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This study was performed to determine the effects of the densification process and glue type in wood material on dowel tensile performance. For this purpose, 8 mm and 10 mm diameter dowels were obtained from black poplar (Populus nigra) and Eastern spruce (Picea orientalis L.), which were densified at 50% and 75% ratios. The dowels were bonded with PVAc and D-VTKA glue separately after drilling 18 mm deep holes in the edge of the melamine-coated particleboard. The tensile performance test was determined with the Universal test device according to TS 2475 and ASTM-D 1035 principles. As a result, Eastern spruce wood had the highest tensile performance (kg/cm2), and poplar wood had the lowest (173.66). For the dowel diameter parameter, the highest value (195.11) was found at 8 mm in diameter and the lowest value (161.05) was found at 10 mm in diameter. In terms of glue type, the highest value (185.92) was seen at PVAc while the lowest value (170.24) was seen at D-VTKA. And for the densification ratios, the highest value (191.4) was determined at 75%, while the lowest value was found in control samples at (167.4). According to the wood species, densification ratio, dowel diameter and glue type interaction, the highest value was determined at Es + d75% + 10mm + PVAc as (303.5) and the lowest value was found at P + d50% + 10mm + Dv as (110). As a result, where the dowel's high tensile performance is sought, using a 10 mm diameter dowel made from 75% densified spruce wood with PVAc glue may be advantageous.

In this study, the fuel characteristics of biodiesel produced from jojoba [Simmondsia chinensis (Link) Schneider] oil and biodiesel obtained from the jojoba oil procured under laboratory conditions were compared. For this purpose, jojoba seed endosperm and oil, which was attained from the jojoba endosperm calli via soxhlet extraction, was obtained. Biodiesel was produced from this oil via the transesterification method. It was determined that the fuel characteristics of the biodiesels produced from the oil procured under the laboratory conditions and the oil attained from the seeds were close to each other, and it was observed that the other features were in parallel with the standards, except for the viscosity and freeze point. This research study offers a solution for the raw material problem, which is one of the most important obstacles against the widespread use of biodiesel, in terms of environmental and economic aspects.

With the improvement of lithium-ion battery (LIB) technology, safety is becoming increasingly urgent topic for battery electric vehicles (BEVs). Short circuits, overcharging, high temperatures and overheating can cause thermal runaway reactions and the release of the flammable electrolyte which makes fire suppression very difficult. This study focuses on the mechanism of thermal runaway and fire suppression applications of LIBs. In order to understand this, 10 experiments were carried out. The experiments were divided into as Exp. A and Exp. B. A manual water suppression system was used in Exp. A and an automatic boron-based suppression system (AUT-BOR) was used in Exp. B. LIBs were heated in a controlled manner with a heat source and the effects of thermal runaway and fire suppression were observed. In Exp. A, a large amount of water was required to extinguish the LIB fires. The holes and slits which formed in the LIB after a fire were useful for injecting water. A projectile effect of cylindrical cells was observed in Exp. A. The Exp. B results showed that AUT-BOR mitigates risks effectively and safely. Also, AUT-BOR provides an early fire warning system and spot cooling to prevent thermal runaway reactions while localizing and suppressing the fire. In Exp. B, fire detection and suppression occurred without any explosion.

COVİD-19 salgını ilk olarak 31 Aralık 2019 tarihinde Çin hükümetinin Dünya Sağlık Örgütüne bildirmesiyle kamuoyunun gündemine geldi, Küresel olarak 3,4 milyondan fazla teyit edilmiş vaka ve 86 binden fazla ölüm vakasına neden oldu (5 Mayıs 2020 itibariyle). Covid-19 dünya ekonomisini etkilediğinden dolayı küresel bir konu haline gelmiştir. Bu çalışma mevcut raporları kullanarak salgının Dünya ekonomisine ve Türkiye’nin tedarik zincirine etkisini analiz eden bir inceleme makalesidir. Sonuç olarak Salgının diğer ülke ekonomileri gibi Türkiye ekonomisini de kötü yönde etkileyeceği ama Türkiye virüsün yayılmasını kısa vadede engelleyebilirse tedarik zincirinde yaşanan aksaklıkları doğru stratejiler kullanarak fırsata çevirebileceği sonucuna varılmıştır.

Unmanned air vehicles (UAVs) are used successfully in many different fields mainly various military and civilian applications. Recently electric powered UAVs have become more preferable due to their better accessibility, cost, transportation and silence. However, the batteries used in electric UAVs still do not have enough energy density for long endurance flights. Due to the difficulty of using piston and gas turbine engines in small-sized UAVs, hydrogen fuel cells are seen as one of the considerable options to increase endurance and range. In this study, conceptual design of hybrid UAV including fuel cell, solar unit and battery is presented. Small, light and high endurance UAV was designed using aerodynamic calculations and minimum power requirement for cruise flight was determined. 100 W fuel cell produced by Horizon Fuel Cell Technologies and 3S, 5 Ah of battery were used for main power supplies, moreover solar cells to charge the battery were designed to mount on the surface of the wings. Also, a new power management system is designed for switching between the energy sources. As a result of this work, it is determined that fuel cells and solar units are the significant options which can increase the endurance of UAV up to 8 times depending on the design, solar flux, hydrogen capacity etc.

