Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(102)
- Güler, Ömer(69)
- Akkurt, Nevzat(68)
- Tekin, H.O.(52)
- ALMisned, Ghada(49)
- Yucesan, Melih(49)
- Celik, Erkan(45)
- Zengin, Gokhan(40)
- Serdar, Osman(39)
- Kocabaş, Mehmet(37)
- Aslan, Naim(31)
- Baskonus, Haci Mehmet(31)
- Bulut, Hasan(31)
- Mete, Suleyman(31)
- Paksoy, Mehmet Yavuz(30)
- Kök, Mediha(27)
- Ince, Muharrem(26)
- Yildirim, Ozal(26)
- Özkul, İskender(26)
- Sulaiman, Tukur Abdulkadir(25)
- Topal, Murat(25)
- Guler, Omer(24)
- Serin, Faruk(23)
- Benzer, Fulya(22)
- Erten, Fusun(22)
- Alataş, Mevlüt(21)
- Güler, Seval Hale(21)
- Baykal, Duygu Sen(20)
- Taşgın, Yahya(20)
- Kutlu, Banu(19)
- Onat, Onur(19)
- Sahin, Kazim(19)
- Tanyol, Mehtap(19)
- Torğut, Gülben(19)
- Yildirim, Numan(19)
- Kahraman, Gökhan(18)
- Orhan, Cemal(18)
- Say, Yakup(18)
- Susam, Selim Orhun(18)
- Utku, Anıl(18)
Yayınlar
- MakaleAçık Erişim2023Scopus SJRQ1DEEP LEARNING BASED AN EFFICIENT HYBRID PREDICTION MODEL FOR COVID-19 CROSS-COUNTRY SPREAD AMONG E7 AND G7 COUNTRIES
Utku, Anil
The COVID-19 pandemic has caused the death of many people around the world and has also caused economic problems for all countries in the world. In the literature, there are many studies to analyze and predict the spread of COVID-19 in cities and countries. However, there is no study to predict and analyze the cross-country spread in the world. In this study, a deep learning based hybrid model was developed to predict and analysis of COVID-19 cross-country spread and a case study was carried out for Emerging Seven (E7) and Group of Seven (G7) countries. It is aimed to reduce the workload of healthcare professionals and to make health plans by predicting the daily number of COVID-19 cases and deaths. Developed model was tested extensively using Mean Squared Error (MSE), Root Mean Squared Error (RMSE), Mean Absolute Error (MAE) and R Squared (R2). The experimental results showed that the developed model was more successful to predict and analysis of COVID-19 cross-country spread in E7 and G7 countries than Linear Regression (LR), Random Forest (RF), Support Vector Machine (SVM), Multilayer Perceptron (MLP), Convolutional Neural Network (CNN), Recurrent Neural Network (RNN) and Long Short-Term Memory (LSTM). The developed model has R2 value close to 0.9 in predicting the number of daily cases and deaths in the majority of E7 and G7 countries.
AtıfScopus9OpenAlex11
İncele - 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.
AtıfScopus9WoS6OpenAlex7
İncele - 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.
AtıfScopus34OpenAlex37
İncele - 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 Erişim2023On Curvatures of Semi-invariant Submanifolds of Lorentzian Para-Sasakian Manifolds
Sari, Ramazan; Ünal, İnan
A Lorentzian para-Sasakian (LP-Sasakian) space form is a kind of para-Sasakian manifold with constant φ− holomorphic sectional curvature. The presented paper is on the curvatures of semi-invariant submanifolds of an LP-Sasakian space form. Firstly, the definition of a semi-invariant submanifold of LP-Sasakian space form is given and an example is presented. Then, some important results on Ricci and scalar curvatures have been obtained by using the Gauss equation related to curvatures. Furthermore, by suffering from these results, the conditions of a distribution is being Einstein have been examined. Finally, semi-invariant products of Lorentzian para-Sasakian manifolds have been considered and an important inequality for the second fundamental form is proved.
AtıfOpenAlex1TR Dizin1
İncele - 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.
