Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(82)
- Akkurt, Nevzat(67)
- Güler, Ömer(66)
- Baskonus, Haci Mehmet(62)
- Bulut, Hasan(60)
- Tekin, H.O.(52)
- ALMisned, Ghada(49)
- Yucesan, Melih(43)
- Yildirim, Numan(42)
- Yildirim, Nuran Cikcikoglu(38)
- Paksoy, Mehmet Yavuz(36)
- Serdar, Osman(36)
- Zengin, Gokhan(36)
- Ince, Muharrem(34)
- Celik, Erkan(33)
- Benzer, Fulya(32)
- Kocabaş, Mehmet(30)
- Sulaiman, Tukur Abdulkadir(30)
- Tanyol, Mehtap(29)
- Yildirim, Ozal(28)
- Aslan, Naim(26)
- Kök, Mediha(26)
- Özkul, İskender(26)
- Ates, Mehmet(25)
- Danabas, Durali(25)
- Kutluyer, Filiz(25)
- Can, Erkan(24)
- Kutlu, Banu(23)
- Onat, Onur(23)
- Demir, Veysel(22)
- Erten, Fusun(22)
- Guler, Omer(22)
- Say, Yakup(22)
- Güler, Seval Hale(21)
- Yaman, Mehmet(21)
- Baykal, Duygu Sen(20)
- Sançar, Taylan(20)
- Susam, Selim Orhun(20)
- Cakilcioglu, Ugur(19)
- Orhan, Cemal(19)
Yayınlar
- MakaleAçık Erişim2023Scopus SJRQ4Nurses’ Opinions About Patient Restraint Methods in a Psychiatric Hospital and Their Ethical Sensitivity
Durmaz, Yadigar Çevik; Ersöğütçü, Filiz
Methods of restraint can be used to prevent hospitalized psychiatric patients from injuring themselves or others, but use of restraints causes various ethical problems in psychiatric nursing. This study examined the relationship between nurses’ sociode-mographic characteristics, types of restraint methods used, nurses’ opinions about those methods, and their level of ethical sensitivity toward their use. We found the moral sensitivity of our participants to be moderate, and sta-tistically significant differences were found related to marital status, shift type, and restraint method used. Based on our results, we recommend improving nurses’ working conditions, increas-ing their level of ethical knowledge, and expanding the number of stud-ies on these issues.
AtıfScopus1WoS1OpenAlex2
İncele - MakaleAçık Erişim2023Scopus SJRQ1A study on the combustion performance and NOx emissions characteristics of a novel U-type radiant tube based on MILD combustion theory
Fan, Huanbao; Feng, Junxiao; Bai, Wei; Wang, Hui; Akkurt, Nevzat; Li, Weidong; Gao, Jun; AliAkbaria, Omid; Xu, Qian
Based on the theory of moderate or intense low-oxygen dilution (MILD) combustion, a 3D steady-state CFD model coupling dual flue gas recirculation and dispersion combustion was developed to describe the flow field, combustion temperature field, wall temperature distribution, and NOx concentration field during the operation of a novel U-type radiant tube (N-URT). A user-defined function (UDF) method was implemented to simulate the dilution of O2 concentration in the combustion air due to external flue gas recirculation (E-FGR). The effects of the E-FGR ratio on combustion characteristics and NOx emission were evaluated. The simulated results were consistent with experimental results. The simulated NOx concentration at the outlet was reduced to 105.5 mg/m3 at 8% O2, which was about 35.2% lower than the conventional combustion method. The study found that when the E-FGR ratio was increased from 0 to 25%, the standard deviation of wall temperature decreased from 30.3 °C to 23.3 °C, and the non-uniformity coefficient decreased from 0.2598 to 0.2183, indicating an improvement in temperature uniformity. However, the thermal efficiency decreased from 82.1% to 76.2%. Moreover, at higher E-FGR ratios, the volume of the high-temperature region (above 1500 ℃) gradually decreased, and both the maximum flame temperature and the outlet NOx concentration decreased sharply. Regression equations for the E-FGR ratio (β) on the maximum combustion temperature (Tmax) and the outlet NOx concentration (CNOx) were obtained, and an E-FGR ratio greater than 13.4% was recommended to meet the emission requirements.
