Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(7)
- Araz, Onur(6)
- Ozdes, Duygu(6)
- Duran, Celal(5)
- Şahin, Rıdvan(5)
- Kankal, Murat(4)
- Reis, Hatice Catal(4)
- Saydam Eker, Çiğdem(4)
- Şan, Murat(4)
- Alemdag, Selcuk(3)
- Anaç, Halil(3)
- Cakir, Tufan(3)
- Günen, Mehmet Akif(3)
- Ozturk, Kasif Furkan(3)
- Turk, Veysel(3)
- Çelik, Orkun(3)
- Öztürk, Serkan(3)
- Adali, Zafer(2)
- Alemdağ, Selçuk(2)
- Alkan, Hamdi(2)
- Aydin, Aydanur(2)
- Baltacı, Cemalettin(2)
- Bayram, Adem(2)
- Büyüksaraç, Aydın(2)
- Catal Reis, Hatice(2)
- Cebi, S.(2)
- Cevik Onar, S.(2)
- Dağ, Serhat(2)
- Ekici, Lutfiye(2)
- Gül, Abdulkadir(2)
- Kahraman, C.(2)
- Kahraman, Muhammet Mustafa(2)
- Karatas, Seyda Merve(2)
- Kaya, Ayberk(2)
- Khoshelham, Kourosh(2)
- Köseoğlu, Ali(2)
- Melek, Mesut(2)
- Merdan, Mehmet(2)
- Nacar, Sinan(2)
- Ozeken, Sengul Tugba(2)
Yayınlar
- MakaleYalnız künye2021Scopus SJRQ2Design of series tuned mass dampers for seismic control of structures using simulated annealing algorithm
Araz, Onur; Kahya, Volkan
The effectiveness of the series tuned mass dampers (STMDs) in reducing the dynamic vibrations of the structures under the ground motion is investigated, and their optimum parameters are obtained based on the simulated annealing (SA) optimization. The STMD is one of the most well-known passive control devices which consists of two TMD units arranged in series. However, only a few studies are available on the control performance and optimum parameters of the STMDs for structural systems subjected to ground motion. Thus, the goal of this study is to carry out a thorough optimization analysis based on the SA algorithm for the structures equipped with an STMD under the effect of ground motion. The objective function is selected as the reduction of the displacement response of the structure. It is proved that the optimum STMD has better effectiveness than the optimum TMD in suppressing the maximum story displacement of the structure. Further, the effect of the frequency shift on the effectiveness of the optimally designed STMD is investigated.
AtıfScopus38WoS32OpenAlex37
İncele - MakaleYalnız künye2021Scopus SJRQ2Investigating the historical development of accuracy and precision of Galileo by means of relative GNSS analysis technique
Yalvac, Sefa
Galileo navigation system has significantly expanded satellite constellation over the last few years and now serves with 22 satellites in three orbital planes. The development of the Galileo is not only limited to the number of satellites in the space segment, but also the quality of the IGS MGEX products produced by different Analysis Centers has increased gradually and brought up the topic of investigation of the accuracy and precision of the Galileo-only positioning. However, almost all of the studies on Galileo-only positioning in the literature have been performed with Precise Point Positioning method and comprehensive studies with the relative positioning technique are quite a few. In this study, the development of the accuracy and precision of the Galileo from 2016 to the end of 2019 (4 years) has been investigated for the first time by means of relative positioning technique. For this purpose, data of eight GNSS stations selected from the IGS MGEX network were obtained and analyzed with GAMIT/GLOBK software as GPS-only and Galileo-only, separately. Using the daily solutions obtained from both navigation systems, time series were produced and the differences between them were compared in order to reveal the Galileo accuracy. According to the results, the accuracy of the Galileo was variable during the experiment and it could be examined in three periods. The averages of 3D positioning error in the first period (2016-2017) is 14.92 mm and improved by 56%, and decreased to 6.55 mm in the second period (2017-2018), and then improvement at 23% in the third period (2018 to the end of 2019) and decrescent to level of 5.13 mm on average for all stations. Similarly, standard deviations obtained from Galileo increased during the experiment and during the 3rd period it was closed to a few mm with GPS. It was concluded that the accuracy and precision of the Galileo showed parallel development and the development was directly related to the number of satellites in the Galileo constellation, and as a result, nowadays, Galileo-derived coordinates are close to the coordinates obtained from the GPS by a few mm.
