Search

Real-world multi-objective optimization problems encounter different types of uncertainty that may affect the quality of solutions. One common type is the stochastic noise that contaminates the objective functions. Another type of uncertainty is the different forms of dynamism including changes in the objective functions. Although related work in the literature targets only a single type, in this paper, we study Dynamic Multi-objective Optimization problems (DMOPs) contaminated with stochastic noises by dealing with the two types of uncertainty simultaneously. In such problems, handling uncertainty becomes a critical issue since the evolutionary process should be able to distinguish between changes that come from noise and real environmental changes that resulted from different forms of dynamism. To study both noisy and dynamic environments, we propose a flexible mechanism to incorporate noise into the DMOPs. Two novel techniques called Multi-Sensor Detection Mechanism (MSD) and Welford-Based Detection Mechanism (WBD) are proposed to differentiate between real change points and noise points. The proposed techniques are incorporated into a set of Dynamic Multi-objective Evolutionary Algorithms (DMOEAs) to analyze their impact. Our empirical study reveals the effectiveness of the proposed techniques for isolating noise from real dynamic changes and diminishing the noise effect on performance.

In this research, the numerical integral method procedure on uniform mesh is used to solve the singularly perturbed problem which has integral boundary value. This method also includes the trapezoid method, the finite difference method, and the Thomas algorithm. The problem is converted to finite difference problem by using finite difference approximations and trapezoid method. Finally, the convergence of the presented method is analyzed through sample application. Thus, the correctness and sufficiency of the method are shown.

In this study, a legged and wheeled robot model was proposed for cleaning the glass of greenhouses. The robot has four wheels and four legs, each with three degrees of freedom (DOF). The design, kinematic analysis and simulation of the robot was carried out. Glass greenhouses are created by placing glass sheets on T-shaped iron bars arranged in parallel at certain intervals. The robot performs the glass cleaning task by performing two different movements on greenhouse roof. As a first movement, the robot moves like a train moving on the rail on iron bars with wheels, cleaning the glass as it travels. After cleaning the glasses placed between two iron bars along a column, as second movement, the robot passes the next column using legs. These two movements continue until the entire roof of the greenhouse is cleaned. Kinematic analysis of this robot, which is designed with mechanical properties that can make these movements, has been made. Walking simulation of the robot was carried out according to the kinematic analysis. The simulation results showed that this proposed robot can be used to clean glass on the greenhouse roof.

Granular soils are used in different areas of civil engineering due to their easy accessibility and low cost as a material. The sieve analysis method, which has been conducted in rock physics measurements for many years, has been practicing determining the particle size distributions for those materials. In this study, a method based on image analysis technique has been developed as an alternative to traditional sieve analysis method for determining the particle size distribution in granular soils. This technique based on image processing to determine particle distributions via the experimental setup that consist of a camera, tripod, light box and mechanical shaking apparatus. In order to assess the reliability of this technique, each sample was subjected to traditional sieve analysis and the results of both analysis methods were compared. In conclusion, it was observed that the results obtained with the image processing technique had a minimum 95.22% closeness with the sieve analysis experiment data.

Since oleuropein has long been known in the health sector and is abundant directly in our country as the fourth largest olive producer, oleuropein, the predominant phenolic ingredient in olive leaves, was recovered in this study using Soxhlet extraction. The effects of different solvent types (acetonitrile, ethanol, methanol, and water), extraction period (4 cycles, 4 h, and 8 h), particle size (250-500 µm and 900-2000 µm), and pretreatment of olive leaves on the yield of oleuropein were examined to determine the maximum yield. A greater oleuropein yield was obtained when the particle size of olive leaves utilized for extraction was lowered. Furthermore, aqueous solvents revealed a higher yield of oleuropein than pure solvents and prolonging the extraction duration resulted in a significant increase in the amount of oleuropein extracted. On the other hand, pretreatment of olive leaves resulted in a reduction in oleuropein output. As a result, with 36% extraction efficiency in terms of olive leaf conversion, the highest oleuropein extraction yield was obtained as 13.35 mg g-1 dry leaf for 8 h of extraction time using olive leaves with a particle size of 250-500 µm and an 80% methanol solution as solvent.

In this study, synthesis of CsPbBr3 perovskite single-crystals in a hydrobromic solution was investigated. Single-crystal growth experiments were conducted at the solution-nucleation border at a constant temperature or controlled cooling conditions. Working at the solution-nucleation border poses some practical difficulties such as fast precipitation. Often researchers opt to oversaturate the solution and use the supernatant after filtration. However, for conditions where the A to B ratio in the precursor solution for the formation of ABX3 is not 1, oversaturation is a waste of resources. In this work, precursor solutions were prepared for a particular working temperature and either held at a constant temperature or were gradually cooled to a predetermined temperature. The constant temperature method resulted in large and clear crystals as it reached saturation more slowly. Crystals prepared at high temperatures appeared to be more transparent with clear facets. Crystals prepared at low temperatures appeared to be opaque with multiple nuclei growth on a single-crystal. Seeding of the saturated solution resulted in larger single-crystals. The procedure adapted in this work made possible the production of clear CsPbBr3 perovskite single-crystals in a hydrobromic acid solution with sizes of up to 5 mm in only 10 days.

