • SDG 12 · Sorumlu Üretim ve Tüketim
    AtıfScopus44WoS36OpenAlex42
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  • MakaleAçık Erişim2021Scopus SJRQ3
    Effect of heating on structure and leaching characteristics of a zinc carbonate ore

    Kumas, Cavit; Obut, Abdullah

    In this work, the structural changes occurred in a zinc carbonate (smithsonite) ore sample following heating at temperatures between 523 K and 1173 K were investigated in detail using X-ray diffraction (XRD), thermal (TG/DTA) and Fourier-transform infrared (FT-IR) spectroscopy analyses. Afterwards, the leaching characteristics of zinc from the ore sample and the heated ore samples in sodium hydroxide solutions were determined. While heating at 523 K did not cause any structural change in the ore sample, heating at 723 K completely converted smithsonite (ZnCO3) in the ore sample to zinc oxide (ZnO), which resulted lower zinc leaching efficiencies of 40.6% and 62.0% for 3 and 4 mol/dm3 NaOH concentrations, respectively, in comparison to zinc leaching efficiencies (67.2% and 70.7%) obtained for the unheated ore sample. On the other hand, due to neoformation of dissolution resistant ZnFe2O4, Ca2ZnSi2O7 and ZmSiO4 phases during heating and formation of CaZm(OHD2H2O phase during leaching, the leaching efficiency of zinc further decreased to 22.2% and 31.3%, respectively, in 3 and 4 mol/dm3 NaOH solutions for the ore sample heated at 1173 K. The formation of zinc-containing dissolution resistant phases by high-temperature heating was observed to be the only reason for the reduction in the zinc leaching efficiency (49.4% at 1173 K) at the highest NaOH concentration (8 mol/dm3) studied. In this work, the comparative precipitation studies were also conducted and crystalline zinc oxides with different morphologies could be precipitated at considerably high efficiencies from the selected pregnant solutions obtained following leaching.

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  • MakaleYalnız künye2020Scopus SJRQ1
    Eocene tonalite–granodiorite from the Havza (Samsun) area, northern Turkey: adakite-like melts of lithospheric mantle and crust generated in a post-collisional setting

    Temizel, Irfan; Arslan, Mehmet; Yücel, Cem; Abdioğlu Yazar, Emel; Kaygusuz, Abdullah; Aslan, Zafer

    Eocene intermediate to felsic plutons of different sizes and compositions are widespread in the Eastern Pontides Orogenic Belt in northern Turkey. Of these, the Taşlık Tepe pluton in the Havza (Samsun) area is fine-to-medium-grained, with granular, porphyritic, and micrographic textures, and include mafic microgranular enclaves (MMEs). LA-ICP-MS U-Pb zircon dating yielded emplacement ages of 42.9 (± 1.4) and 40.5 (± 1.3) Ma for the host granodioritic pluton and the dioritic MMEs, respectively. Petrochemically, the host pluton has I-type, high-K calc-alkaline, and metaluminous-to-slightly peraluminous features (A/CNK = 0.95–1.06). The host pluton also shows geochemical features of adakite-like rocks with high SiO2 (67–68 wt%) and Al2O3 (15.5–16.0 wt%) content and Ba/La (17–23), Sr/Y (40.7–61.6), and LaN/YbN (14.4–23.7) ratios and low Y (8.2–9.9 ppm) and YbN (3.1–4.4) contents. Whole-rock major and trace element variations suggest that fractional crystallisation played a significant role in the pluton evolution. The N-MORB normalised trace element patterns of the pluton are similar to those of MMEs with enrichment in large-ion lithophile elements, Th and Ce, and negative Nb and Ti anomalies. Chondrite-normalised rare earth element plots show moderate-to-highly enriched concave patterns (LaN/LuN = 14.2–21.6) with insignificant negative Eu anomalies (EuN/Eu* = 0.86–1.14), all of which imply hornblende fractionation during magmatic evolution. The pluton samples have 87Sr/86Sr ratios of 0.704767 to 0.704927, 143Nd/144Nd ratios of 0.512767–0.512774, εNd values of (+2.52)–(+2.65), and δ18O values of 7.9–9.7‰. The isotopic compositions of the host pluton and MMEs are similar to I-type granitoids derived from mantle sources. The MMEs show incomplete magma mixing/mingling, representing small bodies of mafic parental magma. Combined with regional studies, these new data suggest that the parental magma of the studied adakite-like pluton was generated from the lithospheric mantle and then modified by fractional crystallisation and assimilation in a post-collisional setting.

