Dept of Ecology and Encironmetal Science

We studied the Indian Golden Gecko, Calodactylodes aureus, at a new locality in the hill ranges of Tamil Nadu. The highest numbers of geckos were recorded from Valli Malai, followed by Shyed Basha Malai and the Sathgar Hill. Geckos were encountered at an elevation range of 185-702 m a.s.l. A total of 70 geckos were recorded in 20 rocky caves, and 72 egg deposition sites were noted, bearing signs of hatched and unhatched eggs. The number of egg deposition sites varied from 2 to 8 in the surveyed caves. A total of 477 unhatched live eggs were observed during the study. Psammophilus dorsalis is the most commonly encountered lizard species locally; Cnemaspis otai and Hemidactylus graniticolus were also found in sympatry.

We studied the amphibian community structure, spatial overlap and herpetofaunal assemblage at Mannampandal, Tamil Nadu during October, 2010 to January, 2011. The survey methods involved careful visual estimation of amphibians in all the possible microhabitats present in the study area. Five different microhabitat categories were selected, viz., leaf litters, temporary water pools, tree holes, shrubs & grasses (ground vegetation), pathways, open floor & outer edges of buildings. We identified 26 species of reptiles and 14 species of amphibians. There was a significant difference found among the amphibian species occupying in different microhabitats. Species diversity was calculated, Shanon-Wiener H'= 1.55. The high niche overlap was found between Duttaphrynus scaber and Uperodon systoma followed by Fejervarya sp. and Sphaerotheca breviceps. The present study on amphibian community is just a representation to show the microhabitat occupancy and adjustment by the amphibians in human settlements and competition among them as, spatial resource partitioning.

We for the first time describe the larval morphology of Günther's toad, Duttaphrynus hololius (Günther, 1876) from shallow rainwater puddles on rocks in Gingee hills, Eastern Ghats, India. We observed 123 metamorphosing tadpoles of various stages on 14 puddles surveyed. A few samples from each stage were examined for morphological characterization. No other amphibian species was seen syntopically in or around these rocky puddles.

Rainwater is an important untapped resource for all water managers and can be collected and used personally for all uses and simultaneously diverted to ground for recharge of depleting aquifers. Rain water is the most purest form of water until it is contaminated by the atmospheric pollution. Evaluation of rainwater quality analysis is also essential for non-potable applications and to match quality to specific uses. Rainwater quality analysis is, therefore, carried out to understand the problems of rainwater contamination with various pollutants. Rainwater samples were collected from the pre-monsoon season of March 2010 to post-monsoon of October 2013, from seven sampling sites namely Irongmara, Badarpur, Bongaigaon, Dolaigaon, BGR Township, Kolkata and Kharagpur, which characterised typical suburban, urban and industrialised locations respectively. A total of 943 samples were collected during this period from the sampling sites, taking utmost care in sampling and storage were analysed for heavy metals determination. Results for pH, EC, Pb, Cd, Ni, Zn, Cr and Co were reported in this study. The samples were collected using PVC bottles.The highest concentration of elements was observed at the beginning of the rainfall season when large amounts of dust accumulated in the atmosphere scavenged by rain. The values of pH in rainwater samples were relatively within the World Health Organization (WHO) standard for drinking water. Multivariate statistical analysis especially varimax rotation was applied to bring to focus the hidden yet important variables which influence the rainwater quality. It is also observed that rainwater contamination may not be restricted to industrial areas alone but vehicular emission may also contribute significantly in certain areas.

Water is essential for all socioeconomic development and for maintaining healthy ecosystems. The present study is an attempt to make a preliminary analysis of the rainfall patterns in Silchar over the last two decades. The study throws some light over the annual and monthly rainfall in this area that is influenced by the South West Monsoon as well as the pre-monsoon rains. The study reveals the significant role played by heavy rainstorms in governing the rainfall-flood regime in this area. This assumes considerable significance in the backdrop of global climate change altering the weather patterns in this area. The average annual rainfall in Silchar during 1986-2007 over a 22 year period was 3001.2 mm. The highest rainfall occurred in 1989 (4042.9 mm) followed by 1991 (3890.8 mm), while the lowest rainfall was in 1988 (1856.9 mm) and that in 2006 (2328.9) being the second lowest. It can also be observed that the highest rainfall occurred in the month of July in 9 years out of the 22 years. It was observed that the number of Heavy Rainfall Events is found to be the highest in the year 2007 which is a flood year and the least is found in the year 2006 which is a drought year.