AtıfScopus10WoS10İncele - BildiriYalnız künye2021Scopus SJRQ4Sequential Pattern Mining Method for Predictive Maintenance of Large Mining Trucks
Kahraman, Abdulgani; Kantardzic, Mehmed; Kahraman, M. Mustafa; Kotan, Muhammed; Hasic Telalovic, J.; Kantardzic, M.
In recent decades, various solutions had been sought for reducing operating costs while increasing the production of minerals in mining operations. Equipment health monitoring technologies had been used for monitoring and increasing the availability of machines. However, the data obtained from these technologies had only been used for monitoring the equipment health, and not for the prediction of failures. In this paper, it was relied on alarms and signals collected through real-time health monitoring technologies for predicting crucial mining truck failures. Sequential Pattern Mining (SPM) Method for Predictive Maintenance had been developed and implemented as a methodology to discover which group of alarms and signals might be related to specific truck failures. The results indicate that the SPM method is able to detect machine failures of trucks with high accuracy with an average 96%. The proposed methodology may reduce the maintenance time, and the expenditures caused by truck breakdowns in the mining industry.
AtıfScopus3OpenAlex4İncele - MakaleYalnız künye2021Scopus SJRQ2Exopolysaccharide of Anoxybacillus pushchinoensis G11 has antitumor and antibiofilm activities
Genc, Berna; Taskin, Mesut; Adiguzel, Ahmet
Exopolysaccharides (EPS/EPSs) possess several various applications in the food and pharmaceutical industries. This study was performed to investigate the biological (antibiofilm and antitumor), rheological (temperature, shear rate, and density) and chemical (solubility, carbohydrate and protein content, composition, molecular weight, functional group analysis, thermal analysis, X-ray diffraction pattern and scanning electron microscopy) properties of the EPS, which was purified from the locally isolated thermophilic bacterium Anoxybacillus pushchinoensis G11 (MN720646). EPS was found to have antibiofilm and antitumor [lung (A-549) and colon (Caco-2 and HT-29) cancer] activities. The viscosity of EPS showing Newtonian flow was temperature dependent. As chemical properties, the EPS was found to be a heteropolysaccharide containing arabinose (57%), fructose (26%), glucose (12%), and galactose (5%). EPS contained 93% carbohydrates and 1.08% protein. The molecular weight of EPS was determined as 75.5 kDa. The FTIR analysis confirmed the presence of sulfate ester (band at 1217 cm−1), an indication of the antitumor effect. The EPS was semi-crystalline. It could maintain 36% of its weight at 800 °C and crystallization and melting temperatures were 221 and 255.6 °C. This is the first report on the EPS production potential and the biological activity of A. pushchinoensis.
AtıfScopus22WoS21OpenAlex25
İncele - MakaleYalnız künye2021Scopus SJRQ2Effect of working pressure and post-annealing on structural, optical and electrical properties of p-type NiO thin films produced by RF magnetron sputtering technique
Şenaslan, Fatih; Taşdemir, Muharrem; Çelik, Ayhan
Nickel oxide (NiO) films were deposited on glass and silicon substrates using a Ni target by radio-frequency (RF) sputtering at various working pressure ranging from 5 to 20 mTorr. The films were annealed for 2 h at 400 °C in the air ambient. The effect of working pressure on structural, optical and electrical properties of NiO films was investigated in detail. The deposition rate of the films gradually increased with decreasing working pressure. The X-ray diffraction (XRD) presented that the crystal quality and the average crystallite size of annealed films increased with decreasing working pressure. The X-ray photoelectron spectroscopy (XPS) confirmed the presence of Ni2+ and Ni3+ ions along with the main peak and satellite peaks in the NiO films. Raman spectroscopy exhibited the one-phonon and two-phonon vibrations modes corresponding to Ni–O bond. UV–Visible analyses showed that annealed NiO thin films have higher transmittance than deposited ones. The band gap of the films increased from 3.33 to 3.52 eV with decreasing working pressure and further increased after the annealing process. The electrical properties were affected by the varying crystallinity and lattice defects depending on the deposition condition. All annealed NiO films exhibited p-type conductivity. The lowest resistivity (4.2 Ω.cm) was obtained from the annealed film after deposition at 5 mTorr.
