Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(66)
- Merdan, Mehmet(56)
- Duran, Celal(50)
- Ozdes, Duygu(47)
- Kaygusuz, Abdullah(42)
- Demir, Selim(37)
- Turan, Ibrahim(37)
- Ashyralyyev, Charyyar(34)
- Dokuz, Abdurrahman(33)
- Araz, Onur(31)
- Öztürk, Serkan(31)
- Sipahi, Ferkan(30)
- Kandemir, Raif(28)
- Arslan, Mehmet(27)
- Karsli, Orhan(27)
- Kulakaç, Nurşen(26)
- Baltacı, Cemalettin(25)
- Gücer, Mehmet Ali(25)
- Kurt, Kemal(25)
- Maden, Nafiz(25)
- Ozturk, Samet(25)
- Topal, Fevzi(25)
- Baltaci, Cemalettin(24)
- Yücel, Cem(24)
- Aliyazicioglu, Yuksel(23)
- Bayrakdaroglu, Serdar(23)
- Kankal, Murat(23)
- Peker, Iskender(23)
- Yolcu, Halil(23)
- Reis, Hatice Catal(21)
- Topal, Meryem(21)
- Vural, Alaaddin(21)
- Aydin, Aydanur(20)
- Aydin, Faruk(20)
- Bayraktar, Alemdar(20)
- Kurnaz, Muammer(20)
- Çelik, Necati(20)
- Ürkek, Bayram(20)
- Cakir, Tufan(18)
- Günen, Mehmet Akif(18)
Yayınlar
- MakaleYalnız künye2021Scopus SJRQ3The First Measurement for Mass Attenuation Coefficients, Effective Atomic Numbers, and Electron Densities of Y123 and Y358 High-Temperature Superconductors (HTS) for the Energies from 46.6 to 1332 keV
Düzgün, İbrahim
Y123 and Y358 high-temperature superconductor phases have experimental mass attenuation coefficients (MAC) determined at 46.5, 81, 122, 302, 356, 383, 662, 1173, and 1332 keV photon energies. The experimental values have been compared with theoretical values acquired employing the XCOM software and database. It has been observed that the theoretical and the empirical results were in perfect agreement. Also, it has been seen that the comparison of the MACs for all specimens examined with the corresponding photon energies complies with the exponential absorption law. The effective atomic numbers (Zeff) and electron densities (Nel) of Y123 and Y358 superconducting phases in different energy ranges have determined experimentally and theoretically. The Y358 superconductor specimen is a relatively better absorber than the Y123 between 40 and 100 keV.
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İncele - MakaleYalnız künye2021Scopus SJRQ2Performance evaluation of IEEE 802.15.7 CSK modulation under blue shift effect of optical receiver filters
Küçük, Mehmet Ali; Türk, Kadir
In recent years, the use of light-emitting diodes (LEDs) in lighting, which has higher energy efficiency and longer-lasting environmentally friendly lighting compared to conventional lighting devices, has accelerated the development of a promising new technology for short-range wireless optical transmission called visible light communication (VLC). Besides other applications, VLC switches the LEDs at very high speeds to simultaneously realize indoor lighting and data transmission. But the intensity and color of the lighting may vary because of data transmission. Color shift keying (CSK) modulation defined in the IEEE 802.15.7 VLC standard guarantees constant light intensity and color. The CSK receiver uses a band-pass optical filter to separate the light channels. However, the transition band of optical filters shifts towards the blue wavelength depending on the incidence angle of the light which is called the blue shift effect. In this paper, the performance of the CSK receiver is investigated for the first time under the blue shift effect in the case of single and multiple transmitter LED cells. The numerical results show that the blue shift effect significantly decreases system performance. To eliminate the distorting effect, various methods and an adaptive equalizer-based CSK receiver are proposed. The proposed structures provide notable improvement.
