Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Bayram, Sinan(9)
- Ayata, Ümit(8)
- Can, Zehra(8)
- Dertli, Enes(8)
- Esmer, Yusuf(8)
- Kaya, Yunus(8)
- Semerci, Vahide(8)
- Akyol Özcan, Kübra(6)
- Kara, Yakup(6)
- Maden, Sedat(6)
- Şahin, Engin(6)
- Bilgin, Yusuf(5)
- Dirican, Ebubekir(5)
- Ertugrul, Mehmet(5)
- Gülden, Bahadır(5)
- Gıdık, Betül(5)
- Imamoglu, Ilyas Kays(5)
- Kaplan, Kadir(5)
- Kaya, Musa(5)
- Koçak, Lokman(5)
- Kutlu, Naciye(5)
- Sönmez Sarı, Ebru(5)
- Ünalan, Ozlem(5)
- İspirli, Hümeyra(5)
- Ates, Fatih(4)
- Bulut, Mehmet(4)
- Bülbül, Ali Savaş(4)
- Ecem Bayram, Nesrin(4)
- Gökçe, H.S.(4)
- Gültekin, Ömer Faruk(4)
- Kadakal, Huriye(4)
- Kahveci, Hakan(4)
- Kamiloğlu, Aybike(4)
- Kaya, Metin(4)
- Kırbaş, Zila Özlem(4)
- Teber, Ahmet(4)
- Uzunçakmak, Sevgi Karabulut(4)
- Uğur, Uçar(4)
- Yilmaz, Sevda(4)
- Öztürk, Mesut(4)
Yayınlar
- MakaleAçık Erişim2023Scopus SJRQ2A simulation study on colloid diffusion under time-varying optical potentials
Yücel, Harun
With its momentum transfer, light is a primary tool for manipulating microscale objects in various research fields, including physics, chemistry, and biology. Optical force fields, also known as energy landscapes, play a crucial role in manipulating micro- and nano-sized objects, enabling the sorting of mixed micro-sized particles. This study investigates the effect of time-varying periodic optical fields created by a structured light illumination technique on the diffusion motion of micro-sized colloidal particles suspended in a liquid. A simulation code is developed to calculate the optical force acting on particles due to any time-varying optical force field. Simulations are performed to produce trajectories of particles of different sizes suspended in a liquid for different illumination patterns. The results show that the average velocities of the particles depend on the projected optical pattern parameters and that mixtures of particles of different sizes can be separated using time-varying sequential patterns, thereby improving particle separation resolution.
AtıfScopus2WoS2OpenAlex3
İncele - MakaleYalnız künye2023Scopus SJRQ1Gamma-ray and neutron shielding capability of blended cement-stabilized barite fillers developed by maximum density method
Gökçe, H.S.; Öksüzer, N.; Kamiloğlu, H.A.; Yılmaz, F.
The disposal of radiological wastes in the deep geological repositories has become an important issue for the reduction of hazardous risks on the human and biological environments. In this study, blended cement-stabilized barite fillers against gamma rays and neutrons have been developed with the use of the maximum density method by considering various amounts of water (100–300 kg/m3), binder (4–10%), and compaction energy (500–2000 kJ/m3). According to the experimental series of these filler materials, satisfactory response surface results have been achieved in the study. The experimental results revealed that compacted filling material can ensure an efficient shielding capability for gamma rays and neutrons when designed with a density of 3.064 g/cm3. An increase in binder content, water content, and compaction energy has improved the compressive strength of these materials up to 37 times according to that of the poorest series. Neutron and gamma-ray shielding capabilities were found to be 119 and 14% higher than those of the poorest filler material, respectively when theoretical and experimental results are considered in the study.
