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Koleksiyondaki öğeler
- MakaleAçık Erişim2021Scopus SJRQ1An insight into Verbascum bombyciferum extracts: Different extraction methodologies, biological abilities and chemical profiles
Angeloni, Simone; Zengin, Gokhan; Sinan, Kouadio Ibrahim; Ak, Gunes; Maggi, Filippo; Caprioli, Giovanni; Kaplan, Alevcan; Bahşi, Muammer; Çakılcıoğlu, Uğur; Bouyahya, Abdelhakim
The genus Verbascum, commonly known as "mullein", bears several species traditionally used to treat various infections, inflammations and wounds. In this study, extracts from V. bombyciferum, an endemic Verbascum species from Turkey, obtained by different solvents and extraction techniques, were investigated for their bioactive contents using spectrophotometry and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and evaluated for their antioxidant, as well as enzyme inhibitory potentials. While spectrophotometric determination revealed the homogenizer assisted extraction/methanolic extract to yield the highest total phenolic and flavonoid contents (41.80 ± 0.70 mg GAE/g and 39.44 ± 0.30 mg RE/g, respectively), the most significant total bioactive compounds (polyphenols) in the amount of 272.862 mg kg−1, established by HPLC-MS/MS analysis, was noted for the maceration/methanolic extract. Overall, the extracts showed varied antioxidant potency, displaying free radical scavenging ability (DPPH assay: 1.04–51.33 mg TE/g; ABTS assay: 80.04–85.60 mg TE/g), reducing power (CUPRAC: 51.48–183.26 mg TE/g; FRAP: 36.33–90.04 mg TE/g; metal chelating activity (18.48–19.80 mg EDTAE/g) and total antioxidant capacity (phosphomolybdenum assay: 0.78–1.92 mmol TE/g). However, extract of homogenizer assisted extraction/methanol exhibited the highest antioxidant activity in most assays. Only the maceration/methanolic extract inhibited all the studied enzymes (acetylcholinetserase: 2.02 ± 0.20 mg GALAE/g; butyrylcholinesterase: 4.57 ± 0.09 mg GALAE/g; tyrosinase 21.44 ± 3.41 mg KAE/g and amylase: 0.46 ± 0.01 mmol ACAE/g). This study is the first attempt to highlight the potential industrial applications of the endemic plant V. bombyciferum, as a natural source of bioactive compounds that could be considered for future development of phytopharmaceuticals, targeting specific oxidative stress-linked diseases including diabetes, skin hyperpigmentation, and neurological disorders.
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İncele - MakaleAçık Erişim2022Scopus SJRQ2The effect of COVID-19 restrictions on sleep quality of university students and variables predicting sleep quality
Bulut, Arzu; Sengul, Halil; Uslu, Yeter Demir; Bas, Kazim; Tosun, Nurperihan
BACKGROUND/AIM: The COVID-19 pandemic has created a long period of stress for people worldwide and has significantly affected sleep duration. The pandemic revealed new stress factors that are likely to affect sleep. Uncertainty is a factor that leads to anxiety and depression, which affects sleep. It should also be noted that reductions in sleep quality rather than sleep duration are associated with negative consequences on mental health. This study aims to investigate online that how this situation affected university students. MATERIALS AND METHODS: This research, with a descriptive study design, was conducted in Turkey between June 01, 2021 and July 30, 2021. The sample included 604 people who accepted voluntary participation, chosen by the random selection method. In the study, sociodemographic information form, Pittsburgh sleep quality index (PSQI), morningness-eveningness questionnaire scale (MEQ Scale), Beck depression inventory (BDI), and Beck anxiety inventory (BAI) were used as data collection tools. Pearson correlation analysis was utilized to examine the relationship between the scales. Multiple regression analysis was performed to investigate the role of morningness-eveningness, anxiety, depression, and insomnia severity on sleep quality. RESULTS: Sleep quality was negatively correlated with morningness-eveningness scores (r = -0.32, P < 0.01), and positively and significantly related with anxiety (r = 0.43, P < 0.01), depression (r = 0.40, P < 0.01) and insomnia severity (r = 0.55, P < 0.01). According to regression coefficients, while anxiety (β = 0.041, P < 0.001) and insomnia severity scores (β = 0.226, P < 0.001) positively predicted sleep quality, depression did not predict it significantly (β = 0.009, P > 0.05). A significant difference was found in sleep quality according to morning, evening, and intermediate types (F = 27.401, P < 0.001). CONCLUSION: Events related to the COVID-19 pandemic are associated with reduced sleep quality in connection with increasing negative moods. Considering the importance of sleep for a healthy life, efforts should be made to raise awareness about this issue and to provide psychological help to affected individuals.