AtıfScopus14OpenAlex14İncele - MakaleAçık Erişim2023Scopus SJRQ1Deep learning based hybrid prediction model for predicting the spread of COVID-19 in the world's most populous countries
Utku, Anil
COVID-19 has a disease and health phenomenon and has sociological and economic adverse effects. Accurate prediction of the spread of the epidemic will help in the planning of health management and the development of economic and sociological action plans. In the literature, there are many studies to analyse and predict the spread of COVID-19 in cities and countries. However, there is no study to predict and analyse the cross-country spread in the world's most populous countries. In this study, it was aimed to predict the spread of the COVID-19 epidemic. The motivation of this study is to reduce the workload of health workers, take preventive measures and optimize health processes by predicting the spread of the COVID-19 epidemic. A hybrid deep learning model was developed to predict and analyse COVID-19 cross-country spread and a case study was carried out for the world's most populous countries. The developed model was tested extensively using RMSE, MAE and R2. The experimental results showed that the developed model was more successful in predicting and analysis of COVID-19 cross-country spread in the world's most populous countries than LR, RF, SVM, MLP, CNN, GRU, LSTM and base CNN-GRU. In the developed model, CNN performs convolution and pooling operations to extract spatial features from the input data. GRU provides learning of long-term and non-linear relationships inferred by CNN. The developed hybrid model was more successful than the other models compared, as it enabled the effective features of the CNN and GRU models to be used together. The prediction and analysis of the cross-country spread of COVID-19 in the world's most populated countries can be presented as a novelty of this study.
AtıfScopus23WoS20OpenAlex31
İncele - MakaleAçık Erişim2023Scopus SJRQ2Binary PCL–waste photopolymer blends for biodegradable food packaging applications
Gürler, Nedim; Pekdemir, Mustafa Ersin; Torğut, Gülben; Kök, Mediha
The aim of this study is to prepare waste photopolymer (WPP) / poly ɛ-caprolactone (PCL) blends that can be used in food packaging with different ratios (5%, 10%, 20% and 30%) WPP. The structural properties of the blend films were characterized by attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Opacity, surface color, water vapor permeability and shape memory properties of these films were examined. Pure PCL film exhibited more thermal stability compared to PCL/WPP blend films. Therewithal, the glass transition temperature of the pure PCL film showed a shift. Water vapor permeability improved with the addition of WPP. L*, a* and transmittance values reduced with increasing WPP, but b* value increased. It was thought that these polymer blends would enable to be used as packaging material in terms of compatibility and waste evaluation.
AtıfScopus14WoS13OpenAlex14İncele - MakaleAçık Erişim2023Scopus SJRQ2Shape Memory Polymer-Based Nanocomposites Magnetically Enhanced with Fe3O4 Nanoparticles
Pekdemir, Mustafa Ersin; Aydin, Derya; Selçuk Pekdemir, Sibel; Erecevit Sönmez, Pınar; Aksoy, Edanur
This work aimed to investigate the effect of magnetic Fe3O4 nanoparticles (MNP), which are known to have a wide range of applications in recent years, on nanocomposite films prepared with shape memory polymers. Herein, PLA–PEG blend nanocomposite films were prepared by solution casting method using MNP at different ratios. PLA–PEG Blend/MNP nanocomposite films were characterized with Attenuated total reflection infrared spectroscopy (ATR-IR) to determine the –C=O stretching of PLA and Fe–O stretching signals of Fe3O4. The thermal stability, morphology, and magnetic behavior were studied by comparing the results among PLA–PEG blend, PLA–PEG blend/MNP nanocomposite with thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and a vibrating sample magnetometer (VSM), respectively. The effect of MNP on the shape memory properties of PLA/PEG blend was investigated. Moreover, the comparison of antimicrobial activity between PLA/PEG blend and PLA–PEG blend/MNP nanocomposite films were conducted by the disk diffusion method. The results showed that MNP increased the thermal stability of the PLA/PEG blend and the nanocomposites inhibited the growth of C.albicans microorganism. Graphical Abstract: [Figure not available: see fulltext.].
