Yayınlar
Koleksiyondaki öğeler
- Derleme MakaleAçık Erişim2020Scopus SJRQ4Coronavirus disease 2019 infection and nursing in patients undergoing hemodialysis treatment
Demirag, Hatice; Hintistan, Sevilay
Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2. Patients undergoing chronic hemodialysis treatment are at a high risk of serious complications if infections occur because of suppressed immune system, cardiovascular disease, and important comorbidities, such as diabetes mellitus. To control and prevent the spread of the outbreak to patients and other healthcare professionals, it is necessary to be informed about COVID-19, to diagnose cases early, and to be treated. The purpose of this review is to discuss the communication, transport, predialysis screening and triage, and COVID-19 nursing management in patients undergoing hemodialysis treatment.
AtıfScopus2WoS3OpenAlex1TR Dizin2
İncele - MakaleYalnız künye2021Scopus SJRQ2Analysis of Mining Lost Time Incident Duration Influencing Factors Through Machine Learning
Kahraman, Muhammet Mustafa
Despite technological advancements and organizational adjustments, lost time accidents are major issues in occupational safety. However, there is very limited work that focuses on variables influencing days lost as a result of occupational accidents. In this study, decision tree and artificial neural network methods were used as machine learning techniques to investigate the impact of factors on accident lost day duration. Degree of injury, worker age, and worker activity were found to be the top three variables impacting loss of time from work. It was also identified that the mining method, location, and nature of injury had a moderate influence on duration lost due to occupational accidents. However, worker experience and ore type did not have any significant impact on the duration, which is an unexpected result. These results confirmed that some accident factors that might have a large influence on the number of mine accidents can be less critical when it comes to accident lost day duration.
AtıfScopus14WoS14OpenAlex11İncele - MakaleYalnız künye2019Scopus SJRQ1Ohmic heating assisted hydrodistillation of clove essential oil
Tunç, Merve Tuğçe; Koca, İlkay
Ohmic heating assisted hydrodistillation is a novel green technology for the extraction of essential oils. In this study, clove bud essential oils (CEO) were extracted by ohmic heating assisted hydrodistillation (OAHD) and compared with conventional hydrodistillation (HD) process, in terms of extraction yield, energy consumption and chemical properties. Ohmic heating assisted hydrodistillation process conditions were optimized by response surface methodology. Voltage gradient (7.5–12.5 V/cm, A), process time (30–120 minutes, B) and mass of clove bud (20–40 g, C) were varied in order to maximize CEO yield and to minimize energy consumption. Optimized extraction conditions were determined as, 12.5 V/cm voltage gradient, 97.967 min for process time and 40 g of mass of clove bud. Yield of CEO and energy consumption were found 13.18 ± 1.50% and 0.214 ± 0.030 kW h/g CEO at optimum extraction conditions, respectively. Under optimum conditions, both OAHD and HD methods were used for CEO extraction. Yields of CEO obtained by OAHD, HD-D (distilled water) and HD-S (salted water) were 13.18 ± 1.50, 8.23 ± 0.35 and 7.88 ± 0.60 respectively. Energy consumptions of OAHD and HD methods were not significantly different (P > 0.05). The main chemical component of CEO was eugenol and the yield of eugenol (g/100 g clove bud) was found higher with OAHD (6.95±0.6) method than HD-D (5.16 ± 0.20) and HD-S (5.13 ± 0.28). Antioxidant and antimicrobial properties of CEOs were investigated by FRAP, DPPH and disk diffusion method. Antioxidant properties of CEOs obtained by different extraction methods were not significantly different (P > 0.05) according to FRAP and DPPH analysis. Although inhibition zones of CEOs extracted with different methods were not significantly different (P > 0.05) for gram positive bacteria's, CEO obtained by OAHD and HD-D have significantly higher (P < 0.05) inhibition zones for K. pneumonia and E. coli, respectively. The results of this study showed that OAHD method is applicable for CEO production.