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İncele - Kitap BölümüYalnız künye2023A Multi-parameter Occupational Safety Risk Assessment Model for Chemicals in the University Laboratories by an MCDM Sorting Method
Gul, Muhammet; Yucesan, Melih; Karacahan, Mehmet Kayra
University laboratories are high-risk working environments where many chemicals coexist to conduct teaching and scientific research. The frequent occurrence of such chemical-related occupational accidents in recent times highlights the importance of ensuring these units’ safety in universities for researchers, students, workplaces, and institutions. In occupational safety risk assessment, very few studies have grouped risks. Many of them also ignored some important risk parameters. Overcoming these disadvantages, this study developed a multi-parameter and multi-criteria decision-making (MCDM) sorting-based methodology for the occupational safety risk assessment of chemicals in a university laboratory. First, six different risk parameters (probability, severity, exposure, detectability, worsening factor, sensitivity to non-usage of personal protective equipment) were determined. The weight value was calculated using the best–worst method (BWM). Then, a risk priority value and classification for each chemical with TOPSIS-Sort, the MCDM sorting method. Finally, some control measures are recommended to reduce the safety risk of the laboratory. The applicability of the proposed methodology has been tested with a real case study. The methodology is intended to adapt to university laboratories’ risk assessment and become a primary reference for university safety analysts.
AtıfScopus2OpenAlex1İncele - MakaleAçık Erişim2021Scopus SJRQ1The effect of ethnocentrism and moral sensitivity on intercultural sensitivity in nursing students, descriptive cross-sectional research study
Kaya, Yunus; Arslan, Sevda; Erbaş, Atiye; Yaşar, Beril Nisa; Küçükkelepçe, Gülhan Erkuş
Background: Factors affecting intercultural sensitivity and care are becoming an increasingly important issue due to ethnic diversity. Nurses play a crucial role in care and therefore should keep up with this trend and improve their intercultural sensitivity. Objective and design: This descriptive cross-sectional study investigated the effects of ethnocentrism and moral sensitivity on intercultural sensitivity in nursing students. Methods and participants: Data were collected using a demographic characteristics questionnaire and the Intercultural Sensitivity Scale, Generalized Ethnocentrism Scale, and Moral Sensitivity Scale. The sample consisted of 1343 nursing students. The Pearson correlation coefficient was used to determine correlations between scale scores. Multiple linear regression was used to determine the effects of ethnocentrism, moral sensitivity, and demographic characteristics on intercultural sensitivity. Results: Intercultural sensitivity was found to be negatively correlated with ethnocentrism and positively correlated with moral sensitivity. Ethnocentrism predicted intercultural sensitivity more than moral sensitivity. Ethnocentrism and moral sensitivity explained 16.8% of the total variance of intercultural sensitivity. However, ethnocentrism affected intercultural sensitivity more than moral sensitivity did (beta = −0.406). Conclusion: Nursing education should adopt strategies to reduce ethnocentrism by helping students develop cultural competence and intercultural sensitivity. Such education can equip nurses to provide higher quality care to patients of different cultural backgrounds.