Additive manufacturing (AM) is a novel manufacturing technology group that revolutionizes the design and production processes behind material production. This approach is used in a wide range from simple prototypes to direct parts manufacturing in different industries such as aviation, automotive, energy, biomedical, and bioengineering. Stereolithography (SLA), fused deposition modeling, selective laser sintering, laser metal deposition approaches are the most widespread AM methods. SLA method is one of the most attractive approaches in the AM field as high-dimensional sensitivity is achieved by using liquid photosensitive resin and laser light. However, although it is possible to manufacture complex-shaped three-dimensional (3D) polymer structures with the SLA approach, the mechanical, thermal, and electrical properties are not at the desired levels. To develop more functional 3D polymer materials, various additives are dispersed into polymer structures such as metal nanoparticles, inorganic particles, fibre, carbon nanotube, and nanoclay. Titanium dioxide (TiO2) nanoparticles are a very appealing type of additive among these additives owing to their superior mechanical properties. In this study, the photosensitive resin was mixed with four different TiO2 nanoparticle concentrations (pure, 0.25, 0.5, and 1% reinforced). These slurries were then placed in the SLA device, and 3D polymer structures were fabricated. Scanning electron microscope (SEM), thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), tensile tests, and Charpy impact tests were carried out to characterize mechanical, thermal, and morphological properties of developed polymer materials. It was observed that the particle size was below 1 µm and some agglomerations occurred. The elasticity modulus of the 0.5% TiO2 nanoparticle reinforced sample was measured as 694 MPa and was found to be approximately 20% higher than the pure polymer sample. In addition, polymer structures exhibited more brittle behavior. It was noted that 5% weight loss was experienced at 337 °C in all samples. Besides, the existence of unreacted carbon–carbon bonds was proven by the DSC analysis.

Yeni bir kavram olan lovemark ve kurumsal kimlik inşa etmek birçok firma için önemli bir kavramdır. Lovemark tüketicinin psikolojik etkenler doğrultusunda kurumla ilişki kurduğunu öne süren bir kavramdır. Kurum kimliğini konumlan-dırmada müşteri ile duygusal bağ kuran firmalar tüketicinin satın alma davranışını şekillendirmede psikolojik etkenlere başvurmaktadır. Firmalar tüketici ile duygusal bir bağ kurarak hem satın alma davranışı gerçekleştirmeyi hem de satın alma davranışının tekrarını sağlamayı amaçlamaktadır. Bu araştırmanın amacı ise firmaların lovemark olarak kurumsal kimliklerini nasıl konumlandırdıklarının analiz edilmesidir. Bu kapsamda Mediacat’in 2018 yılında açıkladığı lovemark firmalarından beyaz eşya ve otomobil sektöründe faaliyet gösteren 16 firmaya ait 160 adet reklam filmi incelenmiştir. Her firma için rastgele örneklem yöntemiyle seçilen on reklam filmi içerik çözümlemesi yöntemiyle analize tabi tutulmuştur. Reklam filmlerinde, kurumsal kimlik, sıra dışılık, tutku ve bağlılık boyutları ve bu boyutların birbirleri ile olan ilişkisi irdelenmiştir. Elde edilen bulgulara göre araştırmaya dahil olan firmalar, Volkswagen, Bmw, Mercedes, Renault, Ford, Fiat, Toyota, Audi ve Hyundai otomobil segmentinde; Arçelik ,Bosch, Beko ,Vestel, Samsung ,Siemens, Profilo beyaz eşya segmentinde değerlendirilmiştir. Elde edilen bulgularda firmaların reklam filmi yaratırken başta aşk, haz, güven, gibi duygusal kavramlarla satın alma davranışı için ikna edilmeye çalışıldığı gözlemlenmiştir., Lovemark, as a new concept is an important for many companies when building corporate identity. Lovemark is a concept suggestings that the consumer has a relationship with the institution in accordance with psychological factors. Companies that establish an emotional connection with the customer in positioning the corporate identity resort to psychological factors in shaping the consumer's purchasing behavior. Companies aim to achieve both purchasing behavior and repetition of purchasing behavior by creating an emotional connection with the consumer. The aim of this research is to analyze how companies position their corporate identities as lovemark. In this context, 160 advertising films belonging to 16 companies operating in the white household goods and automobile sectorfrom lovemark companies announced by Mediacat in 2018 were examined. Ten adverti-sing films selected by random sampling method for each company were analyzed by content analysis method. In advertising films, the dimensions of corporate iden-tity, uniqueness, passion and commitment and the relationship of these dimensions with each other were examined. According to the results obtained, the companies, Volkswagen, Bmw, Mercedes, Renault, Ford, Fiat, Toyota, Audi and Hyundai involved in the research were evaluated to be in the car segment; Arçelik, Bosch, Beko, Vestel, Samsung, Siemens, Profilo as white goods segment. In the results ob-tained, it was observed that companies try to convince them firms to buy behavior with emotional concepts such as love,pleasure,trust, when creating advertising films.

