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

Canıl İSKAKOVA

Article | 2023 | MANAS Journal of Engineering (MJEN)11 ( 1 )

Maksym is a Kyrgyz ethnic beverage made from milled cereals such as wheat, barley, or maize, boiled in water, and then fermented using yeast and lactic acid bacteria as a starter culture. The aim of this study was to investigate the changes in the consistency and sensory properties of Maksym after industrial production during refrigerated storage. The acidity of the beverage increases and the total soluble solids decrease after 21 days. The amount of lactic acid bacteria (LAB) and yeast after production were 9.36 and 9.46 log cfu/mL, respectively. After 21 days it is indicated that the amount of both starter cultures decreased by 2 . . .log units. In terms of acceptability, the sensory properties after 7 days of storage received the highest rating. However, the acidic taste after 21 days of storage received the lowest rating. Rheological measurements carried out at 5, 10, 20, and 30°C also revealed these changes. Four rheological models (Newtonian, Herschel-Bulkley, Ostwald De-Waele, and Casson) were used to describe the flow behaviour of the beverage. The Casson model was superior to other rheological models. The effective viscosity of Maksym was decreased from 2.66 to 1.96 mPa·s after 21 days of cold storage. The activation energy was decreased from 23.10 and 14.94 kJ/mol and indicated the thinning of viscosity of the beverage. The obtained parameters can be used to predict the shelf-life model and product labelling by its expiry period, as well as to control the quality of Maksym. Keyword: maksym; fermented beverage; rheological properties; microbiology; sensory; storag More less

Dağıstan ŞİMŞEK | Peyil Esengul Kızı

Article | 2018 | MANAS Journal of Engineering (MJEN)6 ( 2 )

In this paper the solutions of the following difference equation is examined

Gulida KIMSANOVA | Rita İSMAİLOVA | Rayımbek SULTANOV

Article | 2015 | MANAS Journal of Engineering (MJEN)3 ( 2 )

Көптөгөн ачык ачкычтуу криптосистемалардын негизи катары колдонулган натуралдык санды факторизациялоо проблемасы заманбап компьютерлер үчүн да оор маселе болуп саналат. Биз бул иште С программалоо тилинде GMP китепканасын колдонуп, 4 алгоритмди иштеп чыктык жана бул алгоритмдердин иштөө убакыттарын салыштырдык. Алгоритмдер ар кандай өлчөмдөгү сандарды, ошондой эле факторлорунун ортосунда ар кандай аралык болгон сандарды факторизациялоо үчүн колдонулду.Биздин жыйынтыктар 296 биттик санды факторлорго ажыратууда Поллард rho алгоритминин эң бат иштешин, ошол эле учурда, факторлордун ортосундагы аралык кичине болгон учурда Ферма алгоритм . . .инин эң бат иштешин көрсөттү. Мындай сандар үчүн Брент алгоритминин жай иштегени байкалды, бирок бул алгоритм Ферма алгоритми натыйжа бере албаган учурларда ийгиликтүү жыйынтык бере алды. - Keywords: Натуралдык сандын факторизациясы, GMP,Тривиалдык бөлүү, Ферма алгоритми, Поллард rho алгоритми, Брент алгоритми = Integer factorization problem, which is used as the basis in many public key cryptosystem, is generally thought to be hard problem even on a modern computers. In this work we implement 4 integer factorization algorithms using GMP library on c++ and compare the running time of these algorithms. Algorithms were used to factor numbers of different sizes, as well as for number with different distance between factors. Our results showed that for numbers up to 296 bits the Pollard rho algorithm is the fastest one, while Fermat algorithm is fast when distances between factors are small. Brent algorithms appeared to run slower for this rage of numbers, however it succeeded to factor numbers which Fermat algorithm fail to factor More less

Ercan ÇELİK

Article | 2023 | MANAS Journal of Engineering (MJEN)11 ( 2 )