SRMs have high torque ripples. Modifying the stator and rotor shape of SRMs is one of their methods to remove torque ripples. In this study, new rotor and stator geometries have been proposed for SRM. Performance characteristics are obtained and dynamic analyses are carried out for both novel and classical 6/4 SRMs. FFT analyses of the torque characteristics are also performed for the both SRMs. The changes in performance and the FFT results of torque characteristics are determined for both the current-controlled and uncontrolled operations in both SRMs. 23.60% and 15.20% improvements in torque ripples are achieved for the uncontrolled and current-controlled operations in SRMs respectively. When the FFT analyses are applied to the torque characteristics, the THD values are obtained as 21.19% and 8.31% in the uncontrolled and controlled motor current operations respectively. A 122 W three-phase 6/4 SRM simulation based on the MATLAB–SIMULINK environment is performed to validate the improvement of the torque ripple of the proposed model.

Senkron generatörler elektrik enerjisinin üretiminde temel makina olma görevini sürdürmektedir. Senkron generatörlerin çıkış gerilimi ve frekansı uyartım akımı ve devir sayısı değiştirilerek kolayca ayarlanabilmektedir. Genellikle senkron generatörler şebekeye bağlı olarak çalıştıkları için çıkış gerilimi ve frekansının sabit olması gerekmektedir. Gerilimin ayarlanması için kullanılan Otomatik Gerilim Regülatörlerinde çeşitli denetleyici sistemler kullanılmaktadır. Bu çalışmada MATLAB/Simulink programında bulanık mantık tabanlı anahtarlamalı bir hibrit denetleyici yapısı önerilmiştir. Önerilen hibrit denetleyici, Yapay Arı Kolonisi Algoritması kullanılarak optimize edilen PID denetleyiciyle ve Ziegler-Nichols yöntemine dayalı farklı denetleyicilerden elde edilen sonuçlarla karşılaştırılmıştır. Karşılaştırma kriterleri maksimum aşım miktarı, yükselme zamanı ve oturma zamanı olarak belirlenmiştir. Karşılaştırmanın sonuçları da çok kriterli karar verme tekniklerinden biri olan TOPSIS metodu ile analiz edilerek değerlendirilmiş ve sunulmuştur., Synchronous generators are still the main machines in the production of electrical energy. Changing the excitation current and the rotation speed easily adjust their output voltage and frequency. Since synchronous generators are operated with the grid, the output voltage and frequency must be fixed. Various control systems are used in Automatic Voltage Regulators for adjusting the voltage. In this study, a hybrid controller structure proposed and it operates in MATLAB / Simulink program. The simulation results of the proposed AVR is compared with PID adjusted by Artificial Bee Colonies algorithm and Ziegler-Nichols based different controllers. The comparison was made on maximum overshoot, rise and settling time. According to the comparison made, it was seen that the proposed hybrid controller has better response than the other controllers in terms of maximum overshoot, rise and settling time.

Otomotiv sektöründe özellikle ağır ticari araçlarda araçların ön ve arka akslarında süspansiyon elemanı olarak yaprak yaylar kullanılmaktadır. Her türlü yol koşulunda ve yük altında çalışan yaprak yaylar, tekerlekten ve yerden şasiye iletilen yüklerin sönümlenmesini sağlar. Bu sayede araçta güvenlik ve çalışma konforu sağlar. Yeni nesil araçlarda mekanik süspansiyon sistemleri yerini havalı süspansiyon sistemlerine bırakmıştır. Havalı süspansiyon sistemlerinde; Özellikle ağır ticari araçlarda kullanılan Z tipi parabolik yaprak yaylar, hava körükleri ile geri esneme sağlayan yaprak yay türüdür. Bu çalışmada, Z tipi parabolik yaprak yay tasarımı ve bu yayın sonlu elemanlar analiz yöntemi ile hazırlanan model üzerinden form ve gerilme analizleri yapılmıştır. Sonlu elemanlar analizi kullanılarak bu yaprak yayın yüksek gerilim bölgeleri belirlenmiş ve uygun tasarım seçilmiştir. Son olarak N-Code programında ve fiziksel testler ile bu yaprak yaya ait yorulma ömrü elde edilmiştir., Leaf springs are used as suspension elements in the front and rear axles of vehicles in the automotive industry, especially in heavy commercial vehicles. Leaf springs working all road conditions and under load, it provides damping of the loads transmitted from the wheel and from the ground to the chassis. In this way, it ensures the safety and working comfort in the vehicle. Mechanical suspension systems have been replaced by air suspension systems in new generation vehicles. In air suspension systems; Z type parabolic leaf springs, especially used in heavy commercial vehicles, is a type of leaf spring that provides spring back with air bellows. In this study; Z type parabolic leaf spring design and finite element model of this leaf spring were prepared and form and stress analyzes were performed on the model. By using finite element analysis, high-tension regions of this leaf spring were determined and the appropriate design was selected. Finally, the fatigue life of this spring was obtained in the N-Code program and physical test.