AtıfScopus30WoS25OpenAlex32İncele - MakaleYalnız künye2021Scopus SJRQ2Assessment of the concentration and environmental impacts of potential hazardous elements in coalfields in Northeastern Turkey
Saydam Eker, Ç.; Sipahi, F.; Akpınar, I.
To investigate the impact of potential hazardous element (PHE) contamination on environmental and human health, the coaly shale, coal and shale coal outcrops of four sites, namely Ozyurt, Tarhanas, Kayadibi (Gümüşhane), and Manas (Bayburt), were selected as sampling areas for this study. The samples were analyzed using inductively coupled plasma (ICP) emission spectrometry and inductively coupled plasma-mass spectrometry (ICP-MS) and a Rock–Eval 6 analyzer with a total organic carbon module. The enrichment factor (EF), potential ecological risk index (RI), and potential health risk index (HI) assessment models were used to evaluate the environmental and health risks in the vicinity of the coals. Results indicated that the mean concentrations of PHEs extensively changed and even exceeded the upper continental crust and world average values of low-rank coal concentrations. The assessment of the EF, RI and HI models revealed that the contamination levels of As, Hg, and Cd were higher than those of Pb, Co, Ni, V, and Mo. The evaluation of the EF revealed that the largest and lowest contamination levels of As, Hg, and Cd were observed in Ozyurt (29) and Kayadibi (1.8), Manas (9.6) and Kayadibi (1), and Kayadibi (5.6) and Tarhanas (1.9), respectively. A high-potential ecological risk was present in Ozyurt and Manas, whereas a considerable risk exists in Kayadibi and Tarhanas. The potential health risk values of As for children in Ozyurt, Tarhanas, and Manas and adults in Ozyurt were excessively high. This finding suggested the possibility of transferring the contamination from the coal, shale coal, and coaly shale outcrops
AtıfScopus5WoS4OpenAlex6İncele - MakaleYalnız künye2021Scopus SJRQ2The effects of freeze-thaw cycles and block size on the use of the Gümüşhane Granitoid (Gümüşhane/Turkey) as building stone
Dağ, Serhat; Alemdağ, Selçuk; Kaya, Ayberk
The present study aims to examine the usability of the Gümüşhane Granitoid as a building stone taking into consideration the short-term freeze-thaw cycles and mean block volume. A total of 180 specimens were used in the study prepared from the block samples compiled from 10 different areas in the Gümüşhane (NE Turkey) provincial borders. Mean block volume was calculated about 8 dm3 during the discontinuity studies carried out on the Gümüşhane Granitoid; as a result of which, it was determined that the granitoids are suited for obtaining blocks. The annual freeze-thaw cycle map of Turkey was used for determining the number of freeze-thaw cycles to be applied on the rocks in addition to taking into account the weathering of monzogranites. A total of 25 freeze-thaw cycle tests were applied on the rocks with experimental studies repeated at every 5 cycles. It was determined following the freeze-thaw tests that significant changes have occurred especially in the strength and water absorption parameters of the monzogranites and that they have been affected negatively. This indicates that the monzogranites are not suited for outdoor use as building stone in regions such as the Gümüşhane province and regions with similar climate characteristics, but that they can be used in a lot of regions with more moderate climates. As a building stone, monzogranites can be used either as cobblestone, curbstone, or paving stone subject to their mean block volume. It is considered that the widespread of the Gümüşhane Granitoid may provide a substantial economical income to the country.