AtıfScopus41WoS39OpenAlex42İncele - MakaleAçık Erişim2023Scopus SJRQ3Statistical Analysis and EEG Signal Filtering Using Design of Window Function Based on Optimization Methods
Serbet, Fatmanur; Kaya, Turgay
The window functions, which are widely used in Finite Impulse Response (FIR) digital filter design with the Fourier Series Methods, aim to eliminate the oscillations adversely affecting the filter performance that occur during the filter design. Window functions, which were developed with different methods in the literature, were designed with three different optimization techniques in this study. By using Particle Swarm Optimization (PSO), Grey Wolf Colony Optimization (GWCO), Cuckoo Search Optimization (CSO) algorithms, which are among current metaheuristic optimization methods, new window functions are designed for FIR digital filter design such that the designed new window functions have different window coefficients and design parameters. The difference of the designed window functions was analyzed with the Friedman and Wilcoxon tests, which are statistical data analysis methods, and the originality of the designed window functions was proven. FIR digital filters that can perform the same operation as the designed window functions have been produced and the results obtained by performing the filtering application of the EEG signal with the produced filters are presented in the study.
AtıfScopus9WoS6OpenAlex7İncele - MakaleYalnız künye2023Scopus SJRQ2Silver-Doped Diamond-Like Carbon (DLC:Ag) Nanocomposite Films for Solar Tracking Applications
Aslan, Naim; Kurt, Mustafa Şükrü; Koç, Mümin Mehmet
Diamond-like carbon (DLC) films are often investigated for their mechanical properties. In this report, we assessed the electrical and photovoltaic characteristics of DLC:Ag composite films produced for solar tracking and/or photodetector device purposes. We used the magnetron sputtering technique to prepare DLC:Ag thin films where DLC and Ag were co-deposited on Si wafers. Structural characterization of the thin films was performed using AFM, EDX, and Raman spectroscopy. Current–voltage, capacitance–voltage and conductance–voltage characterizations were employed to assess the electrical characteristics and photovoltaic characteristics of the DLC:Ag thin films. I–V characteristics were characterized under various illumination intensities to assess the effect of light intensity on the DLC:Ag composite films. We found that silver-doped DLC composite thin films are responsive to light and exhibit detector-like behaviour. Barrier height was found to be between 0.55 eV and 0.81 eV while the ideality factor was calculated to be between 1.94 and 7.11. It was found that photovoltaic and diode properties were affected by applied illumination intensities. C–V characteristics indicated that the electrical properties of the thin films are responsive to the signal frequency. The density of interface states was calculated which was thought to be a factor related to this behaviour.
AtıfScopus17WoS16OpenAlex14İncele - MakaleYalnız künye2023Scopus SJRQ2Microplastic pollution in two remote rivers of Türkiye
Gündoğdu, Sedat; Kutlu, Banu; Özcan, Tahir; Büyükdeveci, Ferhat; Blettler, Martin C. M.
Microplastic pollution in aquatic ecosystems presents an emerging environmental threat that can have adverse effects on ecology, endanger aquatic species, and result in economic damage. Despite the numerous studies reporting the presence of microplastics in marine environments, research into their presence in freshwater systems or inland waters remains limited. This study aimed to assess the level of microplastic pollution transported by the Munzur and Pülümür Rivers and some small rivers that flow into the Uzunçayır dam lake, which is the confluence of the Munzur and Pülümür Rivers in Türkiye. Samples were collected from 23 stations, with the concentration of microplastics ranging from 0.01 MP/m3 at P-4 station to 28.21 MP/m3 at P-10, a station located near a city. Microplastics comprise four types: fiber, film, fragment, and glitter. The average size of microplastics was 1.46 ± 0.05 mm, with the average size of fibers, films, fragments, and glitter-type microplastics being 1.58 ± 0.07 mm, 1.23 ± 0.10 mm, 1.21 ± 0.11 mm, and 0.78 ± 0.16 mm, respectively. The most frequent polymers were polyethylene (31.8%), polystyrene (21.1%), and polypropylene (10.5%). Despite being considered remote and less populated rivers compared to other river systems in Türkiye, all sampling sites showed varying concentrations of microplastics.