AtıfScopus48OpenAlex54İncele - MakaleAçık Erişim2021Scopus SJRQ4Perceptions and experiences of older people regarding the covid-19 pandemic process: A phenomenological study
Akkuş, Yeliz; Parlak, Ayşe Gül; Karacan, Yasemin; Karatay, Gülnaz
Introduction: From the start of the coronavirus disease 2019 (COVID-19) outbreak in 2020 to the present, older people have been the worst affected among all age groups. This study was conducted to examine thoroughly the perceptions and experiences of older people regarding the COVID-19 outbreak. Materials and Methods: A qualitative study was conducted using a semi-structured, in-depth interview method with 16 older people living in the east of Turkey. The interviews were conducted through the mobile application WhatsApp, as the older people were in the risk group for infection. The sample group was reached using the snowball method. When the data obtained from the participants reached the saturation level, two more interviews were conducted, and then the interviews were ended. After the recorded interviews were transcribed, they were subjected to conventional content analysis. Results: Four main themes emerged from the interviews in line with the purpose of this study. These themes are The Meaning of COVID-19, Outcomes of COVID-19, Need for Support and Resources, and Attitudes toward Vaccination. Conclusion: It was determined that the older people experienced fear during the COVID-19 pandemic; the social restrictions affected them psychologically, physiologically, and economically and they could not get enough support and felt lonely in this process; but nevertheless, they were hopeful about the vaccine. To address these findings, this study suggested support for home care of older people and the development of psychosocial and economic support programs for them.
AtıfScopus2WoS3OpenAlex4TR Dizin1
İncele - MakaleYalnız künye2021Scopus SJRQ4A classification of para-kenmotsu space forms
Ünal, İnan; Sari, Ramazan
A para-Kenmotsu space form is a para-Kenmotsu manifold with constant φ− sectional curvature. In this study, we work on para-Kenmotsu space forms under some flatness conditions of generalized quasi-conformal curvature tensor which is a generalization of conformal, concircular, conharmonic, projective, M-projective and pseudo-projective curvature tensors. We examine GQC-flat and ξ−GQC flat p-Kenmotsu space forms.
AtıfScopus1İncele - Derleme MakaleAçık Erişim2023Scopus SJRQ3Obtaining haploid plants by irradiated pollen culture in oil seed crops
Yaman, Hümeyra; Sanyürek, Nesrin Karaca
Haploid plant production is of great importance to shorten the breeding period in plant breeding programs. Obtaining pure lines in plant growing programs require an intensive work with huge labor and time. Obtaining one hundred percent homozy-gous pure lines is a key point for the improvement and development of new cultivars. Haploid plants with a single set of homozygous chromosomes have become a valuable tool in plant breeding. Dihaploid plants that are homozygous at all loci with dou-bling of their chromosomes can be propagated by seed and reach full homozygosity in a single generation. Traditional methods take seven years to reach homozygosity. Dihaploidization methods provide significant advantages in terms of gaining homozy-gosity in a short period of one year and bringing pure lines into agriculture. Anther culture and irradiated pollen technique are among the most widely used techniques in this respect; where physical or chemical agents are used to induce mutated pollen grains and anthers that are subsequently employed to develop dihaploids through in vitro cultures. These techniques are a good source to facilitate gene mapping, cyto-genetic research, and evolutionary studies. Irradiated pollen culture techniques have been applied to many oilseed crops to obtain pure lines. This study highlights some salient features of producing dihaploids using irradiated pollen grains and their maintenance.
AtıfScopus1OpenAlex2TR Dizin1İncele - MakaleAçık Erişim2022Scopus SJRQ1Effects of the BHA and basil essential oil on nutritional, chemical, and sensory characteristics of sunflower oil and sardine (Sardina pilchardus) fillets during repeated deep-frying
Erol, Nida Demirtas; Erdem, Ömer Alper; Yilmaz, Sebnem Tolasa; Kayalar, Hüsniye; Cakli, Sukran
This study was to evaluate the BHA and basil essential oil on the quality attributes of deep-fried sardine fillets and frying oil. The extent of lipid oxidation was monitored by measuring peroxide value (PV), thiobarbituric acid reactive substances (TBARS), TBA, and changes in free fatty acids. Sensory analysis and color values upon the frying period were also determined. PV, FFA, TBA, and TBARS values in fish fillets and frying oil have peaked and then decreased at the end of frying except for the control. BEO showed the highest sensory scores compared to others. As a result, it is not possible to make a clear judgment about the effect of the natural or synthetic antioxidants on all lipid oxidation products that may occur during frying both fish fillets and frying oil. This study suggests that secondary oxidation products in frying oil and the sensorial quality of fish fillets can be better controlled by using basil essential oil.