AtıfScopus87WoS66OpenAlex90İncele - MakaleAçık Erişim2021Scopus SJRQ3Predicting stock prices using machine learning methods and deep learning algorithms: The sample of the istanbul stock exchange
Demirel, Ugur; Cam, Handan; Unlu, Ramazan
Stock market prediction in financial and commodity markets is a major challenge for speculators, investors, and companies but also profitable with an accurate prediction. Thus, obtaining accurate prediction results becomes extremely important especially while the stock market is essentially volatile, nonlinear, complicated, adaptive, nonparametric and unpredictable in nature. This study aims to forecast the opening and closing stock prices of 42 firms listed in Istanbul Stock Exchange National 100 Index (ISE-100) using well-known machine learning methods, Multilayer Perceptrons (MLP) and Support Vector Machines (SVM) models and deep learning algorithm, Long Short Term Memory (LSTM) by comparing their forecasting performances. The analysis includes 9 years of data from 01.01.2010 to 01.01.2019. For each firm 2249 data for the opening and 2249 for the closing stock prices were established as daily data sets. Forecasting performance of these methods was evaluated by applying different criteria for each model: root mean squared error (RMSE), mean squared error (MSE) and R-squared (R2). The results of this study show that MLP and LSTM models become advantageous in estimating the opening and closing stock prices comparing to SVM model.
AtıfScopus25WoS9OpenAlex37TR Dizin5İncele - MakaleAçık Erişim2020Numerical solution to elliptic inverse problem with Neumann-type integral condition and overdetermination; [Интегралдық шарты бар және қайта анықталған Нейман типтi эллипстiк керi есептiң сандық есептеуi]; [Численное решение эллиптической обратной задачи с интегральным условием и переопределением типа Неймана]
Ashyralyyev, C.; Cay, A.
In modeling various real processes, an important role is played by methods of solution source identification problem for partial differential equation. The current paper is devoted to approximate of elliptic over determined problem with integral condition for derivatives. In the beginning, inverse problem is reduced to some auxiliary nonlocal boundary value problem with integral boundary condition for derivatives. The parameter of equation is defined after solving that auxiliary nonlocal problem. The second order of accuracy difference scheme for approximately solving abstract elliptic overdetermined problem is proposed. By using operator approach existence of solution difference problem is proved. For solution of constructed difference scheme stability and coercive stability estimates are established. Later, obtained abstract results are applied to get stability estimates for solution Neumann-type overdetermined elliptic multidimensional difference problems with integral conditions. Finally, by using MATLAB program, we present numerical results for two dimensional and three dimensional test examples with short explanation on realization on computer.
AtıfScopus7WoS6OpenAlex9İncele - MakaleYalnız künye2021Scopus SJRQ1Nature of the Early Cretaceous lamprophyre and high-Nb basaltic dykes, NE Turkey: Constraints on their linkage to subduction initiation of Neotethyan oceanic lithosphere
Karsli, Orhan; İlhan, Mehdi; Kandemir, Raif; Dokuz, Abdurrahman; Aydin, Faruk; Uysal, İbrahim; Duygu, Levent
Late Mesozoic evolution of the Neotethys Ocean is critical and still remains unclear along the entire Sakarya Zone (SZ), Turkey, because previous interpretations of the Middle to Late Jurassic rifting of the SZ have not been consensually accepted. We identified, for the first time, the Early Cretaceous dykes intruded into the Late Jurassic and Late Carboniferous bodies in the Çamlıkaya (Erzurum) area in the SZ. Here, we present a data set of new field observations, 40Ar/39Ar geochronology, whole-rock geochemical and Sr–Nd isotopes to find out the tectonic setting of previously undated basic to intermediate igneous rocks. 40Ar/39Ar technique on the groundmass separations yielded the plateau ages of 128.78 ± 1.02 to 122.89 ± 0.82 Ma. The investigated dykes are compositionally divided into two sub-groups: calc-alkaline lamprophyres (CAL) and high-Nb alkaline basalts (HNB). They show enrichment in large ion lithophile elements (LILE: e.g., Rb, Ba, K) and depletion in high field strength elements (HFSE: Nb and Ti) as well as moderate fractionation of light rare earth elements relative to heavy rare earth elements. The HNB have high Mg# (47–66), and relatively unradiogenic Sr [87Sr/86Sr(t) = 0.70385 to 0.70510] and Nd [εNd(t) = +0.5 to +5.3] isotopic composition, whereas the CAL possess moderate to high Mg# (32–72), and relatively high Sr [87Sr/86Sr(t) = 0.70586 to 0.71379] and Nd [εNd(t) = +1.5 to −9.9] isotopic composition. Early Cretaceous high-angle subduction triggered upwelling of the