AtıfScopus34OpenAlex37İncele - MakaleYalnız künye2023Scopus SJRQ1Cytoprotective, antimutagenic/antirecombinogenic and antibacterial properties of Lallemantia iberica extracts
Yilmaz Kardas, Begumhan; Diken, Mehmet Emin; Bayhan, Hamza; Acar, Mikail; Dogan, Serap
BACKGROUND: Plants have important chemical compounds to protect organisms from many mutagens but they may also have dangerous toxic substances that must be tested before use. Lallemantia iberica has been used by local people for treatment of some diseases but it was never tested for its cell protective and antimutagenic/antirecombinogenic properties. In this study, it was aimed to determine the cytoprotective, antimutagenic/antirecombinogenic, antibacterial, antioxidant and phenolic profile of L. iberica by MTS assay, micronucleus test/somatic mutation recombination test (SMART), disc diffusion method, ABTS/DPPH tests and liquid chromatography (LC), respectively. RESULTS: MTS assay results showed that both of the extracts supported the normal growth of healthy human lymphocytes and there was no significant difference between extracts. Although there was no significant increase in micronucleus concentration (‰) of the cultures treated with ethanol or methanol extracts, methanol extract caused slightly lower micronucleus concentration (12.64 ± 3.65‰) than the ethanol extract (24.46 ± 4.50‰). SMART results showed that ethanol and methanol extracts prevented harmful mitotic recombination. Lallemantia iberica also showed antibacterial activity against all of the strains tested, and the largest inhibition zones were observed with Pseudomonas aeruginosa (17.9 mm) and Enterobacter aerogenes (13.8 mm). Methanol extracts showed better antioxidant activities (ABTS IC50: 104.07 μg mL−1, DPPH IC50: 58.8 μg mL−1) than ethanol extracts (ABTS IC50: 344.03 μg mL−1, DPPH IC50: 233.7 μg mL−1). According to the LC results, the most abundant phenolic compounds were rutin hydrate (1796.4 ± 62.9 mg kg−1) and p-coumaric acid (228.1 ± 7.60 mg kg−1). CONCLUSION: Lallemantia iberica extracts had cell-protective, antimutagenic/antirecombinogenic, antibacterial and strong antioxidant characteristics in relation to their rich phenolic content.
AtıfScopus7WoS5OpenAlex9İncele - MakaleAçık Erişim2023Scopus SJRQ2Prediction of Paleoclimate of Eocene Salt, Kohat Basin, Khyber Pakhtunkhwa, Pakistan
Ahmed, Noor; Kashif, Muhammad; Dou, Bin; Tariq, Muhammad; Sami, Muhammad; Ullah, Zahid
Fluid inclusion analysis is a significant tool to evaluate the paleoclimate reconstruction of ancient evaporite precipitation. The current study is a significant research to evaluate the ancient climate of Eocene salt. The thin sections petrography, XRD, SEM, Laser raman spectroscopy, and Microthermometric analysis have been used to evaluate the prediction of paleoclimate of Eocene salt. Two sections were measured and samples were collected for thin sections analysis. Under thin section, halite is mainly cubic shape euhedral form and also consists of other minerals like gypsum, anhydrite, polyhalite, sylvite, and dolomite. Geochemical data obtained from XRD, indicates the presence of Na and Cl as major ions, with subordinate Ca, SO4, Mg, etc. Laser raman spectroscopy analysis reveals that water and CO2 fluids are trapped within the inclusions. Generally, fluid inclusion analysis and geochemistry are useful tools to evaluate the origin and paleoclimate of Eocene Salt. Geochemical data shows that the Eocene salt is not a product of marine water but it also consists of meteoric and surface water. Low concentration of Br- and presence of SO4 shows that halite is precipitated from SO4 type water. Homogenization temperature (Th) ranges from 14°C to 43°C. Microthermometric data shows that fluids were entrapped during and after salt precipitation. Histogram of fluid inclusions also shows that primary and secondary inclusions have discontinuous behavior that shows