AtıfScopus9WoS9OpenAlex7İncele - MakaleYayıncıda açık erişim2021Automatic extraction of trees by using multiple return properties of the lidar point cloud
Ozdemir, Samed; Akbulut, Zeynep; Karsli, Fevzi; Acar, Hayrettin
Airborne laser scanning has been a valuable tool for forestry applications since it began to be used commercially. Thanks to the high 3D resolution provided by the Light Detection and Ranging (LiDAR) point cloud, it has provided great convenience in complex 3D modeling processes needed for forestry applications such as forest inventory, forest management, determination of carbon stocks and the characterization of biodiversity. LiDAR data provides a new dimension in forestry applications with its high 3D resolution and multiple return characteristics. The extraction of woodland areas from the LiDAR point cloud has great importance for automating the determination of tree heights, species and stand frequency which will be used for generating canopy height models (CHM). In this study, woodland areas in the urban scene were automatically extracted by using the multiple return properties of the LiDAR point cloud. The proposed approach consists of three major steps namely pre-processing, parameter calculation and k-d tree search for trees which were implemented in MATLAB. In the first step, multiple return points have been identified from the LiDAR point cloud, which will be then used to determine possible tree locations. Then, by using Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm, neighborhood relations among the multi return points which were extracted from the initial point cloud data, were formed and a rule-based filter was applied by taking advantage of neighborhood relations. In addition, the initial point cloud was filtered with the Cloth Simulation Filtering (CSF) algorithm to separate ground and non-ground points where non-ground points used to extract trees. In the second step, non-vegetation points were removed by applying a threshold based on the change of curvature and planarity parameters, which are derived from the filtered non–ground point cloud. In the last step, in order to extract trees, a k-d tree structure was created from the filtered non-ground points to find nearest neighbors of each multi return point within a given diameter in the k-d tree structure. In order to evaluate the accuracy of the approach, the extracted boundaries were compared with the manually digitized woodland boundaries from the true orthophoto of the study area using correctness, completeness and quality metrics.
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İncele - MakaleYalnız künye2021Scopus SJRQ3The Effect of Grain Growth Temperature on the Trapped Magnetic Field of Y358 Superconductors
Başoğlu, M.
In this study, three different Y358 samples were produced by the melt-powder-melt-growth (MPMG) method at different maximum grain growth temperatures of 1030 °C, 1040 °C, and 1050 °C. The differential thermal analysis (DTA), X-ray powder diffraction (XRD), magnetic levitation force, trapped magnetic field values and magnetization measurements were performed. According to the results, the highest magnetic levitation force, the highest critical current density and the highest trapped magnetic field values were obtained from the sample produced at the temperature of 1050 °C.
AtıfScopus5WoS5OpenAlex5İncele - MakaleYalnız künye2021Scopus SJRQ2The effect of complementary and integrative medicine on symptom management and quality of life in Turkish oncology patients: a cross-sectional study
Demir Doğan, Melike; Savuci, Yıldız; Aydın Sayılan, Aylin
Aim: This study was conducted to determine the perceived effect of complementary and integrative medicine CIM) methods used by oncology patients on their symptom management and quality of life patients attending a Turkish oncology setting. Methods: 145 oncology Turkish oncology patients were surveyed between July 2018 and August 2018. Data were collected on personal and demographic information, the Edmonton Symptom Assessment Scale, The Nightingale Symptom Assessment Scale. Complementary and integrative medicine use was determined by the Complementary and Alternative Medicine (CAM) Scale. Results: Age had a positive significant correlation with CIM use, particularly manipulative and herbal approaches. Educational status had a negative significant correlation with CIM use and cognitive-behavioral therapy subscale. A positive significant correlation was determined between the duration of cancer diagnosis and the cognitive-behavioral therapies subscale. A positive significant correlation was determined between cognitive-behavioral therapies subscale and social well-being state. Conclusion: CIM approaches are commonly used by Turksih oncology patients.