asthenosphere at 126 Ma, which likely generated a heat anomaly. This anomaly has probably induced melting of the oceanic slab and the metasomatized mantle to form the CAL and HNB. The HNB were generated by low degrees of melting of mantle domain that was previously reacted by oceanic slab-related adakitic melts at the depths of the garnet stability field (≥70 km). However, the CAL were probably formed at shallower mantle levels within the garnet-amphibole field by a relatively higher degree of melting of the mantle, also modified by subducted slab sediments. A new field, age, and petrochemical data from the Early Cretaceous dykes, combined with the presence of Aptian deep-water sediments to the north and the Late Jurassic-Early Cretaceous platform carbonates deposited in the passive margin setting along the entire SZ, imply the initiation of active-margin magmatism in the SZ. We suggest that the coexistence of the Early Cretaceous CAL and HNB points to the formation of an Andean-type active margin above a north-dipping Neotethyan oceanic slab. Their emplacement ages are associated with the inception of the magmatic arc structure and refer to a significant geodynamic turnover from passive-margin to active-margin tectonics along the SZ.
AtıfScopus15WoS15OpenAlex17İncele - MakaleAçık Erişim2021Scopus SJRQ1A data-driven multi-regime approach for predicting energy consumption
Kahraman, Abdulgani; Kantardzic, Mehmed; Kahraman, Mustafa; Kotan, Muhammed
There has been increasing interest in reducing carbon footprints globally in recent years. Hence increasing share of green energy and energy efficiency are promoted by governments. There-fore, optimizing energy consumption is becoming more critical for people, companies, industries, and the environment. Predicting energy consumption more precisely means that future energy management planning can be more effective. To date, most research papers have focused on predicting residential building energy consumption; however, a large portion of the energy is consumed by industrial machines. Prediction of energy consumption of large industrial machines in real time is challenging due to concept drift, in which prediction performance deteriorates over time. In this research, a novel data-driven method multi-regime approach (MRA) was developed to better predict the energy consumption for industrial machines. Whereas most papers have focused on finding an excellent prediction model that contradicts the no-free-lunch theorem, this study concentrated on adding potential concept drift points into the prediction process. A real-world dataset was collected from a semi-autonomous grinding (SAG) mill used as a data source, and a deep neural network was utilized as a prediction model for the MRA method. The results proved that the MRA method enables the detection of multi-regimes over time and provides a highly accurate prediction performance, thanks to the dynamic model approach.
AtıfScopus18WoS15OpenAlex17İncele - MakaleYalnız künye2022Scopus SJRQ1Scrutinizing blockchain applicability in sustainable supply chains through an integrated fuzzy multi-criteria decision making framework
Erol, Ismail; Ar, Ilker Murat; Peker, Iskender
Sustainability has become increasingly important over the last three decades and has proven to be a key enabler for constructing resilient supply chains. Customers who want their products to be authenticated for sustainability put pressure on Original Equipment Manufacturers and suppliers to become more sustainable on a global scale. Moreover, social sustainability issues have become more challenging to address, and a growing number of stakeholders put emphasis on societal concerns. To this end, decision-makers are becoming increasingly interested in applying disruptive technologies to address societal, environmental, and economic concerns and accomplish sustainability goals. Researchers argue that disruptive technologies such as blockchain may be implemented to assist supply chains towards building sustainability. However, our literature analysis concluded that existing research has not quantitatively examined the critical functions of sustainable supply chain (SSC) for blockchain applicability using a decision framework. Therefore, this research, through Fuzzy SWARA-COPRAS-EDAS and COPELAND-based framework, is aimed at investigating the most feasible functions of a SSC for potential blockchain implementations. Using this framework, the critical functions of a SSC were ranked against the benefits of blockchain. The findings of this study implied that while sourcing, delivery, transformation and product recovery proved to be the most appropriate functions of SSCs for blockchain applications, customers and product use was the least feasible one. This study aids decision-makers in gaining a more thorough understanding of where in a SSC blockchain may create additional value.