inclusions were not trapped at the same time of deposition. Some are formed at the time of precipitation and some are formed after precipitation. The presence of impurities like Fe, Mg, Ca, and other ions within the halite show that halite was exposed to the atmosphere by tectonic activities and meteoric water/surface water percolates through fractures and is trapped as inclusion along with the micro fractures. So the Th variation indicates that fluid was trapped at various seasons. Low temperature show inclusions were trapped in winter/spring seasons and high temperatures indicates inclusions were trapped in the summer season. The maximum homogenization temperature of fluid inclusions in halite is 43°C which is closed to the maximum climatical temperature of the present summer. The result shows that Eocene salt has been deposited in hot, arid, and dry conditions during Eocene time. The alternating period of desalination and evaporation is responsible for the formation of soluble halite.
AtıfScopus3WoS3OpenAlex1İncele - MakaleYalnız künye2023Scopus SJRQ1Oxides dispersion-strengthened (ODS) FeCoNiCuZn high entropy alloys through different rare earth elements: Synthesis, structural, physical, and experimental radiation transmission properties
Güler, Ömer; Kavaz, E.; Güler, Seval Hale; Almisned, Ghada; Özkul, İskender; Basgoz, Oykum; Tekin, H.O.
The oxide dispersoids within ODS alloys can act as sinks for radiation-induced defects, such as vacancies and dislocation loops, effectively reducing their mobility and preventing their accumulation. This property is crucial for HEAs employed in radiation-intensive environments, such as nuclear reactors. The objective of this research is to examine the impact of rare earth elements (REE) such as Y2O3, Er2O3, Pr2O3, and Sm2O3, on Oxides Dispersion-Strengthened (ODS) FeCoNiCuZn High Entropy Alloys (HEAs). The mechanical alloying technique is employed to produce a high entropy alloy consisting of Fe, Co, Ni, Cu, and Zn in their raw form. Subsequently, the raw alloy powder is enriched with separate amounts of Y2O3, Er2O3, Pr2O3, and Sm2O3. The microstructural analysis of the samples obtained from the mechanical alloying process was performed utilizing the X-ray diffraction (XRD) technique. In addition, scanning electron microscopy (SEM) was employed to analyze the ODS-HEA samples encoded S1, S2, S3, S4, and S5. To investigate the transmission properties of gamma-ray and neutron radiation, experimental studies are carried out using two types of detectors: Ultra High Purity Germanium (HPGe) detector and Canberra NP-100B BF3 gas proportional detector, respectively. The X-ray diffraction (XRD) spectra of samples did not display any observable peaks that could be attributed to the presence of dispersed rare earth element (REE) oxides. The uniform distribution of the metallic constituents that make up the High Entropy Alloy (HEA) is observed in the samples. Additionally, it can be observed that the implementation of the ODS-HEA technique, incorporating a 3% (wt.) Er2O3 additive, results in the most advantageous results with respect to the characteristics of gamma ray absorption. The S3 sample demonstrated the greatest degree of neutron absorption, as demonstrated by a recorded value of 0.857 μSv/h, where the S1 sample demonstrated the minimum level of absorption, as evidenced by a recorded value of 0.452 μSv/h. Based on the observed effects on neutron and gamma-ray attenuation behaviors in ODS-HEAs, it can be concluded that Er2O3 exhibits characteristics of a monotonic oxide. This feature is particularly advantageous for applications that necessitate a dual enhancement in these behaviors. It can also be concluded that the S1 sample may be deemed appropriate for situations where the utmost consistency of chain reactions in nuclear reactor fuel rods is desired, due to its possession of the lowest neutron absorption properties.