    AtıfScopus33WoS30OpenAlex35
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  • MakaleAçık Erişim2020Scopus SJRQ2
    In situ monitoring of sugar content in breakfast cereals using a novel ft-nir spectrometer

    Aykas, Didem Peren; Ball, Christopher; Menevseoglu, Ahmed; Rodriguez-Saona, Luis E.

    This research demonstrates simultaneous predictions of individual and total sugars in breakfast cereals using a novel, handheld near-infrared (NIR) spectroscopic sensor. This miniaturized, battery-operated unit based on Fourier Transform (FT)-NIR was used to collect spectra from both ground and intact breakfast cereal samples, followed by real-time wireless data transfer to a commercial tablet for chemometric processing. A total of 164 breakfast cereal samples (60 store-bought and 104 provided by a snack food company) were tested. Reference analysis for the individual (sucrose, glucose, and fructose) and total sugar contents used high-performance liquid chromatography (HPLC). Chemometric prediction models were generated using partial least square regression (PLSR) by combining the HPLC reference analysis data and FT-NIR spectra, and associated calibration models were externally validated through an independent data set. These multivariate models showed excellent correlation (Rpre ≥ 0.93) and low standard error of prediction (SEP ≤ 2.4 g/100 g) between the predicted and the measured sugar values. Analysis results from the FT-NIR data, confirmed by the reference techniques, showed that eight store-bought cereal samples out of 60 (13%) were not compliant with the total sugar content declaration. The results suggest that the FT-NIR prototype can provide reliable analysis for the snack food manufacturers for on-site analysis.

    • SDG 2 · Açlığa Son
    AtıfScopus15WoS14OpenAlex14
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  • BildiriAçık Erişim2021
    QUALITY ASSESSMENT of PANSHARPENED RASAT and LANDSAT-8 IMAGES USING SYNTHETIC SENTINEL-2 PANCHROMATIC IMAGE

    Gunen, M.A.

    Technical and physical limitations often do not allow images to be acquired with high spatial and spectral resolution. Pansharpened images obtained by fusing high spatial resolution panchromatic images and multi-spectral images are widely used in GIS applications. In this study, it is aimed to increase the spatial resolution of the RASAT and Landsat-8 multispectral satellite images with synthetic Sentinel-2 panchromatic data. Six different pansharpening methods were used to test the success of the synthetic panchromatic data generation method using dataset with two different land use/land cover properties. Seven full reference image quality assessment metrics and two referenceless image quality assessment metrics were used to perform quantitative comparison.

    AtıfOpenAlex1
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  • MakaleYalnız künye2021Scopus SJRQ2
    Origin, petrogenesis and geodynamic implications of the early Eocene Altınpınar adakitic andesites in the eastern Sakarya Zone, northeastern Turkey

    Gücer, Mehmet Ali

    Early Cenozoic magmatism in the eastern Sakarya Zone (NE Turkey) provides an important constraint on the regional tectono-magmatic evolution of the region. Early Eocene syn-collisional adakitic rocks are observed as small stocks with outcropping areas commonly less than 10 km2. This study presents petrography, whole-rock geochemistry and Sr-Nd-Pb isotope data, as well as in-situ 40Ar/39Ar age constraints on one of these adakitic andesites in the Altınpınar area of Gümüşhane, and discusses source region, petrological processes and geodynamic setting prevailed during their genesis. Andesites commonly show microlitic porphyric and vitrophyric porphyric textures, and include significant amounts of mafic microgranular enclaves (MMEs). Plagioclase, hornblende, Fe-Ti oxides and minor pyroxene are the main mineral phases. In-situ 40Ar-39Ar amphibole dating constrains the cooling age of andesites into a time span from 52.8 ± 1.3–48.8 ± 1.9 Ma. Andesites are medium to high-K calc-alkaline and display most of the signatures typical of those of the adakites. They are characterized by moderate MgO (1.7–4.1 wt%), low Y (9−14 ppm), Yb (0.9–1.5 ppm), and HREE and high Sr (325−964 ppm) contents, and high Sr/Y (36–76) ratios. 87Sr/86Sr(t) (0.704948−0.705100) and 143Nd/144Nd(t) (0.512588−0.512628) ratios are in the isotopic range of the adakites. All these geochemical and isotopic data suggest that the parental magma of adakitic andesites has been produced by partial melting of oceanic basalts under amphibole-eclogite facies conditions during the breakoff of the northern Neotethyan oceanic slab.