AtıfWoS1OpenAlex1İncele - MakaleYalnız künye2021Scopus SJRQ2The effects of noise levels on pain, anxiety, and sleep in patients
Aydın Sayılan, Aylin; Kulakaç, Nurşen; Sayılan, Samet
Background: Intensive care is a noisy environment for patients and one that affects pain, anxiety levels, and sleep quality. Aims and objectives: To determine the relationship between noise levels and pain, anxiety, and sleep levels in patients in intensive care units. Design: A descriptive and observational study design was used. Methods: This study was conducted between June and December 2018 in a public hospital and included 111 patients admitted to surgical critical care for at least 24 hours. Three Benetech Gm1351 manual sound level metres were used to measure noise. A Patient Information Form, a pain Visual Analog Scale (VAS), the Spielberger State-Trait Anxiety Inventory, and the Richards Campbell Sleep Questionnaire (RCSQ) were used for data collection. Results: The mean age of the patients was 57.29 years. The mean noise level detected in the intensive care unit was 66.52 dB (dB). Patients' mean pain VAS score was 3.79 ± 1.72, the mean State Anxiety Inventory score was 39.74 ± 2.98, and the mean total RCSQ score was 25.10 ± 13.17. Our findings show that patients in the intensive care unit are exposed to high noise levels and that, while this has no effect on pain, it significantly impacts anxiety and quality of sleep. Conclusions: Noise levels in intensive care units significantly exceed recommended thresholds, and this adversely affects patients' anxiety levels and sleep quality. It is important for suitably restful conditions to be provided for patients, to be aware of the potential for anxiety, and for these factors to be borne in mind when planning nursing interventions. Relevance to clinical practice: Further studies on the effects of noise levels on pain, anxiety, and sleep levels in patients admitted to intensive care units are needed.
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İncele - MakaleAçık Erişim2021Scopus SJRQ2The effect of COVID-19 anxiety levels of healthcare professionals on the quality of working life and related factors
Aydın, Aykut; Kulakaç, Nurşen; Aydın Sayılan, Aylin
Aim: This study aims to determine the effect of COVID-19 anxiety levels of healthcare professionals on their working life quality. Method: The sample of the descriptive, cross-sectional and correlational study consisted of healthcare professionals working in two university hospitals in western Turkey between May and July 2021. We used the “Personal Information Form, Coronavirus Anxiety Scale, and Working Life Quality Scale” as data collection tools. We used numbers and percentage calculations, arithmetic mean, median (25th–75th percentile), Mann–Whitney U test, Spearmen correlation analysis and Linear Regression analysis to analyse the data. Results: The mean score on the Quality of Life Scale of healthcare professionals was 3.74 ± 0.28, and the mean score on the Coronavirus Anxiety Scale (CAS) was 9.66 ± 6.06 (min. 0; max. 20). We found a negative and weakly significant relationship between the mean score of the CAS of healthcare professionals and the mean score of the employee quality of life scale. According to the results of the multiple linear regression analysis, we found the factors significantly affecting the anxiety states of healthcare professionals related to the Coronavirus are the quality of working life, age, sex and the state of caring for a patient with COVID-19. Conclusion: As a conclusion of this study, it was determined that healthcare professionals experienced anxiety, and anxiety decreased as ages, working years and the number of children they have increased. In addition, it was determined that as the anxiety of healthcare professionals increased, the quality of working life decreased.
AtıfScopus9WoS6İncele - MakaleAçık Erişim2021Scopus SJRQ1Performance of AC overlays using geogrids on PCC contraction joints
Çelik, Muhammet; Seferoğlu, Mehmet Tevfik; Akpınar, Muhammet Vefa
It is widely known that vertical displacements and strains occur on the joints and these cause defects on the asphalt concrete (AC) overlays on existing Portland cement concrete (PCC) pavements. Various approaches were introduced to minimize these defects. In this study, the effect of joint support formed using the geogrid material with grout mortar on the vertical displacement of PCC and the strain at the bottom of the AC layer. Produced layers were exposed to 1,186,000 Equivalent Single Axle Load (ESAL) in an APT (Accelerated Pavement Test) facility and the results were monitored. According to the obtained results, the use of AC overlay reduces vertical displacement in the PCC by 75%. When geogrid reinforced AC overlay was used, an additional reduction in displacement by 41.2% was achieved. Geogrid reinforcement reduced strain values formed at the bottom of the AC layer from 29.5% to 92.5%. The use of geogrid at joints instead of increasing the thickness of the AC layer from 50 to 80 mm resulted a more significant reduction in both strain and displacement. Besides, the usage of a geogrid interlayer instead of increasing the thickness of the AC layer also provided a significant cost reduction of 57.9% in overall cost.