AtıfScopus22OpenAlex26İncele - MakaleAçık Erişim2023Scopus SJRQ4The Effects of Perineal Massage Performed During Labor on Childbirth Comfort, Perineal Pain, and Trauma in Nulliparous Women: A Quasi-Experimental Study
Yaşar Yetişmiş, Habibe; Aksoy Derya, Yeşim
Objective: The purpose of this study was to examine the effects of perineal massage performed during labor on childbirth comfort, perineal pain, and genital tract trauma in nulliparous women. Material and Methods: This is a quasi-experimental study with a control group. The sample consisted of a total of 182 pregnant women, including 91 in the experimental group and 91 in the control group. Perineal massage was performed in the experimental group two, four, and four to six times during the latent, active, and transition phases, respectively. The participants in the experimental group continued to receive perineal massage with every push throughout the second stage of labor. Data were collected using the “Personal Introductory Form”, “Visual Analog Scale (VAS)”, “REEDA Scale” and “Childbirth Comfort Questionnaire (CCQ)”. Results: There was a statistically significant difference between the groups in terms of labor conditions including duration of the second stage of labor, perineal trauma status, severity of perineal trauma, and episiotomy application status (p<0.05). After perineal massage, the CCQ mean score at the end of the active phase was 30.53±8.78 in the experimental group and 26.83±7.78 in the control group (p<0.05). Additionally, the postpartum VAS mean score was 3.04±2.08 in the experimental group and 5.72±2.64 in the control group (p<0.001). The REEDA mean total score was 3.23±0.53 in the experimental group and 5.50±1.70 in the control group (p<0.001). Conclusion: Perineal massage administered to nulliparous women during labor increased childbirth comfort and decreased perceptions of perineal pain, and it was associated with lower rates of genital tract trauma.
AtıfOpenAlex1
İncele - MakaleAçık Erişim2023Scopus SJRQ3EFFECT of the COOLING with AIR and WATER VAPOR on MILLING PERFORMANCES
Mahmat, Aybars; Tosun, Nihat; AǦar, Salih
This study aims to investigate experimentally and analytically the effects of different machining parameters such as cooling methods and cutting tool materials on surface roughness and chip thickness ratio for milling of AA7075-T6 aluminum alloy. The carbide and high-speed steel (HSS) end mills were used as cutting tools and the conventional, vapor, and compressed air were used as cooling methods in the experiments. The experiment conditions for compressed air at the cutting zone were 6 bar pressure and 30 m/s speed flow rate. A mixture of boron oil and water (1/20 mixture ratio) was used as cutting fluid in conventional cooling. The study was carried out using three levels of feed rates (20, 40, 80 mm/min), rotational speeds (780, 1330, 2440 rpm), and a constant 2 mm deep cut. As a result of the experiments, the surface roughness values increased with the increasing levels of feed rate. Besides surface roughness values decreased with increasing levels of the rotational speed. In addition, a better surface quality was obtained in milling processes by using carbide cutting tools compared to HSS tools. It was concluded that the most important parameter affecting the surface roughness and chip thickness ratio is feed rate and the rotational speed, respectively. Better surface roughness and chip thickness ratio were obtained from the vapor processing than the conventional and compressed air.
AtıfScopus2WoS1İncele - MakaleAçık Erişim2023Scopus SJRQ3Two Moss Species New to Turkey and South-West Asia
Batan, Nevzat; Özcan, Osman; Özen-Öztürk, Öznur; Erata, Hüseyin; Alataş, Mevlüt; Ezer, Tülay
Abstrat: —Sphagnum russowii and Leptodontium flexifolium found as new to Turkey following a recent bryofloristic foray in Artvin region (Caucasus), from the East Black Sea region of Turkey and Leptodontium is the first record of the genus from Turkey. Descriptions, illustrations, a distribution map, ecological characteristics, and comparisons with morphologically similar taxa were presented.