    AtıfScopus11WoS7OpenAlex11
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  • MakaleAçık Erişim2020Scopus SJRQ3
    Effects of starter culture and storage on volatile profiles and sensory characteristicof yogurt or cream butter; [Utjecaj starter kulture i skladištenja na hlapive sastojke i senzorska svojstva maslaca od vrhnja i maslaca od jogurta]

    Gundogdu, Engin; Cakmakci, Songul; Hayaloglu, Ali Adnan

    In this study volatile compounds and sensory properties of butter produced from cream or yogurt using Lactococcus lactis subsp. lactis biovar. diacetylactis or Leuconostoc mesenteroides subsp. cremoris as well as a mixture of these two bacteria were investigated over 60 days. A total of 10 esters, 6 aldehydes, 11 ketones, 16 alcohols, 6 acids, 2 sulphides, 3 terpenes, and 3 miscellaneous compounds were detected. There were more volatile compounds in cream butter than in yogurt butter. While S-methyl thioacetate was only found in yogurt butter samples, hexanal, ethanol, 2-nonanone, 2-pentanone, 2-heptanone, acetic, butanoic (butyric) and hexanoic acid were the most abundant volatiles in both cream and yogurt butter. The results showed that the use of starter in the manufacturing of yogurt butter, which is traditionally produced without starters, affected the volatile compounds and sensory properties. The highest general acceptability scores were given to the butter samples containing mixed cultures at the end of storage.

    • SDG 2 · Açlığa Son
    AtıfScopus16WoS15OpenAlex16
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  • MakaleAçık Erişim2021Scopus SJRQ2
    Investigation of corrosion and thermal behavior of PU-PDMS-coated AISI 316L

    Taşdemir, Muharrem; Senaslan, Fatih; Çelik, Ayhan

    Polydimethylsiloxane (PDMS) is widely used from biomedical to industrial applications due to its nontoxic, hydrophobic, and transparent characteristics. PDMS has good thermal and adhesion properties; however, its mechanical properties are comparatively weak. Therefore, PDMS is blended with various polymers to effectively improve its mechanical properties. In this study, polyurethane (PU)-polydimethylsiloxane (PDMS) blended coatings of different concentrations were applied on the AISI 316L stainless steel surface. Their effects on corrosion and tribocorrosion properties were investigated in Ringer's solutions. The blended polymer coatings were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The thermal properties of samples were examined by TGA and DSC. The surface images and cross-sectional were investigated using scanning electron microscopy (SEM). Tribocorrosion tests were carried out at open circuit potential (OCP). It was determined that hydrophobicity and thermal stability of polymer coating increased, while corrosion resistance slightly decreased with the increasing PDMS concentration in the polymer blended. The friction coefficient of blends decreased as the PU concentration increased. As a result, it was determined that the polymer-coated samples containing up to 50% PDMS prevented corrosive wear under the OCP wear test in Ringer's solutions.

    AtıfScopus20WoS18OpenAlex16
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  • MakaleAçık Erişim2021Scopus SJRQ3
    PREDICTION SULPHURIC ACID AND WATER VAPOUR DEW POINT TEMPERATURES OF FLUE GASES AND COMBUSTION ANALYSIS FOR SOLID FUELS IN TURKEY

    Terhan, Meryem

    In the study, the combustion analysis is examined for the solid fuels in Turkey. The principal aim of the analysis is determined the limits and obstacles in the design heat exchanger to avoid the corrosion risk on the heat exchanger surfaces in the latent heat recovery applications from waste flue gas. To do this, in which regions of the heat exchanger the flue gas temperature reached to the sulphuric acid and water vapour dew point temperatures are required to predict. In order to predict the condensing zone, an air preheater for the coal-fired boiler in a heating system is designed using finite difference method. Designed the air preheater is consists of the counter-cross flow, U-shaped stainless steel tube bundle. The tube is discredited 200 cells to one-dimensional during the flow. The heat transfer rates, the flue gas and air inlet and outlet temperatures, surface temperatures of the tube wall, the mole fractions of water and sulphuric acid vapour, the other non-condensing gases in the flue gas are calculated in each discrete cell. According to the results of the study, while the dew point temperature of the water vapour changes over the range 30-40 °C, the acid dew point temperature waves to 125 °C from 140 °C for the coal types mined in Turkey.