AtıfScopus25WoS23İncele - Kitap BölümüYalnız künye2023Healthcare Logistics and Digital Transformation
Kaya, Sema Kayapınar
Due to the complex and diverse structure of the healthcare industry, the healthcare industry's logistics practices have lagged far behind sectors such as retail and manufacturing. Therefore, in today's increasingly competitive and risky environment, it is critical for hospitals to improve their logistics management performance, increase the efficiency of health services, and reduce costs. This chapter synthesizes the contributions of healthcare logistics, the impact of medical logistics on healthcare providers, types of healthcare logistics. Addition, this chapter enables us to capture the research challenges associated with the healthcare logistics process, pharma logistics and show how digitalization initiatives can address them.
AtıfScopus2OpenAlex2İncele - Derleme MakaleAçık Erişim2022Scopus SJRQ1Dietary exposure to acrylamide: A critical appraisal on the conversion of disregarded intermediates into acrylamide and possible reactions during digestion
Aktağ, Işıl Gürsul; Hamzalıoğlu, Aytül; Kocadağlı, Tolgahan; Gökmen, Vural
The amount of acrylamide in asparagine rich thermally processed foods has been broadly monitored over the past two decades. Acrylamide exposure can be estimated by using the concentration of acrylamide found in foods and alternatively, biomarkers of exposure are correlated. A better estimation of dietary acrylamide exposure is crucial for a proper food safety assessment, regulations, and public health research. This review addresses the importance of the presence of neglected Maillard reaction intermediates found in foods, that may convert into acrylamide during digestion and the fate of acrylamide in the gastrointestinal tract as a reactive compound. Therefore, it is questioned in this review whether acrylamide concentration in ingested foods is directly correlated with the dietary exposure to acrylamide.
AtıfScopus32WoS26OpenAlex31İncele - BildiriAçık Erişim2023Yolov5 Based Fault Detection Approach in Railway Components
Yilmazer, Merve; Karakose, Mehmet
For safe transportation on the railway, the faults occurring in its components must be detected and repaired. Recently, fault detection methods have been developed on railway visual data using methods such as image processing, machine learning and deep learning. Especially since deep learning-based algorithms have a self-learning structure, the data used in model training and testing significantly affect the performance of the model. In the proposed method within the scope of this study, railway visual data were obtained using autonomous drone. YOLOv5 deep neural network is trained to detect faults that may occur in various components such as rail, fastener, sleeper and ballast in the railway. In order to increase the efficiency of the model, images obtained under different lighting conditions were included in the data set. In addition, by using the OpenCV library, the video stabilization process and the vibrations that occur during data acquisition in the video are eliminated. Thus, with the proposed method, it has been shown that the errors due to many components in the railway can be detected with a mAP rate of 94.5%.
AtıfScopus5OpenAlex3İncele - MakaleYalnız künye2022Scopus SJRQ1Performance evaluation of Turkish Universities by an integrated Bayesian BWM-TOPSIS model
Gul, Muhammet; Yucesan, Melih
This study aims to develop a university ranking model with the aid of performance measures in the “University monitoring and evaluation reports-2019” published by the Council of Higher Education Institution in Turkey. In this context, some of the performance criteria stated in these reports are filtered and 34 sub-criteria under five main criteria are weighted using the Bayesian Best-Worst Method (BBWM). Then, 189 listed public and private universities are ranked using the TOPSIS multicriteria decision-making (MCDM) method. We have adopted the MCDM concept because many evaluation criteria/sub-criteria and alternative universities are taken into account. For this study, we apply an integrated MCDM model. First, we use BBWM to accomplish the first goal and adopt the TOPSIS method for the second purpose, using the BBWM results. Our purpose in using BBWM is due to its probabilistic structure that reduces the loss of information when handling group decisions. In this context, the evaluations of 11 academic experts are combined and a solid weighting is made by obtaining the credal rankings of performance criteria. Using TOPSIS is its logic of proximity to ideal and the ability to evaluate many alternatives. In the context of the study, state-private university-based, nomenclature of territorial units for statistics-2 (NUTS-2)-based and classical geographical regions-based rankings are also discussed. The study seeks to help universities optimize their performance efficiently. The results of the study can be adapted as a reference for other educational institutions and public institutions in their efforts to evaluate, improve their performance and form various policies.
