Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(62)
- Merdan, Mehmet(58)
- Duran, Celal(50)
- Ozdes, Duygu(47)
- Kaygusuz, Abdullah(43)
- Ashyralyyev, Charyyar(38)
- Karsli, Orhan(33)
- Öztürk, Serkan(32)
- Araz, Onur(31)
- Demir, Selim(29)
- Kulakaç, Nurşen(29)
- Dokuz, Abdurrahman(28)
- Arslan, Mehmet(27)
- Baltacı, Cemalettin(27)
- Maden, Nafiz(27)
- Sipahi, Ferkan(27)
- Topal, Fevzi(27)
- Turan, Ibrahim(27)
- Kandemir, Raif(25)
- Kurt, Kemal(24)
- Ozturk, Samet(24)
- Peker, Iskender(24)
- Vural, Alaaddin(24)
- Reis, Hatice Catal(23)
- Yücel, Cem(23)
- Aydin, Faruk(22)
- Baltaci, Cemalettin(22)
- Gücer, Mehmet Ali(22)
- Günen, Mehmet Akif(22)
- Kankal, Murat(22)
- Topal, Meryem(22)
- Karimullah, Suud Sarim(21)
- Uysal, Ibrahim(20)
- Kurnaz, Muammer(19)
- Tuncer, Metin(19)
- Yolcu, Halil(19)
- Çelik, Necati(19)
- Ürkek, Bayram(19)
- Şan, Murat(19)
- Aliyazicioglu, Yuksel(18)
Yayınlar
- MakaleYalnız künye2021Scopus SJRQ2Enological properties of red wine produced from native Kösetevek grapes (Vitis vinifera L.) cultivated in Eastern Anatolia
Arpa Zemzemoglu, Tuba Eda; Darıcı, Merve; Cabaroglu, Turgut
The aim of this study was to determine the potential of red wine production from the Kösetevek grape variety (Vitis Vinifera L.) cultivated in Elazig province of Turkey and to define the characteristics of Kösetevek wines. To determine the grapes for wine production quality, the general composition, phenolic compounds, aroma compounds and sensory analysis of the wines were carried out. Aroma compounds were performed by solid-phase extraction (SPE) and then analyzed by gas chromatography (GC) along with gas chromatography/mass spectrometry (GC/MS). Results showed that the red wines obtained from Kösetevek grapes consisted of 50 aroma compounds for 2014 vintages and 49 aroma compounds for 2015 vintages. Esters were the main components contributing to the Kösetevek wine aroma along with ethyl hydrogen succinate and ethyl–4–hydroxy butanoate. The amount of total phenolic compounds, total anthocyanin, and the tannin in Kösetevek wines were found to be between 3705.45 and 3015.63 mg/L, 554.25–502.35 mg/L, and 4.5–3.95 g/L at 2014–2015 vintages, respectively. As to sensory evaluation, Kösetevek wines were characterized as a deep purple color, middle to high body, and rich in red fruit (cherries, plums), and dried fruit odors. This study has provided enological properties and aroma characterization of Kösetevek wines. The results of the study showed that Kösetevek wines could be considered as an alternative to other wines obtained from native grape varieties of the region.
AtıfScopus4WoS4OpenAlex4
İncele - MakaleYalnız künye2021Scopus SJRQ1Simultaneous 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.
AtıfScopus44WoS36OpenAlex42İncele - MakaleAçık Erişim2021Scopus SJRQ3Effect 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.
AtıfScopus8WoS6OpenAlex5İncele - BildiriAçık Erişim2021QUALITY ASSESSMENT of PANSHARPENED RASAT and LANDSAT-8 IMAGES USING SYNTHETIC SENTINEL-2 PANCHROMATIC IMAGE
Gunen, M.A.; Karas, I.R.; Ben Ahmed, M.; Boudhir, A.A.; Ane, B.K.
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.
AtıfOpenAlex1İncele - MakaleYalnız künye2021Scopus SJRQ2Origin, 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.
AtıfScopus11WoS7OpenAlex11İncele - MakaleAçık Erişim2021Scopus SJRQ2Investigation 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.
AtıfScopus20WoS18OpenAlex16İncele - MakaleAçık Erişim2021Scopus SJRQ3PREDICTION 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.
AtıfScopus6WoS6OpenAlex6
İncele - MakaleYalnız künye2021Scopus SJRQ3Long 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.
AtıfScopus13WoS11OpenAlex16İncele - MakaleAçık Erişim2021Analysis 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.
AtıfScopus20WoS20OpenAlex28TR Dizin4İncele - MakaleYalnız künye2021Scopus SJRQ3The 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.