Bu çalışmada farklı güç parametrelerinde lazer kaynağı ile birleştirilen HSLA300 sac malzemelerin bükülme operasyonu sonrası geri esneme davranışına etki eden parametreler deneysel araştırılmıştır. Kaynak parametresi olarak kaynak gücü (1300, 1400 ve 1500 watt), proses parametresi olarak da kalıp açısı (15, 30, 45, 60 ve 75 derece) ve ütüleme süresi (0, 10 ve 20 saniye) deney parametreleri olarak belirlenmiştir. Kaynaklı numunelerde kaynak bölgesindeki ani soğumaya bağlı olarak yüksek miktarda martenzit fazı gözlemlenmiştir. Ancak kaynak gücünün artmasıyla birlikte HSLA yapısındaki karbon ve mangan miktarının az olmasından dolayı sertlik miktarında ve geri esneme açısında azalma meydana gelmiştir. Deneysel çalışmalarda da lazer kaynak gücünün 100 watt artmasıyla geri esneme açısının ortalama 0,15 derece azaldığı gözlenmiştir. Kalıp açısındaki 15 dereceden 45 derece açıya kadar olan artışın bükme operasyonlarında geri esneme açısını ortalama 0,14 derece arttırdığı, 45 derece açıdan 75 derece açıya kadar artışın bükme operasyonlarında geri esneme açısını ortalama 0,52 derece azalttığı gözlemlenmiştir. Ütüleme süresinin 10 saniye artmasıyla geri esneme açısının ortalama 0,14 derece azaldığı belirlenmiştir., In this study, the parameters that affect the springback behavior of HSLA300 sheet materials bonded with laser welding at different power parameters were investigated experimentally. Welding parameters (1300, 1400 and 1500 watts), die angle (15, 30, 45, 60 and 75 degrees) and holding time (0, 10 and 20 seconds) were determined as test parameters. A high amount of martensite phase was observed in welded samples due to sudden cooling in the weld zone. However, as the welding power increased, the amount of carbon and manganese in the HSLA structure was reduced, resulting in a decrease in the hardness amount and the bending angle. In experimental studies, it was observed that the springback angle decreased by 0.15 degrees with an increase of 100 watts of laser welding power. It has been observed that the increase in the die angle from 15 degrees to 45 degrees increases the bending angle in the bending operations by an average of 0.14 degrees. It was determined that the springback angle decreased by 0.14 degrees with an increase of 10 seconds holding time.

Teknolojik gelişmeler arasında üç boyutlu yazıcılar, gelecek için barındırdığı potansiyeller bakımından öne çıkan başlıklardan biri olmaktadır. Çalışmada, mobilya sektöründe üç boyutlu yazıcılarla tasarım ve yeni nesil teknolojilerle malzeme kullanımının yenilikçi mobilya tasarımlarına yönelik genel bir bakış sağlamak amaçlanmıştır. Çalışmanın içeriğinde, üç boyutlu yazıcıların günümüz çalışma prensipleri, mobilya sektöründe kullanılma olanakları, kullanılan malzemeler ve hammaddeler ile mobilya tasarım örnekleri açıklanmaktadır. Üç boyutlu yazıcılar, yeni nesil malzemeler, tasarımcıdan üreticiye ve kullanıcıya kadar sunduğu kolaylıklar, alternatifler ve yeniliklerle mobilya tasarım sektöründe gelecek için önemli potansiyeller taşımaktadır.

Yakın gelecekte petrol rezervlerinin tükeneceği öngörülmemektedir, fakat hidrokarbon kökenli yakıtların kullanılması canlılar için sağlığa olumsuz etki eden emisyonlar oluşturmaktadır. Bu nedenle dünya genelinde yenilenebilir, alternatif ve temiz enerji kaynaklarına yönelim söz konusu olmaktadır. Yakıt pilleri, sessiz ve verimli çalışabilen, aynı zamanda zararlı emisyonları olmayan bir elektrik üretecidir. Ticari uygulamaları da bulunan yakıt pilleri, havacılık, otomotiv, askeri, denizaltı yerel ve mobil uygulamalarda kullanılabilmektedir. Bu da kapsamlı bir uygulama alanı olduğunun göstergesidir. Bu çalışmada yakıt pili tiplerinden PEM yakıt pilleri araştırma konusu olarak seçilmiş ve PEM yakıt pili bileşenlerinden bipolar plakaların üretim teknikleri ele alınmıştır. Geleneksel ve yenilikçi üretim tekniklerinin araştırıldığı bu çalışmada, üretim trendinin ne aşamada olduğu tartışılmış ve konunun gelecek perspektifi göz önünde bulundurularak yapılan araştırmalar değerlendirilmiştir.

Temiz ve alternatif enerji arayışı, insanlığın sürekli artan enerji talebini karşılama doğrultusunda artış göstermektedir. Yakıt pilleri, yakıtın kimyasal enerjisini kullanarak doğrudan elektriğe dönüştüren yüksek verimli enerji dönüşüm sistemleridir. Klasik elektrik enerjisi üretim çevriminde yakıt önce yakılarak ısı enerjisi elde edilmekte, ardından buhar etkisi ile türbin döndürülmekte, jeneratörde akım elde edilmekte ve depolanmaktadır. Bu enerji dönüşümü oldukça karmaşık ve çok makineli bir sistem gerektirirken, her enerji dönüşümünde enerji kayıpları da meydana gelmektedir. Yakıt pillerinde ise sadece yakıtın elektronlarını devreden geçirerek yüksek elektriksel verimle enerji elde edilmektedir. Bu çalışmada yakıt pili çeşitlerinden PEM yakıt pilleri ele alınarak, PEM yakıt pillerinde kullanılan bipolar plakaların akış alanları incelenmiştir. Literatürde nümerik çalışmalar da bulunmakla birlikte, yakıt pillerinin oldukça değişken çalışma şartlarından dolayı deneysel olarak test etmek büyük önem arz etmektedir. Bu nedenle son on yılda yapılmış olan deneysel çalışmalar, yöntemleriyle sunulmuştur. Günümüzde çok popüler bazı akış kanalları verilmekle beraber, akış kanallarını birbirleriyle karşılaştırma yöntemiyle üstünlüğün belirlendiği anlaşılmış ve günümüzde hala optimum akış kanalına ulaşılamadığı gözlemlenmiştir.