AtıfScopus5OpenAlex5İncele - MakaleYalnız künye2021Scopus SJRQ2Effects of GSM 1800 band radiation on composition, structure and bioactivity of exopolysaccharides produced by yoghurt starter cultures
Karatas, Seyda Merve; Ekici, Lutfiye; Develi, Ibrahim; Dertli, Enes; Sagdic, Osman
In this study, the effects of GSM 1800 band radiation on composition, structure and bioactivity of exopolysaccharides (EPSs) produced by Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus were determined. For this, GSM 1800 band radiation was applied to both cultures and characteristics of EPSs extracted from the control groups (K) and the radiation stressed groups (R) were determined. An alteration in the chemical composition of the EPSs was observed and EPS production levels and molecular weights of the EPSs increased following the GSM 1800 band radiation application. Alterations in the functional groups, thermal and morphological characteristics of EPSs following the GSM 1800 band radiation application were confirmed by FTIR, TGA and SEM analysis, respectively. Importantly no alterations in the antioxidant and antibacterial activity of the EPSs were observed following the radiation application. These results suggested the effects of the GSM radiation on final characteristics of EPSs from yogurt starter cultures.
AtıfScopus8WoS5İncele - MakaleYalnız künye2021Scopus SJRQ2Analysis of Mining Lost Time Incident Duration Influencing Factors Through Machine Learning
Kahraman, Muhammet Mustafa
Despite technological advancements and organizational adjustments, lost time accidents are major issues in occupational safety. However, there is very limited work that focuses on variables influencing days lost as a result of occupational accidents. In this study, decision tree and artificial neural network methods were used as machine learning techniques to investigate the impact of factors on accident lost day duration. Degree of injury, worker age, and worker activity were found to be the top three variables impacting loss of time from work. It was also identified that the mining method, location, and nature of injury had a moderate influence on duration lost due to occupational accidents. However, worker experience and ore type did not have any significant impact on the duration, which is an unexpected result. These results confirmed that some accident factors that might have a large influence on the number of mine accidents can be less critical when it comes to accident lost day duration.
AtıfScopus14WoS14OpenAlex11İncele - MakaleYalnız künye2021Scopus SJRQ2Geochronology, petrogenesis and tectonic importance of Eocene I-type magmatism in the Eastern Pontides, NE Turkey
Vural, Alaaddin; Kaygusuz, Abdullah
Eastern Pontides are hosted to many granitoids with different composition, size and age ranges from Paleozoic to Cenozoic. Of these granitoids, especially those of the Cenozoic age are commonly observed in the southern part of the Eastern Pontides, and rarely in the northern part. This paper focuses on the Eocene aged Avliyana Granitoid, located south of the Eastern Pontides, intruding into Late Cretaceous and Eocene volcanic and sedimentary rocks. The Avliyana Granitoid is mainly diorite and tonalite and composed of plagioclase, quartz, orthoclase, hornblende, biotite, pyroxene, and Fe-Ti oxides. It shows granular, locally poikilitic and micrographic texture. The Avliyana Granitoid has I-type, medium to high-K calc-alkaline, and metaluminous character, and has a narrow SiO2 contents (57–64 wt.%). The rocks are enriched in light rare earth elements (LREEs) and large-ion lithophile element (LILEs), and depleted in high field strength elements (HFSEs). Chondrite-normalized REE distributions are concave shaped (LaN/LuN = 5.87–11.92) and show negative Eu anomaly (Eu / Eu * = 0.55–0.81). Geochemical results show that plagioclase, pyroxene, hornblende, and Fe-Ti oxide fractionation are effective in the development of the rocks. The εNd(i) values of the rocks are between – 1.0 and – 0.1, 87Sr/86Sr(i) values are between 0.70531 and 0.70563, and the model ages (TDM) are between 0.79 and 0.93. U-Pb SHRIMP zircon ages of the Avliyana Granitoid rocks range from 45.60 ± 0.55 to 44.75 ± 0.36 Ma. In calculations made from zircon and apatite, the crystallization temperatures vary between 714 and 867 °C. The data revealed that the parental magma of the Avliyana Granitoid was derived from the enriched lithospheric mantle, and fractional crystallization and lesser assimilation played a role in the evolution of the rocks.