This study focuses on recovery options for end-of-life tires (ELTs). One of the most proper recovery options for ELTs is incineration of them in cement plants. There are 49 integrated cement factories which have Environmental Permit and License Certificate in Turkey as the final processing plant. Besides benefits of recovering ELTs to environment, cost aspect of process is crucial. In this study, logistic network design of waste tires sent from collection points to these factories to minimize the costs involved is planned. There are three echelons of supply chain as waste tires collection point, contractor firms and cement factories. Model for this network considers transshipment plan of waste tires between the echelons of supply chain and routes used to gather them. Model that deal with this system are expressed as mixed integer linear programming (MILP) problem. As a case study, model verified with data’s for Ankara

Enerjinin verimli bir şekilde kullanılması, su ve gıda sorunlarından sonra çözümlenmesi gereken en önemli konulardan birisidir. 2020 yılında Türkiye’de yaklaşık 290 milyar kilowatt saat elektrik tüketimi gerçekleşmiştir. Endüstride elektrik tüketiminin yaklaşık olarak %10’u sıkıştırılmış havanın üretimi için kullanılmaktadır. Bu sebeple sıkıştırılmış hava eldesinde kullanılan kompresörlerin performansının arttırılması endüstri ve ülkemiz açısından büyük önem taşımaktadır. Bu çalışmada, son zamanlarda buzdolabı ve klimalarda yaygın olarak kullanılan döngüsel kompresörlerin verimini arttırmaya yönelik çalışmalar konu başlıkları altında derlenmiş ve incelenmiştir. Ayrıca döngüsel kompresörlerin avantaj, dezavantaj ve teknolojik olarak gelişimleri de değerlendirilmiş olup, literatüre katkı sağlanması amaçlanmıştır., The efficient use of energy is one of the most important issues to be solved after water and food problems. In 2020, approximately 290 billion kilowatt-hours of electricity was consumed in Turkey. About 10% of the electricity consumption in industry is used for the production of compressed air. Therefore, increasing the performance of compressors used in the production of compressed air is of great importance for the industry and our country. In this study, studies aimed at increasing the efficiency of rotary compressors, which are widely used in refrigerators and air conditioners, have been compiled and examined under the titles. In addition, advantages, disadvantages and technological developments of rotary compressors were evaluated and it was aimed to contribute to the literature.

Bu çalışma, düşük Reynolds sayılarında yüksek taşıma sağlayan yaygın olarak kullanılan iki kanat profilini, ticari kod ANSYS Fluent 19 ile çeşitli türbülans modelleri kullanarak sayısal olarak incelemeyi amaçlamaktadır. Eppler 423 kanat profilini sayısal olarak analiz etmektir. Eppler 423 kanat profili, yüksek taşıma kabiliyeti nedeniyle rüzgâr türbini kanatlarında, çapraz akış fanlarında, planörlerin ana kanatlarında, sportif uçuşlar ve yarışmalar için tasarlanmış radyo kontrollü uçaklarda yaygın kullanılan bir profildir. NACA 6409 kanat profili, serbest uçuş model uçaklarda kullanılır. Literatür taramasında k-ω SST, k-kl-ω ve 𝛾-𝑅𝑒𝜃 geçiş modellerinin sürükleme poler bölgesinin Cl-Cd tahminlerinde, geçiş bölgesi akış rejiminde ve laminer ayrılma noktasında iyi bir tahmin yeteneğine sahip olduğu görülmüştür. Çalışmada RANS modellere ek olarak laminer model de incelenmiştir. Sayısal çözümlerin doğruluğunu ve hassasiyetini sağlamak için kafes duyarlılık çalışması ve yakın duvar modeli kullanılmıştır. Akış yönü vektörü ayrışması tekniği, sadece tek bir ağ kullanarak tüm hücum açılarını simüle etme avantajını sağlamak için kullanılmıştır. Taşıma katsayısı eğrileri ve kutup şemaları, -4 derece hücum açısından başlanarak stol hücum açısına kadar oluşturulmuştur. Deneysel veriler, XFoil analiz verileri ve nümerik analiz verileri en iyi süzülme oranı- (Cl/Cd)maks ve minimum çöküş- (Cl1.5/Cd)maks kriterleri açısından değerlendirilmiştir. Beklendiği gibi, yüksek hücum açısında, üst yüzeydeki geçiş rampası ileri doğru hareket eder ve üst yüzeydeki basınç gradyanı negatif hale gelmiştir. Sonuçlar, ince ağın diğer ağ boyutlarına göre daha iyi sonuçlar verdiği; γ-Reθ SST modelinin diğer türbülans modellerine göre geçiş olayını modellemede daha başarılı olduğunu göstermiştir., The present study aims to numerically examine two commonly used airfoils that provide high lift at low Reynolds numbers, using various turbulence models with the commercial code ANSYS Fluent 19. Eppler 423 airfoil is widely used in wind turbine blades, wings of gliders and R/C airplanes designed for sport flying and competitions thanks to high lift capability. NACA 6409 airfoil is seen in free-flight model planes. In literature review, it has been found that k-ω SST, k-kl-ω and 𝛾-𝑅𝑒𝜃 transition models have a good prediction in Cl-Cd estimation of drag bucket region, transition flow regime, and laminar separation point. In addition to RANS models, laminar model was also investigated. In order to ensure the accuracy and precision of numerical investigations; the grid sensitivity study and near wall model were used. The method of decomposition of flow direction vector procedure has been used to provide the advantage of simulating all angle of attacks using only a single mesh. The lift coefficient curves and polar diagrams were formed from the angle of attack of -4 degree up to the stall. Experimental data, XFoil analysis data and numerical analysis data were evaluated in terms of best glide ratio-(Cl/Cd)max and minimum sink-(Cl1.5/Cd)max criteria. As expected, at high angle of attack, the transition ramp on the upper surface moves forward and the pressure gradient became more adverse. The results showed that fine mesh gives better results than other mesh sizes and transitional γ-Reθ SST model was successful in modelling the transition event than other turbulence models.