Water is essential for all socioeconomic development and for maintaining healthy ecosystems. The present study is an attempt to make a preliminary analysis of the rainfall patterns in Silchar over the last two decades. The study throws some light over the annual and monthly rainfall in this area that is influenced by the South West Monsoon as well as the pre-monsoon rains. The study reveals the significant role played by heavy rainstorms in governing the rainfall-flood regime in this area. This assumes considerable significance in the backdrop of global climate change altering the weather patterns in this area. The average annual rainfall in Silchar during 1986-2007 over a 22 year period was 3001.2 mm. The highest rainfall occurred in 1989 (4042.9 mm) followed by 1991 (3890.8 mm), while the lowest rainfall was in 1988 (1856.9 mm) and that in 2006 (2328.9) being the second lowest. It can also be observed that the highest rainfall occurred in the month of July in 9 years out of the 22 years. It was observed that the number of Heavy Rainfall Events is found to be the highest in the year 2007 which is a flood year and the least is found in the year 2006 which is a drought year.

The term 'turnaround' in airport operations refers to the period beginning when a flight arrives at an airport and ending when the aircraft takes off again. Unfortunately, turnaround operations are known to play a primary role in aircraft flight delays.In order for an airline company to achieve maximum profit it has to reduce the aircraft on-ground time. However, due to maintenance task require by the manufacturer which is related to the safety of an aircraft and the maintenance tasks as specified in the checklists and as scheduled by the manufacturer/owner/operator and approved by the concerned airworthiness authority it is hard to reduce the aircraft ground time .Then if the airline has to increase their profit then they have to decrease the aircraft turnaround time which is the only variable. Most carrier will try to reduce their turnaround time to be as low as

Entrepreneurship plays an important role in the development of a country and is one of the most important inputs in economic development. The crucial and significant role played by the entrepreneurs in the economic development of advanced countries has made the people of developing and under developed countries conscious of the importance of entrepreneurship for economic development. If we understand the benefits and drawbacks, a balanced approach to nurturing entrepreneurship will definitely result in a positive impact on economy and society. The role of entrepreneurs is not identical in the all the economies. It varies depending on the material resources, industry types, demographic conditions and responsiveness of the political system. The objective of this paper is to focus on relevant issues of entrepreneurship education in the context of aircraft maintenance engineering. We have used the TPB model as the theoretical framework for our study. The Global Entrepreneurship Monitor (GEM) report is referred to while carrying out the research for comparative study on entrepreneurial behavior among the Asian countries .To study and analyze the current growth in Malaysian Aviation industry (2016-2017), WAYPOINT report was studied in detail. Last but not the list the relevant pages of ICAO documents and UN documents are also referred to in preparing the report. It is suggested that entrepreneurship courses run by universities must be specific industry oriented and must focus on developing the EA of the potential would be entrepreneurs.

A valve is a mechanical device that blocks a pipe either partially or completely to change the amount of fluid that passes through it. A valve is used to drain off material that has separated from a fluid or gas stream. Valves are quite diverse in their operations and constructions and may be categorized into a number of types. Ball valve, Butterfly valve, Check valve or Non-return valve, Gate valve, Needle valve, Poppet valve, Spool valve, Thermal expansion valve, Pressure Reducing Valve are some of the commonly used valves as used in modern aviation to name a few. Correct functioning of respective valves is very essential. This paper attempts to construct a theoretical perfect equation for the correct attachment angle of the drain valves to ensure entire waste fluid exit out. This paper, further, attempts to look into a mathematical equation in order to maintain the correct angle taking into account the thermal stresses and mechanical stresses which the aircraft is subjected to during different phases of the flight. A hypothetical situation is further considered regarding the use of the valves for infinite duration at different stress levels and the analysis are done using different infinite series. The paper is left open for further discussion on the physical interpretation of the results obtained using infinite series.

Keywords: Drain valve, attachment angle, mathematical equation, thermal stresses, mechanical stresses, infinite series

ABSTRACT
Maintenance programs have a very important role in the aviation industry. Every operator aims to undertake the minimum operating costs and gain profit as much as possible. One of the significant elements of operator’s operating costs is the maintenance costs. During maintenance scheduling, operator needs to calculate the maintenance cost that needs to be budget. Earlier works show that this calculation includes only costs that are directly related to the maintenance process such as cost labor costs, materials, overhead costs and equipments but excluding the aircraft downtime costs. The purpose of this paper is to introduce a new mathematical model that would include the aircraft downtime costs due to maintenance. This paper uses the decision making strategies as applicable to Game theory and concluding that the maximum possible profit attainable is fifty percent of its net income by reaching a Nash cooperative equilibrium position in the game. This paper further uses a heuristic approach to formulate a general equation to maximize the profit margin of the operator by minimizing the maintenance costs involved.

Keywords: Maintenance program, maintenance costs, downtime costs, game theory, nash equilibrium, heuristic