AtıfScopus16OpenAlex22İncele - MakaleYalnız künye2021Scopus SJRQ3Flame atomic absorption spectrometric determination of total chromium and cadmium in bean samples after ultrasonic-assisted microextraction using ionic liquid Aliquat-336
Elik, Adil; Karakoy, Tolga; Çilesiz, Yeter; Altunay, Nail
A new and rapid microextraction approach termed as ultrasonic-assisted ionic liquid-based microextraction (UA-ILME) was developed using ionic liquid Aliquat-336 as extraction solvent for the extraction of chromium and cadmium in bean samples collected from different regions in Turkey. The total amounts of analytes in the samples were measured by flame atomic absorption spectrophotometry. The basis of the extraction step is based on the complexation of Cr(III) and Cd(II) with diethyldithiocarbamate at pH 4.0. The hydrophobic ternary complexes containing analytes were then rapidly extracted from the sample solution to the ionic phase under the ultrasonic effect using tricaprylylmethylammonium chloride (Aliquat-336). Some experimental variables (pH, ligand amount, extraction solvent volume, ultrasound time, extraction temperature and sample volume) were optimized in detail. Following the optimization steps, the limits of detection (LODs, 3Sblank/m) for Cr(III) and Cd(II) were calculated as 0.45 ng mL−1 with linear range of 1.5–380 ng mL−1 and 0.25 ng mL−1 with linear range of 0.8–220 ng mL−1, respectively. Enrichment factors and average recoveries were ranged from 125.8–96.4 to 92.7–106.5%, respectively. The accuracy and precision of the method were validated by analyzing a certified reference material and spiked recovery tests. The UA-ILME method was successfully applied to the determination of Cd and Cr in the samples, highlighting that the matrix ions under consideration do not affect the extraction and determination steps.
AtıfScopus4OpenAlex6İncele - Derleme MakaleYalnız künye2021Scopus SJRQ1Assessment of the relationship between renewable energy and employment of the United States of America: Empirical evidence from spectral Granger causality
Çelik, Orkun
In this study, the spectral Granger causality nexus between renewable energy generation and employment for the period February 1973–September 2019 in the USA is examined. The results obtained from the study expresses that there is no spectral Granger causality relationship between renewable energy generation and employment for aforementioned period in the USA. Furthermore, these findings support neutrality hypothesis, which means that there is no causality relation between the variables. In other words, renewable energy generation does not influence employment and employment does not have an effect on renewable energy generation.
AtıfScopus16WoS14OpenAlex20İncele - MakaleYalnız künye2020Scopus SJRQ2Distinct contamination indices for evaluating potentially toxic element levels in stream sediments: a case study of the Harşit Stream (NE Turkey)
Saydam Eker, Çiğdem
This paper revealed that the level of certain potentially toxic elements (PTEs) can be reflected in stream and terrace sediments from Harşit Stream in Northeast Turkey. The potential toxicity of these elements was established by determining and interpreting the enrichment factor (EF), contamination index (Pi), ecological risk index (Eri), modified hazard quotient (mHQ), hazard quotient (HQ), and hazard index (HI). The distribution of PTEs in the sediment samples was non-uniform along the different sites of the stream. The change in concentration was attributed to the release of these elements from different sources (agricultural activities, industrial activities, and gasoline discharges). Results indicated that the stream sediments were locally contaminated by the following PTEs: Pb, As, and Cd based on EF values; Cu, Pb, Zn, As, Cd, and Hg based on Pi; Pb, Cd, and Hg based on Eri; and Pb, As, Cd, and Hg based on mHQ. According to the HQ and HI values of Pb, risks were posed to human health especially to children. Meanwhile, terrace sediments were locally contaminated as follows: Zn and As based on EF; Cu, Pb, Zn, As, and Cd based on Pi; and Zn and Cd based on Eri. The HQ and HI values of As were found to be > 1, suggesting a high chance of health risk to children. The PTE levels and the local distribution pattern revealed that agricultural activities, industrial functions, and gas stations along the stream were probable sources of toxic element contamination in sediments from the Harşit Stream. These findings can help evaluate the potential toxicity risks affecting living organisms.