Transparan İletken Oksit (TCO) ince filmler günümüzde güneş pilleri, LED’ler, lazerler gibi optoelektronik cihazlarda sıklıkla kullanılmaktadır. Bu kontakların kullanımı cihazların verimliliğini doğrudam etkilemektedir. Bu çalışmanın amacı heteroeklemli güneş hücrelerinin (HJSCs) (n+) a-Si:H yüzünde ve yüksek elektron hareketliliği olan tranzistörlerde (HEMT) kullanmak üzere atomik katman kaplama (ALD) tekniği kullanarak alüminyum katkılı çinko oksit (AZO) üretmek ve optimize etmektir. Bu çalışmada büyütme sıcaklığı ve alüminyum katkılama oranının ALD’de büyütülmüş AZO’nun yapısal, elektriksel ve optik özelliklerine etkisi çalışılmıştır.Sonuçlar göstermiştir ki filmler görünür bölgede %80-90 arasında ışık geçirgenliğine, düşük elektriksel rezistansa (2.04x10-3 ohm.cm) ve 5.25 cm2/V.s değerinde mobiliteye sahiptir., Transparent Conductive Oxide (TCO) films are widely used in optoelectronic devices, such as solar cells, LEDs, and Lasers. Utilization of these contacts directly affects the device efficiencies. Purpose of this study is to produce and optimize properties of Aluminum doped Zinc Oxide (AZO) using a vapor phase technique, Atomic Layer Deposition (ALD) for (n+) a-Si:H surface of silicon Heterojunction Solar Cells (HJSCs) and High Electron Mobility Transistor (HEMT) applications. This study is focused on the effect of the deposition temperature and aluminum atomic concentration on structural, electrical and optical properties of ALD grown AZO ohmic contact films. The results show that as-deposited films have 80-90% transmittance in the visible spectra, low resistance (2.04x10-3 ohm.cm) and mobility value of 5.25 cm2/V.s.

In this study, California Bearing Ratio (CBR) tests in a laboratory were performed to observe the behaviour of granular layer fills reinforced with discrete fibers. Six different fiber types were used in granular road layer by using different methods. Firstly, fibers were added in the road as a layer, then they mixed with soil particles, and as a third method they mixed with soil by laying a geotextile in the road layer, in other words it was used as combine reinforced model. And as the last method only a geotextile was laid and used in the pavement soil. By using these methods, the influence of different type of reinforcements on CBR and bearing capacity ratio values were investigated. Additionally, effects on the pavement layer thickness were calculated and for the best configuration of fiber reinforced sample a cost analysis was conducted. As a result of the study, CBR test values for each fiber type used in the study have different values, and for small penetration levels some test results show no improvement for bearing capacity ratio of the road. It was noticed that when increasing the penetration level, the bearing capacity ratios have larger values. Thus, cost and layer thickness numbers were various for different reinforced road layer models. Therefore, in the real life road projects before using fiber types, cost and performance analysis should be made to determine the more effective one., Bilindiği gibi, lifler yol üstyapısının tasarımı için iyileştirme malzemelerinden biri olabilir. Ancak farklı tiplerin California Rulman Oranı (CBR) ve kaplama kalınlığı üzerindeki etkileri henüz bilinmemektedir. Bu nedenle, bu çalışmada granüler kaplama tabakasında farklı yöntemlerle altı farklı lif türü kullanılmıştır. Kompozit donatılı modeller için öncelikle kaplama tabakasına lifler katman olarak eklenmiş, daha sonra toprakla karıştırılmış ve son olarak toprakla karıştırılmış ve katman olarak geotekstil eklenmiştir. Bu üç yöntem kullanılarak farklı tipteki donatıların CBR ve taşıma gücü oranı değerlerine etkisi araştırılmıştır. Ek olarak, kaplama tabakası kalınlığı üzerindeki etkiler hesaplanmış ve lif takviyeli numunenin en iyi konfigürasyonu için bir maliyet analizi yapılmıştır. Çalışma sonucunda, farklı liflerin farklı davranışlar gösterebildiği ve küçük penetrasyon seviyeleri için bazılarının CBR değerlerini iyileştiremediği ve artan penetrasyon taşıma kapasite oranları artırıldığı gözlenmiştir. Bu nedenle gerçek projeler için lif donatı kullanmadan önce maliyet ve performans analizi yapılması gerekliliği belirlenmiştir.

