Gasoline Direct Injection

Non

New Pre-Pottery Neolithic sites and cult centres in the Urfa Region

The present study assesses the sites and the corresponding artefacts that were recently discovered during cultural inventory studies in the Urfa region in south-eastern Turkey. The studies were conducted at PPN sites located at Herzo Tepe, Basaran Höyük and Kocanizam, Taslı Tepe and  ̇Inanlı Tepe within the borders of Viransehir and Siverek boroughs; the already known site at Sefer Tepe is also re-examined. The sites extend in a north-south direction and were founded within a 3–5km distance, and they exhibit unique characteristics for this region. Recently discovered sites are compared to already known PPN sites in the region to reveal similar features and characteristics. In particular, the article elaborates similarities and discrepancies between sites with T-shaped pillars and sites with circular structures. The recently discovered sites demonstrate that the pillar tradition is predominant in the region and that the settlements have a distinct layout.V študiji ovrednotimo najdišča in pripadajoče artefakte, ki so bili nedavno odkriti pri študijah kulturnih inventarjev v regiji Urfa na območju južno-vzhodne Turčije. Analize so bile opravljene na najdiščih predkeramičnega neolitika na območjih kot so Herzo Tepe, Basaran Höyük in Kocanizam, Taşlı Tepe in İnanli Tepe znotraj mestnih okrajev Viransehir in Siverek; ponovno smo preiskali tudi že znano najdišče Sefer Tepe. Najdišča se raztezajo v smeri sever-jug in so postavljena v razdalji od 3 do 5km, poleg tega pa izkazujejo edinstvene značilnosti za to območje. Nedavno odkrita najdišča primerjamo z že znanimi predkeramičnimi najdišči v regiji in na ta način ugotavljamo njihove podobnosti in značilnosti. V članku se podrobneje ukvarjamo s podobnostmi in razlikami med najdišči s stebri v obliki črke T in najdišči s krožnimi strukturami. Nedavno odkrita najdišča kažejo, da v tej regiji prevladuje tradicija stebrov in da imajo naselbine značilne prostorske ureditve

The effect of compression ratio in constant load and speed conditions on engine characteristics

İçten yanmalı motorlarda yakıt ekonomisi ve egzoz emisyonlarının iyileştirilmesi ile ilgili araştırmalar günümüzde yoğunlaşmıştır. İşletme parametrelerinin motor performansı üzerindeki olumlu etkisini artırmak için çalışmalar yapılmaktadır. Bu çalışmada motor performansını etkileyen en önemli parametrelerden biri olan sıkıştırma oranının motor gücü, yakıt ekonomisi ve egzoz emisyonlarına olan etkileri deneysel olarak incelenmiştir. Deneyler; buji ile ateşlemeli, tek silindirli, dört zamanlı, hava soğutmalı, sıkıştırma oranı 4/1 ile 10/1 arasında ayarlanabilen değişken sıkıştırma oranlı bir motorda yapılmıştır. Sabit kısmi yük ve hızda sıkıştırma oranının artması ile birlikte motor gücünde % 29 artma, özgül yakıt tüketiminde % 23 azalma elde edilmiştir. Ayrıca CO emisyonlarında % 20 düşme kaydedilirken HC misyonlarının % 38 oranında arttığı gözlenmiştir.Studies on improving fuel economy and exhaust emissions in the internal combustion engines have been gained more importance day by day. Currently, the improvements of the effects of operating variables on the engine performance have been researched. In this study, the important operating variable that is compression ratio affecting on engine power, fuel economy and exhaust emissions were investigated. For the experiments, spark ignited, single cylinder, air-cooled and four stroke variable compression ratio engine was used. This engine's compression ratio is variable between 4/1 and 10/1. The results show that the increment on compression ratio increases 29 % engine power and decreases 23 % specific fuel consumption in constant load and speed conditions. In addition, the increment on compression ratio was provided almost 20 % decreases at CO and 38 % increases at HC emissions

The Impact of Diesel/LPG Dual Fuel on Performance and Emissions in a Single Cylinder Diesel Generator