In this study, quadratic convergent new bigeometric Newton's method (nBGNM) was developed. For this, the basic definitions and theorems of bigeometric analysis, which is one of the non-Newtonian analysis, were used. Using the bigeometric Taylor expansion, a convergence analysis of this new method was given. Also, the new bigeometric Newton method (nBGNM) was compared in detail with the geometric (multiplicative) Newton method (GNM) and the classical Newton method (NM). Keyword: bigeometric analysis; bigeometric newton method; quadratic convergence; bigeometric taylor expansion

Dağıstan ŞİMŞEK | Burak OĞUL

Article | 2016 | MANAS Journal of Engineering (MJEN)4 ( 1 )

Aşağıdaki fark denklem sisteminin çözümlerinin periyodikliği ve davranışları incelenmiştir.- Keywords: Fark Denklemi, Maksimum Operatörü, Yarı Dönmeler, Periyodiklik

Ümit GÜRBÜZ

Article | 2018 | MANAS Journal of Engineering (MJEN)6 ( 2 )

This study was conducted to determine the application of the ohmic heating system in meat thawing process and its effects on the microbiological quality of the meats. For this purpose, traditional thawing methods (room temperature and refrigerator) are compared with the ohmic system. Beef loin (Longissimus lumborum, LL) was used as the material in the experiments by cutting into 5x10cm pieces. The samples were divided into three groups by taking the thawing methods into consideration. The grouped meat samples were frozen at -35±1°C for 24 hours and stored at -18°C for 6 months. During the storage period, changes in color (L*,a*,b*) . . .and microbiological condition of the samples were determined periodically throughout the storage period. In all experimental meat samples thawed by different methods, considering the period of frozen storage; There were statistically significant differences in total microorganism, Pseudomonas spp and coliform numbers after the second month (p0.05). When the thawing methods applied in this study evaluated in terms of L*, a*, b* values, there was no statistically difference between the groups (p> 0.05). As a result, it has been concluded that the ohmic heating system can be used as an alternative method for thawing frozen meat More less

Dağıstan ŞİMŞEK | Burak OĞUL

Article | 2016 | MANAS Journal of Engineering (MJEN)4 ( 2 )

Aşağıdaki fark denklem sisteminin çözümlerinin periyodikliği ve davranışları incelenmiştir. (1) Başlangıç şartları pozitif reel sayılardır.- Keywords: Fark Denklemi, Maksimum Operatörü, Yarı Dönmeler

Elman HAZAR | Dağıstan ŞİMŞEK | Asan ÖMÜRALİEV | Burak OĞUL | Ella ABILAYEVA | Peyil Esengul Kızı

Article | 2015 | MANAS Journal of Engineering (MJEN)3 ( 2 )

In the present study, a boundary-value problem corresponding to forced vibration of an imperfectly bonded bi-layered plate-strip resting on a rigid foundation is considered. In the framework of three-dimensional linearized theory of elastic waves in initially stressed bodies, the mathematical modelling of considered problem is given. Then, the variational formulation of the problem considered is obtained in the framework of the principles of calculus of variation. The problem considered differs from the previous studies in the view of imperfect boundary conditions between the layers of the plate-stip and between the plate-strip and . . .the rigid foundation. - Keywords: Forced vibration, plate-strip, variational formulation More less

Sebahattin BALCI | Ali Osman SOLAK

Article | 2014 | MANAS Journal of Engineering (MJEN)2 ( 1 )

pKa values of the organic surfaces were determined with ionizable carboxylic acid groups, obtained by the modification of gold electrode by reduction of p-benzoic acid diazonium tetrafluoroborate and oxidation of p-aminobenzoic acid. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques were used in the surface pKa determination, by exploiting the barrier effect arising from the charged nature of the surface against the electrochemistry of Fe(CN)64-/3- redox probe. Contact angle measurement (CAM) technique was also used to compare the accuracy of the surface pKa values acquired by electrochemical method . . .s. pKa values for Au-BA were found as 2.938±0.283, 4.128 ± 0.342 and 4.251±0.089 by CV, EIS, and CAM, respectively : while the values are 4.084±0.101 5.326±0.323 and 5.102±0.147 for Au-NHBA. - Keywords: Surface pKa of benzoic acid; modified gold electrode; cyclic voltammetry; electrochemical impedance spectroscopy; contact angle measuremen More less