Poly(ethylene oxide) (PEO)-based polymer electrolytes are a promising class of materials for use in lithium-ion batteries due to their high ionic conductivity and flexibility. In this study, the effects of polymer architecture including linear, star, and hyperbranched and salt (lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI)) concentration on the glass transition (Tg), microstructure, phase diagram, free volume, and bulk viscosity, all of which play a significant role in determining the ionic conductivity of the electrolyte, have been systematically studied for PEO-based polymer electrolytes. The branching of PEO widens the liquid phase toward lower salt concentrations, suggesting decreased crystallization and improved ion coordination. At high salt loadings, ion clustering is common for all electrolytes, yet the cluster size and distribution appear to be strongly architecture-dependent. Also, the ionic conductivity is maximized at a salt concentration of [Li/EO ≈ 0.085] for all architectures, and the highly branched polymers displayed as much as three times higher ionic conductivity (with respect to the linear analogue) for the same total molar mass. The architecture-dependent ionic conductivity is attributed to the enhanced free volume measured by positron annihilation lifetime spectroscopy. Interestingly, despite the strong architecture dependence of ionic conductivity, the salt addition in the highly branched architectures results in accelerated yet similar monomeric friction coefficients for these polymers, offering significant potential toward decoupling of conductivity from segmental dynamics of polymer electrolytes, leading to outstanding battery performance.

Gas turbines efficiently produce high amounts of electrical power hence they have been widely deployed as dependable power generators. It has been detected that the performance of gas turbines is a function of plenty of operational parameters and environmental variables. The impacts of those variables on the said performance can be mitigated using powerful monitoring techniques. Thus, extra maintenance costs, component defect costs, and manpower costs can be illuminated. This paper has enlisted the factors impacting gas turbine efficiency. It has also reviewed multiple monitoring solutions for the said impacting factors, It has been concluded that all types of sensors have ignored errors in their work, which may exacerbate the problems of malfunctions in gas turbines due to the critical environment in which they operate (heat, fumes, etc.); however, the machine learning-based monitoring systems excel in addressing such problems. The most cost-effective and accurate monitoring task can be achieved by using machine learning and deep learning tools.

© 2022 The Author(s)Battery energy storage systems (BESS) are essential for flexible and reliable grid performance as the number of renewable energy sources in grids rises. The operational life of the batteries in BESS should be taken into account for maximum cost savings, despite the fact that they are beneficial for economical grid operation. In this context, this paper present a new battery cycle counting perspective for energy management of grid-connected BESS. For this purpose battery\"s one full charge–discharge cycle characteristic is compared with the operating battery charge–discharge cycle every time step. This comparison was explained mathematically and graphically in detail. The results are compared with the rain flow counting method which is the most popular cycle counting algorithm. Consequently, this cycle counting approach successfully counts the battery charge/discharge cycles and it has shown that has an advantage for BESSs due to being specifically developed just for batteries.

Experimental criteria for sound insulation material recommendation and design have an important share in indoor acoustic control. Among these criteria, laboratories with devices such as impedance tubes, alpha cabins and reverberation rooms used to measure and analyze parameters such as sound transmission loss and sound absorption coefficient have been investigated. In literature, it has been observed that there are studies on acoustic materials and the tests applied to these materials, but the application is more limited. According to research data, an Alpha Cabin model system design that can be used to develop new types of acoustic sound materials has been proposed. In addition to the fact that a large number of experimental measurements can be performed at lower costs using the designed Alpha Cabin model system, many tests can be performed easily for different material designs in a very short time. To perform these tests, the Alpha Cabin system has been designed based on noise and sound insulation. For example, floating flooring, ribbed connection, and so on. Afterward, different insulation materials were used for insulation purposes and standards were achieved. The Alpha Cabin test system, which was designed and developed, overlaps the experimental and theoretical data for 500, 2000, and 4000 Hz when compared with the values of 29.1 dB for 500 Hz, 38.6 dB for 2000 Hz, and 49 dB for 4000 Hz measured in the Acoustic Facade Panel Test Room, and it has been observed that it can be used in the development of new sound insulation materials.