- MakaleYalnız künye2021Scopus SJRQ1Effects 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.
AtıfScopus22WoS17OpenAlex38İncele - MakaleYalnız künye2021Scopus SJRQ3The 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.
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İncele - MakaleAçık Erişim2021Scopus SJRQ2Determination of the effect of wheat germ on the mineral and fatty acid composition and aroma compounds of tarhana: A traditional fermented cereal food
Tekgül, Yeliz; Çalışkan Koç, Gülşah; Erten, Edibe Seda; Akdoğan, Arda
In this study, to supply to the trend toward natural and functional foods that do not include synthetic products, the wheat germ which exists as waste in nature was added to tarhana formulation in order to increase the nutritional content of tarhana. Wheat germ supplemented tarhana samples met the recommended dietary allowances of iron. A total of 63 compounds were detected and quantitated in all samples. Terpenes and terpenoids were observed as the dominant compound group. The addition of wheat germ to tarhana dough resulted in an increase in the number of volatile compounds. The most abundant odor-active compounds were acetic acid and 2-acetylpyyrole.The mineral (Mg, K, Zn, Mn), fatty acid (undecaenoic, linoleic, gondoic acid, and α-linolenic), oil, acid (propanoic and hexanoic), alcohol (linalool, benzyl, phenylethyl), aldehyde ((E)-2-heptenal, nonanal, 5-methyl-2-phenyl-2-hexenal), ketone (3-Octen-2-one), terpene (junipene, citronellol, trans-Carveol) contents of tarhana samples can be increased by addition of the wheat germ. Practical applications: The wheat germ which exists as waste in nature and contains a high amount of essential amino acids, proteins, fatty acids, minerals, dietary fiber, vitamins, etc. Wheat germ can be added to cereal-based food formulation such as tarhana in order to supply to the trend toward natural and functional foods that do not include synthetic products. Tarhana (basically made from yogurt, wheat flour, herbs, tomato, pepper, onion, etc.) which is a traditional fermented dry Turkish soup is rich in vitamins, minerals, and proteins. Wheat germ based-fermented products such as Tarhana may be considered promising new functional foods due to its probiotic effects in order to expand the market due to the increasing trend toward functional foods.
AtıfScopus18WoS14İncele - MakaleAçık Erişim2021Scopus SJRQ3Crank-nicolson difference scheme for reverse parabolic nonlocal problem with integral and neumann boundary conditions
Ashyralyyev, Charyyar; G¨onenc¸, Ahmet
In this paper, we study Crank-Nicholson difference scheme for approximate solutions of parabolic nonlocal reverse problem with integral and Neumann boundary conditions. Stability estimates for its solution are established. Via Mathlab framework, we give numerical example with explanation on computer realization.
AtıfScopus5OpenAlex3İncele - MakaleAçık Erişim2021Scopus SJRQ3A comprehensive spatiotemporal evaluation of the current earthquake activity in different parts of the Frakull-Durrës fault zone, Albania
Öztürk, Serkan; Ormeni, Rrapo
This study presents a detailed spatiotemporal analysis for the Frakull-Durrës (F-D) fault zone at the beginning of 2020. For this purpose, the most frequently used statistical seismicity parameters such as magnitude completeness, Mc-value, Gutenberg-Richter b-value, recurrence times, annual probabilities and standard normal deviate, Z-value, were mapped. The F-D fault zone was divided into two seismogenic subregions, and Mc-value was taken as 2.5 for both the south and north parts. The b-value was estimated as 0.83 ± 0.06 for the south part and 0.85 ± 0.06 for the north part. b-values for both zones are smaller than 1.0 and these values may be considered to be a larger stress accumulation to build up over time and to be released by the next possible earthquakes. Clear decreasing trends were observed in time variations of b-values before the occurrences of several strong main shocks. Analyses of annual probabilities and recurrence times suggest that the study region has an intermediate/long-term earthquake hazard in comparison to occurrences of strong/destructive earthquakes in the short term. Some anomaly regions of a small b-value and a large Z-value were found along the F-D fault zone at the beginning of 2020: i) among Lushnje-Tirana-Durrës including the middle part of the F-D fault zone, ii) in and around Lezha including the north end of the F-D fault zone. Thus, the combination of regions with the lowest b-value and largest Z-value may supply preliminary results for earthquake hazard, and these regions may be considered to be the most likely regions for future strong/large earthquakes in the F-D fault zone.