AtıfScopus60WoS49OpenAlex62İncele - MakaleAçık Erişim2021Fatigue analysis of the vehicle brake disc; [Araç fren diskinin yorulma analizi]
Karabudak, Filiz
In this study, the fatigue analysis of the vehicle brake disc was simulated using the finite element program, and life calculations were made in accordance with the analysis. The main purpose is to simulate experimental tests, which take a long time to result, in the computer environment and to obtain results in a short time and at a very low cost. With the help of the ANSYS computer program, which operates with the finite element logic, the disk brake system was created in three dimensions, and the boundary conditions closest to reality were determined and analyzed using the finite element method. In the disc brake system selected, the data obtained by conducting stress, fatigue life, and safety coefficient analyses in line with the forces formed on the wheel and the vehicle during braking were examined. According to the analysis results, our brake disc is in different life ranges in accordance with the material used and the load applied, and when the force is increased, the life decreases and vice versa.
AtıfScopus2OpenAlex1İncele - MakaleAçık Erişim2021Investigation of the effect of urbanization on land surface temperature example of Bursa
Yamak, Beyzanur; Yagci, Zekeriya; Bilgilioglu, Burhan Baha; Comert, Resul
Today, industrialization and urbanization in large cities cause an increase in the surfaces covered with man-made objects such as concrete and asphalt. The expansion of urban areas and increase in the using materials with high heat storage properties, directly affect the Land Surface Temperature (LST), which shows an increase in the sensible temperature of the region. LST is directly connected to the natural green vegetation of the land and varies widely in large urban areas, these differences related to the temperature is defined as the ‘urban heat island’. In this study, it was investigated the temporal variation of land surface temperature due to urbanization. Bursa, which is considered as a study area, has shown a rapid population increase since 1990 and a rapid increase in the number of buildings with the impact of urbanization and industrialisation. To determine the effect of this urbanization and industrialisation on land surface temperature, temporal change analysis of the surface temperature in the Bursa was observed with Landsat satellite images of 1988, 1998, 2008 and 2018. From produced maps, it was observed that the amount of green vegetation in urban areas decreased and as a consequence of this decrease, the surface temperature increased in the urban areas.
AtıfScopus17WoS16OpenAlex21TR Dizin2İncele - MakaleAçık Erişim2022Scopus SJRQ2Consumers’ willingness to pay for traditional products with geographical indication: a case study on pestil from Gümüşhane, Turkey
Dogan, Nilgun; Adanacioglu, Hakan
The main purpose of this study is to analyze the willingness to pay (WTP) geographical indications (GI)-labelled pestil as a traditional product. Considering the data obtained from a survey conducted with 166 households in Gümüşhane, Turkey were used. Contingent valuation method was taken to determine WTP for GI-labelled pestil (dried fruit pulp). In order to find WTP price amounts Tobit model was used. Tobit model showed that individuals who were in the upper age group, have a high frequency of purchasing pestil, have a high level of knowledge about GI-labelled products, and consume GI-labelled products want to consume more. The average amount that consumers will be willing to pay for 1 kg of price bids ranging from 60-100 TRY has been determined as 68.74 TRY. While establishing a target market, those who are in the upper age group, have a high frequency of purchasing pestil, have a high level of knowledge and consume GI-labelled products should be taken into consideration. Since individuals with a high level of knowledge regarding GI-labelled products are willing to pay a higher amount of extra payment, it is recommended that marketers carry out promotional activities that will increase communute awareness for GI-labelled products.
AtıfScopus7WoS6OpenAlex9İncele - MakaleYalnız künye2020Scopus SJRQ2Development of a healthy corn-based snack with sage (Salvia officinalis L.) seed
Yuksel, Ferhat; Ilyasoglu, Huri; Baltaci, Cemalettin
A healthy corn-based snack was developed from the corn flour and sage (Salvia officinialis L.) seed flour. The effects of the process variables (sage seed flour: 0–15%, frying temperature: 170–190 °C, and frying time: 40–60 s) on the nutritional properties, fatty acid composition and oxidative stability of the snack chips were evaluated via Response Surface Methodology (RSM). The response models explaining 72–96% variability in the responses were obtained. Only sage seed flour presented significant effects on the nutritional properties (p < 0.05). The interaction term of sage seed flour and frying temperature showed significant effects on the fatty acid composition (p < 0.05). The sage seed flour could decrease total starch and in vitro glycemic index and increase total dietary fiber. The snack chips contained unsaturated fatty acids more than 60%, and their oils had acceptable peroxide value. The fortification of corn-based snack with sage seed enhanced the nutritional value.