Stereolithography (SLA) is one of the most attractive methods in additive manufacturing approaches since obtained high dimensional sensitivity using liquid photosensitive resin and laser light. In this study, 3D polymer materials were fabricated by SLA device, and the ultraviolet post-curing process was applied at different durations (30, 60, 180, and 300 min) to investigate the effect of post-curing time on mechanical (tensile, Charpy impact tests) and thermal (DSC) properties of polymer materials. Elasticity Modulus value of post-cured polymer materials was increased by approximately 49% and achieved the level of 63.71 MPa. It was shown with the results of DSC analysis that the post-curing processes with the 180 min. and above is adequate since the carbon-carbon double bonds occurred., Sıvı fotoduyarlı reçine ve lazer ışığı kullanılarak yüksek boyutsal hassasiyetin elde edildiği Stereolitografi (SLA) yöntemi, eklemeli imalat yöntemleri arasında en dikkat çeken tekniklerden birisi olmuştur. Bu çalışmada, SLA cihazı kullanılarak 3B polimer parçalar basılmış, ikincil kürleme süresinin polimer yapıların mekanik (çekme testi, çentik darbe testi) ve termal (diferansiyel taramalı kalorimetre (DSC) analizi) özelliklerine etkisini incelemek için farklı sürelerde (30, 60, 180 ve 300 dk) UV ikincil kürleme işlemi uygulanmıştır. İşlem uygulanmış polimerlerin elastisite modülü değerinde yaklaşık %49’luk bir artış gerçekleşmiş ve 63,71 MPa mertebelerine ulaşılmıştır. DSC analiz sonuçları 180 dakika ve üzeri ikincil kürleme proseslerinin karbon-karbon çift bağlarının oluşması için yeterli olduğunu göstermektedir.

Developing technology, new technologies, and changing world standards have led researchers to search for new energy sources. In addition to countries such as America, Germany, and Japan, most automobile manufacturers have been able to adapt to changing standards, have done major researches on alternative energy vehicles, and have started to market their products. In this study, a prototype hydrogen vehicle was developed for TÜBİTAK Efficiency Challenge Electric Vehicle Organization. Design criteria were determined within the limits of the competition rule book. A computer-aided design (CAD) program was used in the vehicle shell and mechanical part designs. Vehicle flow analysis was carried out with the help of computational fluid dynamics (CFD) program. Laboratory condition long-term performance test of the fuel cell has been carried out and whether the fuel cell power was sufficient for the vehicle.

Selective Catalytic Reduction (SCR) is an emission control system used in diesel engines to reduce NOx emissions. In this study, synthesized of catalyst for SCR system was investigated as experimentally. For this purpose, silver nitrate (AgNO3), niobium (V) chloride (NbCl5) and tetra amine platinum (II) nitrate (Pt(NH3)4(NO3)2) were used to coat the cordierite (2Al2O3-5SiO2-2MgO) structure with impregnation method. X-ray Fluorescence (XRF), Scanning Electron Microscope (SEM) and Brunauer, Emmett, and Teller (BET) analyzes were carried out in order to determine the chemical and physical properties of the catalyst. Results showed that the coating materials penetrate the entire surface of the pores. It was also determined that the BET specific surface areas of the produced catalyst and cordierite are 0.2918 m2/g and 0.4568 m2/g, respectively. The reduction of surface area could be attributed to the increment of crystallization with chemical reactions occurred at the high sintering temperature. Besides, XRF analysis results demonstrated that content of Ag, Pt and Nb in the in the catalyst was found to be 3.67%, 0.19% and 0.12%, respectively, whereas Ag content in cordierite structure was 0.03%.&nbsp

Dizel motorlarin cevre kirliligindeki rolu cok buyuktur. Ne yazik ki, fosil yakitlarin yakilmasi hem iklim degisikligine yol acan global emisyonlari (CO2, N2O, CH4), hem de saglik acisindan olumsuz etkilere sahip olan ve dogal cevreye zarar veren bolgesel emisyonlari (PM, NOx, HC, CO, O3), beraberinde getirmektedir. Bu calismanin amaci emisyon seviyelerini dusurmek icin alternatif bir yol olarak yakitlara metal oksit esasli nano partikul katki maddesi ilave etmektir. Ayrica SCR sisteminde puskurtulen ure cozeltisi miktari degistirilerek ve ure cozeltisine %3 ve %5 oranlarinda amonyum sulfat (NH4)2SO4 eklenerek NOx emisyonlarini azaltma etkisi incelenmistir. Elde edilen neticeler sonrasinda egzoz emisyonlarini azaltmak icin uygun katki dozaj miktari tespit edilmis olup kullanilan nanopartikul katkilarinin NOx ve CO gibi zararli egzoz emisyon degerlerini azalttigi belirlenmistir.

Nowadays energy requirements have been rapidly growing due to increasing population and industrialization. Diesel engines have a huge role in environmental pollution. Harmful gas emissions increase along with energy consumption, therefore, new ways to restrict harmful gases and to take precautions are sought. In this study, MgO nanoparticle additive with extra oxygen content were used in diesel fuel in compression ignition engines, in order to monitor fuel properties, performance and emission values. Dosage of additive into diesel fuel were 25, 50 and 100 ppm and the optimum dosage of additives was determined in relation to decrease of NOx and CO emissions. Article DOI: https://dx.doi.org/10.20319/mijst.2017.33.7285 This work is licensed under the Creative Commons Attribution-Non-commercial 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.

Conventional fossil fuel sources face with scarcity risk. Therefore, researchers are trying to find new renewable alternative energy sources which have potential to replace conventional sources. Alcohol and biodiesel are prominent sources among others. In this study, performance and emission characteristics of a diesel fuel and ethanol added (20% vol.) diesel fuel (E20) operated compression ignition engine was studied in between 1000 - 2600 engine speed. Torque, power, specific fuel consumption curves as performance and carbon monoxide (CO), nitrogen oxides (NOx) curves as emission parameters with respect to engine speed were obtained. Energy and exergy efficiency curves versus engine speed in order to assess the system thermodynamically were also obtained. Results showed that, while torque, power, CO emission were decreased, specific fuel consumption, NOx emission were increased with use of diesel-ethanol blends. On the other hand, both energy and exergy efficiency values were decreased when alcohol was added to diesel fuel. Article DOI: https://dx.doi.org/10.20319/mijst.2017.33.5161 This work is licensed under the Creative Commons Attribution-Non-commercial 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.