AtıfScopus1OpenAlex3İncele - MakaleYalnız künye2023Scopus SJRQ3Synthesis, Characterization and Biocompatibility of Cross-linked Dicarboxylic Acids from Waste Potato Peel Starch
Paşa, S.; Gürler, N.; Erdoğan, Ö.; Cevik, O.
Abstract: People have become conscious about recycling or reusing many things they use in the 21st century because diminishing vital resources make it necessary, both personally and socially. The evaluation of waste is also critical in terms of national economies. In this study, starch dicarboxylic compounds were synthesized using waste potato peels (WPP) in the presence of sodium hypophosphite monohydrate as a catalyst for the formation of the ester cross-links. Adipic acid, succinic acid, and glutaric acid were employed with waste potato starch (WPS) to obtain cross-linked samples: WPS-A, WPS-S, and WPS-G, respectively. The obtained compounds were characterized by attenuated total reflectance Fourier transform infrared (FTIR-ATR), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX), X-ray diffraction (XRD), and their cytotoxicity properties were investigated. The biocompatibility of the obtained WPS-dicarboxylic acid compounds against NIH-3T3 and L929 murine fibroblast cells with MTT assay was determined. Studies have shown that these compounds do not harm healthy cells and are found to be bioavailable.
AtıfScopus6OpenAlex6İncele - MakaleAçık Erişim2023Scopus SJRQ1A comparative framework for criticality assessment of strategic raw materials in Turkey
Göçmen Polat, Elifcan; Yücesan, Melih; Gül, Muhammet
The rapid development of innovative technologies, population growth, shifting resource management patterns, and decarbonization challenges are expected to increase the demand for raw materials labeled as critical in the following years. The increasing concerns have led to evaluate the critical raw materials (CRMs) with high economic importance and supply risk. In this context, this paper aims to develop a conceptual methodology to identify CRMs in Turkey. The methodology integrates a multi-criteria decision-making method (MCDM) to provide the raw material criticality matrix regarding various criteria, the EU (European Union) method, which represents supply risk and economic importance indicators, and the time series analysis method, in which dynamic evaluation of materials over time instead of the static indicators. We first provide a Bayesian Best-Worst method (B-BWM) and TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) based model for the criticality matrix, which enables evaluations of participated experts to be combined to reveal the weights of the criteria and sub-criteria from a probabilistic point of view without loss of knowledge. The main and sub-criteria include supply risk and economic importance, which are frequently studied in the literature, but also environment, price, secondary production, and socio-economic indicators are evaluated in the criticality matrix. Then, exponential smoothing forecast, one of the Time Series Analysis models, which determine the element criticality in the perspective of future years with the data of import figures of Turkey, is superior to the other models. Finally, with some modifications, the EU criticality methodology is used to quantify the raw materials regarding each material associated with the sector applications and their value-added and supply disruptions. Thus, a comprehensive criticality list integrating the results of the three mentioned methods is important because Turkey's raw materials characterize many sectors. The findings should also interest practitioners and researchers as the detailed assessment of raw material criticality ensures a sufficient database for future studies.
