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Öğe Investigation of mechanical properties of composites obtained from textile wastes(Batman Üniversitesi, 2022-07-02) Adin, Mehmet ŞükrüThe textile industry is one of the manufacturing sectors that pollutes the world the most. Since textile wastes are destroyed by burning traditionally, they cause great damage to the environment. Therefore, recycling of these wastes is of great importance. One of these recycling methods is their use in the production of composite materials, the application areas of which have increased in recent years. In this study, the mechanical properties of composite materials produced using cotton and polyester fabrics from waste textiles were investigated. It has been observed that 22% of the composite materials produced with reinforcement elements at different angles (0°, 45°, 90°) are reinforcement elements and 78% are resins. As a result of the tensile tests, the highest tensile strength value was obtained with the polyester fabric with 0° reinforcement angle as 55.72 MPa. It has been found that the increase in the reinforcement angles positively affects the tensile strength in cotton fabric reinforced composites, whereas this situation occurs in the opposite way in polyester fabric reinforced composites. When the highest tensile strength values of polyester fabric and cotton fabric reinforced composite samples were compared, it was seen that the sample using polyester fabric (55.72 MPa) had 69% higher tensile strength than the sample using cotton fabric (33.05 MPa). In addition, the elongation values of polyester fabric reinforced composites were higher than cotton fabric reinforced composites.Öğe Synthesis and characterization of hydrogen bonded 4-octyloxy benzoic acid/sebacic acid binary liquid crystal complex(Bitlis Eren Üniversitesi, 2017) Okumuş, Mustafa; Sünkür, MuratIn this study, the binary liquid crystal complex system was synthesized from mesogenic 4-octyloxy benzoic acid (8BAO) and non-mesogenic sebacic acid (SEA) chemical compounds. The thermal and microstructural properties of the synthesized 8BAO/SEA binary liquid crystal complex system were investigated by differential scanning calorimeter (DSC) and polarized optical microscopy (POM). The formation of the hydrogen bond between the 8BAO and SEA compounds was confirmed by Fourier Transformed Infrared spectroscopy (FTIR) assays. The DSC and POM results showed that the 8BAO/SEA binary complex exhibited liquid crystalline properties due to the hydrogen bonds formed. The 8BAO/SEA binary liquid crystal complex showed four phase transition peak indicating Cr↔SmG↔SmC↔N↔I phase sequence during continuous heating and cooling by DSC. This phase sequence has also been confirmed by POM observations. Furthermore, the effect of the heating rate on the phase transition temperature and enthalpy change values was investigated, and as the heating rate increased, the phase transition temperature and enthalpy values generally increased. Additionally, the thermal stability factor and the phase transition order parameter were calculated and the phase transitions were found to be regular.Öğe Investigation of optimal MIG welding parameters and energy consumption for Invar alloys(Batman Üniversitesi, 2022-07-02) Adin, Mehmet ŞükrüInvar alloys are materials used in aviation and aerospace industries to make precision components and test equipment due to their excellent coefficient of thermal expansion. Therefore, the diversity of the joining methods of these materials and their joint strength have gained importance. In the presented study, the optimum welding parameters required for the minimum use of energy consumed during MIG welding of Invar alloy materials and for the joints to have the highest tensile strength were investigated. The lowest tensile strength was found to be 375 MPa at 15 mm/s welding speed and 6 mm/s wire feeding speed, and the highest tensile strength was 405 MPa at 20 mm/s welding speed and 18 mm/s wire feed. It has been understood that the power consumed for joining Invar alloy bars generally increases in direct proportion to the parameter increases up to 20 mm/s welding speed. It was observed that the lowest consumed power value was 1.61 kW with 15 mm/s welding speed and 6 mm/s wire feeding speed, while the highest consumed power value was 3.93 kW with 25mm/s welding speed and 18 mm/s wire feeding speed. It has been understood that an average of 38% energy savings can be achieved thanks to the optimum parameters obtained.Öğe Electrical characteristics of the Al/Congo Red (CR)/p-Si semiconductor diodes(Dumlupınar Üniversitesi, 2015-05) Güllü, Ömer; Pakma, Osman; Turut, Abdulmecit; Arsel, İsmailIn this work, we have studied the electrical characteristics of the Al/CR/p-Si MIS Schottky structures formed by coating of the organic material directly on p-Si substrate. It has been seen that the CR thin film on the p-Si substrate has indicated a good rectifying behavior. The barrier height and the ideality factor of the device have been calculated from the I-V characteristic. We have also studied the suitability and possibility of the MIS diodes for use in barrier modification of Si MS diodes. In addition, we have compared the parameters of the Al/CR/p-Si MIS Schottky diodes with those of conventional Al/p-Si MS diodes. We have observed that the b value of 0.77 eV obtained for the Al/CR/p-Si device was significantly larger than BH value of the conventional Al/p-Si MS contact. Thus, the modification of the interfacial potential barrier for metal/Si diodes has been achieved by using the CR organic interlayer. This was attributed to the fact that the CR interlayer increased the effective b by influencing the space charge region of Si. The interface-state density of the MIS diode was found to vary from 1.24×1013 eV-1 cm-2 to 2.44×1012 eV-1 cm-2.