    • SDG 7 · Erişilebilir ve Temiz Enerji
    AtıfScopus6WoS6OpenAlex6
    ScopusWeb of ScienceTR Dizinİncele
  • MakaleYalnız künye2021Scopus SJRQ3
    Long and short-term assessment of surface area changes in saline and freshwater lakes via remote sensing

    Yagmur, Nur; Bilgilioglu, Burhan Baha; Dervisoglu, Adalet; Musaoglu, Nebiye; Tanik, Aysegul

    Advances in remote sensing technology enable monitoring and detection of these vulnerable water bodies that bear numerous functions and ecological services beyond their intended use. As such, valuable data and information may be provided for long and short-term analyses and stored in a database for future projections. This paper initially grouped 18 natural lakes of the Konya Closed Basin of Turkey according to their salinity level. Freshwater, saline and brackish lakes have then undergone temporal analysis for every 5-year intervals via Landsat satellite images. Freshwater lake surfaces have not changed noticeably during the inspection period; however, saline waters have decreased in surface area by 32%. Beysehir Lake constituting 94% of the freshwater category and Tuz Lake representing 97% of the saline group were selected for the short-term analysis that was monthly conducted for years 2017 and 2018 with optical and SAR images to better verify cause and effect relationship.

    • SDG 6 · Temiz Su ve Sanitasyon
    • SDG 13 · İklim Eylemi
    AtıfScopus13WoS11OpenAlex16
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  • MakaleYalnız künye2020Scopus SJRQ2
    Investigation of the relationship between rare earth elements, trace elements, and major oxides in soil geochemistry

    Vural, Alaaddin

    Investigation on the behavior of elements in the soil is important both in exploration and environmental geochemistry studies. Rare earth elements (REEs) are the most useful among all trace elements. REE studies have shown that they have important applications in igneous, sedimentary, and metamorphic petrology. This work aims to investigate the relationship of these elements with one another and the behavior of the major oxides and trace elements with REEs. Soil samples were obtained from the alteration site possibly related to mineralization and were analyzed for major oxides, trace elements, and REEs. The relationships between the major oxide–trace element/heavy metal and REE were investigated by statistical methods, such as descriptive statistics, correlation coefficient, and principle component analysis. According to the correlation coefficient matrix, light REEs (LREEs) showed weak to moderate negative correlation with MgO and MnO and moderately positive correlation with SiO2 and K2O. No association was detected between the heavy REEs (HREEs) and the main oxides, but a strong positive correlation with LREEs was observed. For the trace elements, LREE showed a weak positive correlation with Ba and Sn and moderate to strong positive correlation with As, Hf, Nb, Rb, Ta, Th, U, W, and Zr. They also displayed weak to moderate correlation with Sc, Co, Zn, Ni, and V. HREE showed weak to moderate positive correlation with Ni, Cs, Ga, Hf, Th, Zr, As, and LREE. Although REEs exhibited no direct correlation with Au and Ag, they showed a good correlation with some trace elements that are related to hydrothermally altered products. This study showed that REEs can also be used in exploration and environmental geochemistry studies by exploiting the relationship between REEs and other trace/heavy metal elements.

    AtıfScopus28WoS26OpenAlex25
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  • MakaleAçık Erişim2022Scopus SJRQ3
    MULTIPLICATIVE CHEBYSHEV DIFFERENTIAL EQUATIONS AND MULTIPLICATIVE CHEBYSHEV POLYNOMIALS

    Yalcin, Numan

    In this work, the definition of the first and second types of multiplicative Cheby-shev differential equations is given and the solutions of these equations are inves-tigated with the help of multiplicative power series. Also, the properties of first and second type multiplicative Chebyshev polynomials are given and proved. Fi-nally, these studies are supported with numerical examples.