AtıfScopus24WoS14İncele - MakaleAçık Erişim2023Scopus SJRQ2Preparation of composite supported phase change materials from inorganic-based microcapsules of cetyl alcohol and investigation of their phase change material (PCM) behaviors
Karabulut, Serap; Sekerci, Memet; Adiguzel, Ragip; Karagoz Genc, Zuhal
In this study, cetyl alcohol (CA) (CH3(CH2)15OH), which is a fatty alcohol, was microencapsulated by the coacervation method with the titanium-n-butoxide (TNBO). Firstly, at the beginning of the experimental process by thermal and structural analyses, the CA was determined as having a phase change material (PCM) property, then it was microencapsulated with TNBO. In the second step of the study, barite, boron nitride, marble powder, and fly ash were separately added to prepare a series of microencapsulated with TNBO. Lastly, structural and thermal properties of both microencapsulated PCM and composite supported microencapsulated PCMs (CSM-PCMs) have been analyzed by FTIR, DSC, TGA, and SEM devices. Surprisingly, the SEM image of CA turned from torn fiber structure into a particulate structure in the form of groundnut in the SEM images of the microencapsulated CA-Ti taken at different magnifications. After the thermal cycling test, the same analyses have been made before and after thermal cycling to compare the structural and thermal properties. It has been investigated whether to use as insulation material. It is concluded that the most suitable samples, compared with structural and thermal properties, are barite (B) and boron nitride (BN) with microencapsulated samples. The obtained results are shown that CATi-B and CATi-BN are CSM-PCMs and could be suggested in terms of thermal energy storage in buildings as promising PCMs.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2023Scopus SJRQ4Cu(II) Complexes of New Sulfa Drug Schiff Base Ligands: Synthesis, Structural Characterization, Antimicrobial Activities, and Time-Killing Kinetics
Şahal, Hakan; İdil, Önder; Canpolat, Erdal; Özkan, Mustafa
Abstract: Synthesis of three different new sulfonamide compounds (L1–L3) and their Cu(II) complexes were carried out. Their structures were characterized by spectroscopic methods such as Fourier transform infrared, Proton nuclear magnetic resonance and elemental analysis. Cu(II) complexes were screened for Gram-positive, Gram-negative bacteria and against yeast using the microdilution method. In particular, CuL2 was found to have significant antimicrobial effects on Gram (–), Gram (+) and eukaryotic yeast. The results showed that CuL2 exhibited better antimicrobial activity than other complexes. Depending on the antimicrobial activity results, time killing experiments of CuL2, the most effective complex, were performed.
AtıfScopus3WoS2OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ2Investigation on application of plate-tube evaporative condensating technology for data centres in the northwest of China
Wu, Xueyuan; Shao, Shuangquan; Akkurt, Nevzat
The rapid development of data center leads to a rapid increase in energy consumption. In this paper, the plate and tube evaporative condenser is proposed for the water-cooled chiller and the data center cooling system to improve the energy efficiency in hot and dry summer and avoid icing in cold winter. The chiller can operate in the wet mode for compressor refrigeration and the dry mode for free cooling with the coefficient of performance (COP) of 5.2 in wet mode and up to 33.3 in dry mode. Furthermore, the system is applied in a data center in Ulumiqi, which is located in the dry and cold region and its ambient air temperature can vary from −32 °C to 45 °C throughout the year. The actual operation results show that the power usage effectiveness (PUE) value of the whole data centre is 1.349 in June, 1.229 in December, and 1.320 as the annual average, which is stable and efficient for five consecutive years. These results ensure the proposed system is an important technical solution for energy saving and emission reduction in data centres in cold regions.
AtıfScopus9WoS5OpenAlex8İncele - MakaleAçık Erişim2023Scopus SJRQ2Stress analysis of the contact problem in a functionally graded layer loaded with a distributed load and two rigid circular punches resting on an elastic two quarter planes
Kaya, Fatih; Polat, Alper
In this study, the solution of the contact problem in a functionally graded (FG) layer resting on elastic two quarter planes was done using the finite element method (FEM). The contact problem consists of two rigid circular punches loaded FG and two elastic quarter planes. P and Q loads are transmitted to the FG layer by two rigid circular punches. All surfaces in the problem were considered as frictionless and the weight effect is also taken into account. The two-dimensional model of the contact problem was created with the ANSYS package program based on FEM and the stress analyzes were performed. All operations of quarter planes and circular punches are done with standard ANSYS menus. However, defining the material properties of the FG layer and dividing into meshes in finite elements cannot be done with standard menus. For this reason, a special macro was added to the program in order to define the material properties of the FG layer and to perform the mesh division, and the necessary parameters were applied to the layer by this macro. In the study, the effects of external load, stiffness parameter (βh), density parameter (γh) and contact stresses of distributed load change, normal stresses, and stresses along the depth were investigated.
AtıfScopus6WoS6OpenAlex5İncele