AtıfScopus4WoS3OpenAlex5İncele - MakaleAçık Erişim2023The effects of artificial weathering on the pendulum hardness of chestnut wood applied with polyurethane varnish after heat treatment; [Isıl işlem sonrası poliüretan vernik uygulanmış kestane odununda salınımsal sertlik üzerine yapay yaşlandırmanın etkileri]
Ulay, Göksel; Ayata, Ümit
The effects of artificial weathering (576 h) on the pendulum hardness values of Anatolian chestnut (Castanea sativa Mill.) wood applied with polyurethane varnish (PU) after heat treatment at 190°C for 1.5 h and at 212°C for 2 h were investigated. The results revealed that heat treatment, weathering period, and interaction were significant. The hardness values of the heat-treated materials were higher than those of the non-heat-treated test samples. The highest hardness value was determined in the un-weathered group of the test samples that were heat-treated at 190°C for 1.5 h while the lowest value was determined in the group that was heat-treated at 190°C for 1.5 h and weathered for 432 h. The highest reduction rates after weathering were obtained on samples that were heat-treated at 190°C for 1.5 h, followed by heat-treated at 212°C for 2 h and non-heat-treated. It was observed that the heat treatment application caused different pendulum hardness values in chestnut wood samples covered with polyurethane varnish.
AtıfScopus3OpenAlex2
İncele - MakaleAçık Erişim2023Scopus SJRQ1Food Price Bubbles: Food Price Indices of Turkey, the FAO, the OECD, and the IMF
Akyol Özcan, Kübra
Food price bubbles are a phenomenon in which the cost of some food items or food commodities climbs quickly and unreasonably before collapsing due to reasons such as speculation, supply and demand imbalances, meteorological occurrences, and governmental actions. Governments and academics keep an eye on food prices to spot and address these bubbles. The aim of this paper is to analyze the food price bubble phenomenon despite the global slowdown by examining its origins, consequences, and policy solutions. The study’s contribution lies in its investigation of the presence of a potential bubble formation in food prices, which have experienced a surge globally and particularly in Turkey in recent years. The research examines the behavior of bubble formation in food prices in Turkey, the FAO, the OECD, and the IMF between 1992 and 2022 using the ADF, SADF, and GSADF tests. These tests can help identify when asset prices deviate significantly from their fundamental values and may be at risk of a sharp correction. The TUR, FAO, OECD, and IMF variables all show distinct bubble formations, with the TUR variable having 130 periods from 1995 to 2006, the FAO having 8 price bubble occurrences, the OECD having 12 different bubble formations, and the IMF having 4 distinct bubble formations. The results indicate the existence of food price bubbles that demonstrate disparities from their inherent values grounded in market fundamentals.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ2Magnetic Force Performance of Hybrid Multisurface HTS Maglev System With Auxiliary Onboard PMs
Ozturk, U. Kemal; Abdioglu, Murat; Mollahasanoglu, Hakki
The vertical levitation force, guidance force, and magnetic stiffness values, and thus the loading capacity and movement stability of high-temperature superconducting (HTS) Maglev systems, are aimed to be increased in this study by using auxiliary permanent magnets (PMs) in the onboard unit together with the multisurface HTS-permanent magnetic guideway (PMG) arrangement (hybrid multisurface arrangement). First, the magnetic levitation force, guidance force, and stiffness performances of the hybrid multisurface arrangement were investigated at different field cooling heights (FCH). Then, to compensate for the negation of instability that results from the higher repulsive force between the onboard PMs and the PMG and to obtain an optimal magnetic field medium, we have changed the vertical position of the auxiliary onboard PMs (ZPM) to ZPM = 0, 2, and 4 mm, at the cost of a bit of adecrement in the vertical levitation force. The bigger levitation force, together with the guidance force values for FCH = 25 mm and ZPM = 0 mm, indicates that the hybrid multisurface HTS-PMG arrangements are beneficial to increasing the practical applicability of Maglev systems.
AtıfScopus16WoS14OpenAlex14İncele - MakaleAçık Erişim2023Scopus SJRQ3Examination of the Effectiveness of School Leadership: A Second-order Meta-analysis Study
Kaya, Metin
This study aimed to examine the effectiveness of school leadership by exploring the relationships between various school leadership models and practices and different school outcomes, including organizational, teacher, and student outcomes. Data for this study were retrieved from multiple databases, including Web of Science, Scopus, ERIC, Academic Search Ultimate, and TR Dizin-Turkish national index. The analysis synthesized findings from 23 meta-analysis studies, utilizing second-order meta-analysis with the random-effects model. The study revealed a significantly positive relationship between school leadership and school outcomes, with a high level of correlation (mean effect size: 0.46). Additionally, this relationship varied significantly based on the type of school leadership, school outcome, and the quality of the studies conducted.
