Zamirgül KAZAKBAYEVA

Article | 2023 | Journal of Applied Spectroscopy90 ( 5 )

The luminescence of Er3 ions in silica glasses synthesized by the direct sol–gel–glass transition method and by melting of activated gel grit using various precursors of optical centers was studied. The formation of complex centers including erbium, aluminum, and alkali metal ions was found to be one way of essentially increasing the half-width of the 4 I 13/2 → 4 I 15/2 luminescence band of these ions. Keyword: complex optical centers; luminescence; rare earth ions; sol–gel method

Burak OĞUL

Article | 2019 | MANAS Journal of Engineering (MJEN)7 ( 2 )

The behaivour of the solutions of the following system of difference equations is examined, x(n+1)=x(n-20)/[1+x(n-2)x(n-5)x(n-8)x(n-11)x(n-14)x(n-17)] where the initial conditions are positive real numbers. The initial conditions of the equation are arbitrary positive real numbers. Also, we discuss and illustrate the stability of the solutions in the neighborhood of the critical points and the periodicity of the considered equations

Mirlan MOLDOBAYEV | Zarlık MAYMEKOV

Article | 2023 | Theoretical Foundations of Chemical Engineering57 ( 5 )

To predict and evaluate the carbon footprint in the gas phase, furnace fuel oil oxidation in excess air (alpha factor 1.3) was studied over a wide temperature (T 298–3000 K, P 0.1 MPa). Equilibrium thermodynamic parameters (entropy, enthalpy, and internal energy) and the concentration distributions of C-, S-, N-, O-, and H-containing components and active particles in the gas phase were determined. Based on the total concentration distribution of C-, S-, N-, O-, and H-containing components and active particles in the gas phase, the weight content of carbon was calculated. Taking into account the chemical matrix of the furnace fuel o . . .il–air system and the weight content of carbon, the man-made load of carbon in the gas phase was found. The results of the work made it possible to evaluate the carbon footprint in the gas phase because of the combustion of fuel, in particular, furnace fuel oil in air. Reduction of the man-made load of carbon oxides (CO, CO2) in the gas phase was achieved by modifying and burning furnace fuel oil in the form of oil-in-water (reverse) emulsions in E-1/9M industrial boilers. Keyword: carbon footprint; concentration distribution; furnace fuel oil–air; gas phase; man-made loa More less

Özgül SALOR-DURNA

Proceedings Paper | 2023 | IEEE Industry Applications Society Annual Meeting

The research work presented in this paper proposes a method for modeling the behavior of the Electric Arc Furnace (EAF) currents for a tap-to-tap time based on the DFT amplitude histograms of the EAF current waves. The method is used to model the EAF current behavior separately for each phase of the EAF operation: boring, melting and refining. The model is verified by comparing the THD histograms and the flicker measurements of the original and modeled EAF current waveforms. The proposed model can be used as an EAF model in the simulation environment for various purposes before the installation of an EAF. The method has low computat . . .ional load compared to various other techniques, since it utilizes only the amplitude distribution parameters of the first 13 frequency components and the one-cycle signal representing the higher order harmonics. The model is novel in the sense that every time the EAF current signal is generated, a unique waveform reflecting the corresponding distributions is generated, which is compatible with the random behavior of the EAF operation. Keyword: EAF current; EAF modeling; electric arc furnace (EAF); power quality; steel makin More less

Ercan ÇELİK

Article | 2023 | Advances in Mathematical Physics2023

In this article, we investigate a nonlinear Petrovsky equation with variable exponent and damping terms. First, we establish the local existence using the Faedo-Galerkin approximation method under the conditions of positive initial energy and appropriate constraints on the variable exponents p & sdot; and q & sdot;. Finally, we prove a finite-time blow-up result for negative initial energy. Keyword: global existence; wave-equation

Ercan ÇELİK

Article | 2023 | Journal of Applied Mathematics2023

In this study, we applied an approximate solution method for solving the boundary value problems (BVPs) with retarded argument. The method is the consecutive substitution method. The consecutive substitution method was applied and an approximate solution was obtained. The numerical solution and the analytical solution are compared in the table. The solutions were found to be compatible. Keywords: approximate solution; boundary-value problem; numerical solution; retarded argument; solution methods; substitution method; boundary value problems

Ercan ÇELİK

Article | 2023 | Journal of Function Spaces

In this study, the modification of the concept of exponentially convex function, which is a general version of convex functions, given on the coordinates, is recalled. With the help of an integral identity which includes the Riemann-Liouville (RL) fractional integral operator, new Hadamard-type inequalities are proved for exponentially convex functions on the coordinates. Many special cases of the results are discussed. Keywords: hadamard-type inequalities; rectangle

Camilya SMANALİYEVA | Canıl İSKAKOVA | Cıldız ÖSKÖNBAEVA

Article | 2019 | European Food Research and Technology245 ( 10 )