    AtıfScopus4WoS2OpenAlex9
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  • MakaleAçık Erişim2021
    Analysis of literature on 3D cadastre

    Döner, Fatih

    In this study, it is aimed to analyse the three-dimensional (3D) cadastre literature in terms of legal, institutional, and technical aspects. For this purpose, 441 publications published between 2001 and 2019 were examined. In the literature, which includes publications from 59 different countries the studies mostly focused on technical issues. An international consensus on legal, institutional, and technical aspects of a 3D cadastre solution seems difficult. Since rights, restrictions, and responsibilities with a 3D component are somehow registered administratively, stakeholders from the legal domain are reluctant to 3D cadastre. From a technical point of view, the technology required to use 3D digital data for registration has matured sufficiently in the past twenty years. However, further research on a real 3D cadastre solution, creating a workflow that considers both current legal and technical framework beyond pilot studies, is needed.

    • SDG 16 · Barış, Adalet ve Güçlü Kurumlar
    AtıfScopus20WoS20OpenAlex28TR Dizin4
    ScopusWeb of ScienceTR Dizinİncele
  • MakaleYalnız künye2021Scopus SJRQ3
    The performance of wong-zakai approximations for the investigation of stochastic differential equation models with nonlinear multiplicative noise

    Sengul, S.; Bekiryazici, Z.; Merdan, M.

    In this study, Wong-Zakai approximation method has been applied for the analysis of stochastic differential equations appearing in engineering sciences. Wong-Zakai approximation has been used with similar stochastic approximation methods to compare the approximate solutions of the problems and comment on the performance of the method. Models for lake pollution and computer virus spread under antivirus protection have been used with nonlinear stochastic noise as numerical examples to demonstrate the efficiency of Wong-Zakai method.

  • Derleme MakaleAçık Erişim2019Scopus SJRQ2
    The importance of antioxidants and place in today’s scientific and technological studies

    Zehiroglu, Cuma; Ozturk Sarikaya, Sevim Beyza

    Antioxidants have become scientifically interesting compounds due to their many benefits such as anti-aging and anti-inflammatory. Today, it is still used in many areas. In food technology, antioxidants are added to many foodstuffs in order to enrich the foods and eliminate the problems. Therefore, studies to determine the antioxidant activities of natural foods and their components are also continuing rapidly. Antioxidants have also been replaced in the encapsulation studies used for the preservation and stabilization of food components. Of course, preservation of foods is as important as their production. The latest packaging techniques for food preservation are edible films and coatings. The protective function of edible films and coatings can be improved by the addition of antioxidants. Unlike these, studies on plants and animals have been investigated in vivo in terms of how the antioxidant activity changes as a result of metabolic activities. The role of antioxidant enzymes in these studies is quite large. Many results have been found for the elimination of diseases by either in vivo or in vitro studies regarding antioxidants. Thus, the importance of antioxidants increased with the use in pharmacology, cosmetics and medicine. In this study, we tried to bring a current perspective to antioxidants played an active role in many fields by combining the technological applications and scientific studies of antioxidants. In order to further customize the issue, we have done this especially for the food and health field and we have tried to emphasize the importance of antioxidants in this way.

    • SDG 2 · Açlığa Son
    AtıfScopus252WoS190OpenAlex273
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  • MakaleYalnız künye2021Scopus SJRQ1
    Effects of puzzolanic materials in surface paste disposal by pilot-scale tests: observation of physical changes

    Bascetin, A.; Adiguzel, D.; Eker, H.; Odabas, E.; Tuylu, S.

    There are only a few pilot schemes, especially among scientific studies carried out to solve numerous environmental and ecological problems created by water during tailing storage on the surface. It is extremely important to establish precautions that can be taken, especially in the tailing storage process by examining the physical, chemical, mineralogical, and geotechnical changes that develop due to the effect of moisture in the tailing and surface water. In this study, 2 different pilot-scale designs of storage with no additions (reference) and with binder additions (cement and fly ash) to some layers were observed in field conditions for about 1 year to determine the effects of seasonal changes on paste material. The results of the measurements revealed that the water content of the reference design was ~ 10% higher than that of the design with cement addition at the substrates that provide stability and sudden temperature changes at the top layer of the reference design was found to be ~ 35 °C. Maximum sudden temperature changes in layers with cement addition and layers with cement and fly ash addition were observed to be ~ 15 °C. As a result, the use of cement has made the material more resistant to external factors. However, the study also revealed that fly ash could be used instead of cement with a substitute rate of 50% to reduce the cost for long-term storage in terms of industrial applications.