AtıfScopus9OpenAlex9İncele - MakaleAçık Erişim2021Scopus SJRQ1A single-valued neutrosophic multicriteria group decision approach with DPL-TOPSIS method based on optimization
Rıdvan, Şahin; Fuat, Aslan; Gökçe Dilek, Küçük
Due to the uncertainty of human subjective judgments, it is sometimes very difficult to obtain accurate evaluation information. The technique for order preference by similarity to ideal solution (TOPSIS) is one of the functional methods used to solve the multicriteria decision-making (MCDM) problems. However, the traditional TOPSIS is based only on a distance measure and takes into account neither a similarity measure nor a likelihood measure. Therefore, in this article, we define two new information measures which are called as the projection and divergence and more functional than some other existing ones in the neutrosophic sets. Then we develop an innovative TOPSIS (DPL-TOPSIS) based on the hybrid closeness coefficient which is an optimization of the divergence (distance), projection (similarity), and likelihood (magnitude) closeness coefficients that can also use separately to make the decision in neutrosophic environment. To develop the DPL-TOPSIS, we define three kinds of analogical factors: the distance-like positive and negative divergence decision-making factors, the similarity-like positive and negative projection decision-making factors, and the magnitude-like positive and negative likelihood decision-making factors. In addition, we provide an objective weight determination model to determine expert judgment with the proposed divergence measure. Finally, to demonstrate the functionality of the developed DPL-TOPSIS, an application has been made on selection of the masks used as one of the protection methods in the COVID-19 epidemic, which has recently affected our world, and the results are compared with other existing methods.
AtıfScopus21WoS10OpenAlex14İncele - MakaleYalnız künye2022Angular Momentum Control for Preventing Rollover of a Heavy Vehicle
Ünker, Faruk
In this article, gyroscopes and flywheels are used to prevent the rollover of a vehicle due to external forces. The rollover preventing performance of the flywheels for a heavy trailer (an inverted pendulum problem) is investigated at a high road bank angle risk. Two control moment gyroscopes (CMG) and a reaction wheel are controlled by proportional torques to keep the vehicle in a stable motion in the vertical position. The reaction wheel was used only to eliminate the dissipation energy of damper. By using the energy stored in the flywheels of gyroscopes, the sprung mass of a vehicle can make a stable oscillating motion of small amplitude, standing upright without tipping over. The optimum flywheel speed was derived from the frequency equations with the appropriate controller gain. Most importantly, the required angular momentum to keep the vehicle upright without tipping over depends on the amplitude of the gimbal oscillation and the frequency. It has also been observed that Matlab simulations of Lagrangian equations and simulations modeled in RecurDyn software are in perfect harmony.
AtıfScopus4TR Dizin3İncele - MakaleYalnız künye2020Scopus SJRQ1Visual Perception for Multiple Human-Robot Interaction from Motion Behavior
Benli, Emrah; Motai, Yuichi; Rogers, John
Visual perception is an important component for human-robot interaction processes in robotic systems. Interaction between humans and robots depends on the reliability of the robotic vision systems. The variation of camera sensors and the capability of these sensors to detect many types of sensory inputs improve the visual perception. The analysis of activities, motions, skills, and behaviors of humans and robots have been addressed by utilizing the heat signatures of the human body. The human motion behavior is analyzed by body movement kinematics, and the trajectory of the target is used to identify the objects and the human target in the omnidirectional (O-D) thermal images. The process of human target identification and gesture recognition by traditional sensors have problem for multitarget scenarios since these sensors may not keep all targets in their narrow field of view (FOV) at the same time. O-D thermal view increases the robots' line-of-sights and ability to obtain better perception in the absence of light. The human target is informed of its position, surrounding objects and any other human targets in its proximity so that humans with limited vision or vision disability can be assisted to improve their ability in their environment. The proposed method helps to identify the human targets in a wide FOV and light independent conditions to assist the human target and improve the human-robot and robot-robot interactions. The experimental results show that the identification of the human targets is achieved with a high accuracy.