AtıfScopus7WoS2OpenAlex4İncele - MakaleAçık Erişim2021Scopus SJRQ2A Data-Driven Approach to Control Fugitive Dust in Mine Operations
Kahraman, Muhammet Mustafa; Erkayaoglu, Mustafa
Particulate matter (PM) is one of the main actors related to air pollution caused by surface mining. Fugitive dust, considered as particulate matter that cannot be collected by conventional measures, is classified by the particle size. The Environmental Protection Agency (EPA) categorizes PM as coarse and fine particles based on the particle size being less than 10 μm (PM10) and less than 2.5 μm (PM2.5). Basic operations of surface mining such as drilling and blasting, loading, haulage, and processing are processes that can potentially generate fugitive dust. Regulations and legislations enforce the mining industry to use environmental monitoring systems, fugitive dust level measured by PM10 level as part of this. Air quality monitors are positioned at different locations around surface coal mines and track air quality levels during production. This study introduces a data-driven methodology to handle air quality issues related to fugitive dust at surface coal mines. Data is sourced from different mine equipment in real-time and they are integrated with air quality monitoring systems to provide information to support decisions for fugitive dust. The method is implemented and demonstrated in a case study at a large surface coal mine.
AtıfScopus22WoS18OpenAlex13İncele - MakaleAçık Erişim2021Scopus SJRQ1Diagnosis of COVID-19 and non-COVID-19 patients by classifying only a single cough sound
Melek, Mesut
In the last month of 2019, a new virus emerged in China, spreading rapidly and affecting the whole world. This virus, which is called corona, is the most contagious type of virus that humanity has ever encountered. The virus has caused a huge crisis worldwide as it leads to severe infections and eventually death in humans. On March 11, 2020, it was announced by the World Health Organization that a COVID-19 outbreak has occurred. Computer-aided digital technologies, which eliminate many problems and provide convenience in people's lives, did not leave humanity alone in this regard and rushed to provide a solution for this unfortunate event. One of the important aspects in which computer-aided digital technologies can be effective is the diagnosis of the disease. Reverse transcription-polymerase chain reaction (RT-PCR), which is a standard and precise technique for diagnosing the disease, is an expensive and time-consuming method. Moreover, its availability is not the same all over the world. For this reason, it can be very attractive and important to distinguish the COVID-19 disease from a cold or flu through a cough sound analysis via smartphones which have entered into the lives of many people in recent years. In this study, we proposed a machine learning-based system to distinguish patients with COVID-19 from non-COVID-19 patients by analyzing only a single cough sound. Two different data sets were used, one accessible for the public and the other available on request. After combining the data sets, the features were obtained from the cough sounds using the mel-frequency cepstral coefficients (MFCCs) method, and then, they were classified with seven different machine learning classifiers. To determine the optimum values of hyperparameters for MFCCs and classifiers, the leave-one-out cross-validation (LOO-CV) strategy was implemented. Based on the results, the k-nearest neighbors classifier based on the Euclidean distance (kNN Euclidean) with the accuracy rate, sensitivity of COVID-19, sensitivity of non-COVID-19, F-measure, and area under the ROC curve (AUC) of 0.9833, 1.0000, 0.9720, 0.9799, and 0.9860, respectively, is more successful than other classifiers. Finally, the best and most effective features were determined for each classifier using the sequential forward selection (SFS) method. According to the results, the proposed system is excellent compared with similar studies in the literature and can be easily used in smartphones and facilitate the diagnosis of COVID-19 patients. In addition, since the used data set includes reflex and unconscious coughs, the results showed that conscious or unconscious coughing has no effect on the diagnosis of COVID-19 patients based on the cough sound.
AtıfScopus38WoS26OpenAlex45İncele - MakaleYalnız künye2021Scopus SJRQ1Sodium silicate effect on setting properties, strength behavior and microstructure of cemented coal fly ash backfill
Cavusoglu, Ibrahim; Yilmaz, Erol; Yilmaz, Ali Osman
Representing an engineered mixture of coal fly ash, cement and water, cemented coal fly ash backfill (CCB) is typically employed for filling the openings created after coal excavation in the earth. A high rate of productivity for coal mines requires a high early-age strength backfill design. Therefore, the use of admixtures in CCB is key for accelerating the backfill setting time and augmenting short-and long-term strength. This study offers the effect of sodium silicate (SS) as an accelerator on early age mechanical and microstructure properties of CCB. SS-based admixture was used for a dosage of 0.5, 1 and 1.5 wt% in CCB that contains 25 wt% ordinary Portland cement OPC and 75 wt% coal fly ash. Backfill setting time was done by using the Vicat system while its strength and pore structure were measured by using the uniaxial compressive strength test, and scanning electron microscopy and Hg intrusion porosimetry. Results display that use of SS in CCB increases its short-term strength gain up to 14% and shortens the mining cycle by cutting its setting time up to 58%. The microstructure analyses also indicate that CCB formulated with SS has a finer pore structure than that without admixture. The outcomes of the present study will be advantageous to evaluate both setting time and strength behavior of CCB used in coal mines, thereby causing the effective backfill plan in terms of money saving and easy operation.