Öğe Investigation of the most suitable drilling parameters and power consumption for energy saving(Batman Üniversitesi, 2022-07-02) Adin, Mehmet ŞükrüDue to the continuous increase in the cost of energy used in the manufacturing industry, the cost of the product is also increasing. Therefore, studies that do not affect product quality and save energy gain importance. For this purpose, in this study, the minimum amount of energy required to obtain the best hole surface quality was investigated by blind drilling of the AISI 4140 workpiece with a 5.2 mm diameter AISI M2 HSS drill at different spindle speeds (1000, 2000, 3000 rev/min) and different feed rates (150, 200, 250 mm/min). When the effects of drilling parameters on the surface roughness were examined, it was understood that it tended to decrease depending on the increase in the number of revolutions, and increased depending on the increase in the feed rate. It has been understood that the power required (consumed) of the CNC vertical machining center to open blind holes on the workpiece increases in direct proportion to the increase in cutting and feed rate. It was found that 3000 rpm and 150 mm/min feed rate were the most suitable machining parameters for the lowest surface roughness and the required optimum power value was 3.14 watts. As a result of the study, it has been understood that at least 11% energy saving can be achieved thanks to the determined parameters and optimum power value.Öğe Forecasting and analyzing the dynamics of the outbreak in Hubei and Turkey(Bilim Akademisi, 2020) Aslan, İbrahim Halil; Demir, Mahir; Wise, Michael Morgan; Lenhart, SuzanneAs the pandemic of Coronavirus Disease 2019 (COVID-19) rages throughout the world, accurate modeling of the dynamics thereof is essential. However, since the availability and quality of data varies dramatically from region to region, accurate modeling directly from a global perspective is difficult, if not altogether impossible. Nevertheless, via local data collected by certain regions, it is possible to develop accurate local prediction tools, which may be coupled to develop global models. In this study, we analyze the dynamics of local outbreaks of COVID-19 via a coupled system of ordinary differential equations (ODEs). Utilizing the large amount of data available from the ebbing outbreak in Hubei, China as a testbed, we estimate the basic reproductive number, R0 of COVID-19 and predict the total cases, total deaths, and other features of the Hubei outbreak with a high level of accuracy. Through numerical experiments, we observe the effects of quarantine, social distancing, and COVID-19 testing on the dynamics of the outbreak. Using knowledge gleaned from the Hubei outbreak, we apply our model to analyze the dynamics of outbreak in Turkey. We provide forecasts for the peak of the outbreak and the total number of cases/deaths in Turkey, for varying levels of social distancing, quarantine, and COVID-19 testingÖğe Determination of thermal ınsulation properties of lightweight building materials using artificial neural network for energy efficient buildings(Muğla Sıtkı Koçman Üniversitesi, 2015) Oktay, Hasan; Fidan, Şehmus; Polat, SüleymanÖğe I V characteristics of the orange G P type silicon contacts(Dumlupınar Üniversitesi, 2015) Güllü, Ömer; Arsel, İsmail; Pakma, Osman; Özaydın, Cihat; Turut, AbdülmecitÖğe On some maps with P and Q properties in non normal cone metric spaces(TOBB Ekonomi ve Teknoloji Üniversitesi, 2010) Bozkurt, Hacer; Öztürk, Mahpeyker; Başarır, MetinÖğe Investigation of optimum friction welding parameters and energy consumption for Ramor 500 and AISI 420 steels(Batman Üniversitesi, 2022-07-02) Adin, Mehmet ŞükrüRamor steels are widely used materials in the defence and automotive industries due to their superior strength to high-speed impacts. However, many problems are encountered during the use of traditional fusion welds, which are applied to join these steel types with dissimilar metal materials. Therefore, in recent years, friction welding known as solid state welding method has attracted attention instead of traditional melting welding. In this experimental study, the effects of different welding parameters applied during friction welding of Ramor 500 and AISI 420 rod materials on the tensile strength of the joints were examined and the most suitable welding parameters were investigated. In addition, the optimum power requirement for energy saving has been examined. It was found that the lowest tensile strength was 575 MPa for 5 seconds friction time and 45 MPa friction pressure parameters, while the highest tensile strength was 633 MPa for 7 seconds friction time and 55 MPa friction pressure parameters. It was observed that the lowest consumed power was 1.44 kW at 5 seconds friction time and 45 MPa friction pressure, while the highest consumed power was 2.45 kW at 9 seconds friction time and 55 MPa friction pressure. Thanks to the obtained data, the optimum power requirement was determined and 10% energy saving was achieved.