In this study, emissions of compression ignition engine fueled by diesel fuel with nanoparticle additives was modeled by regression analysis, artificial neural network (ANN) and adaptive neuro fuzzy inference system (ANFIS) methods. Cetane number (CN) and engine speed (rpm) were selected as input parameters for estimation of carbon monoxide (CO), oxides of nitrogen (NOx), and carbon dioxide (CO2) emissions. The results of estimation techniques were compared with each other and they showed that regression analysis was not accurate enough for prediction. On the other hand, ANN and ANFIS modelling techniques gave more accurate results with respect to regression analysis; linear and non-linear. Especially ANFIS models can be suggested as estimation method with minimum error compared to experimental results.

Formability and springback behaviours of dual-phase 600 (DP600) sheet material bonded with laser welded in different power parameters were investigated experimentally. In the first stage of the study, springback behaviours of non-welded DP600 sheet material were investigated. In the next stage of the study, springback behaviours of DP600-DP600 samples, which were bonded with three different power parameters (1400 watts, 1500 watts, 1600 watts) by welding, were investigated by bending in V bending dies. Die angle (15, 30, 45, 60 and 75 degree) and holding time (0, 10 and 20 s.) were determined as process parameters in the study. In higher welding powers, it was observed that both the melting zone and the heat-affected zone were expanded. Then ferrite phases in these expanding zones have been transformed into martensite phase. This case provided to increase the stiffness and thereby improved the spring-capability. Because of increase hardness due to the increase in laser welding power, average springback angle of welded sheet increased by 5.72%. In addition die angle is one of the parameters that strongly change the springback angle. Negative springback was observed at the die angle of 15 degrees. It was found that the springback angle increased on an average of 57.2% as the die angle was increased from 30-degree to 45-degree. On the other hand, the springback angle decreased on an average of 18.7% as the die angle was increased from 45-degree to 75-degree. This case is due to the conglomerating of the stresses in a narrow space after a 45-degree die angle. Depending on the increase in holding time, the springback angle decreased by 10.05% because of an increase of residual stresses.

Noise is a very important phenomena for passenger comfort in a vehicle. Engine of the vehicles produce disturbing noises in different frequencies. In the application of acoustic, there are different filters to predict the sound pressure level and disturbing noises. The aim of the present study is to investigate the noise characteristic of a compression ignition engine at different weighting filters. In the experiments, the engine was fuelled with low sulphur diesel and sunflower biodiesel fuels and it run at different engine speeds ranging from 1200 to 2400 rpm, with steps of 300 rpm. The results indicated that noise characteristic of compression engine with engine speed shows different trends at A- weighting filter than C- and Z- weighting filters especially at 1500 rpm. Moreover, in the study, it was cleared that the SPL decrease with the addition of biodiesel fuel regardless of its ratio.

Katmanlı imalat teknolojisine olan ilgi son yıllarda artış göstermektedir. Katmanlı imalat tekniği, geleneksel imalat yöntemlerinin aksine malzeme eksiltme değil de, malzeme eklenmesi prensibine dayanmaktadır. Yüksek tasarım serbestliği, artık malzeme oluşmaması, kullanıcıya özel ürünlerin imal edilebilmesi, tasarımdan imalata geçiş süresinin düşük olması, hücresel yapılar ve optimum tasarımlar ile daha hafif ürün elde edilebilmesi katmanlı imalat tekniğinin avantajlarındandır. Bunun yanında katmanlı imalat tekniğinin bir takım dezavantajları da bulunmaktadır. Bunlardan bir tanesi katmanlı imalat ile üretilen ürünlerin boyutlarının sınırlı olmasıdır. Araştırmacılar bu problemi ortadan kaldırmak amacıyla katmanlı imalat tekniği ile üretilen metalik malzemeleri kaynak yöntemiyle birleştirerek çalışmalar yapmaktadır. Bu çalışmada lazer ergitme-sinterleme ve elektron ışını ergitme yöntemleri kullanılarak üretilen malzemelerin kaynak kabiliyetinin araştırıldığı çalışmalar derlenmiştir., The interest in additive manufacturing technology has increased in recent years. The additive manufacturing technique is based on the principle of adding material, not material reduction, as opposed to conventional manufacturing methods. High design freedom, no residual material, the manufacture of user-specific products, the low transition time from design to manufacturing, the ability to obtain lighter products with the cellular structures and optimum designs are among the advantages of the additive manufacturing technique. In addition, there are some disadvantages of the additive manufacturing technique. One of them is the limited size of the products produced by additive manufacturing. In order to eliminate this problem, researchers have been working by joining the metallic materials produced by the additive manufacturing technique with the welding method. In this study, studies on the welding ability of the materials produced by using laser melting-sintering and electron beam melting methods were collected.