Diflubenzuron is a commonly used larvicide/biocidal substance. The present study aimed to reveal the effects of diflubenzuron on Acetylcholinesterase (AChE) enzymatic activity and liver histopathology of a mammalian species (rats). The animals fed with various doses of diflubenzuron and the liver tissues of rats were taken on the 10th, 20th, 25th, 45th days and sixth month. AChE activity of liver was measured by spectrophotometer. Tissues were embedded in Araldite 502 (Sigma), took ultrathin sections, and examined under a 100 CX II Transmission Electron Microscope. AChE activity in the chronic dose of diflubenzuron group was like that in the control group. The enzymatic activity in the subacute dose was found to be significantly different from the control group. After subacute dose exposure was terminated, the AChE activity was still lower on the 45th day compared with the control group. Chronic and subacute doses caused adverse effects to liver tissues, such as numerous mitochondria, abnormally structured nuclei in the hepatocytes and many lipid droplets in the sinusoids of the liver ultrastructure. After the subacute dose was terminated, liver damage was still observed on the 20th and 25th days, but the liver tissue was partly regenerated on the 45th day. Cellular damage might recover after 45 days, but AChE activity probably takes more time to reach a normal level.

This research focused on higher education graduates in Germany and Turkey on all fields of education, especially engineering programs in terms of all education levels and gender. The study has provided situational awareness in general on all fields of education, levels of education and gender, but on the “Engineering, manufacturing and construction” field in detail. In the research, many important findings are identified. Turkey’s ED7 (Master’s or equivalent level) and ED8 (Doctoral or equivalent level) graduate numbers and ratios are significantly lower than Germany when compared to the ED6 level. The research also revealed us that the graduation ratios of ED6 (Bachelor’s or equivalent level) and ED7 among female engineers in Germany are close to each other, indicating that female engineers in Germany are more likely to hold a master's degree after undergraduate education. Among these findings, the most important finding is; while the gender ratio of higher education graduates in Germany at all education levels is almost equal between male and female students, this ratio has started to increase in favor of female graduates in Turkey. This situation developed differently among graduates of engineering programs. While engineering graduates in Germany had a fixed ratio of approximately 80.5% male and 19.5% female graduates between 2014 and 2019. In Turkey, this ratio is improving in favor of female graduates from 32.8% in 2014 to 34.9% in 2019. In this research, it is concluded that the higher education intelligence needs to be top priority for higher education officials.

The ability to describe the nonlinear process dynamics is an essential feature of the Hammerstein model that paved more research and application studies in system identification and control. Using the Hammerstein model, this study shows an alternative approach to identify and control the highly nonlinear pH neutralization process. This Hammerstein model called Laguerre Least Square Support Vector Machines (LLSSVM) models the static nonlinearity with LSSVM and the linear part with Laguerre filter. The identified LLSSVM Hammerstein model performance evaluation with Mean Squared Error (MSE) and Variance Accounted For (VAF) is better than the Linear Laguerre model. We apply the identified LLSSVM Hammerstein model to implement a Nonlinear Model Predictive Controller (NMPC) to control the pH neutralization process. Then evaluated NMPC performance in terms of Integral Squared Error (ISE), Integral Absolute Error (IAE), and Total Variation (TV) and Control Effort (CE) parameters to verify its effectiveness in set-point tracking and disturbance rejection problems. The comparison of the NMPC with the Linear Laguerre Model-based Predictive Controller (LMPC) shows better performance of the NMPC than the LMPC. Results show that the LLSSVM Hammerstein model replicates the pH neutralization process well than the Linear Laguerre model. Also, the identified LLSSVM Hammerstein model provides an efficient NMPC than the LMPC for the pH neutralization process.

This study numerically examined the impacts of central winglets and Al2O3-water nanofluid on the thermo-hydraulic performance in a zigzag channel. The analyzes based on Computational Fluid Dynamic (CFD) using the SIMPLE algorithm are actualized for nanofluid flow in Reynolds numbers (Re) varying between 200 and 1200. The volume fraction of nanoparticle (φ) is changed from 1% to 5 %. The upper and lower zigzag surfaces are kept at Tw = 350 K constant temperature. The results are given in terms of thermal improvement (η), dimensionless friction factor (Γ), and thermo-hydraulic performance (THP). In addition, the work is compared with the zigzag channel without winglet for the base fluid. The temperature and velocity distributions are obtained for the zigzag channel with and without winglet at different Reynolds numbers. The results show that the nanofluid and winglets contribute considerably to the enhancement of heat transfer, but the friction factor slightly increases. The heat transfer improves with increasing inlet velocity and particle volume fraction. The highest thermo-hydraulic performance is obtained as approximately 2.12 for Re = 400 and φ = 0.05.