Mirlan MOLDOBAYEV | Kubat KEMELOV | Zarlık MAYMEKOV

Article | 2022 | MANAS Journal of Engineering (MJEN)10 ( 2 )

Soot is one of the products of incomplete combustion of hydrocarbon fuels. It has the property of adsorption of active and carcinogenic substances on the surface of soot particles. In this regard, in burner equipment of medium and small power, it is required to develop and implement effective environmental measures to reduce emissions of soot particles. In this paper, the fuel oil-water-air system at a wide temperature range (T500-3000K) was studied and the ratio of gas-liquid flows (water content in fuel oil 5-15) at the maximum entropy of the system and the formation of soot in flue gases was revealed. To reduce the concentration . . .of soot in flue gases, a fuel oil-water emulsion was used. The particle sizes of the fuel oil-water emulsion were determined by sedimentation analysis. It is shown that they have a polydisperse character (diameter from 8.96 to 59.02 μm). The water content in fuel oil during the preparation of fuel oil-water emulsion in the boiler room was controlled by a capacitive sensor. The water flow was automatically maintained by an ejector-dosing device. The thermodynamic parameters of the system (entropy, enthalpy, internal energy) were calculated and their comparative characteristics were obtained. The concentration distribution of hydrogen, carbon, nitrogen, sulfur and oxygen containing molecules, particles and condensed phases in the gas phase has been established. During the combustion of the fuel oil-water emulsion, the concentration of soot in the gas phase decreased due to an increase in hydrogen-containing particles in the gas phase, i.e. an increase in the H/C ratio, as well as a change in the concentration of condensed carbon (mol/kg): (fuel oil without water C(c) 63.3 mol/kg); fuel oil with water: 5 H2O, C(c) 54.96; 10 H2O, C(c) 50.45; 15 H2O, C(c) 46.3. It is noted that the H/C ratio in the case of burning fuel oil -water emulsion is 2.26 times higher. A technological scheme for the preparation and combustion of fuel oil in the form of fuel oil-water emulsions in industrial boilers of the E-1/9-M(3) type of the Bridge Construction Detachment of the Kyrgyz Railway, Bishkek, has been developed. It has been established that when burning fuel oil-water emulsions in boiler units, the soot content in flue gases is reduced by 75 due to the developed contact surface of the interacting phases and more complete combustion of particles of fuel oil-water emulsions More less

Camilya SMANALİYEVA | Cıldızay ÖZBEKOVA | Asılbek KULMIRZAYEV

Article | 2019 | MANAS Journal of Engineering (MJEN)7 ( 1 )

The objective of this paper was to study the fatty acid composition, and thermal and rheological behavior of Kyrgyz yak (Bos grunniens) visceral fats compared to visceral fats of cow (Bos taurus) and horse (Equus caballus). The result of the studу revealed that the content of saturated fatty acids (SFA) in yak fat was higher than those of unsaturated fatty acids (UFA) (about 58.3 and 38.0 %, respectively). The UFA content in yak fat was higher compared to cow fat (about 27.1 %) and lower than that of horse fat (about 60.0 %). The melting temperatures determined using DSC were found to be 55.18±0.71, 54.98±3.01, 37.60±1.92 °C for yak . . ., cow and horse fat, respectively. These results were close to the solid-liquid transition temperature determined by oscillation rheology (52.20±0.89 °C for yak, 53.56±3.53 °C for cow and 33.7±1.84 °C for horse fat). Rotational rheological measurements at 35 °C have shown that yak fat had shear thinning flow behavior with high a viscosity of 226 mPas compared to horse fat, which has Newtonian flow behavior with a viscosity of about 36 mPas (γ=100s-1). Results on properties obtained in this study will help to understand the contribution of yak fats to the structural properties of new products with these alternative fat sources More less