AtıfScopus79WoS61OpenAlex79İncele - MakaleAçık Erişim2022Scopus SJRQ2Comparison of nutrient contents of wild and farmed rainbow trout (Oncorhynchus mykiss, Walbaum 1792) from Keban Dam Lake in Eastern Anatolia region of Turkey
Özçiçek, Esin; Can, Erkan; Yılmaz, Ökkeş
In this study, fatty acids, fat-soluble vitamins (A, D, E, K vitamins) and cholesterol contents of wild-caught and farm-raised rainbow trout (Oncorhynchus mykiss) were compared. The amounts of docosahexaenoic acid (22:6 n-3, DHA) in wild and farmed forms were 21.56%–18.14%, 18.79%–16.21% and 14.34%–11.49% in April, May and June, respectively. Vitamin E, which is one of the fat-soluble and antioxidant vitamins, showed highest level among the vitamins. Vitamin E levels in both wild and farmed fish were 5.11–4.26, 4.83–2.89 and 0.99–1.95 mg/100 g in April, May and June, respectively. The substantial difference between wild and farmed rainbow trout was found in May (p < 0.05). In conclusion, both wild and farmed rainbow trout from Keban Dam Lake (Pertek Region) can be considered as good sources of n-3 polyunsaturated fatty acids (PUFA). However, it was observed that the n-3 PUFA level in wild form was higher than the culture fish within the investigated monthly periods. On the other hand, farmed fish demonstrated higher levels of n-6 PUFA over the wild individuals.
AtıfScopus11WoS9OpenAlex8İncele - MakaleYalnız künye2021Scopus SJRQ1Identification of failure mechanisms in existing unreinforced masonry buildings in rural areas after April 4, 2019 earthquake in Turkey
Yön, Burak
Many unreinforced masonry buildings are completely destroyed after destructive earthquakes but, their failure mechanisms cannot be precisely determined. More specifically damage to such buildings is evinced during low or moderate magnitude earthquakes. The aim of this study is to identify the failure mechanisms of existing unreinforced masonry buildings and present a reconstruction strategy or offer strengthening procedures, in order to inhibit damage to masonry structures after destructive earthquakes. For this purpose, a moderate magnitude earthquake which occurred on April 4, 2019 near the township of Sivrice in Elazığ city, in the east of Turkey, was investigated. The magnitude of the studied seismic motion was expressed as Mw=5.2 by the Ministry of Interior Disaster and Emergency Management Presidency. Although this seismic effect was a moderate magnitude earthquake, significant failures occurred. Many masonry buildings and adobe dwellings in the villages of Sivrice were severely damaged by the earthquake. For field observations, ten villages located around the epicentre were visited 65 dwellings were observed and the damage patterns were assessed in detail. The observations showed that the main reasons for the damage to the dwellings were weak structural detailing of wall-to-wall and wall-to-roof connections, inhesion of earthen roofs, and a lack of bond beams in the structural walls. According to field observations, it is deduced that the performance of the undamaged masonry dwellings after earthquakes does not prove that they have adequate seismic safety. Therefore, reinforcing methods (shotcrete implementation, decreasing of space, corner reinforcing etc.) and innovative strengthening procedures (fibre reinforced polymer) are recommended for the undamaged existing unreinforced buildings at the end of the paper.
