A study of methods of prediction and measurement of the transmission of sound through the walls of light aircraft

The acoustic intensity technique was applied to the sound transmission loss of panel structures (single, composite, and stiffened). A theoretical model of sound transmission through a cylindrical shell is presented

Large scale farming of green mussel in Ashtamudi Lake, Kerala

Green mussel, Perna viridis, farming is spreading fast in the lower stretches of Ashtamudi Lake in Kollam district of Southern Kerala. Huge demand for green mussel in the northern part of Kerala has resulted in significant increase in its price. The price has increased to ` 10,000 per gunny bag of 70 kg for medium sized mussel (50-100 mm) whereas larger ones (120 -150 mm) fetch prices as high as ` 400 per kg (8 pieces). This has prompted local fishermen to try mussel farming using on bottom method of mussel culture which some farmers practiced earlier with locally available seed

First report of Spotted reef crab off Vizhinjam coast

Carpilius maculatus (Linnaeus, 1758), commonly known as ‘Seven-eleven crab’, ‘Spotted reef crab’, ‘Dark finger coral crab’, or ‘Large spotted crab’ is a member of the family Carpiliidae. One male specimen of the spotted reef crab C. maculatus measuring 130 mm in carapace width was caught by a bottom set gill net along with Portunus sanguinolentus from the rocky area in Vizhinjam coastal waters

Unusual landings of Aluterus monoceros (Linnaeus, 1758) along Vizhinjam coast

On the13th of July 2009, unusual heavy landings of Aluterus monoceros (unicorn leather jacket) of the family Monacanthidae were observed along the coast, from Vizhinjam to Marianadu about 40 km north of Vizhinjam (Fig. 1). These fishes, locally known as “komban clathy” or “mara clathy” are rarely observed in large numbers in the landings at Vizhinjam which has become a subject of surprise to the fishermen. This has been the first incident of such a heavy landing of bigger sized unicorn leather jacket in this area

Coating of alumina on ceno-spheres of fly-ash

A study is reported that fly-ash behaves as an excellent raw-material for synthesising hollow alumina composite. Coating of alumina onto the surface of ceno spheres was accomplished by controlled precipitation around pH-10. Dopants like Ni/Co have also been successfully tried. The resultant co-precipitated composites were then characterized using DTA, XRD,Particle size analysis and specific-gravity measurements. Calcination of co- precipitated samples at 1500°C, for 1h and haracterisation of the calcined product also discussed. The results indicate that alumina can be successfully coated on ceno-spheres

Emerging clam fishery in Muthalapozhi Estuary

Muthalapozhi Estuary is located in northern part of Thiruvananthapuram District, Kerala. Perunguzhi and Azhoor are commercial bivalve landing centers located along the Muthalapozhi Estuary, where large-scale clam exploitation has emerged during the recent past (Fig. 1). This new development is due to the increased domestic demand for clams in Karnataka, Goa and Maharashtra consequent to the decreased availability of clams in their traditional local clam fishing grounds

Wear behavior of secondary processed spray formed Al-28Si-5Cu-4Mg alloy

In the present study Al-28Si-5Cu-4Mg alloy has been spray formed and hot pressed for densification. Hot pressing refined the microstructure and reduced the porosity in the spray formed alloy from 10 to 1%. The microstructure of spray formed and hot pressed alloy exhibited equiaxed grain morphology with fine and uniform distribution of both primary and eutectic Si with fine needles of Q-Al 12 Si 7 Mg 4 Fe intermetallics and Chinese script like θ- Al 2 Cu precipitates in α-Al matrix. The size of Si particles ranged from 3–10 µm. In contrast the microstructure of as-cast alloy consisted of coarse primary and eutectic Si, long needles of Q-Al-Si-Mg-Cu-Fe phase and bright grey θ-Al 2 Cu phase in the α-Al matrix. The size of primary Si varied from 30–250 µm. The spray formed and hot pressed alloy exhibited a higher hardness compared to the as-cast alloy. The wear behavior of both the alloys, under dry sliding conditions, showed an increase in the wear rate with an increase in the load. However, the spray formed and hot pressed alloy exhibited maximum wear resistance and minimum coefficient of friction, while as-cast alloy exhibited minimum wear resistance and maximum coefficient of friction over the entire range of applied load. The high wear resistance and high hardness of spray formed and hot pressed alloy are explained in the light of its microstructural modifications induced during spray forming and subsequent hot pressing and also the topographical features of worn surfaces and morphology of debris particles

