2,576 research outputs found
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
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
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
Mitral Leaflet Separation Index in Assessing the Severity of Mitral Stenosis
Determining the severity of mitral stenosis (MS) is important for both prognostic and therapeutic reasons. The mitral valve area (MVA) can be measured by planimetry, pressure half-time, continuity equation, and proximal isovelocity surface area methods. In this study, we propose a novel yet simple, independent measure of MS severity–the mitral leaflet separation (MLS) index. This new index could be a useful surrogate measure of the MVA. This index would also help when there is a discrepancy between severities of MS estimated by existing methods, in the presence of atrial fibrillation and in the presence of mitral regurgitation
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