AtıfScopus53WoS48OpenAlex56İncele - MakaleAçık Erişim2022Scopus SJRQ1Preparation of ε-Caprolactone/Fe3O4 Magnetic Nanocomposite and Its Application to the Remazol Brilliant Violet 5R Dye Adsorption from Wastewaters by Using RSM
Pekdemir, Mustafa Ersin; Tanyol, Mehtap; Torğut, Gülben
In this study, poly (ε-caprolactone)/Fe3O4 magnetic nanocomposite (PCL/Fe3O4 MNC) was synthesized by ring-opening polymerization. Then, PCL/Fe3O4 MNC was used as a novel adsorbent to remove remazol brilliant violet 5R (RBV 5R) from the aqueous media. The effects of PCL/Fe3O4 MNC dosage, process time, and initial RBV 5R concentration on the removal of RBV 5R were studied using the central composite design (CCD) method. The adsorption process was optimized using the response surface methodology, and the optimum conditions were defined. Optimum RBV 5R removal of 95.40% was obtained at a contact time of 167.98 min, PCL/Fe3O4 MNC dosage of 0.40 g, and RBV 5R concentration of 7.18 mg L−1. The process was also designed using the adsorption kinetic models and isotherm. The experimental data of RBV 5R adsorption on PCL/Fe3O4 MNC followed the Langmuir isotherm and pseudo-second-order kinetic models than the other models. Morphological and chemical properties of the adsorbent-adsorbate system indicated the high adsorption yield of RBV 5R on PCL/Fe3O4 MNC was achieved. The structural characteristics of the PCL/Fe3O4 MNC were analyzed by Fourier-transform infrared, attenuated total-reflectance (ATR), and X-ray diffraction. ATR tests showed that no significant change in chemical bond is found in PCL/Fe3O4 MNC before and after the adsorption process. The morphology of composites was investigated by scanning electron microscopy. A vibrating sample magnetometer (VSM) was used for the measurement of the magnetic property. Thermal analysis of MNC was studied using thermogravimetric analysis and differential scanning calorimetry instruments.
AtıfScopus6WoS5OpenAlex6İncele - MakaleAçık Erişim2021Scopus SJRQ2Investigation of the potential human health risk of toxic mercury determined in the grapevine exposed to mine gallery waters
Topal, Murat
In the present study, mercury was selected because of its toxicity. It was detected in the grapevines exposed to mine gallery waters. The potential health risk of mercury in leaves of grapevine those are consumed by human worldwide was investigated. The grapevines were harvested and separated into organs of roots, stems, and leaves. The concentrations of mercury were determined in roots, stems, and leaves. The translocation and bioconcentration factors were calculated. Maximum concentrations of mercury were stem < root < leaf. The health risk potential of mercury on human health was calculated. The estimated daily exposure doses of mercury followed an order for children and adults: dietary > ingestion > inhalation > dermal. The HQ values calculated for exposure ways of dietary, ingestion and inhalation were male < female < children. As a result, it was determined that grapevine exposed to mine gallery waters that cause environmental contamination may cause non-carcinogenic risks on human health.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2023Scopus SJRQ3Evaluation of waste polyethylene terephalate in polyol and polyurethane production
Fırat, Tülay; Kar, Filiz
As technology advances and human population grows, we must meet our diverse needs while minimising harm to the environment. One solution is to prioritise recycling and using second-hand consumer goods. In this study, PET flakes were depolymerised by glycolysis using different molar ratios of glycol such as propylene glycol(PG), triethylene glycol(TEG) and polyethylene glycol(PEG 400) in the presence of two different catalysts: zinc acetate- zinc sulphate. As a result, glycated products (polyols-PO) were obtained. The obtained polyols were then used to synthesise polyurethane films (PU) via acetone process. The thermal and chemical characterisations of the polyurethane films (PU) were analysed. In similar studies, zinc acetate was used as a transesterification catalyst for the glycolysis process. In this study, the same process was carried out using zinc sulphate and zinc acetate. Zinc sulphate was found to be a cheaper and eco-friendlier catalyst alternative to zinc acetate for the glycolysis process.
