Dynamic-mechanical properties as a function of luffa fibre content and adhesion in a polyester composite

In this work, the characteristics of a vegetable fibre (luffa cylindrica) polyester composite are studied as a function of fibre surface treatment (with NaOH, Ca(OH)2 and silane) and fibre content (30%, 40% and 50%). Composites were prepared through compression moulding and characterized with thermogravimetric and dynamic-mechanical analyses. Higher storage modulus was obtained with Ca(OH)2 treated composites, reaching nearly 70% increase. Higher loss modulus (E”) was noted in for silane treated fibre (at 50%) and a high peak in damping factor was noted for Ca(OH)2 treated fibre (at 50%). Cole-cole plot showed highest homogeneity for the Ca(OH)2 treated composites. Electron microscopy revealed the fracture modes in static tested composites. The general properties obtained indicate that the composites can only be used for low loading applications

Observations on tuna fishery at Ratnagiri-Malwan area, north-west coast of India

Ratnagiri and Malwan, on the coast of Maharashtra State, support a good tuna fishery which is of considerable importance to the local fishermen. Except for the preliminary note by Ranade (1961), no scientific information is available on the tuna fishery of this coast. With a view to enhance our knowledge on the fishery and biology of tunas from this area, a survey was conducted by the Central Marine Fishereis Research Institute during September to December, 1979. The present account deals with the relevant information collected during the period of survey and thereafter

Sequence-specific recognition of DNA by the C-terminal domain of nucleoid-associated protein H-NS

The molecular determinants necessary and sufficient for recognition of its specific DNA target are contained in the C-terminal domain (H-NSctd) of nucleoid-associated protein H-NS. H-NSctd protects from DNaseI cleavage a few short DNA segments of the H-NS-sensitive hns promoter whose sequences closely match the recently identified H-NS consensus motif (tCG(t/a)T(a/t)AATT) and, alone or fused to the protein oligomerization domain of phage λ CI repressor, inhibits transcription from the hns promoter in vitro and in vivo. The importance of H-NS oligomerization is indicated by the fact that with an extended hns promoter construct (400 bp), which allows protein oligomerization, DNA binding and transcriptional repression are highly and almost equally efficient with native H-NS and H-NSctd::λCI and much less effective with the monomeric H-NSctd. With a shorter (110 bp) construct, which does not sustain extensive protein oligomerization, transcriptional repression is less effective, but native H-NS, H-NSctd::λCI, and monomeric H-NSctd have comparable activity on this construct. The specific H-NS-DNA interaction was investigated by NMR spectroscopy using monomeric H-NSctd and short DNA duplexes encompassing the H-NS target sequence of hns (TCCTTACATT)with the best fit (8 of 10 residues) to the H-NS-binding motif. H-NSctd binds specifically and with high affinity to the chosen duplexes via an overall electropositive surface involving four residues (Thr109, Arg113, Thr114, and Ala116) belonging to the same protein loop and Glu101. The DNA target is recognized by virtue of its sequence and of a TpA step that confers a structural irregularity to the B-DNA duplex

Trends in secondary production in the inshore waters of the seas around India

CMFRI has been monitoring the microscopic organisms which belong to the categories of phyto and zooplanktons, being a reliable tool for the identification of areas prone to industrial and natural pollution and for understanding its extent and intensity, especially in the inshore areas selected centres along the Indian coasts.These studies assist in foretelling any alarming situations developed in the living environment that may affect the commercially important resources adversely. The pattern of the occurrence and abundance of zooplankton along the Indian coasts from Bombay on the west coast upto Madras on the east coast were described.The samples were collected from Bombay, Karwar, Calicut, Vizhinjam, Tuticorin, Mandapam and Madras. In conclusion,the rate of secondary production on the west as well as on the east coasts during the 1981-82 period was comparatively lesser than during the previous year

Selective Laser Melting Process Parameter Optimization on Density and Corrosion Resistance of 17-4PH Stainless Steel

The 17-4 PH Stainless Steel material is known for its higher strength and, therefore, extensively used to build structures for aerospace, automotive, biomedical, and energy applications. The parts must operate satisfactorily in different environmental conditions to widen the diverse application. The selective laser melting (SLM) technique build parts cost-effectively, ensuring near-net shape manufacturability. Laser power, scan speed, and hatch distance operating at different conditions were used to develop parts and optimize for higher density in printed parts. Laser power, scan speed, and hatch distance resulted in the percent contribution towards density equal to 73.74%, 24.48%, and 1.78%. The optimized conditions resulted in higher density and relative density equal to 7.76 g/cm 3 and 99.48%. Printed parts' corrosion rate and wear loss showed more stability in NaCl corrosive medium even at 75 °C than 1M of HCL corrosive medium. Less pitting corrosion was observed on the samples treated in NaCl solution at 25 °C and 75 °C at 72 Hrs than in HCL solution. Therefore, 17-4 PH SS parts are best suited even in marine applications

Tuna fisheries in India: Recent trends

Tuna is one of the least exploited resources of the Indian seas accounting for 0.98 % of the total marine fish catch of India at the 1978 level. On the other hand tuna resources have been exploited by countries such as Japan, Korea and Taiwan from the Indian Ocean. Relevant portions of the recommendations of the 'Symposium on scombroid fishes' held at Mandapam camp. The authorities involved with the planning of the Indian Ocean Expedition give due consideration to gathering and collating the information which should be useful in aiding the development of high seas fisheries for scombroid fishes in the Indian Ocean. In the context of these developments and the need for efficient utilisation of the resources of the Exclusive Economic Zone, a brief account on the trend in the tuna fisheries in the country is presented here

The spine of the swan: A Herschel study of the DR21 ridge and filaments in Cygnus X

In order to characterise the cloud structures responsible for the formation of high-mass stars, we present Herschel observations of the DR21 environment. Maps of the column density and dust temperature unveil the structure of the DR21 ridge and several connected filaments. The ridge has column densities larger than 1e23/cm^2 over a region of 2.3 pc^2. It shows substructured column density profiles and branching into two major filaments in the north. The masses in the studied filaments range between 130 and 1400 Msun whereas the mass in the ridge is 15000 Msun. The accretion of these filaments onto the DR21 ridge, suggested by a previous molecular line study, could provide a continuous mass inflow to the ridge. In contrast to the striations seen in e.g., the Taurus region, these filaments are gravitationally unstable and form cores and protostars. These cores formed in the filaments potentially fall into the ridge. Both inflow and collisions of cores could be important to drive the observed high-mass star formation. The evolutionary gradient of star formation running from DR21 in the south to the northern branching is traced by decreasing dust temperature. This evolution and the ridge structure can be explained by two main filamentary components of the ridge that merged first in the south.Comment: 8 pages, 5 figures, accepted for publication as a Letter in Astronomy and Astrophysic