Bu çalışmada sac metal malzemelerin oda sıcaklığında bükülerek şekillendirilmesi sonrası gözlenen ve şekillendirmede istenmeyen bir durum olan geri esneme davranışı deneysel olarak araştırılmıştır. Çalışmada DP600 ve HSLA300 sac malzemeler farklı kalıp açılarında ve ütüleme sürelerinde V bükme yöntemiyle şekillendirilmiştir. Çalışma sonunda ütüleme süresinin 10 saniye artmasıyla elastik gerilmelerin kalıcı gerilmelere dönüşmesinden dolayı geri esneme açısının DP600 sac malzemede ortalama %14,8, HSLA sac malzemede ise ortalama %9,7 azaldığı tespit edilmiştir. Kalıp açısının artmasıyla elastik gerilim miktarının da artmasından dolayı her iki malzemede de esneme açısının arttığı, açının büyümesiyle de elastik gerilmelerin dar bir alanda hapsolmasından dolayı da esnemenin daha sonra azaldığı belirlenmiştir. DP600 sac malzemede 15 derece kalıp açısından 45 derece kalıp açısına kadar esnemenin ortalama %15,2 arttığı, 45 dereceden sonra ise %27,6 azaldığı tespit edilmiştir. HSLA sac malzemede ise 15 derece kalıp açısından 30 derece kalıp açısına kadar esnemenin önce ortalama %10,4 arttığı, 30 dereceden sonra ise %26,4 azaldığı gözlenmiştir. Ayrıca DP600 sac malzemenin sertliğinin HSLA sac malzemeden daha yüksek olmasından dolayı oluşan geri esneme değerinin HSLA sac malzemeye göre %12,3 daha yüksek olduğu belirlenmiştir., The springback behaviour which is undesirable situation after the bending operation in room temperature was experimentally investigated. DP600 and HSLA sheet materials were formed by V-bending method in different bending angle and holding time. Due to transformation of elastic stress to permanent stress 10 second increasing in the holding time were caused to decrease in springback angle in 14.3% for DP600 and in 9.7% for HSLA sheets. Increasing the bending angle were caused to increase in springback angle both material due to increasing elastic stress. However, more increasing the bending angle were caused to decrease in springback angle both material due to summing of elastic stresses in narrow angle. In DP600 material, its observed that increasing the die angle from 15 degrees to 45 degrees were caused to 15.2% increase the springback angle but after the 45 die angle the springback angle decreased 27.6% degree. In HSLA300 material, its observed that increasing the die angle from 15 degrees to 30 degrees were caused to 10.4% increase the springback angle but after the 30 die angle the springback angle decreased 26.4% degree. In addition to, its determined that due to the higher hardness of DP600 sheet metal than HSLA sheet metal, the springback angle for DP600 higher 12.3% than HSLA 300 sheet material.

WOS: 000370306300103, Pilot diesel injection phenomenon consisted by gaseous fuels such as hydrogen and natural gas; ensure the way of exert fuels without any structural modification in compression ignition engines. This study investigates of using 30HCNG (Hydrogenated Compressed Natural Gas) fuel mixture on a non-modified diesel engine operated with diesel fuel replacement rate experimentally. HCNG was used as an additional fuel with air fumigation in a non-modified diesel engine via intake manifold and reduction of diesel fuel by dint of pilot injection. Reduction of diesel fuel was prepared as two different substitutions like 25 and 50% diesel replacement rates controlled by stepping motor devices. 30% Hydrogen and 70% CNG (Compressed Natural Gas) (by volumes) fuel mixture were tested in a 3.6 L, four cylinders, four stroke and water coolant diesel test engine between 1200 and 2600 rpms. Effects of these two different diesel reductions on engine performance and exhaust emissions parameters were compared and illustrated with graphics as brake power, brake torque, and brake specific fuel consumption; CO, CO2 and NOx. Brake thermal efficiency and a minor cost analyses were also performed. It was observed that, 30HCNG fuel mixture with 50% diesel replacement rate affect the engine performance as brake torque, brake power and BSCF values were decreased 4.3%, 8%, 26.8% respectively. Exhaust emission values of NOx and CO2 were decreased 47.2%, 16.7% respectively; however CO emission values were increased 8%. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved., TUBITAK (The Scientific and Technological Research Council of TURKEY) [114M798], This work is a part of a project under grant number "114M798" which is supported and funding by TUBITAK (The Scientific and Technological Research Council of TURKEY).

Injection behaviors of internal combustion engines are very substantial fact that provides developments to future strategies about optimizing the engine and fuel parameters. During the combustion process, pilot diesel injection technique is more preferable option while using alternative gas fuels in a diesel engine. In this experimental study, a 3.6 L commercial, four stroke, four cylinders and mechanical fuel pump non-modified diesel test engine operated with hydroxy (HHO) and compressed natural gas (CNG) fuel mixtures under 25% and 75% (vol/vol), respectively. Diesel fuel injection quantities were reduced with the help of steeping motor devices which mounted on mechanical fuel pump plunger pin. Sensitive removes of steeping motor, plunger pin twisted clockwise 360°, 720° and 1080°, respectively. Comparisons of engine performance and exhaust emissions were explained briefly and illustrated via graphs. As a result, 720° clockwise twisted pin is the optimum point for experimental fuel pump plunger while using 25HHOCNG fuel mixtures.

Ergime sicakligi yakin, ayni veya farkli turdeki malzemelerin ergitilerek birlestirilmesi islemi kaynak olarak tanimlanmaktadir. Lazer kaynagi yuksek enerji yogunluguna sahip bir isinla birlestirme islemi olup, kaynak enerjisi isik dalgalarinin konsantrasyonu ile saglanmaktadir. Lazer kaynagi; yuksek kaynak ilerleme hizi, cok dusuk isi girdisi, dar kaynak dikisi, kucuk isidan etkilenen bolge, otomasyona uygunluk, farkli malzemelerin basarili kaynagi ve farkli kalinliklari kaynatabilme ozellikleri gibi avantajlarindan dolayi son donemde ozellikle endustriyel imalat icin onem kazanmaktadir. Bu calismada cesitli sektorlerde sikca kullanilan ayni veya farkli turdeki sac malzemelerin lazer kaynagi ile birlestirilmesine ait calismalar derlenmistir.