Effect of Cu and Mg on the wear properties of spray formed Al -22Si alloy

In the present study, the effect of Cu and Mg on the wear behavior of spray formed Al-22Si alloy has been investigated and the same has been compared with that of its counterpart as-cast alloy. Al-22Si and Al–22Si–4Cu–1.7Mg alloys prepared by spray deposition process were hot pressed to reduce the porosity. The microstructures were examined by optical and scanning electron microscopes. The microstructure of spray formed Al-22Si alloy is fine and homogeneous and primary silicon phase distributed in the aluminum matrix evenly are fine and faceted having a mean size of 12 µm. The microstructure of spray formed Al–22Si–4Cu–1.7Mg alloy exhibited equiaxed grain morphology with fine and uniform distribution of both primary and eutectic Si with fine Q-Al-Si-Mg-Cu phase and θ-Al 2 Cu precipitates dispersed evenly in α- Al matrix. In contrast the microstructure of as-cast Al–22Si alloy consisted of coarse plates of primary Si of size 350 µm and eutectic Si needles. The as-cast Al–22Si–4Cu–1.7Mg alloy consisted of coarse primary Si with Chinese script like θ-Al 2 Cu precipitates and needles of Q-Al- Si-Mg-Cu phase in α-Al matrix. The wear study of both as-cast and spray formed and hot pressed alloys under an applied load of 10 to 50 N and sliding velocity of 0.4 to1.5 ms -1 indicated two distinct regimes of mild and severe wear. In both the regimes, the spray-formed and hot pressed alloys consistently indicated a low wear rate compared to that of as-cast alloys. The high wear resistance of spray formed and hot pressed Al–22Si and Al–22Si–4Cu–1.7Mg alloys were explained in the light of their microstructural modifications induced during spray forming and subsequent hot pressing

Agricultural Information Needs of Rainfed Farmers: A Study from Telangana

A paradigm shift in rainfed agriculture can be obtained mainly through technological interventions. In this context, the role of extension and advisory services that are saddled with this responsibility should focus on novel approaches. Application of relevant information in agriculture sector brings positive impacts on farm productivity. Timely access to information on weather aspects, best farming practices, market information etc. help farmers to make correct decisions about what crops to plant, when to plant and where to sell their products. The best way to satisfy the rainfed farmers is to understand and consider their specific needs, constraints and capabilities properly, which helps to serve them in an efficient manner. A study has been undertaken to understand the different agricultural information needs of rainfed farmers in the Mahabubnagar district of Telangana state India. It is observed that farmers need various types of information related to agricultural activities and the major agricultural information needs of the farmers were found to be related to farm implements and machinery, water management, seed varieties, seed treatment, alternate crops and pest and disease management. In order to address these information needs, farmers were accessing a number of sources. It is important to enhance the information search capacity of the rainfed farmers to improve the farm productivity and income leading to enhanced livelihoods

Experiencing space–time: the stretched lifeworlds of migrant workers in India

In the relatively rare instances when the spatialities of temporary migrant work, workers’ journeys, and labour-market negotiations have been the subject of scholarly attention, there has been little work that integrates time into the analysis. Building on a case study of low-paid and insecure migrant manual workers in the context of rapid economic growth in India, we examine both material and subjective dimensions of these workers’ spatiotemporal experiences. What does it mean to live life stretched out, multiplyattached to places across national space? What kinds of place attachments emerge for people temporarily sojourning in, rather than moving to, new places to reside and work? Our analysis of the spatiotemporalities of migrant workers’ experiences in India suggests that, over time, this group of workers use their own agency to seek to avoid the experience of humiliation and indignity in employment relations. Like David Harvey, we argue that money needs to be integrated into such analysis, along with space and time. The paper sheds light on processes of exclusion, inequality and diff erentiation, unequal power geometries, and social topographies that contrast with neoliberalist narratives of ‘Indian shining