AtıfScopus15WoS12OpenAlex16İncele - MakaleYalnız künye2020Scopus SJRQ2Geochemical composition of magnetite from different iron skarn mineralizations in NE Turkey: implication for source of ore-forming fluids
Sipahi, Ferkan; Gücer, Mehmet Ali; Saydam Eker, Çiğdem
Iron oxide mineralizations in the eastern part of the Pontides (NE Turkey) are hosted in the skarn environments which are the Pontide paleomagmatic arc. These mineralizations always occur in the contacts between granitoid and limestone. Magnetites are hosted in carbonate rocks and generally formed during garnet-magnetite-epidote-quartz phase. Magnetites have high Co (15.8–43.4 ppm for the Kopuz, 11–12.5 ppm for the Eğrikar, and 3.8–1266.7 ppm for the Karadağ) concentrations suggesting that the sulfide decreased from the early to the late phases in the iron skarn mineralization forming systems. The Co/Ni ratios in the magnetites (0.12 to 35.38 for Karadağ, 2.19 to 13.53 for the Kopuz, and 2.39 to 5.21 for the Eğrikar) show the hydrothermal effect on the magmatic source in iron skarns in the study area. Thus, variable Co/Ni ratios reflect interactions between the magma with the host rock during successive alteration stages. Magnetites in this study have Sc-Nb-Mg-Ti depletions and Ta enrichment. In this study, high Co, Ti, and V contents in magnetites suggest the high temperature (300–500 °C) and low ƒO2. The V contents of the magnetite in the Karadağ increase with the decreasing oxygen fugacity of fluid(s) forming magnetites, whereas the V contents of the magnetites in the Kopuz and Eğrikar decrease with increasing oxygen fugacity of fluid(s) forming magnetites. Element patterns and Ni/Cr ratio (< 1) of the magnetite are geochemically similar to those of magnetite in Fe-skarn deposits and partly magmatic accessory magnetite of I-type granites. As a result, the Co, Ni, V, and Ti elements of the magnetite have played an important role in the discriminating and interpreting of skarn mineralizations in the eastern Pontides and support a calcic skarn origin with studies of the mineralization geology.
AtıfScopus17WoS10OpenAlex19İncele - DüzeltmeYalnız künye2021Scopus SJRQ1Corrigendum to “The effect of reiki on pain: A meta-analysis” [Compl. Ther. Clin. Pract. 31C (2018) 384–387] (Complementary Therapies in Clinical Practice (2018) 31 (384–387), (S1744388117303626), (10.1016/j.ctcp.2018.02.020))
Demir Doğan, Melike
The authors wish to inform that the correct abstract for the article is given below: Objective: Pain is one of the most common symptoms and may lead to important psychological, mental, and physiological problems in individuals. According to data by The Center for Reiki Research, Reiki is an effective approach to decrease the levels of pain, depression, and anxiety. Therefore, the aim of this meta-analysis was to investigate the effect of Reiki on pain level. Methods: Randomized controlled clinical trials in databases of Pubmed, ISI Web of Sciences, and Google Scholar were investigated. Four randomized controlled studies which involving 212 participants were included in the meta-analysis. Results: The result obtained after the final Reiki application was evaluated in VAS pain score. When Reiki (n = 104) group was compared with control group (n = 108), standardized mean difference was observed to be −0.927 (95% CI: −1.867 to 0.0124). Conclusion: Consequently, meta-analysis shows there is a trend towards lower pain scores after Reiki intervention. It is recommended to repeat the study when the number of studies with specific patient groups and types of pain increase. The authors would like to apologise for any inconvenience caused.