AtıfScopus2WoS2OpenAlex3İncele - MakaleYalnız künye2021Scopus SJRQ1Extraction of Metals from Scrap Marble Cutting Segments in Nitric Acid Solutions
Celep, Oktay; Orak, Mürsel; Yazici, Ersin Y.; Deveci, Hacı
Extraction of cobalt, copper, and silver from scrap saw-blade segments using nitric acid solutions (0.1–0.4 M, 20–60°C) were investigated using response surface methodology. Extraction of cobalt and iron was more extensive than copper and silver, i.e., 35.7–96.2% Co and 72.6–100% Fe versus 8.50–35.4% Cu and 8.11–22.5% Ag. Statistical analysis of the experimental data has shown that increasing the acid concentration or temperature enhances the rate and extent of leaching of metals. Under suitable conditions, almost complete leaching of cobalt (99.9%), as well as high extractions of copper (95.9%) and silver (94.9%), were achieved. The activation energy, calculated to be 40.3 kJ/mol, indicates that nitric acid leaching of these metals occurs as a chemically controlled reaction. These findings have demonstrated that nitric acid as an effective oxidant/leaching agent could be suitably used for the extraction of cobalt, copper, and silver from scrap segments.
AtıfScopus4WoS3OpenAlex4İncele - MakaleYalnız künye2021Scopus SJRQ2N epeta meyeri essential oil ameliorates fungal infection and the antioxidant response in grapevines (Vitis vinifera) infections by gray mold (Botrytis cinerea)
Karakuş, Sinem; Atici, Ökkeş; Köse, Cafer; Aydin, İhsan
The essential oil (EO) obtained from Nepeta meyeri Benth. used to struggle allelopathically with gray mold (Botrytis cinerea Pers.), which causes significant damage to vineyards (Vitis vinifera L. cv. Karaerik). The EO from N. meyeri was determined to contain 4aα, 7α, 7aα-nepetalactone (71.68%) at the highest rate when analyzed with GC/MS. Then, the doses (0.6, 0.8, and 1.0 µL/leaf) of 1 ppm EO solution were applied to the leaves together with the fungus inoculation (EO + F), as well as 1 day (EO + F1D) and 2 days (EO + F2D) before inoculation. The fungus application alone was evaluated as a control. Seven days after the inoculations, fungus development, lipid peroxidation level (as malondialdehyde), the contents of reactive oxygen species (ROS), photosynthetic pigments and soluble proteins, and the activities of antioxidant enzymes (superoxide dismutase, catalase, peroxidase, and glutathione reductase) were determined in the leaves. Findings revealed that EO + F1D among the applications and 1.0 µL/leaf among the EO doses significantly prevented fungus development on the leaf, compared to the control. Moreover, the same applications decreased ROS levels, such as H2O2 and O2·− and lipid peroxidation, while they increased antioxidant enzyme activities, as well as chlorophyll and soluble protein contents. Therefore, it can be suggested that the EO from N. meyeri has a potentially powerful usage as biofungicide in the allelopathic struggle against the infection of B. cinerea in vineyards.
AtıfScopus5WoS4OpenAlex6İncele - MakaleYalnız künye2021Scopus SJRQ2The impact of export dynamics on trade balance in emerging and developed countries: An evaluation with middle income trap perspective
Akbas, Yusuf Ekrem; Sancar, Canan
In this study, it was analyzed whether the export dynamics affected net exports in fourteen emerging countries and eight developed countries between the years of 1995–2019. Export sophistication, export product diversification, export market diversification, export product concentration, export market concentration, and real effective exchange rate were used as the proxy of export dynamics. Panel data methods that take into account cross-section dependency and structural breaks were used for the analysis. As a result of the study, in developed countries, it was concluded that export sophistication, export product concentration, and export market diversification positively affected the net export, and the real effective exchange rate negatively affected the net export. For the emerging countries, it was concluded that export market concentration and real exchange rate negatively affected the net exports. Also, in emerging countries, it was found that export sophistication and export product diversification do not have any impact on net exports since export sophistication and export product diversification are not an adequately high level compared to developed countries for increasing the net export. The fact that in these countries the proportion of high-tech product exports are low in total exports and the product range in exports are not wide cause these indexes to be low. This situation poses a significant risk in terms of falling into the middle-income trap.