Multiplication is the key crucial operation in realizing digital signal processing (DSP) functions. It is accomplished by using diverse multiplier architectures. Multiplication operation is furthermost basic and normally used action in the central processing unit (CPU). The multiplication operation is the most fundamental and commonly performed activity in the central processing unit (CPU). An efficient multiplier design should have a high speed, small area, and a low power consumption. Compact, efficient multipliers with minimal power dissipation are needed. The proposed paper provides a thorough inspection of multipliers such as the Array multiplier, Booth multiplier, column bypass multiplier, Baugh-Wooley multiplier, and Vedic multiplier based on their operational activities and working, as well as their benefits and limits. A comparison of these multipliers' performance parameters such as speed, area, power consumption, quantum cost, garbage generation and circuit complexity.

In this study, we present higher order Jacobsthal numbers. Then we define higher order Jacobsthal quaternions by using higher order Jacobsthal numbers. We give the concept of the norm and conjugate for these quaternions. We express and prove some propositions related to these quaternions. Also, we find the recurrence relation, the Binet formula and the generating function for these quaternions. Finally, we calculate Cassini, Catalan, Vajda and d’Ocagne identities for higher order Jacobsthal quaternions.

The electronic, magnetic and structural properties of Pd2FeTl compound were investigated in this study. The Vienna Simulation Package program was used to perform calculations, based on DFT and Generalized Gradient Approximation. The lattice parameter of 6.360A0 and its magnetic moment value of 3.063μB/f.u. are calculated. The values for the magnetic moment and lattice parameter were found to be in conformity with those in the literature. As electronic properties and band structures were calculated, also the density of state curves compatible with the band structures were drawn. There is no band gap between the energy bands in terms of Pd2FeTl compound and according to the calculations, this compound has a metallic structure.

In daily life, vitamins fruits and vegetables play a very important role in human life. The farmer produces grains or vegetables in huge quantities. Due to lack of storage problem farmer suffers. It is necessary to store all these things in a special warehouse. Thus, improper storage of grains or fruits is essential to meet the increasing demands. Storage time and fruit quality are greatly influenced by storage environmental factors. Therefore, it is important for the fruit storage environment to perform multi-parameter monitoring and analyze the collected parameters and then regulate and control. The quality of grains and other perishable goods kept in a warehouse usually deteriorates due to lack of monitoring and proper maintenance of their required suitable conditions in such a large area. The proposed methodology deals with the storage of grains, fruits, etc., and to identify their temperature and humidity patterns so that they will not be degraded. Establishing the environment in relation to the nature of the crop so as to determine an optimum threshold with an appropriate pattern of monitoring and change. The main goal of this research article is to provide solutions to prevent rotting of grains and fruits in the storage area.

Production systems have been growing exponentially in size in recent decades. One of the problems in the manufacturing system is that a need of effective and efficient materials transportation between the workstations. Auto-mated guided vehicles (AGV’s) can provide a satisfactory solution to this issue. Because of this, AGV’s is a one of the most important material handling tool used in flexible manufacturing system (FMS). The designing, scheduling and routing of the AGV’s are the key issues for the reason that performance of AVG’s in flexible manufacturing system depends on these parameters. The failure of AGVs may significantly impact the operation and efficiency of the entire system, and it is a critical issue. In this paper the aims to answer How the reliability of individual AGVs in the system assessed? , and How AGVs affects the performance of the whole FMS system?. It was also discussed that optimizing techniques to improve the performance of AGV in FMS. This paper discussed the details studies of approaches and optimization techniques used for optimizing AGV’s in FMS including design and their control.

The cold filter plugging point (CFPP) value of biodiesel fuel blends need to be improved because of it has been reported that utilizing high concentrations of biodiesel blends in cold climates can cause major issues. Therefore, the main objective of the study is to improve CFPP value of biodiesel blends using ethyl proxitol additive. It is also to examine combustion and emission of the blends behavior. Biodiesel blends were prepared as; 5% ethyl proxitol-10% biodiesel-85% ultra-low sulfur diesel (ULSD) named as E5B10 and 5% ethyl proxitol-20% biodiesel-75% ULSD named as E5B20 fuel. These fuel blends were compared with ULSD fuel in a compression ignition engine at a constant engine speed of 1500 rev/min and four different loads (idle, 1, 2, and 3 bar BMEP) of eddy current dynamometer. The addition of ethyl proxitol led to a decrease in in-cylinder pressure and temperature due to an about 1˚ later SOC and 2˚ earlier EOC compared to ULSD. The pressure rise rate was slightly higher compared to ULSD at both low and high loads, with a difference of about 1 bar per degree. As a result, these blends with improved CFPP value can be used in cold climates.

© 2023 Wiley Periodicals LLC.In this study, we have synthesized a series of 3-(pyridin-2-yl)-2-(pyridin-2-ylimino)thiazolidin-4-ol derivatives regioselectively from 2-iminothiazolidin-4-ones using LiAlH4 at room temperature. Due to the presence of the restricted rotation around the N3-Caryl single bond, the formation of M/P isomers was observed. The OH group of the hemiaminal was found to orient itself on the same side with pyridyl nitrogen during this restricted rotation to form an intramolecular hydrogen bond, which was demonstrated by the computational DFT study. This orientation presumably inhibited the occurrence of dehydration and stabilized the molecule.

