No abstract

Önceden kaymış şev, Yüksek ve alçak plastiliteli killi toprak, Reziduel ve kesme kuvveti, Aşırı konsolide, Şev kararlılığı, Özet: Killi zeminler geoteknik biliminin başlangıcından beri incelenmekte olabilir, ancak kilin farklı yükleme durumlarında ve farklı şartlardaki davranışı halen incelenmektedir. Bu çalışma, yüksek ya da düşük plastitedeki killerden oluşmuş önceden kaymış şevlerle ilgilidir. Kaymadan sonra, "zeminin gücü reziduel değere düşer" düşüncesi genel anlamda kabul görmüş ve önceden kaymış şevlerin kararlılık hesaplarında bu değer kullanılmıştır. Bu noktada, eğer şev kilden oluşuyorsa sorusu akıllara gelebilir; daha detaylı düşünürsek, eğer şev yüksek ya da düşük plastisiteli aşırı konsolide killerden oluşuyorsa kesme davranışında ne gibi farklılıklar olabilir? İşte bu çalışmanın ana noktası budur. Deneylerde, düşük plastisiteli örnekler için Kaolin, yüksek plastisiteli örnekler icin ise ağırlıkça %50 Kaolin ve %50 Bentonit karışımı kullanılmıştır. Deney aşamaları olarak, önce örnekler aşırı konsolide edilir, daha sonra reziduel değerlerine kadar kesme deneyi sürdürülür ve son olarak da hızlı kesme deneyi gerçekleştirilir. 30 (otuz) testin sonunda sonuçlar beklendiği gibi elde edilir. Yüksek plastik numuneler aynı normal stres altında daha düşük mukavemet değerleri vermektedir; asıl ilginç sonuç, reziduel mukavemet ile daha yüksek bir kesme hızındaki kesme mukavemeti arasındaki değerler arasındaki farktır.

In recent decades finished and semi-finished commodities are the most common and fastest-growing cargo categories for transportation in Europe. These commodities usually have low density and are of high value. This paper aims to assess the CO 2 emissions, cost, and availability of road, rail, and railroad intermodal transportation used to deliver LDHV goods in a case study involving chemical goods transportation throughout the EU27 countries in 2020. The findings indicated that most chemical goods were transported via road, which emits more CO 2 than a railway. Furthermore, road transport cost is significantly higher than rail. In order to reduce CO 2 emissions and costs, four railroad intermodal scenarios were suggested. According to the analysis, these scenarios for delivering LDHV goods may be feasible to mitigate environmental concerns while also significantly lowering costs. Additionally, the availability and accessibility of intermodal terminals for shipping LDHV goods were analyzed to evaluate these scenarios.

Many railway companies around the world offer slab track (ballast-less track) rail products and solutions. In particular, different types of slab track rail systems are implemented in Japan, Europe and North America. The use of these systems provides railway operators with significant advantages in terms of RAMS (Reliability, Availability, Maintainability and Safety) and life cycle cost. In addition, these systems are preferred in railway lines under heavy train traffic, because it significantly shorten maintenance duration. The biggest disadvantage of ballast-less railway lines is that the initial application cost is 30% to 50% higher than ballast railway applications. In recent years, manufacturers of these systems have introduced innovations that reduce both maintenance and life cycle costs. When these innovations are added to the existing advantages in the design phase in tunnels (reduction of the height) and bridges (reducing dead loads), the applicability of slab track systems increase even more. In addition, maintenance and repair activities have to be carried out in limited time in heavily used railway lines such as high-speed railway lines, which causes slab track systems to be preferred. By the construction of high Speed rail lines in Turkey, the passengers and freight rail transport has gained importance. Increasing rail traffic, maintenance-repair costs and limited maintenance duration have led to the need to step changes on the conventional ballasted railway lines. Within the scope of this study, the slab track systems, which have already utilized in the world are examined and the sustainability of these systems that can be applied in Turkish railways is examined in terms of design and maintenance.

The pressure dependence of the Raman frequencies for the ν21 mode is studied by using the volume data at room temperature close to the transitions among the phases of III, IV and V in cyclohexane. By determining the pressure dependence of the mode Grüneisen parameter γT in the phases and taking the average values, the Raman frequencies of those modes associated with the phase transitions are predicted through the volume data in cyclohexane. Our predicted Raman frequencies agree with those observed experimentally in this organic molecule. The Raman frequencies of the other modes can be calculated in cyclohexane and also in some molecular crystals using the method given here.