AtıfScopus149WoS141OpenAlex146İncele - MakaleAçık Erişim2021Scopus SJRQ1A Two-Phase Approach using Mask R-CNN and 3D U-Net for High-Accuracy Automatic Segmentation of Pancreas in CT Imaging
Dogan, Ramazan Ozgur; Dogan, Hulya; Bayrak, Coskun; Kayikcioglu, Temel
Background and objective: The size, shape, and position of the pancreas are affected by the patient characteristics such as age, sex, adiposity. Owing to more complex anatomical structures (size, shape, and position) of the pancreas, specialists have some difficulties in the analysis of pancreatic diseases (diabetes, pancreatic cancer, pancreatitis). Therefore, the treatment of the disease requires enormous time and depends on the experience of specialists. In order to decrease the rate of pancreatic disease deaths and to assist the specialist in the analysis of pancreatic diseases, automatic pancreas segmentation techniques have been actively developed in the research article for many years. Methods: Although the rapid growth of deep learning and proving satisfactory performance in many medical image processing and computer vision applications, the maximum Dice Similarity Coefficients (DSC) value of these techniques related to automatic pancreas segmentation is only around 85% due to complex structure of the pancreas and other factors. Contrary to previous techniques which are required significantly higher computational power and memory, this paper suggests a novel two-phase approach for high-accuracy automatic pancreas segmentation in computed tomography (CT) imaging. The proposed approach consists of two phases; (1) Pancreas Localization, where the rough pancreas position is detected on the 2D CT slice by adopting Mask R-CNN model, (2) Pancreas Segmentation, where the segmented pancreas region is produced by refining the candidate pancreas region with 3D U-Net on the 2D sub-CT slices generated in the first phase. Both qualitative and quantitative assessments of the proposed approach are performed on the NIH data set. Results: In order to evaluate the achievement of the recommended approach, a total of 16 different automatic pancreas segmentation techniques reported in the literature are compared by utilizing performance assessment procedures which are Dice Similarity Coefficient (DSC), Jaccard Index (JI), Precision (PRE), Recall (REC), Pixel Accuracy (ACC), Specificity (SPE), Receiver Operating Characteristics (ROC) and Area under ROC curve (AUC). The average values of DSC, JI, REC and ACC are computed as 86.15%, 75.93%, 86.27%, 86.27% and 99.95% respectively, which are the best values among well-established studies for automatic pancreas segmentation. Conclusion: It is demonstrated with qualitative and quantitative results that our suggested two-phase approach creates more favorable results than other existing approaches.
AtıfScopus70WoS55OpenAlex68İncele - Kitap BölümüYalnız künye2021Integrated Reporting and Combined Assurance: A Qualitative Research on the Awareness in Turkey*
Selimoglu, Seval Kardes; Yesilcelebi, Gul
Purpose: The aim of this study is to reveal the opinions of the auditors, academicians, and institutions that published integrated reports regarding the development and execution of the assurance process of integrated reports. Design/methodology/approach: For this purpose, interviews were conducted using qualitative research technique to determine awareness about integrated reporting and combined assurance. Within the scope of the research, semi-structured interviews were conducted with six auditors, five academicians, and five workers in institutions that published integrated reports. Qualitative data analysis method was used to analyze the data. Findings: As a result of the research, combined assurance process criteria were proposed in the integrated reports which in line with the opinions of the participants. Originality/value: Institutions around the world are increasingly publishing integrated reports. However, when institutions publish integrated reports, there is no clear standard or any guidance on how to ensure the reliability of these reports. It is seen that AA1000, ISAE3000, GRI Standards, and some local standards are used to provide assurance. At this point, the combined assurance model can be used for the reliability of the information in the integrated reports. Integrated reporting and combined assurance are still relatively new concepts in Turkey. Furthermore, this study is important in terms of the lack of studies on how to provide combined assurance for integrated report when scanned related literature in Turkey. Although readily integrated reporting continued in Turkey, it continues to be an area of application is still under development. In particular, the research reflects the level of integrated reporting awareness and how to ensure assurance of these reports.
AtıfScopus1OpenAlex3İncele