This study was aimed at estimating the variation of several engine control parameters within the rotational speed-load map, using regression analysis and artificial neural network techniques. Duration of injection, specific fuel consumption, exhaust gas at turbine inlet, and within the catalytic converter brick were chosen as the output parameters for the models, while engine speed and brake mean effective pressure were selected as independent variables for prediction. Measurements were performed on a turbocharged direct injection spark ignition engine fueled with gasoline. A three-layer feed-forward structure and backpropagation algorithm was used for training the artificial neural network. It was concluded that this technique is capable of predicting engine parameters with better accuracy than linear and non-linear regression techniques. © 2017 Society of Thermal Engineers of Serbia.

Bu çalışma, uzun süreli minimal demokrasi deneyimine rağmen, demokratik derinleşme ve sağlamlaşmanın tamamlanamadığı ülkelerdeki reform süreçleri hakkında genelleştirilebilir bir açıklama arayışıyla yola çıkmaktadır. İktidarın, çok-partili seçimler yoluyla el değiştirmesi kuralının yerleştiği kimi ülkelerde; etkin, özgür ve adil katılım ve temsile engel teşkil eden bazı demokratik kusurlar varlığını sürdütmektedir. Yani, seçimli demokrasi, onlarca yıllık varlığına karşın, sağlamlaşmış bir liberal demokrasiye dönüşememektedir. Capoccia ve Ziblatt'ın (2010), kıyaslamalı demokratikleşme çalışmaları için sunduğu tarih odaklı analitik ve metodolojik çerçeveden ilham alan bu araştırma; Türkiye, Meksika ve Filipinler'deki uzatmalı demokratikleşme vakalarındaki başarılı ve başarısız reform girişimlerinin karşılaştırmalı tarihsel analizi üzerinden tümevarımsal bir izah ortaya koymaktadır. Bu çalışmanın bulguları ışığında, reformlara olanak tanıyan iki etken öne çıkmaktadır: aktörlerce, reform inisiyatiflerinin gündeme getirildiği bir fırsat penceresi; kurumsal değişikliği siyaseten temellendirmeye ve muhtemel rakiplere ve veto oyuncularına üstünlük sağlamaya olanak tanıyan bir birleştirici söylem. This study seeks to provide a generalizable explanation about democratic reform processes in countries where democratic deepening and consolidation could not be achieved despite a long term experience of minimal democracy. In some countries, although the multiparty elections have become the norm for the incumbent change, several democratic deficiencies which impede effective, free and fair representation and/or participation persist. As a result, the electoral democracy could not transform into a consolidated liberal democracy for decades. Inspired by Capoccia and Ziblatt's (2010) analytical and methodological framework for a historically minded approach to the comparative study of democratization, this study offers an inductive explanation for democratic reforms in minimal democracies, based on the comparative historical analysis of both successful and failed reform initiatives in three protracted democratization cases -i.e. Turkey, Mexico and the Philippines. The findings of the research suggest that a cohesive discourse -to politically justify the institutional change and win over the potential opponents and veto players- is necessary for the implementation of a reform agenda, after a window of opportunity opens. 341

In this study, hydroxy gas (HHO) was produced by the electrolysis process of different electrolytes (KOH (aq), NaOH (aq), NaCl (aq)) with various electrode designs in a leak proof plexiglass reactor (hydrogen generator). Hydroxy gas was used as a supplementary fuel in a four cylinder, four stroke, compression ignition (CI) engine without any modification and without need for storage tanks. Its effects on exhaust emissions and engine performance characteristics were investigated. Experiments showed that constant HHO flow rate at low engine speeds (under the critical speed of 1750 rpm for this experimental study), turned advantages of HHO system into disadvantages for engine torque, carbon monoxide (CO), hydrocarbon (HC) emissions and specific fuel consumption (SFC). Investigations demonstrated that HHO flow rate had to be diminished in relation to engine speed below 1750 rpm due to the long opening time of intake manifolds at low speeds. This caused excessive volume occupation of hydroxy in cylinders which prevented correct air to be taken into the combustion chambers and consequently, decreased volumetric efficiency was inevitable. Decreased volumetric efficiency influenced combustion efficiency which had negative effects on engine torque and exhaust emissions. Therefore, a hydroxy electronic control unit (HECU) was designed and manufactured to decrease HHO flow rate by decreasing voltage and current automatically by programming the data logger to compensate disadvantages of HHO gas on SFC, engine torque and exhaust emissions under engine speed of 1750 rpm. The flow rate of HHO gas was measured by using various amounts of KOH, NaOH, NaCl (catalysts). These catalysts were added into the water to diminish hydrogen and oxygen bonds and NaOH was specified as the most appropriate catalyst. It was observed that if the molality of NaOH in solution exceeded 1% by mass, electrical current supplied from the battery increased dramatically due to the too much reduction of electrical resistance. HHO system addition to the engine without any modification resulted in increasing engine torque output by an average of 19.1%, reducing CO emissions by an average of 13.5%, HC emissions by an average of 5% and SFC by an average of 14%. © 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

In this study, heat, noise and vibrations of 3-axle bus which was produced according to the American regulations were determined. Insulation designs were made according to heat levels, intensity of noise and vibration and frequency. Comfort conditions inside the bus and the American regulations outside the bus were provided. Heat sources of the bus were detected. Insulations which are able to prevent the heat generated by those sources to reach passenger cabin and other badly affected areas. Maps of noise and vibration of bus is determined, according to the intensity, wavelength and frequency of the noise, using these data more insulation designs were made to reach more comfortable and quieter bus.

