24 research outputs found
LIFE CYCLE COST ANALYSIS FOR THE YAW DAMPING SYSTEM OF A WARSHIP FROM A FINANCIAL VIEWPOINT
Life cycle assessment (LCA) is implemented to various processes with a strict exception for naval platforms and warships. Thus, the recent studies for life cycle analysis of military ships are limited. LCA is a holistic method based on developing an optimization between environmental performance, cost-benefit balance and usability. LCC is a supporting subsection of LCA implemented to the analysis in order to calculate the probable costs during whole phases of a product. In this study, LCA and LCC are implemented to a naval platform and a calculation, which is based on escalation, is realized to compare the maintenance costs and initial cost for all life cycle of the platform. A generic warship is selected and yaw damping system of the ship was chosen for implementation of LCA and LCC. It is accepted that the systems and devices are used 1500 hours during cruising and 7260 hours during hoteling. First, the initial cost of yaw damping system is calculated, then, costs of long term maintenance with and without escalation are considered. In the final part, the profit gained by recycling of yaw damping system is calculated. The results has shown that an extra cost of 38 % and 19 % for operation and maintenance and total cost, respectively, must be added according to escalation calculations. While initial cost and operation and maintenance costs have 51 % and 49 % of total costs without escalation, the share of initial cost decreases to 43 % and the share of operation and maintenance increases to 57 % with the utilization of escalation
Life cycle comparison of marine fuels for IMO 2020 Sulphur Cap
Ships, which are the backbone of world trade, are also major emission generators. IMO has prepared a regulation that came into force on January 1, 2020, in particular to reduce ship-related sulphur oxides. Accordingly, the sulphur content of the marine fuels cannot exceed 0.5% by mass. Although these fuels have a significant effect in reducing the sulphur oxides, the holistic environmental effects of the fuels must be examined within a life cycle perspective. In this study, LCA of four different marine fuels were realized and the environmental impacts of the fuels in production, distribution, and operation processes were investigated. The main purpose of this study is to increase precision by focusing on a small number of fuels, while increasing accuracy by obtaining a large number of LCA results. It is concluded that despite the success of low sulphur fuels during operation, the overall environmental effects are higher than other fuels. According to the LCA results, there are no significant differences between the fuels and HFO still remains an important and preferable fuel for the environment. Consequently, in life cycle perspective, it was concluded that the expected results of IMO 2020 Sulphur Cap are not at a desirable level. Thus, alternative fuels would be more beneficial in terms of total environmental issues and IMO should focus more on developing new regulations and policies on alternative fuels
Life cycle assessment and greenhouse gas emission evaluation from Aksaray solid waste disposal facility
WOS: 000435421100006Life cycle assessment (LCA) is a popular tool used to assess the environmental performance of municipal solid waste (MSW) management systems. In this study, LCA method was used to determine the best municipal solid waste management strategy for Aksaray city, Turkey. Four different scenarios were developed as an alternative to the existing waste management system and evaluated for the best environmental solution. The scenario with 75% landfilling-25% composting provided the best results in terms of human health and environmental impact. Current emissions from the present MSW facility were estimated for methane and carbon dioxide emissions. Annual emissions in 2017 were 8674 and 3161 t year(-1) for CO2 and CH4, respectively. The estimated ground-level concentrations of these emissions were 30 and 50 mu g m(-3) for CO2 and CH4, respectively. Both modeled CO2 and CH4 concentrations were expressed as CO2(eq). The total radiative forcing was calculated as 0.021 W m(-2)
Investigation of EU environmental policies from the past to the future in the LCA perspective
*Çetinkaya, Afşin Yusuf ( Aksaray, Yazar )event Bilgili, Afşin Yusuf Çetinkaya, Sadullah Levent Kuzu Investigation of EU Environmental Policies from the Past to the Future in the LCA Perspective Introduction According to the First Law of Thermodynamics, energy can be transformed from one form to another but can be neither created nor destroyed. This law tells us that there is a great balance of energy in nature. This energy balance appears not only in engineering but also in all environmental, social and economic cycles. Humanity, like all other living things in nature, has lived in harmony with environmental cycles in nature for millennia, and there is no waste in any environmental cycle. The energy entering the system does not disappear, changes shape and emerges as another type of energy. The waste products generated during this change process are used as input to another system and a new cycle begins. After the 18th century, when industrial production began, man-made artificial products started to produce outputs that could not be used as energy inputs in any system by disrupting this cycle, and nature was introduced to a concept that did not belong to it: Waste. Waste generation is a part of industrial production and is a process that has the potential to cause great environmental damage if not avoided
Life cycle comparison of membrane capacitive deionization and reverse osmosis membrane for textile wastewater treatment
Çetinkaya, Afşin Yılmaz ( Aksaray, Yazar )The reduced natural water sources on the one hand and the large amount of wastewater produced by the textile industry on the other hand lead to the requirement of an effective reuse of textile wastewater. In this study, the treatment of textile wastewater by the reverse osmosis membrane system and membrane capacitive deionization (MCDI) system has been investigated to improve the quality and the recovery rate of the effluent for reclamation. The maximum chemical oxygen demand (COD) removal efficiency obtained at 10 bar was 96.3% for BW30 reverse osmosis membrane. Diversified operating conditions, including working voltage and flow rate, were investigated systematically in the MCDI system which is an effective water purification technology. According to the obtained experimental results, the COD removal efficiency was thoroughly increased by rising the working voltage (from 0.2 to 1.2 V) and the flow rate (from 5 to 17.5 ml/min). The flow rate and the working voltage at which the COD from textile wastewater removal ratio was the highest were 10 ml/min and 1.2 V, respectively. A life cycle approach has also been implemented for the comparison of environmental impact assessment of the two desalination systems. In this study, a life cycle approach has been implemented for the comparison of environmental friendly impact assessment of the two desalination systems. It is concluded that MCDI system is much more environmental friendlier with 5641 times less values for damage assessment categories, on average...