AtıfScopus31WoS30OpenAlex33İncele - MakaleYalnız künye2020Scopus SJRQ1Decision making with MABAC method under probabilistic single-valued neutrosophic hesitant fuzzy environment
Şahin, Rıdvan; Altun, Fatma
Recently, there has been great interest on single valued neutrosophic hesitant fuzzy set theory. When compared single valued neutrosophic set, it is more convenient for real life situations. But even in this case, there is still missing data for some decision problems. Probabilistic single valued neutrosophic hesitant fuzzy sets (PSVNHFSs) are defined to solve this problem. Even though it contains more information, it needs some improvements. In this paper, the modified PSVNHFS is defined and some improvements in the theory of PSVNHFS are proposed. Also, we improve some algebraic properties of this set theory and define a distance operator for PSVNHFSs. Then we introduce two aggregation operators called probabilistic single valued neutrosophic hesitant fuzzy weighted arithmetic average (PSVNHFWA) operator and probabilistic single valued neutrosophic hesitant fuzzy weighted geometric average (PSVNHFWG) operator related to algebraic properties presented in this paper. Also, we extend the MABAC method under the probabilistic single valued neutrosophic hesitant fuzzy set theory. Finally, we give an illustrative example to demonstrate the stability and reliability of the proposed theory.
AtıfScopus41WoS27OpenAlex34İncele - MakaleYalnız künye2020Scopus SJRQ2Comparison 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.
AtıfScopus9WoS8OpenAlex11İncele - MakaleAçık Erişim2020Scopus SJRQ2Investigation of linear difference equations with random effects
Merdan, Mehmet; Şişman, Şeyma
In this study, random linear difference equations obtained by transforming the components of deterministic difference equations to random variables are investigated. Uniform, Bernoulli, binomial, negative binomial (or Pascal), geometric, hypergeometric and Poisson distributions have been used for the random effects for obtaining the random behavior of linear difference equations. The random version of the Z-transform, the RZ-transform, has been used to obtain an approximation for the random linear difference equation. Approximate expected values and variances are calculated by using the RZ-transform. The results have been obtained with Maple and are shown in graphs. It is shown that the random Z-transform is an effective tool for the investigation of random linear difference equations.
AtıfScopus5WoS5OpenAlex6İncele - MakaleYalnız künye2020Scopus SJRQ2Analytical and finite element solutions of continuous contact problem in functionally graded layer
Kaya, Yusuf; Polat, Alper; Özşahin, Talat Şükrü
In this study, we solve the continuous contact problem of two layers with different material properties, loaded with two rigid flat blocks and resting on a rigid plane, by analytical and finite element methods. All surfaces are assumed to be frictionless. The upper layer is the functionally graded layer (FG), the height h1, the underlying layer is homogeneous, and the height is h2. It is assumed that the FG layer is isotropic and that the shear modulus and density change exponentially. The FG layer is loaded by means of two rigid flat blocks whose external loads are Q and P (per unit thickness in z direction). In the analytical solution of the problem, stress and displacement expressions are substituted in the boundary conditions and the problem is demoted to singular integral equations where the contact stresses are the unknown functions. These singular integral equations are solved numerically using the Gauss–Chebyshev integration formulas. Two-dimensional finite element analysis of the problem is performed using the ANSYS package program. The analyses are performed for different shear modulus ratios (μ2/μ-h1), distances between the blocks ((c − b)/h1) and inhomogeneity parameters (βh1). The contact stresses under the blocks, the normal stresses (σy) between interfaces of the FG layer and the homogeneous layer and between the homogeneous layer and rigid plane are also measured. In addition, the initial separation load and the initial separation distances (χcr, λcr) of the FG layer and homogeneous layer are determined. The results are presented comparatively as graphs and tables.