AtıfScopus19WoS12OpenAlex23İncele - MakaleAçık Erişim2021Scopus SJRQ3Satellite-derived shallow wetland bathymetry using different classification algorithms and datasets
Dervisoglu, Adalet; Yagmur, Nur; Bilgilioglu, Burhan Baha
Remote sensing (RS) effectively identifies, analyzes, and monitors wetlands. In addition to these two-dimensional studies, RS is used with several techniques in determining shallow water depths. The primary purpose of this study is to obtain shallow wetland bathymetry utilizing spectral reflections obtained at different water depths by field study and satellite images. Machine learning (ML) algorithms, which are widely used in remote sensing, are used in this study. Four algorithms were selected as random forest (RF), support vector machine (SVM), Neural Networks (NN), and Maximum Likelihood Classification (MLC). Since machine learning algorithms use training samples/datasets, the classification accuracy is directly related to selecting these data. The effect of pixel counts on classification was investigated by using two different training data set also. Duden (Kulu) Lake, which is a shallow wetland, was chosen as the study area. The Iterative Self-Organizing Data Analysis Technique (ISODATA) classification algorithm divided into as many clusters as possible was applied on Sentinel-2 multispectral images. All classes were rede-fined using measured spectral signatures and were created a bathymetric map. This map was used as reference data in creating training sets and the accuracy assessment of ML algorithms. When the water surface areas obtained from algorithms were compared with the bathymetric map and Normalized Difference Water Index, the best result was obtained with RF. According to the accuracy assessment results, it was seen that the number of training data affects the accuracy, and the best results were obtained with SVM and RF algorithms with training data containing more pixels (overall accuracy 93.87% and 92.64, kappa 0.89 and 0.87, respectively).
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2021Scopus SJRQ2High-resolution total field magnetic anomaly maps of Lake İznik (NW Turkey): assessment of faults which play important roles in tectonics of the lake
Aktaş, Gülten; Hisarli, Z. Mümtaz; Demirel, A. Sinan
In total, 380 km of marine magnetic data were processed and interpreted to reveal the main tectonic elements that control the formation of the lake. Lake İznik, which is an approximately rectangular-shaped active tectonic basin with 32 km length and 12 km width, is located between two segments of the North Anatolian Fault in the northeast Marmara region, Turkey. The purpose of this study is to identify the tectonic elements that played a role in the formation of Lake İznik with the help of new magnetic data and to reveal the tectonic evolution of the region by using other previously collected geophysical data. The Euler deconvolution, tilt angle, analytic signal and source edge detection methods were applied to the total field magnetic data for Lake İznik and its surroundings to determine the boundaries and depths to the source of magnetism. From the structural map obtained as a result of the review of this data, linearity in the magnetic data was detected along the NW–SE direction in the north of Lake İznik, N–S direction in the west and east, and E–W direction in the south. These lineaments were correlated with a limited amount of seismic data obtained from previous studies and were associated with faults. This linearity in NW–SE direction in the north was evaluated as the continuation of the Orhangazi fault and it is thought to play a significant role in the tectonic evolution of Lake İznik. When the results obtained from this study and the paleomagnetic results for the Eocene volcanic rocks in the study area are evaluated together, Lake İznik was connected with Gemlik Bay and the Marmara Sea during the Eocene–Pleistocene and Orhangazi Fault disconnected Lake İznik from Gemlik Bay in the Pleistocene–Holocene. It was deduced that the lake basin is a pull-apart basin developed up to the present day.
AtıfScopus4WoS3OpenAlex5İncele - MakaleYalnız künye2021Scopus SJRQ3An experimental investigation of single lignite particle dried in superheated steam and hot air
Celen, P.; Erdem, H.H.
In lignite (low-rank coal)-fired thermal power plants, thermal efficiency can be improved by decreasing the lignite moisture. The lignite moisture can be removed by using superheated steam and hot air as drying fluids. In this study, Turkish (Afşin-Elbistan) lignite having a diameter of 30 mm was dried with superheated steam and hot air at temperatures of 117°C under atmospheric pressure. The changes in its weight and temperature with time were observed, and the drying characteristics were obtained during the drying process. In the first period of drying, which is called heating period, the drying rate of superheated steam is higher than hot air in contrary to during constant-rate period. Moreover, the experiments revealed that less time is required to heat lignite sample with superheated steam compared to hot air.
