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

Hüseyin ÖĞÜT

Article | 2019 | Energy Sources, Part A: Recovery, Utilization, and Environmental Effects42 ( 19 )

The boron occupies an important place on contributions and its usage is getting widespread. Although the use of boron-added mineral oils serves to reduce friction, environmental risks can not be totally removed. It is necessary to improve the properties of biological oils used for additives so that they can compete with mineral oils technically. In the study, the use of liquid boron as an additive for engine lubrication oil together with vegetable oil was investigated experimentally in two diesel engines. Experiments were first carried out using mineral lubrication oil in the engine, and then the experiments were repeated using mine . . .ral base oil with additives in the second engine with the same technical characteristics as the first engine. Basically, the study was performed in the fields of engine performance (torque, power, consumption per hour, specific fuel consumption) and exhaust emissions (CO, CO2, HC, O-2, SO2, NOx). As a result, it was concluded that the engine, in which boron and mineral oil with wild mustard oil were used, provided more significant fuel saving than in the engine with additive-free mineral oil, and no significant change was seen in the engine performance, also they showed similarities in terms of exhaust emissions More less

Zamirgül KAZAKBAYEVA

Article | 2023 | Журнал прикладной спектроскопии90 ( 5 )

Исследована люминесценция ионов Er3 в кварцевых стеклах, синтезированных методом прямого перехода золь-гель-стекло и плавлением активированной гель-крупки с использованием различных прекурсоров оптических центров. Установлено, что одним из путей существенного увеличения полуширины полосы люминесценции 4I13/2→4I15/2 указанных ионов является формирование сложных оптических центров, включающих в себя ионы эрбия, алюминия и щелочного металла. Ключевые слова: золь-гель метод, редкоземельный ион, люминесценция, сложные оптические центры . . . More less

Tahir GÖNEN

Article | 2018 | Construction and Building Materials177

Millions of tires are discarded every year. Disposal or recycling-reusing of waste tire rubber has become a big environmental problem in the world. In this study, it was aimed to determine the freezing-thawing, impact resistance, compressive strength and capillary water absorption rate, when the granulated waste rubber parts are used in the non-load-bearing concrete. Granulated crumb rubbers obtained from waste tires were used at two different grain diameters of 1 and 2 mm as the maximum value. A total of 9 different series were prepared, one of them being the control group and the others being changed with the aggregate in the rati . . .os of 0.5%, 1%, 2% and 4%. In all of the blends, the water/cement ratio was kept constant at 0.50. A drop-weight type impact test was applied to the specimens produced with and without waste rubbers. The impact energy required for the first crack and final dent was determined with the free-falling steel ball at a certain height. Freezing thawing experiments were carried out on the samples with 3% NaCl solution ponded on the surface, and weight losses were determined. As the result, significant improvements were observed in the freezing-thawing and impact resistances of waste tire added samples. Weight loss of specimens because of the freezing-thawing was decreased about 90% and impact resistance was increased different rate depending using rate. (C) 2018 Elsevier Ltd. All rights reserve More less

Abdullah Erdal TÜMER

Article | 2021 | MANAS Journal of Engineering (MJEN)9 ( 1 )

The advancement of technology nowadays resulted into documents, such as forms and petitions, being filled out in computer and digital environment. Yet in some cases, documents are still preserved in traditional style, on print. Due to its distinct proportions, however, its storage, sharing and filing has become a complication. The relocation of these written documents to digital environment is therefore of great significance. In this view, this study aims to explore methodologies of digitizing handwritten documents. In this study, the documents converted to image format were pre-processed using image processing methods. These operat . . .ions include dividing lines of the document into image format, dividing into words which then divided into characters, and finally, a classification operation on the characters. As classification phase, one of the deep learning methods is the Convolution Neural Network method is used in image recognition. The model was trained using the EMNIST dataset, and in the character, dataset created from the documents at hand. The dataset created had a success rate of 87.81%. Characters classified as finishers are sequentially combined and the document is transferred to the computer afterwards More less

Ebru DURAL

Article | 2022 | Structures47

Laminated glass is made by combining glass layers with polyvinyl butyral (PVB) or a different adhesive with the help of heat and pressure. Its popularity is increasing in the building industry as a protective material. However, despite the popularity of laminated glass as a structural material, delamination is recognized as a highly undesirable problem inducing major damage to laminated glass. The effect of boundary conditions on the delamination strength of laminated glass is observed in this study. It is concluded that the location and size of delamination have a considerable effect in determining the delamination strength of lami . . .nated glass. The results of the previously conducted experiment and the developed finite element model are utilized to validate the model used to determine the delaminated strength of laminated glass. The simulation results and measurements are in good agreement with the results of the mathematical model. The results of the current research can be utilized by design engineers while designing laminated glass for structural applications More less

Raşit YILMAZ

Article | 2022 | Актуальные вопросы образования и науки73 ( 1 )

В статье рассмотрена динамика налоговых поступлений на основе обязательного и добровольного патента Кыргызской Республики и методы по ее оптимизации

Abdullah Erdal TÜMER

Article | 2020 | MANAS Journal of Engineering (MJEN)8 ( 1 )

As the population increases, is more and more increasing the number of vehicles in cities. The increasing number of vehicle make traffic management complicated. Difficult traffic management leads to more fuel consumption, CO2 and other harmful emissions. Therefore, real-time optimization of traffic lights (signaling) used in traffic management can make traffic management more efficient. In this study, green light time is optimized by estimating the number of vehicles in an intersection with signal lights in Konya city center through artificial neural network. The results are evaluated with different performance criteria and it has b . . .een shown that the developed estimation model can be successfully used to optimize the green light durations More less

