Exergetic Sustainability Indicators as a Tool in Commercial Aircraft: A Case Study for a Turbofan Engine

This paper focuses on the exergetic sustainability indicators of a medium-range commercial aircraft engine for constant reference environment and ground running conditions. First, a detailed exergy analysis of turbofan engine have been performed based on engine test cell parameters. Starting from the sustainability considerations and the second law of the thermodynamics, the paper presents six exergy-based sustainability indicators. The indicators of the turbofan engine developed here in conjunction with exergetic analysis and sustainable development are exergy efficiency, waste exergy ratio, exergy destruction factor, recoverable exergy rate, environmental effect factor, and exergetic sustainability index. The investigated sustainable indicators have been calculated by using exergy analysis outputs for aircraft ground running condition. Results from this study show that values of exergy efficiency, waste exergy ratio, exergy destruction factor, recoverable exergy rate, environmental effect factor, and exergetic sustainability index of investigated turbofan engine are found to be 0.315, 0.685, 0.408, 0, 2.174, and 0.460, respectively. These parameters are expected to quantify how the turbofan engine and aircraft become more environmentally benign and sustainable.     

An environment-friendly engine selection methodology for aerial vehicles

Emitted exhaust gases from aircraft are an issue of concern from an environmental perspective. Many research studies have been conducted aiming to reduce aircraft emissions in the hope of preventing any further increase in climate change and global warming. Within this scope, the present study intends to present a methodology for an optimum gas turbine engine selection with regard to emitted exhaust gases. The methodology focuses on five different turbofan engines which constitute the power unit of a commonly used passenger aircraft. At the end of the study, it is considered to be impossible to achieve a minimum exhaust emission for each gas. For this reason, it is considered to be better to optimize the engine with the aim of reducing nitrogen oxide emissions or other exhaust emissions.     

Water quality and impacts of pollution sources for Eymir and Mogan Lakes (Turkey)

Mogan and Eymir Lakes are two shallow lakes, interconnected hydrologically in the close vicinity of Ankara, Turkey. A total of 245 km(2) of the total 971.4 km(2) watershed is under environmental protection status as "G?lba?i Specially Protected Area". Potential impacts from extensive agriculture, recreation, incomplete infrastructure and other human activities, such as residential settlements, are discussed with reference to previous and more recent pollution monitoring. Six monitoring stations enabling follow-up of previous work were selected in this study. These were on the creeks feeding the lake systems. Generally, summer months showed heavier pollution loads, with Eymir Lake concentrating the pollutants due to flow from Mogan Lake. When compared with the 1995 study; COD, total-P, Kjeldahl-N in the six stations were close or slightly decreased in the present study. Suspended solids significantly decreased; possibly due to erosion control measures and decreased domestic wastewater. The improvement in the pollution state of the lakes is attributed to the construction of a sewage system going around Mogan Lake and collecting wastewater discharges and restrictions to urban settlement development around the lakes brought by the 1/25,000 land use plan controlling further impact from residential developments within the protected area boundaries. The study, while addressing water quality and interactions due to human activities in shallow lakes, also discusses problems associated with human impacts in protected areas with the aim of presenting a complicated case study.     

Energy,exergy analysis,and sustainability assessment of different engine powers for helicopter engines

The rapid decrease of energy resources has accelerated studies on energy efficiency. Energy efficiency refers to the effective use of energy, in other words, completing a specific task to the required standard by using less energy. Exergy is an effective instrument to indicate the effective and sustainable use of energy in systems and processes. Transportation is an important part of human life. The studies on energy saving and the effective use of energy in different areas around the world have also increased for transportation systems and vehicles. With the more effective use of fuel, there will be potential benefits for the environment as well as a reduction in operating costs. This study includes energy and exergy analyses as well as a sustainability assessment by using C₈H₁₆ as a fuel at different engine powers (150–600 SHP (shaft horse power)), for the piston-prop helicopter engine. The maximum exergetic sustainability index was found at the power that provided the maximum energy and exergy efficiency. As a result of this index, the lowest waste exergy ratio, the lowest exergy destruction factor, and the lowest environmental impact factor were obtained. The highest exergy destruction and the highest exergy loss value were obtained at maximum power (600 SHP).     

Effects of pH on the mortality and accumulation of copper in tissues of Oreochromis niloticus

In the present study, effect of pH on the mortality and accumulation of copper in various tissue and organs of Oreochromis niloticus were tested at varying concentrations of copper in the medium and over different periods of time. Experimental animals were exposed to pH 5.5, 7.8 and 9.5 and 0.1, 0.5, 1.0 and 5.0 ppm copper over periods of 7, 15 and 30 days in liver, gills and muscle were determined using atomic absorption spectrophotometric techniques. The rate of mortality at 1.0 and 5.0 ppm Cu was 100% after 7 days of exposure at pH 5.5 while at 5.0 ppm Cu was 66% after 30 days of exposure at pH 7.8. No mortality was observed in any of the copper concentrations tested at pH 9.5. In all pH levels, tissue accumulation of copper increased with increasing concentrations of copper in the medium at a given exposure period. In all pH values tested, highest levels of copper were found in the liver of O. niloticus, followed by the gills and muscle tissues. Accumulation of copper in all tissues were higher at pH 5.5 compared with the other pH values in all the conditions tested.     

Spatial variability of depth and salinity of groundwater under irrigated ustifluvents in the Middle Black Sea Region of Turkey

Information on the potential risk for soil salinity buildup can be very helpful for soil salinity management in irrigated areas. We evaluated the spatial and temporal variability of groundwater salinity (GWS) and groundwater depth (GWD), which are two of the most important indicators of soil salinity, by indicator kriging technique in a large irrigated area in northern Turkey. GWS and GWD were measured on a monthly basis from irrigation season (August 2003) to rainy season (April 2004) at 60 observation wells in the 8,187-ha irrigated area. Five indicator thresholds were used for GWS and GWD. The semivariogram for each of the thresholds for both variables was analyzed then used together with experimental data to interpolate and map the corresponding conditional cumulative distribution functions (CCDF). Risk for soil salinity buildup was greater in the irrigation season compared to that in the rainy season. The greatest risk for soil salinity buildup occurred in the eastern part of the study area, suffering from poor drainage problem due to malfunctioning drainage infrastructure, as indicated by the CCDF of GWS and GWD obtained in both seasons. It was concluded that a combination of mechanical and cultural measures should be taken in high-risk locations to avoid further salinity problems.     

Levels of heavy metals in blue whiting caught from the eastern Black Sea area of Turkey

This paper presents data on the concentrations of 5 metals, copper (Cu), cadmium (Cd), iron (Fe), zinc (Zn) and lead (Pb) in Blue Whiting sampled from the Eastern Black Sea coast of Turkey. The highest metal concentrations of Cu, Cd, Fe, Zn and Pb were recorded in Blue Whiting with the values of 2.71, 0.601, 14.137, 15.322 and 1.078 μg g^‐1 dry weight, respectively. On average the metal concentrations in Blue Whiting followed the order of Zn > Fe > Cu > Pb > Cd. Temporal differences of concentrations of these metals were significant (p < 0.05). Spatial fluctuations of Cu, Cd, Fe, Zn and Pb concentrations in Blue Whiting were also significant (p < 0.01). It was found that the concentrations of Cu, Cd, Fe, Zn and Pb in the muscle in Blue Whiting were below the limit of Public Health Regulation in Turkey.     

Development of plant-friendly vermicompost using novel biotechnological methods

Journal of Material Cycles and Waste Management - For the first time in the world, raw tea waste from tea plants was mineralized by rapid biotechnological methods using beneficial worms, enzymes...