AtıfScopus18WoS19OpenAlex14İncele - MakaleYalnız künye2020Scopus SJRQ2Medium scale earthflow susceptibility modelling by remote sensing and geographical information systems based multivariate statistics approach: an example from Northeastern Turkey
Dağ, Serhat; Akgün, Aykut; Kaya, Ayberk; Alemdağ, Selçuk; Bostancı, Hasan Tahsin
The aim of the present study was to produce an earthflow susceptibility map for the city center and environs of the province of Rize located at the Northeastern part of Turkey. The study area is the rainiest region of Turkey, and due to the triggering effect of precipitation earthflows are frequently observed in and around the study area. Besides this point, weathered rock units and steep topography accompany with precipitation for the occurrence of earthflow cases. Considering this point, an earthflow susceptibility mapping was inferred to be a necessity for the area. Parameters, such as lithology, slope gradient, slope aspect, topographical wetness index (TWI), stream power index (SPI), slope curvature, and sediment capacity index (LS) were considered to be earthflow conditioning parameters. A multi-temporal earthflow inventory map for a period of 4 years (2011–2015) was initially generated by way of remote sensing approach and field surveys. Earthflow susceptibility map was produced using the logistic regression method after which the produced susceptibility map was validated. The mapped earthflows were separated into two groups prior to modelling and validation. The first group was for training and the second group was for validation steps. The accuracy of the model was measured by fitting them to a validation set of mapped earthflows. Area under curvature (AUC) approach was applied for validation purposes. The prediction capability of the earthflow susceptibility map produced can be regarded as acceptable in accordance with the AUC values of 0.62 for the logistic regression model. Based on these results, the obtained earthflow susceptibility map can be used to mitigate hazards related to landslides and to aid in land-use planning for the Rize city center.
AtıfScopus26WoS23OpenAlex31İncele - MakaleYalnız künye2020Scopus SJRQ2Discovery and evaluation of inhibitory activity and mechanism of arylcoumarin derivatives on Theileria annulata enolase by in vitro and molecular docking studies
Yakarsonmez, Sinem; Danis, Ozkan; Mutlu, Ozal; Topuzogullari, Murat; Sariyer, Emrah; Yuce-Dursun, Basak; Turgut-Balik, Dilek
Abstract: In this study, the inhibition potential of 3- and 4-arylcoumarin derivatives on Theileria annulata enolase (TaENO) was assessed for the first time in the literature. Firstly, protein stabilization analyses of TaENO were performed and it was found that the enzyme remains stable with the addition of 6 M ethylene glycol at + 4 °C. Inhibitor screening analyses were carried out using 25 coumarin derivatives on highly purified TaENO (> 95%), and four coumarin derivatives [4-(3,4-dimethoxyphenyl)-6,7-dihydroxy-2H-chromen-2-one (C8); 4-(3,4-dihydroxyphenyl)-7,8 dihydroxy-2H-chromen-2-one (C9); 4-(3,4-dihydroxyphenyl)-6,7-dihydroxy-2H-chromen-2 one (C21); and 3-(3,4-dihydroxyphenyl)-7,8-dihydroxy-2H-chromen-2-one (C23)] showed the highest inhibitory effects with the IC50 values of 10.450, 13.170, 8.871 and 10.863 µM, respectively. The kinetic results indicated that these compounds inhibited the enzyme by uncompetitive inhibition. In addition, the successful binding of the most potent inhibitor (C21) into TaENO was confirmed by using MALDI-TOF mass spectrophotometry. Molecular docking analyses have predicted that C8 and C21 coumarin derivatives which showed high inhibitory effects on TaENO were interacted with high affinity to the potential regions out of the active site. Taken together, these coumarin derivatives (C8, C9, C21 and C23) are first known potent, nonsubstrate, uncompetitive inhibitors of TaENO and these results will facilitate further in vitro and in vivo analysis toward structure-based drug design studies. Graphic abstract: [Figure not available: see fulltext.]
AtıfScopus5WoS5OpenAlex6İncele - BildiriYalnız künye2020Scopus SJRQ4Sliding mode control for a quadrotor UAV transporting a cable-suspended payload
Bingöl, Özhan; Güzey, Haci Mehmet; Ronzhin, A.; Shishlakov, V.
In this study, a second-order sliding mode control (2-SMC) strategy has been developed to control a small quadrotor UAV with a suspended payload. It is shown that the existence of a load will cause an oscillation on the system and its movement will remarkably change the dynamics of the quadrotor. In order to overcome this, an upgraded 2-SMC has been suggested to ensure the stability of the system. Firstly, the mathematical model of the quadrotor-suspended payload system is derived based on Lagrange approach, then the suggested controller is designed, and the stability of the system is proved by Lyapunov theory. Finally, numerical simulations are carried out to demonstrate the robustness of the proposed method.
AtıfScopus3OpenAlex4İncele