AtıfScopus2WoS1OpenAlex2İncele - MakaleYalnız künye2023Scopus SJRQ2Free vibration and buckling of functionally graded porous beams using analytical, finite element, and artificial neural network methods
Turan, Muhittin; Uzun Yaylacı, Ecren; Yaylacı, Murat
In this study, an analytical solution based on the first-order shear deformation theory was performed for free vibration and buckling analysis of functionally graded porous beams (FGM-P) subjected to various boundary conditions. Also, this problem is solved by using finite element (FEM) and artificial neural network (ANN) methods. Here a Ritz-based analytical solution is used, and different polynomial series functions are proposed for each boundary condition. Lagrange's principle was used while deriving the equations of motion. A power-law rule describes the variation of the beam's materials in volume. The normalized fundamental frequencies and critical buckling loads are obtained for various boundary conditions, power-law index (k), slenderness (L/h), porosity coefficient (e), and porosity distribution (FGM-P1, FGM-P2). The polynomial series functions used in this study were verified with the literature, and the numerical results obtained were compared with FEM and ANN. The results obtained are quite compatible with each other.
AtıfScopus140WoS136OpenAlex101İncele - MakaleAçık Erişim2023Scopus SJRQ1The effect of local food consumption of domestic tourists on sustainable tourism
Apak, Ömer Ceyhun; Gürbüz, Ahmet
This research aims to determine the effect of local food consumption of domestic tourists on sustainable tourism. In addition, the study also aims to: reveal the impact of local foods on economic, socio-cultural, and environmental sustainability. In this context, data were collected from 394 domestic tourists visiting the provinces of the Eastern Black Sea region (Artvin, Bayburt, Gumushane, Trabzon and Rize). This research was designed in accordance with the correlational research method, one of the quantitative research designs. The research data were tested using structural equation modeling, which is commonly used in the social and behavioral sciences. As a result, it was found that local food has a statistically significant and positive effect on sustainable tourism. In addition, local food was found to have a positive effect on the subscales (economic, socio-cultural and environmental) of sustainable tourism.
AtıfScopus81WoS62OpenAlex87İncele - MakaleYayıncıda açık erişim2023Scopus SJRQ3Sesame seed protein: Amino acid, functional, and physicochemical profiles
Yüzer, Mustafa O.; Gençcelep, Hüseyin
Sesame (Sesamum indicum L.) is an erect herbaceous annual plant with flat seeds. It is one of the oldest cultivated oilseed plants in the world, especially popular in Africa and Asia. The present research objective was to describe a sesame protein isolate, i.e., its amino acid profile, functional and physicochemical properties, zeta potential, and hydrodynamic diameter. The surface charge and hydrodynamic diameter in aqueous solutions were obtained for standard sesame seeds, defatted sesame seeds, and the sesame protein isolate. Defatted sesame seeds yielded the following optimal parameters: salt concentration – 0.6 M, pH – 7, iso-electric point (pI) – 4. The sesame protein isolate was rich in methionine content, which is rare in other plant proteins, but its lysine content was lower than in other isolates. The sesame protein isolate displayed almost identical zeta potential profiles with its pH. The decreasing pH increased the zeta values gradually from the lowest negative value to the highest positive value. The zeta potentials of standard and defatted sesame seeds at pH 7 were –23.53 and –17.30, respectively. The hydrodynamic diameter of the sesame protein isolate (0.33 μm) was smaller than that of sesame seeds (2.64 μm) and defatted sesame seeds (3.02 μm). The sesame protein isolate had a water holding capacity of 1.26 g/g and an oil holding capacity of 3.40 g/g. Its emulsifying properties looked as follows: emulsion capacity – 51.32%, emulsion stability – 49.50%, emulsion activity index – 12.86 m2/g, and emulsion stability index – 44.96 min, respectively. These values are suitable for the sesame protein isolate and are consistent with the literature. The sesame protein isolate was a good source of protein (88.98%). Using sesame proteins as functional components can be an important basis for better knowledge of the relationship between electrical charge interactions in food matrices and the structure, stability, shelf life, texture, structural and functional properties of food. Research prospects include the effects of sesame protein isolates on various food systems.