AtıfOpenAlex1İncele - 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 SJRQ2Physiological peristaltic flow of Jeffrey fluid inside an elliptic cross section with heat and mass transfer: Exact solutions through Polynomial solution technique
Nadeem, Sohail; Akhtar, Salman; Akkurt, Nevzat; Saleem, Anber; Almutairi, Shahah; Ghazwani, Hassan Ali
An interpretation of heat and mass transfer for the peristaltic flow of a non-Newtonian Jeffrey fluid inside a duct having an elliptic cross-section is mathematically investigated. We have considered constant heat absorption for the present study and a descriptive heat as well as mass transfer analysis is carried out. Exact solutions are computed by utilizing a polynomial solution technique to solve the dimensionless partial differential equations appearing in the problem. A purposeful and detailed graphical assessment is provided for the final mathematical results. Velocity as well as temperature profiles attain highest value at the core region of duct while these profiles gradually decline toward duct boundaries. The incrementing value of λ1 is resulting in an increase of flow and since λ1 is the dimensionless ratio of relaxation to retardation time, it means that the increasing value of λ1 results in an increase of relaxation time but it also results in decline of retardation time.
AtıfScopus11OpenAlex10İncele - MakaleYayıncıda açık erişim2023Estimation of Contact Lengths Using Deep Neural Network; [Derin Öğrenme Yöntemi ile Temas Uzunlukları Tahmini]
Polat, Alper
One of the most common problems in engineering is contact problems. In recent years, researchers have turned to alternative methods that can offer effective solutions in a shorter time, instead of solutions containing complex and long mathematical expressions. This study focuses on the estimation of the contact lengths in a homogeneous elastic layer suppressed by two elastic punches with two solution methods. Firstly, a new model was designed for estimation using Deep Learning Neural Network (DNN), one of the deep learning structures. Estimation of contact lengths was provided with the output of the DNN model, which was fed with the homogeneous elastic layer, the ratio of shear modules of the punches and the input parameters of punch radii. The finite element method was used as the second solution method. The problem was modelled in the ANSYS programme, and the solution was made with the same parameters used in DNN modelled. The results obtained from both solutions were compared with the solutions obtained by the theory of elasticity and classical NN in the literature. It had been seen that the results obtained with DNN and ANSYS were compatible with the results obtained with analytical and classical NN and the margin of error was smaller.
AtıfScopus5OpenAlex2İncele - 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 - MakaleYalnız künye2023Scopus SJRQ2An Estimation Proposal for Engineering Properties of Modified Concrete by using Standalone and Hybrid GRELM
Cemalgil, Selim; Onat, Onur; Aruntaş, Hüseyin Yılmaz
The presented study pertains to an attempt to propose a novel prediction model to predict the flexural and compressive strengths of concrete modulated using steel fiber (SFb) and silica fume (SF). A completed experimental investigation is adopted for the current study, and a research plan is employed. Three different superplasticizers amount (SP), different SF replacement ratios, and a constant amount of SFb were used by the weight of cement to meet the C25 target strength. A sum of 16 distinct mixtures designed by changing SP and SF ratios were developed. Furthermore, SFb was added at a fixed rate of 65 kg/m3 to all planned concrete mixes. In addition, SFb was used to create a 16-mix design. Finally, a total of 32 distinct mix designs were created. Produced, hardened specimens were exposed to two different curing conditions. This research uses the mechanical characteristics of concrete treated with SF, SP, and SFb to estimate by conducting standalone and hybridized generalized extreme learning machine (GRELM) algorithms based on available experimental data in terms of the metaheuristic aspects of this work. With continuous input data, four separate data sets were constructed. Compressive strength and flexural strength were estimated separately. With the aid of the Grey Wolf Optimization (GWO) and Particle Swarm Optimization (PSO) algorithms, binary and ternary hybrid approaches were developed and tested on the data. Four distinct estimation models were suggested. Two quality metrics were used to evaluate the estimation performance: Root Mean Square Error (RMSE) and correlation of determination (R2). The estimation results showed that the hybridized GRELM-PSO-GWO estimation model that was built for prediction was relatively successful in all sets.
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