AtıfScopus3WoS3OpenAlex2İncele - MakaleAçık Erişim2021Scopus SJRQ3The Curricular Practical Training Rotation Problem Formulation and the Assessment of Rotation Strategies
Şimşek, Ahmet Bahadır
This study addresses the curricular practical training rotation problem, which is a type of staff assignment problem. Many educational institutions require theoretical knowledge to be complemented by practical training. Although the details of the implementation differ from institution to institution, it is necessary to prepare a rotation plan that determines how long the trainees will practice in which unit in which training period. Because of the complexity of the problem and humanistic reasons, the manual rotation plan can not reach the optimal level that satisfies all stakeholders and takes time. This study defines a general Curricular Practical Training Rotation Planning Problem specific to the curriculum-based trainee assignment process carried out in a university department and proposes an integer mathematical model for its solution. It is one of the important contributions of this study. It also provides a methodological approach to identify the most appropriate rotation strategy that will satisfy stakeholders. The methodological approach followed is a structure that can be adapted to different perspectives. The study has the potential to guide practitioners and researchers in the field and to lead a rich literature that will be formed with different side constraints and purposes to the problem.
- MakaleAçık Erişim2021Scopus SJRQ3Comparison of field and laboratory result of fiber reinforced shotcrete application
Külekçi, Gökhan
Synthetic fibers, which have become one of the main components of shotcrete, have been studied by many researchers in the laboratory environment. Unfortunately, the results obtained as a result of these researches are not suitable for underground chimneys due to the differences in ambient conditions and application differences. In this study, it is aimed to compare the results of the experiment samples prepared and kept in the laboratory with the mechanical properties of the shotcrete applied in underground conditions. For this purpose, keeping the slump and cement proportions constant, 35 cubic samples were prepared using 2 and 6 kg synthetic fiber for 1 m3 in the laboratory, and 30 cylinder samples and 6 plate samples were prepared for underground. While mechanical experiments were carried out on prepared cube and cylinder samples, the EFNARC plate test and freeze-thaw test were carried out on plate samples. It was observed that the set accelerator made a significant increase in resistance at the end of the 28 days and that the resistance of the samples prepared with polyester fibers in the laboratory environment were very high. As a result of the EFNARC panel tests performed, it was determined that the energy absorption of synthetic fibers increased with fiber amount. Thanks to this study, the energy absorption of the synthetic fiber used has been measured, and the reliability and practicality of the experiments carried out in the laboratory have been increased by evaluating the field conditions and laboratory conditions.
AtıfScopus13WoS12OpenAlex11İncele - MakaleYalnız künye2021Experimental Investigation of Usability of Construction Waste as Aggregate
Kulekci, Gokhan; Yilmaz, Ali Osman; Cullu, Mustafa
The aim of this work is to obtain recycled aggregate (RA) from construction debris in order to reduce the rapid consumption of aggregate resources and the environmental impact of these resources. In order to fulfill this aim, the density, porosity, Schmidt hardness test, uniaxial compression resistance, carbonation depth, and ultrasonic p-wave velocity experiments were conducted on different construction debris transported by trucks from 9 different points in Turkey. In addition, the debris samples taken were broken down to the size of the aggregate and subjected to the tests of density, porosity, moisture content, freeze-thaw, and impact resistance. As a result of the conducted experiments, the lowest mass loss as a result of freezing-thawing was in GRA with 9.36%, the highest mass loss was in ORA with 22.58%, the highest ORA average aggregate impact strength index was 21.27%, and the lowest TRA aggregate impact strength index was found to be 18.26%. İt was determined that most of the physical properties of RA obtained from the construction wreckage was within the limit values specified in the literature and that the recycled aggregates could be used instead of natural aggregate. With this work and these results, RA obtained could be used in many areas such as concrete aggregate in the construction sector, underground filling in mining, filling material in gunned concrete, and filling materials on highways.