AtıfScopus36WoS31OpenAlex28İncele - MakaleYalnız künye2023Effect of Alexithymia Severity on Attitudes Toward Hypertension Prevention in Adults: A Cross-Sectional Study
Çetinkaya Özdemir, Serap; Semerci, Vahide; Metin, Tuba
The aim of this study was to evaluate the effect of alexithymia severity on attitudes toward hypertension prevention in adults. In the literature, the effects of alexithymia severity on attitudes toward hypertension prevention in adults have not been clearly elucidated. However, it has been reported that alexithymia is a possible risk factor for various medical conditions and may increase predisposition to diseases. This cross-sectional study included 358 adult individuals. Study data were collected with a personal information form, the Toronto Alexithymia Scale, and the Attitudes Toward Prevention of Hypertension Scale. The data was collected between December 12, 2022, and March 10, 2023. Relationships were analyzed by multiple linear regression. Findings were reported according to the STROBE guidelines. A weak negative correlation was found between the total scores of the Toronto Alexithymia Scale and Attitudes Toward Prevention of Hypertension Scale. The variables of educational status, smoking, having a family member with hypertension, and alexithymia were statistically significant predictors of attitudes toward hypertension prevention. It was further determined that these variables explained 7.6% of the variance in attitudes toward hypertension prevention. Alexithymia severity in adults affects their attitudes toward hypertension prevention. Determining the severity of alexithymia in adults may assist health professionals in implementing initiatives to improve the condition of alexithymia. In addition, new positive behaviors can be developed to prevent hypertension in adults.
- MakaleAçık Erişim2023Scopus SJRQ3Semi P-geometric-arithmetically functions and some new related inequalities
Kadakal, Mahir; İşcan, İmdat; Kadakal, Huriye
In this manuscript, the authors introduce the concept of the semi P-geometric–arithmetically functions (semi P-GA functions) and give their some algebraic properties. Then, they get Hermite-Hadamard’s integral inequalities for semi P-GA-functions (geometric-arithmetically convex). In addition, the authors obtain new inequalities by using Hölder and Hölder-İşcan integral inequalities with the help of an identity. Then, the aouthors compare the results obtained with both Hölder, Hölder-İşcan integral inequalities and prove that the Hölder-İşcan integral inequality gives a better approximation than the Hölder integral inequality. Also, some applications to special means of real numbers are also given.
AtıfScopus5WoS4OpenAlex3İncele - Derleme MakaleYalnız künye2023Scopus SJRQ3An overview of frequency-based power split strategies in electric vehicles with battery/supercapacitor hybrid energy storage system
Çorapsız, Muhammed Reşit; Kahveci, Hakan
Energy management in hybrid energy storage systems (HESSs) consisting of battery and supercapacitor packages has an essential role in the efficient and safe use of energy storage devices. In the mentioned HESSs, with frequency separation-based energy management, the source with slow dynamics (eg, batteries) is supported by other sources with fast dynamics (eg, supercapacitors). To realize power sharing in the battery/supercapacitor HESS, the load current is divided into low- and high-frequency components and supplied/allocated from energy storage devices. This review touches on the historical development of electric vehicles and includes extensive information about the battery and supercapacitor. It also comprehensively analyzes frequency separation-based power allocation strategies for battery/supercapacitors HESS. These strategies were investigated in detail regarding their features, advantages, and restrictions. In addition, interconnection circuit topologies and control techniques used in frequency-based power allocation were explained comprehensively. As a result, this study will serve as a guide on frequency-based power separation principles in HESS.