Mustafa Haluk ÇELİK | Mahmut DURMAZ

Article | 2012 | Contemporary Engineering Sciences5 ( 6 )

In this study, it was tried to obtain bearing concrete by using the pumice and perlite aggregates in certain proportions. Different cement dosages were used in every mixture poured with portland cement and portland composite cement, the 60% pumice and 40% perlite aggregates of which were kept stable. The silica fume was added as much as 10% of cement amount in mixture. Mixtures from 200 to 500 doses were made and poured with every type of cement. The prepared samples left to water cure and their 7 and 28 days compressive strengths were determined. The test results indicated that the mixtures poured with portland cement has a higher . . .compressive strength than those poured with portland composite strength. While the concretes poured with portland composite cement up to 500 doses can be used only insulation, the concretes poured with portland cement at 450 doses and above show the characteristics of side bearing concrete. – Keywords: perlite, pumice, concrete, portland cement, composite cement, compressive strength, silica fum More less

Tahir GÖNEN

Article | 2018 | Arabian Journal for Science and Engineering43 ( 10 )

This paper introduces an experimental research about the influences of the curing type on accelerated carbonation, capillary water absorption and permeability of a range of different self-compacting lightweight concrete (SCLC) mixtures in comparison with those of chosen conventional vibrated lightweight concrete (LC) and self-compacting concrete (SCC). Seven different concrete compositions are considered: four SCLC, two SCC and one LC mixtures. All of the SCLC mixtures and one of the SCC and one LC mixture with a constant powder dosage of 550 kg/m(3) was designed to be containing 440 kg/m(3) of cement and 110 kg/m(3) of fly ash. The . . . other SCC mix was designed to have lower cement dosage for similar strength characteristic. Basaltic pumice aggregate of the SCLC was replaced with expanded perlite aggregate by 10, 20 and 30%. All mixtures were cured by two different curing types. Among the permeability properties of the samples, permeability, capillary water absorption and carbonation properties were measured. The results showed that the production of SCLC mixture as the result of the use of basaltic pumice and expanded perlite seems to be possible. The density of SCLC with basaltic pumice and expanded perlite was about 1900 kg/m(3), while the density of SCC was 2300 kg/m(3). Generally, permeation properties of SCLC such as carbonation and capillary water absorption got worse, since the porous aggregate was used. However, SCLC's compressive strength per density was more efficient than SCC's More less

Hüseyin ÖĞÜT

Article | 2018 | International Journal of Automotive Engineering and Technologies7 ( 4 )

In this study, linseed oil was obtained with the aid of screw presses and linseed oil biodiesel (B100) (linseed oil methyl ester) production was performed by transesterification method. Linseed biodiesel was blended with regular diesel fuel at different ratios as B2 (98% diesel + 2% biodiesel), B5 (95% diesel + 5% biodiesel), B20 (80% diesel + 20% biodiesel), B50 (50% diesel + 50% biodiesel). Fuel properties tests were performed on all fuels. Results revealed that engine performance values of linseed biodiesel and fuel blends were similar with the standard diesel fuel. With regard to maximum torque, while the highest value was obtai . . .ned as about 59.6 Nm at 1000 rpm with diesel fuel, the value was observed as about 53.8 Nm at 1200 1/min with B100 fuels. The highest maximum power output was recorded as approximately 10.96 kW at 2100 rpm with diesel fuel and as approximately 10.23 kW at 2000 rpm with B100 fuels. With regard to minimum specific fuel consumption, while the lowest value was measured as about 231.36 g/kWh at 1000 rpm with diesel fuel, the value was measured as about 296.73 g/kWh at 1200 rpm with B100 fuels. Exhaust emissions are generally improved by the addition of linseed biodiesel to diesel fuel More less

Hüseyin ÖĞÜT

Article | 2017 | Renewable Energy103

In this study, biodiesel was produced from safflower seeds by converting the raw oil obtained through dampening them via the rolling process, roasting at 90 °C and pressing into Safflower Oil Methyl Esther (Safflower Biodiesel) using the trans-esterification method. Experimental fuels were obtained in the forms of D100, B2.5M2.5D95, B5M5D90, B5M2.5D92.5 and B2.5M5D92.5 by mixing the biodiesel fuel obtained from safflower with diesel fuel, adding bio-ethanol at the rates of 2.5% and 5%, and volumetrically in inverse ratio. Tests were conducted to determine the fuel properties of the mixed fuels obtained and the diesel fuel, their kin . . .ematic viscosity, density, water content, pH level, caloric value, flash point, clouding, pour and freezing points, copper bar corrosion test, iodine number, CFPP (Cold Filter Plugging Point) test and cetane number. Moreover, the mixtures obtained and the diesel fuel were tried and examined in a water-cooled, four-stroke, single cylinder diesel engine that had a direct injection fuel system. As a result of the experiments, performance characteristics of the test engine were obtained. Exhaust emission values (CO, CO2, HC, O2, SO2, NOx) were obtained from the exhaust stack of the test engine using the probe of the gas analysis device. - Keywords: Safflower; Safflower biodiesel-bio-ethanol-diesel fuel mixtures; Bio-ethanol; Exhaust emissions; Engine performanc More less