AtıfScopus15WoS12OpenAlex8İncele - MakaleAçık Erişim2021Scopus SJRQ1Land subsidence and its relations with sinkhole activity in karapınar region, turkey: A multi-sensor insar time series study
Orhan, Osman; Oliver-Cabrera, Talib; Wdowinski, Shimon; Yalvac, Sefa; Yakar, Murat
The Karapinar basin, located in the Central Anatolian part of Turkey, is subjected to land subsidence and sinkhole activity due to extensive groundwater withdrawal that began in the early 2000s. In this study, we use Interferometric Synthetic Aperture Radar (InSAR), Global Navigation Satellite System (GNSS), and groundwater level data to monitor and better understand the relations between groundwater extraction, land subsidence, and sinkhole formation in the Karapinar basin. The main observations used in the study are InSAR-derived subsidence velocity maps calculated from both Sentinel-1 (2014–2018) and COSMO-SkyMed (2016–2017) SAR data. Our analysis reveals broad areas of subsidence with rates exceeding 70 mm/yr. The InSAR-derived subsidence was compared with GNSS data acquired by a continuously operating GNSS station located in the study area, which show a similar rate of subsidence. The temporal characteristic of both InSAR and GNSS time series indicate a long-term subsidence signal superimposed by seasonal variability, which follows the overall groundwater level changes, with over 80% cross-correlation consistency. Our results also indicate that sinkhole activity is limited to slow subsidence areas, reflecting strong cohesion of near-surface rock layers that resist subsidence but yield to collapse in response to aquifer system deformation induced by groundwater extraction.
AtıfScopus63WoS55OpenAlex70İncele - MakaleAçık Erişim2021Scopus SJRQ2Geochemistry and Pb isotopic proof for sources of heavy metal(loid)s in Late Cretaceous sandstones from Eastern Pontides (NE Turkey)
Saydam Eker, Çiğdem
Upper Cretaceous sedimentary rocks are widely exposed around Trabzon, Giresun and Gümüşhane in the eastern Pontides. The sedimentary rocks are mainly composed of sandstones and marls, and the thicknesses of these rocks range from 170 to 400 m. This paper focused on Late Cretaceous sandstones of Trabzon, Giresun and Gümüşhane regions to identify the concentrations, sources, deposition environment and conditions of certain heavy metal(loid)s (Zn, Pb, Cu, Ni, As, Co, Mo and V). Enrichment factor (EF), geo-accumulation index (Igeo), Pollution index (Pi), Pollution load index (Pln), Pb isotope and multivariate statistical analysis were performed to elucidate the pollution levels and sources. In general, the evaluation indices exhibited that the sandstones were moderately polluted by As in the Trabzon area, and strongly polluted by Ni and As, moderately polluted by Co and V in the Giresun and Gümüşhane areas. The results of multivariate statistical analyses indicated that As and partly Pb might be originated from anthropogenic sources, whereas other metals were derived from geogenic origin. Lead isotopic analysis demonstrated two characterized signatures of the pollution sources in the sandstones, one related to geogenic origin and the other to coal, gasoline and pesticides. The sandstones were deposited in transition—marine environment under oxic—weak oxic conditions and paleoclimatic conditions ranged from arid to moist during Late Cretaceous period.
AtıfScopus7WoS6OpenAlex10İncele - MakaleYalnız künye2021Scopus SJRQ1Single-step recovery of pectin and essential oil from lemon waste by ohmic heating assisted extraction/hydrodistillation: A multi-response optimization study
Tunç, Merve Tuğçe; Odabaş, Halil İbrahim
The main products obtained from citrus wastes are pectin and essential oil. In this work, ohmic heating assisted extraction/hydrodistillation (OHAE/H) was applied for the simultaneous recovery of pectin and essential oil from lemon waste. Optimum OHAE/H conditions to maximize the yield of pectin and essential oil were determined with response surface methodology. Three independent variables, namely liquid to solid ratio (w:v), extraction/hydrodistillation time (min) and voltage gradient (V/cm) were varied to obtain maximum pectin and essential oil yield. Optimum OHAE/H conditions were determined as 8.7:1 liquid to solid ratio, 58.4 min extraction/hydrodistillation time and 14.2 V/cm voltage gradient. The predicted pectin and essential oil yields at optimum conditions were 16.58 and 3.62 g/100 g lemon waste, respectively. Data analysis showed that all of the independent variables significantly affected the pectin and essential oil yield. In the verification study, close agreement was found between predicted and experimental values. Conventional heating extraction/hydrodistillation (CHE/H) were conducted to evaluate the effectivity of OHAE/H. With OHAE/H process, the yields of the pectin and essential oil were significantly increased when compared to CHE/H. Limonene concentration of the essential oil produced with OHAE/H was higher than the essential oil produced by CHE/H. Results demonstrate that the single-step OHAE/H could be an effective method for simultaneous extraction and hydrodistillation of pectin and essential oils.
AtıfScopus53WoS43OpenAlex54İncele