AtıfScopus23WoS14OpenAlex22İncele - MakaleAçık Erişim2023Scopus SJRQ2Investigating the impact of ICT-trade nexus on competitiveness in Eastern and Western European countries
Soylu, Özgür Bayram; Adeleye, Bosede Ngozi; Ergül, Murat; Okur, Fatih; Lorente, Daniel Balsalobre
Purpose: Since competitiveness is crucial in international trade, this paper contributes to the literature by interrogating the information and communication technology (ICT)-trade nexus on competitiveness in Eastern and Western European countries. Does ICT usage promote or hinder the impact of trade openness on competitiveness? This study attempts to answer two questions: (1) is the interaction of trade and ICT significant in promoting competitiveness? (2) Is the effect significantly different by European classification? Design/methodology/approach: With data on 17 European countries from 2007 to 2020 and using mobile phones and fixed telephone usage as ICT indicators, the study engages the bootstrapped ordinary least squares (BOLS) and method of moments quantile regression (MM-QR) techniques to probe the discourse. Findings: The empirical findings reveal that (1) the interaction of trade and ICT boost competitiveness; (2) the effect of mobile phone is consistent across the full, East, and West European samples; (3) the interaction effect is also significant across the conditional distribution of competitiveness and (4) mobile phones and fixed broadband usage reveal “leapfrog” effect across the quantiles. Overall, the study submits that ICT usage will enhance the impact of trade, and thus, ICT is a critical enabler of competitiveness in Europe; policy recommendations were discussed. Originality/value: To the best of the authors' knowledge, this is the first study examining the interaction effect of trade openness and ICT usage on competitiveness in Europe. In other words, the authors attempt to analyze how ICT usage influences trade-competitiveness dynamics. To fill the gap in the literature, the authors' use a sample of 17 European countries from 2007 to 2020. The variables of interest are the competitiveness index, trade openness, and four ICT indicators (mobile phone, fixed telephone subscriptions, fixed telephone subscriptions, and Internet users).
AtıfScopus16WoS13OpenAlex16İncele - MakaleAçık Erişim2023Scopus SJRQ1Evaluation of Groundwater Vulnerability in the Upper Kelkit Valley (Northeastern Turkey) Using DRASTIC and AHP-DRASTICLu Models
Yıldırım, Ümit
This study aimed to investigate groundwater vulnerability to pollution in the Upper Kelkit Valley (NE Turkey). For this purpose, vulnerability index maps were created using the generic DRASTIC and AHP-DRASTICLu models. The latter model was suggested by adding a parameter to the DRASTIC model and weighting its parameters with the analytical hierarchy process with the GIS technique. The results showed that areas with high and very high vulnerabilities are concentrated around the Kelkit Stream, which flows from east to west in the central part of the study area. In contrast, areas with low and very low vulnerability classes are located in the northern and southern parts of the study area. To validate the model results, a physicochemical characterization of groundwater samples and their corresponding vulnerability index values were statistically compared using the Spearman correlation method. In addition, the single-parameter sensitivity method was applied to analyze the models’ sensitivities. Results revealed a stronger correlation between the vulnerability index values of the AHP-DRASTICLu model (compared to the DRASTIC model) in terms of sulfate (R2 = 0.75) and chloride (R2 = 0.76), while there was a slightly weaker correlation for the electrical conductivity (R2 = 0.65) values of the groundwater samples. Sensitivity analysis indicated that the vadose zone, aquifer media, and land use are the most influential parameters responsible for the highest variation in the vulnerability index. Generally speaking, the results indicated that the AHP-DRASTICLu model performs better than the DRASTIC model for investigating groundwater vulnerability to pollution in the Upper Kelkit Valley.