Evaluation of railway versus highway emissions using LCA approach between the two cities of Middle Anatolia
Çetinkaya, Afşin Yusuf ( Aksaray, Yazar )Transfer of people and transportation of goods is an indispensable part of our daily lives. Choosing the most environmentally friendly alternative will have the least impact on human health, ecosystem, and the materials. This study aims to carry out a comparative assessment of various emission scenarios from highway and railway transportation between Kırşehir and Niğde-Ulukışla in the middle Anatolian Peninsula, in Turkey, to allow making an optimum decision from an environmental viewpoint. Currently, the transportation is sustained through highway, which has 232.6 km length between the cities used as a case study. High-speed railway construction is projected on the same route. We formed different capacity alternatives as alternative scenarios and life cycle assessment approach was applied to these scenarios. Environmental damage ratio decreased with the increasing utilization ratio of the railway. The greatest change was seen in ecosystem quality. We also assessed emissions during the construction activities of both railway and highway. A social cost-benefit analysis suggested that damage cost in the current situation was €562,000. The scenario with 100% replacement of highway with railway transportation showed the lowest damage cost (€157,000) while the highest damage cost was due to NOx emissions...
A New Approach and Concept on Reducing the Environmental Impacts of Shipping: Green Ship
COMPARISON OF DIFFERENT SHIP EMISSION ESTIMATION METHODOLOGIES FOR ANNUAL EMISSION FOOTPRINT AND REDUCTION TECHNIQUES OF A BULK CARRIER
Ships have an indispensable role in trading and transportation. Due to the growth of population and the new demands of the growing economies, the need for shipping but also its harmful effects are increasing and emission problems will grow further in the future
Studies on antioxidant enzymes in mice exposed to pulsed electromagnetic fields
In this study, 56 female albino mice weighing 30-35 g were used. The animals were divided into a control and an experimental group. The animals in the experimental group were subjected to a pulsed electromagnetic field (PEMF) with a field magnitude of 50 Hz and 2 mT for 8 h each day between 0900 and 1700 for 90 days. In both control and experimental groups, blood was sampled at 45, 60, and 90 days in heparinized tubes and erythrocyte malondialdehyde levels, and superoxide dismutase, glutathione peroxidase, catalase, and glucose-6-phosphate dehydrogenase activities were determined. The results revealed that the PEMF applied chronically within the given period and field magnitude does not cause oxidative damage. (c) 2006 Elsevier Inc. All rights reserved
Hip Ultrasonography in the Diagnosis of Developmental Dysplasia of the Hip: Bakırköy Experience
Aim: The purpose of the study was to determine the prevalence, incidence, and etiology as well as the risk factors for developmental dysplasia of the hip in newborns in whom we performed ultrasonography for screening using Graff’s method in our clinic.
Methods: We retrospectively evaluated 2632 hip ultrasonography records of 1316 babies performed between 2008 and 2013. We analyzed the questionnaires of the Turkish Pediatric Orthopaedic Society which were filled by the physician during examination. The babies were divided into two groups according to ultrasonographic hip angles as pathological and normal.
Results: The study is made on 1316 babies [680 girls (51.6%), 636 boys (48.4%)]. The risk for developmental dysplasia of the hip was higher in girls, babies with a family history, babies with metatarsus adductus and those have been swaddled before. The mean gestational age and gestational weight was statistically significantly lower in the pathological group (p=0.0011).
Conclusion: In our cross-sectional study, the incidence of developmental dysplasia of the hip was 0.5%. Female gender, positive family history of developmental dysplasia of the hip,metatarsus adductus and swaddling are still risk factors. Researching risk factors carefully, patient education and adding hip ultrasonograpy to newborn routine screening program are important measures in preventing developmental dysplasia of the hip