Wild fruits and berries from the walnut-fruit forests of Kyrgyzstan may hold nutritional and health benefits for humans. Since information on their nutritional value is scarce, physical properties and nutritional value of naturally occurring red, black, and yellow cherry plum fruits (Prunus divaricata Ledeb.) were evaluated. The wild cherry plums featured moisture contents between 81.07 and 85.87%, reducing sugar contents of 6.83-8.42%, alimentary fiber of 0.78-1.38%, ash contents of 0.48-0.74%, acidity levels of 0.97-2.31%, and ascorbic acid concentrations of 16.00-30.25 mg/100 g. The total phenolic concentrations of wild cherry pl . . .um fruits was determined at 177-365 mg/100 g expressed as gallic acid equivalents. The black wild cherry plum contained the highest amounts of polyphenols and anthocyanins among the analyzed samples as well as the domesticated Prunus varieties. The essential mineral profile indicated that zinc (Zn) featured the lowest concentrations with 0.05-0.18 mg/100 g, while potassium (K) was the most abundant mineral at 127.97-188.74 mg/100 g in all cherry plum samples. 100 g fresh wild cherry plum can contribute up to 26.4% of iron (Fe) to recommended dietary allowance. All these results indicate that wild cherry plum fruits can be beneficial for human nutrition. The determination of physical attributes and chemical composition of these fruits is essential to facilitate the establishment of product standards and to further promote the use of these products in the food industr More less

İbrahim AKGÜN

Article | 2023 | Mathematics11 ( 21 )

In this study, we propose a novel multi-objective nonlinear mixed-integer mathematical programming model for the transit network design and frequency setting problem that aims at designing the routes and determining the frequencies of the routes to satisfy passenger demand in a transit network. The proposed model incorporates the features of real-life transit network systems and reflects the views of both passengers and the transit agency by considering the in-vehicle travel time, transfers, waiting times at the boarding and transfer stops, overcrowding and under-utilization of vehicles, and vehicle fleet size. Unlike previous studi . . .es that simplify several aspects of the transit network design and frequency setting problem, the proposed model is the first to determine routes and their frequencies simultaneously from scratch, i.e., without using line and frequency pools while considering the aforementioned issues, such as transfers and waiting. We solve the proposed model using Gurobi. We provide the results of what-if analyses conducted using a real-world public bus transport network in the city of Kayseri in Türkiye. We also present the results of computational tests implemented to validate and verify the model using Mandl benchmark instances from the literature. The results indicate that the model produces better solutions than the state-of-the-art algorithms in the literature and that the model can be used by public transit planners as a decision aid. Keyword: mathematical programming; nonlinear mixed-integer programming; public transport; real-world application; transit network route design and frequency setting problem; urban public transportation; urban transit network desig More less

Ali ASLAN

Article | 2023 | Niğde Ömer Halisdemir Üniversitesi Mühendislik Bilimleri Dergisi12 ( 3 )

Some trace elements in various lichens as biomonitors of pollution were investigated. Also, the pollution status was assessed by enrichment factor, contamination factor, and pollution load index. Investigated elements were Ta, Bi, Hf, Nb, Ga, Sc, Li, Y, Ce, and Sr. The lichen species were Rhizoplaca chrysoleuca, Umbilicaria vellea, Aspicilia calcarea, Pseudevernia furfuracea, and Cetraria islandica. According to the results, lichen species accumulate Sr element well. The highest trace element accumulated by Pseudevernia furfuracea (21.7±1.0 mg/kg; 75), Rhizoplaca chrysoleuca (31.9±1.6 mg/kg; 61), Umbilicaria vellea (16.3±0.8 mg/kg; . . .59), Aspicilia calcarea (77.9±3.8 mg/kg; 88), and Cetraria islandica (22.7±1.1 mg/kg; 75) was determined as Sr. The highest CFs in lichens investigated were calculated for Sr, Ta, and Li. PLI values for Cetraria islandica, Aspicilia calcarea, and Umbilicaria vellea were greater than 1. As a result, it has been proven that these lichen species can be used as good biomonitors of pollution. Keyword: accumulation; biomonitor; lichen; pollutio More less

Ali ASLAN

Article | 2023 | Revista de Psicologia del Deporte / Journal of Sport Psychology32 ( 2 )

The study aims to determine if stress and anxiety reduction techniques may enhance sports performance. We will do a complete assessment of earlier research on mindfulness training and sporting performance to answer this issue. This research study is based on primary data to determine whether the research study used smart PLS Software and generated informative results. The research examines how mindfulness affects stress, anxiety, and attention and how these elements affect athletic performance. We will also examine how stress and anxiety affect athletes' performance and how mindfulness training may help athletes better control these . . . emotions. Our ultimate objective is to offer insightful analysis and suggestions to coaches and athletes who want to improve their performance via mindfulness training. Overall result found that mindfulness training has the potential to significantly impact players' physical, mental, and athletic performance. To assure widespread acceptance and success, more study is required to examine the obstacles to introducing mindfulness training in sports teams and how these obstacles might be removed. Athletes and coaches can enhance performance by integrating mindfulness training and gaining insightful information about an athlete's well-being. Keyword: mindfulness training; stress; anxiety in sport; smart PLS algorith More less

Ayçürök MACİTOVA | Asılbek KULMIRZAYEV

Article | 2019 | Молочная промышленность ( 1 )