AtıfScopus1OpenAlex4
İncele - MakaleYalnız künye2020Scopus SJRQ2A simplified neutrosophic multiplicative set-based TODIM using water-filling algorithm for the determination of weights
Köseoğlu, Ali; Şahin, Rıdvan; Merdan, Mehmet
Due to the technological developments around the world, the amount of information that researchers work on increases continuously. This information density contains incomplete and uncertain data that cannot be fully expressed with crisp numbers. Fuzzy sets, intuitionistic fuzzy sets, and neutrosophic sets are useful tools to manage such information, but these concepts use a symmetrical and uniform scale to express data, whereas real-life problems contain nonsymmetrical and non-uniform information. Intuitionistic multiplicative sets (IMSs) are effective tools for dealing with these real-life problems. However, IMSs cannot handle real-life problems completely because indeterminate information depends on membership and non-membership information of IMSs, which is a restriction for decision makers and also for decision problems. To overcome this limitation, this paper generalizes the IMSs by using simplified neutrosophic set and introduces a novel approach that is called simplified neutrosophic multiplicative sets (SNMSs). Firstly, we define SNMS, show their set-based operations, and then give a description of simplified neutrosophic multiplicative numbers (SNMNs). Based on SNMNs, we develop two simplified neutrosophic multiplicative aggregation operators on SNMNs that are called simplified neutrosophic multiplicative weighted arithmetic average operator and simplified neutrosophic multiplicative weighted geometric average operator. Furthermore, we define some simplified neutrosophic multiplicative distance measures. Finally, using a model based on water-filling algorithm for determining criteria weights, we give a numerical example to demonstrate the effectiveness of the introduced concept with the proposed simplified neutrosophic multiplicative simplified neutrosophic multiplicative-TODIM method.
AtıfScopus27WoS22OpenAlex30İncele - MakaleYalnız künye2021Scopus SJRQ1Comparison of various turbulence model performance in computational fluid dynamics analyses of the oxidation ditches with experimental validation
Şibil, Rahim; Aras, Egemen; Kankal, Murat
Experimental and numerical studies were carried out to determine the full-scale Oxidation Ditch (OD) hydrodynamics considering various turbulence models. Firstly, the experimental work was carried out in a full-scale plant by Acoustic Doppler Velocimeter (ADV) for field-measurements. Secondly, the experimental data was used to validate numerical models by using Computational Fluid Dynamics (CFD) software Ansys Fluent. Eight different turbulence models were compared in the numerical study to predict full-scale hydrodynamics. Results showed that standard k-ε, renormalization group k-ε, realizable k-ε turbulence models gave more accurate prediction results with relative errors of 13 %, 17 %, and 18 % respectively, whereas the standard k-ω turbulence model gave the worst prediction results with 39 % relative error. This study also shows that the velocities in the ODs are very low without external force such as air diffusers, rotors, and mixer and there is no homogeneous flow field distribution in the ODs. Moreover, the maximum wastewater velocities occurred at the inlet and outlet.
AtıfScopus30WoS26OpenAlex32İncele - MakaleYalnız künye2020Scopus SJRQ2Tribocorrosion behaviour of porous anatase and rutile phases formed on surface of anodised Ti45Nb alloy
Tasdemir, Muharrem; Alsaran, Akgun
Titanium alloys are used across a wide range of sectors—from aerospace to health—because of their low density, high strength, and corrosion resistance properties. In recent years, the use of alloying elements such as niobium (Nb), tantalum (Ta), and zirconium (Zr) has still not eliminated existing wear problems, in spite of being preferred to conventional titanium alloys that are non-toxic and have better corrosion and mechanical properties. In order to overcome this problem of titanium alloys, various surface treatments are applied. This study was mainly aimed at investigating tribocorrosion properties of anatase, rutile, and anatase-rutile phases formed on the surface of Ti45Nb by anodising at different potential values. The structural and mechanical properties of these structures were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), nanoindentation, and a 3D profilometer. Tribocorrosion tests were carried out at open-circuit potential (OCP) and two different anodic in NaCl solutions. It was found that the wear volume was affected by mechanical action rather than chemical effects for all samples during tribocorrosion. It was concluded that while a surface structure including anatase is more sensitive to chemical effects, the rutile structures were shown to be more resistant to both mechanical and chemical attacks during tribocorrosion tests.
AtıfScopus6WoS6OpenAlex6İncele