AtıfScopus9WoS5OpenAlex9İncele - MakaleYalnız künye2023Scopus SJRQ2An algorithmic application with flexible airspace approach
Kökhan, Ahmet; Kökhan, Serhan; Gökdalay, Meriç
Purpose: The purpose of this study is to develop an operational level decision support system model for air traffic controllers (ATCos) within the framework of the Flexible Use of Airspace (FUA) concept to enable more efficient use of airspace capacity. This study produces a systematic solution to the route selection process so that the ATCo can determine the most efficient route with an operational decision support system model using Dijkstra’s Shortest Path Algorithm. Design/methodology/approach: In this study, a new decision support system model for ATCos in decision-making positions was recommended and used. ATCos use this model as a main model for determining the shortest and safest route for aircraft as an operational-level decision support system. Dijkstra Algorithm, used in the model, is defined step by step and then explained with the pseudocode. Findings: It has been determined that when the FUA concept and DSS are used while the ATCo chooses a route, significant fuel, time and capacity savings are achieved in flight operations. Emissions resulting from the negative environmental effects of air transportation are reduced, and significant capacity increase can be achieved. The operational level decision support system developed in the study was tested with 55 scenarios on the Ankara–Izmir flight route compared to the existing fixed route. The results for the proposed most efficient route were achieved at 11.22% distance (nm), 9.36%-time (min) savings and 837.71 kg CO2 emission savings. Originality/value: As far as the literature is reviewed, most studies aimed at increasing airspace efficiency produce solutions that try to improve rather than replace the normal process. Considering the literature positioning of this study compared to other studies, the proposed model provides a new systematic solution to the problems that cause human-induced route inefficiency within the framework of the FUA concept.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ1Characterization of the black cumin (Nigella sativa L.) honey from Türkiye
Kemal, Mehmet; Esertaş, Ülkü Zeynep Üreyen; Kanbur, Esra Demir; Kara, Yakup; Özçelik, Ali Erdem; Can, Zehra; Kolaylı, Sevgi
This case report study investigated the botanical, physicochemical, and phenolic compositions, as well as the antioxidant and antimicrobial properties of varying amounts of black cumin honey (Nigella sativa) from Burdur region of Türkiye. The samples had an average moisture value of 17.23% and a Nigella sativa pollen ratio ranging from 19% to 51%. Electrical conductivity (EC) values ranged from 0.36 to 0.54 mS/cm. The average color values of Hunter (L, a, b) were 43.55 (L*), 32.77 (a*), and 64.52 (b*), respectively. The proline contents were ranged from 875 to 1624 mg/kg. The average F/G ratio and F+G value were 1.43±0.11 and 68.75±4.75, respectively. The average of total phenolic (TP) and total flavonoid (TF) contents were 36.87±7.00 mg GAE/100 g and 5.63±1.45 mg QUE/100 g, respectively. The antioxidant capacities of the samples were tested using the ferric reducing/antioxidant power (FRAP) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assays, with mean values of 179.40±25.35 μmol FeSO4.7H2O/100 g and 46.07±12.87 mg/mL, respectively. The phenolic composition of the samples were tested using the HPLC-PDA method with 25 phenolic standards. Gallic acid, p-OH benzoic acid, t-cinnamic acid, p-coumaric acid, chrysin, and pinocembrin were determined as common components. The samples exhibited high antimicrobial activities against Staphylococcus aureus, Escherichia coli, Chromobacterium violaceum, Bacillus cereus, Klebsiella pneumoniae, and Acinetobacter haemolyticus, but did not affect Candida albicans, Candida parapilopsis, or Mycobacterium smegmatis.
AtıfScopus27WoS27OpenAlex33İncele - MakaleYalnız künye2023Scopus SJRQ2Ultra-thin reflective multifunctional polarization converter with nested circular ring-shaped metasurface-based for C- and X-band applications
Kaya, Yunus
This article presents a single-layer, ultra-thin and multifunctional polarization converter (PC) design using metasurface. The PC, which is proposed as a single layer, consists of a metal metasurface on the front side of a easily accessible FR-4 material and a metal termination on the back surface. The suggested PC features linear polarization (LP) characteristic within a frequency ranges of 5.21- 5.41 GHz and 7.53- 8.08 GHz in C-band, also 10.59- 10.84 GHz in X-band under normal incidence. It indicates the conversion performance of linear polarization to circular polarization (LP-CP) that has the properties of left-handed circular polarization (LHCP) in frequency range of 5.74–7 GHz in C-band and right-handed circular polarization (RHCP) in frequency range of 8.63- 10.15 GHz in X-band. Besides, the suggested PC provides more than 90% polarization conversion ratio (PCR) value in case of normal incidence (0∘) and over 80% PCR value in case of oblique incidence up to 45∘. Again, the suggested PC offers the same CP feature in two frequency regions where CP conversion takes place under normal incidence for angle of incidence up to 60∘. A prototype of suggested PC was produced, measured, and a good match was found between the results simulated via a commercial electromagnetic (EM) simulation program. Finally, the performance of suggested design is compared with existing studies in literature with its high aspects. In this context, the suggested PC may be useful for C- and X-band applications due to its simple structure, ultra-thin and compactness, low-cost, and performance of LP and CP conversion under wide oblique angles.