5th International Conference on Transportation and Traffic Engineering, ICTTE 2016 --6 July 2016 through 10 July 2016 -- -- Reconstruction of traffic accidents has been so crucial scientific process in order to make impartial and judicious decisions. This study focuses on impact speed prediction of accident sufferers just before the collision in a comprehensive scientific way by using an accident reconstruction software called "vCrash" and Function Fitting Neural Network (FITNET) artificial intelligence method (predictor) in case of absence of skid marks or other clues about calculating impact speeds. A sample real world accident was simulated on the software several times by changing collision speeds to form different deformation on the collision regions of the vehicles in every simulation. Every single deformation amount corresponding to each impact velocity was recorded and used as teaching data for FITNET prediction model. Using 10-fold cross validation, mean squared error (MSE) and multiple correlation coefficients (R) were observed to exhibit performance of the prediction model. The model performed high R (close to 1) and acceptable MSE values. This method aims that, in a probable similar accident scene in future, it will be possible to analyze the impact speeds just by entering average deformation amounts into an application on a portable device at the accident scene without requirement of expensive reconstruction tools and it will be a guide for analysis of other accident types. © The Authors, published by EDP Sciences, 2016.

In this study, the turbulence filter, the phase averaging and the proper orthogonal decomposition methods are used to decompose experimentally measured turbulent velocity fields in an SI engine. The radial and circumferential turbulent velocity fields were measured using hot wire anemometer under motored conditions at different engine configurations. The decomposed results of each technique are compared with each other. In addition, the obtained organized and turbulence motions and their energy spectra are examined. Finally, coherent structures of velocity fields and their activities are investigated.

Accident reconstruction is a scientific study field that depends on analysis, research and drawing. Scientific reconstruction of related traffic accident on computer eliminates making decisions depending on initiative or experience of the expert and yields impartial decisions and evidences especially on events like matter for the courts or forensic investigations. In this study, data collected from accident scene (police reports, skid marks, deformation situation of involvements, crush depth etc.) were inserted properly into the software called “vCrash” which is able to simulate the accident scene in 2D and 3D. Then, 784 parameters, related to calculating Energy Equivalent Speed (EES) with a prediction error, were prepared according to several accidents. These parameters were also used as teaching data for the Multi-layer Feed Forward Neural Network (MFFNN) and Generalized Regression Neural Network (GRNN) models in order to predict EES values of involvements, which give idea about severity and dissipation of deformation energy corresponding to the observed vehicle residual crush, without requirement of performing simulation for probable accidents in future. Using 10-fold cross validation on the dataset, standard error of estimates (SEE) and multiple correlation coefficients (R)of both models are calculated. The GRNN-based model yields lower SEE whereas the MFFNN-based model yields higher R.Özet: Kaza yeniden analiz, araştırma ve çizim bağlıdır bilimsel bir çalışma alanıdır. Bilgisayardaki ilgili trafik kazası Bilimsel yeniden inisiyatifi veya bilirkişinin deneyimine bağlı olarak kararlar ortadan kaldırır ve özellikle mahkemeler veya adli soruşturma için madde gibi olaylara tarafsız kararlar ve delilleri verir. Bu çalışmada, veriler kaza sahnesi (polis raporlarında, kızak işaretleri, tutulumunun deformasyon durumuna vs. ezilme derinliği) 2D ve 3D kaza sahnesini taklit edebilen "vCrash" olarak adlandırılan yazılım içine düzgün bir şekilde yerleştirildi toplanan. Daha sonra, tahmin hatası Enerji eşdeğer Speed ​​(EES) hesaplanması ile ilgili 784 parametreleri, çeşitli kazalar göre hazırlandı. Bu parametreler İleri Sinir Ağı (MFFNN) ve Genelleştirilmiş Regresyon Sinir Ağı (GRYSA) yapılan ÇO şiddeti ve karşılık gelen deformasyon enerjisinin dağılımı konusunda fikir vermek bulguların EES değerlerini tahmin etmek için modeller Yem Çok katmanlı öğretim veri olarak kullanıldı Gelecekte muhtemel kazalara karşı simülasyon gerçekleştirme gereksinimi olmadan gözlenen araç artık ezmek. Veri kümesi üzerinde 10 kat çapraz doğrulama kullanarak, tahminler (GDA) ve her iki model çoklu korelasyon katsayılarının (R) standart hatası hesaplanır. MFFNN-tabanlı model yüksek R. verir, oysa GRNN-tabanlı model alt SEE verir.

European Biotechnology Congress -- MAY 16-18, 2013 -- Comenius Univ, Bratislava, SLOVAKIA WOS: 000323298100082 … European Biotechnol Themat Network Assoc (EBTNA), Comenius Univ, Fac Nat Sci

2nd EAI International Summit, Smart City 360 2016 --22 November 2016 through 24 November 2016 -- -- In the current study, a special mobile application was de-signed for the use of drivers, fleet managers and passengers of a smart city bus. In the driver section of the application, some properties of smart city bus can be controlled via mobile application. Driver can start/stop the vehicle, control the A/C system, preheater, lights, doors, horn etc of the bus by using this mobile application. In the fleet manager section, some of important vehicle parameters, like instantaneous/average fuel consumption, engine speed, vehicle speed, engine coolant temperature, brake lining thickness, fuel level in the tank, all error codes for engine, transmission, brake or any other system in the bus etc can be monitored by fleet manager via mobile application. In the Passenger section of the application, passengers can see esti-mated time of arrival for their station with the rate of fullness and real time position of the bus supplied by GPS. If passenger is inside the vehicle, passenger can connect to the media archive of the vehi-cle with Wi-Fi and watch videos or listen music. In the current study, system components, and software details of the application were discussed and explained.