    • SDG 12 · Sorumlu Üretim ve Tüketim
    AtıfScopus22WoS17OpenAlex38
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  • MakaleYalnız künye2020Scopus SJRQ1
    Geochemistry of the Middle Jurassic sediments in Gümüşhane, north-eastern Turkey: Implications for weathering and provenance

    Saydam Eker, Çiğdem; Arı, Uğur V.

    The whole-rock geochemistry and Sr-Nd isotope data of Middle Jurassic sedimentary rocks in the Gümüşhane area (north-eastern Turkey) were analysed to reconstruct the provenance, chemical weathering, sediment recycling history, and tectonic setting of the source area. Based on trace element ratios and rare earth element (REE) patterns, it was interpreted that the sandstones were derived from a source area with felsic-mafic rocks as dominant contributors. The average chemical index of alteration (CIA) and weathering index (WIP) values are low with respect to Upper Continental Crust (UCC) in the studied sandstones and mudstones, but the index of compositional variability (ICV) values are high, thus revealing weak–moderate weathering conditions. The average Th/U ratios of the sandstones and mudstones indicate a relatively simple cycling history. The positive and low negative εNd values support the supposition that the source area did not undergo much sedimentary change. A model mixture composed of 60% granite, 5% granodiorite, and 35% gabbro could be deduced to be the potential source composition of Middle Jurassic sediments; this model was reinforced by the 87Sr/86Sr ratios and εNd(t) values of the sediments. The Middle Jurassic siliciclastic sedimentary rocks of the Gümüşhane region were likely deposited in a tectonic environment with a passive margin.

    AtıfScopus15WoS17OpenAlex16
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  • MakaleYalnız künye2021Scopus SJRQ3
    The effect of homocysteine on the expression of CD36, PPARγ, and C/EBPα in adipose tissue of normal and obese mice

    Mentese, Ahmet; Dogramaci, Seniz; Demir, Selim; Yaman, Serap Ozer; Ince, Imran; Altay, Diler Us; Erdem, Mehmet; Turan, Ibrahim; Alver, Ahmet

    The purpose of this study was to investigate the effect of homocysteine (Hcy) on CD36, PPARγ, and C/EBPα gene and protein expression in adipose tissue obtained from normal and high-calorie diet obesity models. CD36, PPARγ, and C/EBPα gene expression and protein levels in adipose tissue specimens were determined using the RT-PCR and ELISA methods, respectively. Significantly increased CD36 gene expression was observed in adipose tissue from obese mice, while Hcy significantly reduced CD36 gene expression in adipose tissue from normal and obese mice. PPARγ and C/EBPα gene expression levels decreased significantly in all groups compared to the normal group. In addition, levels of both PPARγ and C/EBPα gene expression were lower with Hcy supplementation compared to their own controls. In conclusion, Hcy’s reduction of CD36 gene expression in adipose tissue may be one probable factor in hyperhomocysteinemia representing an independent risk factor for cardiovascular diseases.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus2WoS2OpenAlex2
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  • MakaleAçık Erişim2020
    Political Polarization and Size of Government; [Politik Kutuplaşma ve Devletin Ekonomik Boyutu]

    Keyifli, Nazlı; Akdede, Sacit Hadi

    In this study, it empirically examines the impact of economic and political determinants on the economic size of the government. Political polarization is taken as the variable of interest, along with other control variables. Statistical analysis was carried out using the Ordinary Least Squares and Second Stage Least Squares methods. The scope of the paper includes 61 countries, and the time interval is between 1990 and 2015. The results of the regression analysis show that the share of public consumption spending in national income in countries where political polarization is high is declining. In addition, the increase in levels of ethnic fracturalization, democracy and government fractionalization has an increasing effect on the share of public consumption spending in national income. The study provides descriptive linkages among findings.

    • SDG 8 · İnsana Yakışır İş ve Ekonomik Büyüme
    • SDG 16 · Barış, Adalet ve Güçlü Kurumlar
    AtıfScopus1OpenAlex4TR Dizin5
    ScopusWeb of ScienceTR Dizinİncele