AtıfScopus4WoS3OpenAlex3İncele - MakaleAçık Erişim2023Scopus SJRQ1The effect of various industrial dust particles on the performance of photovoltaic panels in Turkey
Güngör, Okan; Kahveci, Hakan; Gökçe, H. Süleyman
The accumulation of dust is one of the main causes of power loss in photovoltaic (PV) farms, and the effect of dust particles’ size and chemistry on system performance is often overlooked. This study has focused on a comprehensive analysis of the effect of different dust particles collected from common industrial production facilities in Turkey on the performance of PV panels in the indoor laboratory environment. The collected dust samples were analyzed to determine the dust sample particles’ chemical properties, size, character, and topography. The data for dust samples at different weights with changes in maximum power point (MPP) of PV panel has been collected using the artificial solar irradiation source system. Thus, the mathematical correlations (R2≥0.965) between the PV panel Thevenin resistance (RTH), fill factor (FF), MPP, and pollution rate were obtained using these collected data and particle swarm optimization (PSO). According to the results of the obtained mathematical correlations, marble dust is 2.3, 3.4, and 4.2 times less polluting than cement, fly ash, and silica fume, respectively. Additionally, it was observed that smaller dust particles block more light than larger ones of the same weight and reduce MPP, FF while increasing the RTH.
AtıfScopus19WoS14OpenAlex21
İncele - MakaleYalnız künye2023Scopus SJRQ1A New Higher-Order Finite Element for Static Analysis of Two-Directional Functionally Graded Porous Beams
Turan, Muhittin; Adiyaman, Gokhan
A new higher-order finite element for the static analysis of two-directional functionally graded (2D FG) porous beams subjected to various boundary conditions based on parabolic shear deformation theory (PSDT) is presented. The main purpose of this study is to predict the deflections and stresses of 2D FG porous and non-porous beams with the help of the proposed finite element. Since a higher-order finite element with a third order polynomial is used, the deflections and stresses can be accurately and rapidly obtained even for short beams. In addition, the new higher-order element is free of shear locking phenomenon without requiring any shear correction factors. Three types of distribution functions were used for porosity in this study. To the author's knowledge, the sinusoidal uneven distribution function (FGP-3) is presented for the first time. The governing equations are derived by Lagrange’s principle using a parabolic shear deformation theory that considers normal and shear deformations. According to a power-law rule, the material change in the beam volume in both directions is defined. The dimensionless maximum transverse deflections, normal stresses, and shear stresses are obtained for various boundary conditions, gradation exponents (px, pz) in the x- and z-directions, porosity coefficient (e), porosity distribution (FGP-1, FGP-2, FGP-3), and the slenderness (L/h). This study's new higher-order finite element gives results compatible with the literature and it can be used to accurately find the deflections and stresses for the 2D FG non-porous or porous beams subjected to various boundary conditions.
AtıfScopus30WoS28OpenAlex26İncele - MakaleYayıncıda açık erişim2023Scopus SJRQ3Solidification analysis for variable thickness aluminum castings: simulation and chill design insights
Yilmaz, Galip; Colak, Murat; Uslu, Emin
Manufacturing high-quality casting parts with complex geometries requires high engineering skill and precision. One essential quality concern is isolated hot spots within the castings, often in thick sections. Each hot spot must be consistently fed or mitigated through directional solidification techniques. The impact of various mold sands and the geometry of chill parts on solidification direction was investigated using specialized casting and general-purpose simulation programs. A parametric optimization method was employed to analyze directional solidification to adjust the geometry of the chill parts. The results indicate that employing diverse mold sands to enhance cooling in the thick sections was a viable strategy for achieving directional solidification in parts where the feeding pathway is obstructed due to changes in cross-section. Furthermore, the study revealed that intricate details in the chill part’s geometry are not critical; however, a minimum volume (or weight) was necessary for adequate directional solidification. Lastly, an easily applicable mathematical model has been developed to determine the required volume of chill parts to ensure successful directional solidification.
AtıfScopus1WoS1OpenAlex1İncele