The finite element method is the most common method used to solve engineering and mathematical model problems. Related solution areas include structural analysis, heat transfer, mass transport and electromagnetic potential. FEM is a specific numerical method used to solve partial differential equations in two or three space variables. To solve a problem, FEM breaks up a large system into smaller, simpler parts called finite elements. First, a three-dimensional model of the system to be analyzed is produced. While defining the model, the materials and connection types found in the model are also deter-mined. Afterwards, the model is divided into small parts and analyzed under specified conditions. A crash test will be conducted in this study. For this, the conditions of the vehicle parts will be examined by hitting a wall under the conditions of which the model design of the vehicle is determined. Crash tests were carried out for two different bumper thicknesses on the same vehicle and the test results were examined. The vehicle speed is modeled as 20 m/s in the simulation carried out from the moment of impact until 0.14 seconds later. The effect of buffer thickness on axial displacements at impact and energy changes are presented.

IEEEWhile the zeitgeist of today prescribes localization as a key to eliminate the excessive transportation for manufacturing firms, firm-level practical and workable guidelines that go beyond maxims are scant. Laden with analytical methods, this paper offers a phronetic, customizable framework based on Lean Six Sigma (LSS). The framework mimics Define-Measure-Analyze-Improve-Control (DMAIC) process. The early phases of the framework, ex-ante, prescribe the use of a variety tools and techniques from Lean Six sigma (LSS) and employ fuzzy analytic hierarchy process (FAHP) to extract the vital few root-causes that may impede localization. The latter phases suggest the use of design of experiments (DOE) to evaluate the root-causes, ex-post. The paper outlines a clear and established procedure and demonstrates each analytical phase using evidence from a two-year real-world application in steel industry.

The half-metallic calculations of new variant perovskites Li2CrO6 and Li2CuO6 were carried out by using WIEN2k computational code. First, the ferromagnetic (FM) and non-magnetic (NM) phases were compared, and FM phases were obtained energetically more stable. The equilibrium lattice constants were obtained as 7.63 Å and 7.66 Å for Li2CrO6 and Li2CuO6, respectively. Second, the electronic calculations were performed, and the semiconduction properties were seen in spin-up states while spin-down states showed metallic nature. The band gaps were obtained as 1.806 eV and 1.177 eV for Li2CrO6 and Li2CuO6, respectively. Since variant perovskites Li2CrO6 and Li2CuO6 showed 100% spin polarizations, these were obtained as true half-metallic ferromagnetic materials. Then the total magnetic moments were obtained as 4.00 μB/f.u., 5.00 μB/f.u. When both the electronic and magnetic properties of the compounds are examined, the variant perovskites Li2CrO6 and Li2CuO6 are suitable materials for spintronics applications.

Noise barriers are one of the common solutions to control road traffic noise. Many studies have also shown that noise barriers cause reductions in near-road air pollutant concentrations. In this study, the simultaneous effects of a specific noise barrier application on near-road noise and air pollution at a specific location were investigated. In this context, air pollution, noise, and meteorological parameters were measured simultaneously at two points, road and receptor sides of a 50 m long, 4 m high glass fiber reinforced concrete noise barrier on a highway section. Results indicated that the noise barrier has an average 23 % reduction effect on the NOx concentration in addition to the noise level reduction at the receptor side. Besides, bi-weekly average passive sampler measurement results for BTEX pollutants indicate lower values at the receptor side of the barrier compared to the free field measurement results. In addition to real-time and passive sampler measurements, NOx and noise dispersions were modeled using RLINE and SoundPLAN 8.2 software, respectively. Comparisons of the measurement results with the model results indicated strong correlations. Model-calculated NOx and noise values under the free field conditions are highly compatible with a correlation coefficient (r) of 0.78. Although the noise barrier has a reduction effect on both parameters, it has been observed that their dispersion mechanisms are different. This study showed that noise barriers considerably affect the dispersion of road-sourced air pollutants at the receptor side. Further studies are needed to optimize noise barrier designs with different physical and material properties and application scenarios considering noise and air pollutants together.

Considering the increasing demand for cloud computing, and the financial and environmental impact of the increasing energy consumption trend of data centers, improving energy efficiency is vital for cloud service providers. In this study, an energy-aware virtual machine scheduling model is proposed which is based on the multi-unit nondiscriminatory combinatorial auction. The model includes a powerful bidding language that allows users to declare their complicated virtual machine requests using logical AND and OR relations along with the time constraints. The study also presents the formal definition of the model and the associated optimization problem for determining the optimum schedule and energy-efficient placement of VMs on physical servers. The optimization problem is formulated using integer linear programming and several heuristic solution methods including the Genetic Algorithm are proposed for this problem. The performances of the model and the proposed heuristics are assessed on a comprehensive test suite. The proposed model is estimated to provide approximately a 37% improvement in revenues, and the solution methods are estimated to provide high-quality solutions within only 5% of the optimum which enable the model to be deployed in large-scale clouds.