AtıfOpenAlex1İncele - MakaleAçık Erişim2023Scopus SJRQ4COMPARATIVE ANALYSIS OF EMBROIDERY AND SCREEN-PRINTING TECHNIQUES FOR TEXTILE-BASED FREQUENCY SELECTIVE SURFACES; [TEKSTİL TEMELLİ FREKANS SEÇİCİ YÜZEYLER İÇİN NAKIŞ VE SERİGRAFİ TEKNİKLERİNİN KARŞILAŞTIRMALI ANALİZİ]
Üner, İbrahim; Can, Sultan; Gürcüm, Banu Hatice; Yilmaz, A. Egemen; Aksoy, Ertuğrul
Frequency Selective Surface (FSS) is a specialized structure used in the field of electromagnetic waves and radio frequency (RF) engineering. It is designed to exhibit selective transmission or reflection properties based on the frequency of the incident electromagnetic waves. This article describes the design, construction, and analysis of a textile-based band-stop frequency selective surface for use in the highly EM-polluted GSM, Wi-Fi, LTE, and WiMAX bands. A full-wave EM solver called CST Microwave Studio was used to develop and simulate the unit cell of the proposed FSS at the relevant frequency. In this study, embroidered and screen-printed textile based FSSs were designed. According to the results of this study, it was demonstrated that both embroidery and screen printing FSSs exhibit resonance at a frequency of 3.5 GHz. The screen printing method yielded the best results in terms of resonance frequency sensitivity, while the embroidery method showed a resonance frequency shift. It was observed that the stitch directions and density are important parameters in the embroidery method. Gaps between the embroidery paths in the production of embroidered FSSs resulted in differences from simulations due to the disruption of the structural integrity of the unit cell. Consequently, textile-based FSSs offer advantages over traditional FSSs. This study highlights the potential of textile FSSs as an effective means of reducing electromagnetic pollution, and suggests that further improvements in the design and production processes of textile FSSs can be made.
AtıfScopus2OpenAlex4İncele - MakaleYalnız künye2022Scopus SJRQ2Dielectric Biodegradable Biopolymer-Based Graphene Nanocomposites for Use in the Packaging Industry and Capacitor Application
Gürler, Nedim; Torğut, Gülben
In this study, polyhydroxyalkanoate (PHA) and polylactic acid (PLA)-Graphene (G) nanocomposite films were synthesized by taking different concentrations of G via the solution casting process, and their structural, mechanical, opacity, thermal and dielectric properties were examined for the first time. Scanning electron microscopy (SEM) was used for investigating surface morphology. Films containing graphene were more opaque than films without graphene. The incorporation of graphene into the polymer matrix improved the mechanical property. The tensile strengths of the control PHA/PLA film and the graphene-reinforced 1 %G-PHA/PLA nanocomposite films were 18.98 and 24.34 MPa, respectively. Thermogravimetric analysis results showed that PHA/PLA−G nanocomposites had good thermal stability below 300 °C. Considering the dielectric measurements, it is seen that the dielectric constant (έ) and dielectric loss (ϵ”) decreased with increasing frequency and less changed at higher frequencies. The developer feature of graphene is remarkable in both parameters. The electrical conductivity of PHA/PLA−G nanocomposites was also examined as a function of frequency at room temperature. As the amount of G increased from 1 %wt to 5 %wt, the conductivity of the composites increased.
AtıfScopus9WoS8OpenAlex11İncele - MakaleAçık Erişim2023Deterioration analysis of historical village house structure in Mersin Kanlıdivane archaeological area by UAV method
Karataş, Lale; Dal, Murat
The village house located in the Mersin Kanlıdivane archaeological site is one of the oldest settlements in the ruins, built in the second century. The house is mainly built of a yellowish beige limestone. This stone, which is the main material of the building, shows many deterioration patterns today. The aim of the study is to determine the dominant deterioration pattern of the stones in the village house structure in the Mersin Kanlıdivane archaeological site and to investigate the source of the deterioration. In order to investigate the deterioration patterns in the structure, the images obtained by UAV photogrammetry were interpreted and the types of deterioration were mapped. In the study, it is seen that even the types of material problems based on the smallest detail can be determined based on virtual visual inspection, thanks to UAV photogrammetry, without observing the structure in situ with UAV photogrammetry. The findings obtained in the study shows that the color change and surface loss deterioration on the stone surfaces has reached advanced levels as a result of the structure's exposure to the strong climate-induced sun and water effects for centuries. The results of the study show that the main damage observed on the stone surface of the structure is caused by the erosion by the effect of water. Restoration methods should be tried to stabilize the deterioration and replace the most degraded stones. It is recommended to use water-repellent surface coatings to protect the natural stone, especially against the intense water effect in the building.
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