Compared to other engines of the same size, diesel engines are more economical in addition to their ability to generate high power. For this reason, they are widely used in many fields such as industry, agriculture, transportation, electricity generation. The increasing environmental concerns and diminishing oil resources led researchers to improve fuel consumption and emissions. In this context, the usage of Liquefied Petroleum Gas (LPG) fuel in diesel engines is one of the important research subjects that has been keeping up to date. This paper investigates the effects of LPG direct injection towards the end of air inlet period on engine emissions and performance characteristics. A four-stroke, air cooled, single cylinder diesel engine was modified to direct injection of LPG for diesel/LPG dual fuel operation. An Electronic Control Unit (ECU) was designed and used to adjust LPG injection timing and duration. LPG injection rates were selected as 30%, 50% and 70% on a mass base. The test engine was operated at 3000 rpm constant engine speed under varying load conditions. Throughout the experiments, it was observed that smoke density significantly reduced on the dual-fuel operation, compared to the pure diesel operation. Carbon Monoxide (CO) and Hydrocarbon (HC) emissions decreased by 30% and 20%, respectively. Brake Specific Fuel Consumption (BSFC) decreased by 8%. Nitrogen Oxide (NOx) emissions increased by 6% while effective efficiency increased up to 1.25%

50 Hz Şebeke Frekansında Elektrik ve Manyetik Alan Şiddetlerinin Ölçülmesi Ve Ölçüm Sonuçlarının ICNIRP'nin Halk Maruziyeti Limitlerine Göre Karşılaştırılması

Türkiye'nin de içinde bulunduğu birçok ülke tarafından kabul gören Uluslararası İyonlaştırmayan Radyasyondan Korunma Komisyonu (ICNIRP), elektromanyetik alanlara halk ve mesleki maruziyet limitlerini belirleyen ve bu konularda yoğun çalışmalar yapan uluslararası bir komisyondur. ICNIRP elektrik, manyetik ve elektromanyetik alanların biyolojik ve potansiyel sağlık etkilerini incelemek üzere frekans bandını düşük frekans (0-100 Khz) ve yüksek frekans (100 Khz-300 Ghz) bandı olmak üzere ayrı ayrı incelemiş ve farklı kılavuzlar şeklinde yayınlamıştır. Bu çalışmada, düşük frekanslı elektrik ve manyetik alan ölçümleri Diyarbakır İl Merkezi'nin 30 farklı noktasında gerçekleştirilmiştir. Düşük frekans kaynaklı elektrik ve manyetik alan ölçümlerinde ICNIRP'nin belirlemiş olduğu halk maruziyeti limit değerlerini aşan yerlerin olduğu tespit edilmiş ve bununla ilgili durum değerlendirmesi yapılmıştır. Ölçümlerde EHP-50C isimli düşük frekanslı elektrik ve manyetik alan ölçer cihazı kullanılmıştır. Ölçüm sonuçları 6 dakikalık ölçümlerin ortalama değeri alınarak hesaplanmıştır. Ayrıca bir yüksek gerilim hattının altında 60 dakika boyunca elektrik alan şiddeti değerleri ve aynı şekilde manyetik alan şiddeti değerleri kaydedilmiştir. Kayıtlar sonucunda elektrik ve manyetik alan şiddeti değerlerindeki değişimler gözlemlenmiş ve bu değişimler grafik üzerinde gösterilmiştir

Study of phylogenetic relationship of Turkish species ofMatthiola (Brassicaceae) based on ISSR amplification

Matthiola W.T.Aiton is a taxonomically complex genus in which there are many problems, mostly with Matthiola longipetalaand M. odoratissima. Matthiola species native to Turkey were collected from various locations in Anatolia, and their DNA was isolated. Revision studies performed on the basis of molecular data obtained from studies conducted in recent years have made the phylogenetic relationships and systematic positions of the taxa more apparent and reliable. Consequently, the remaining taxonomic problems among the species have been resolved through the use of DNA-based molecular analysis methods, which, unlike phenotype studies, are not affected by environmental factors. The inter-simple sequence repeat (ISSR) fingerprinting method was used in the study because its properties were considered to be more reliable and consistent than those of the randomly amplified polymorphic DNA method. DNA fragments were amplified through the use of ISSR primers. The phylogenetic relationships among the taxa were represented on a dendrogram constructed through means of NTSYSpc 2.02 software. The infrageneric and intergeneric phylogenetic relationships between Matthiola and other related genera were also characterized. It was determined that the taxa Matthiola odoratissima and M. ovatifolia are separate but closely related. Moreover, it was observed that the Matthiola longipetala complex forms a separate group within the genera. Clearly, the genera Matthiola, Sterigmostemum, Strigosella, Malcolmia, and Chorispora are phylogenetically differentiated on the dendrogram