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Composites are proven a better option for automobile, aerospace industry especially due o its specific strength to weight ratio. Aluminium metal matrix composites having its own advantages, stir ca...

Gears are known to be useful in rotating motion transfer or power transmission from small product to larger, used everywhere. It was initially metallic foundation but now the polymeric material gea...

The Hybrid composites are the emerging materials which uses two or more reinforced particles or fibres simultaneously. As potential applications of the composites, wood reinforced thermoplastic composites are commercially attractive for high volume applications, but their properties can be enhanced by adding Nano SiO2 particles. Wood powder and nano SiO2 were mixed with high density polyethylene as matrix material. Wood powder with fixed 5 wt. % and Nano SiO2 with varying weight % (3, 5, 7 wt. %) are reinforced in HDPE to manufacture composite materials by compression moulding process. Mechanical properties including tensile strength, flexural strength and Izod impact strength were evaluated and it was revealed that tensile strength and flexural strength were obtained maximum at 5 wt. % of Nano SiO2 and impact strength was obtained maximum at 3 wt. % of Nano SiO2.

Here we report the full-length cDNA cloning and nutritional regulation of a putative Δ6 fatty acyl desaturase (Δ6 fads ) gene from striped catfish, Pangasianodon hypophthalmus . The 5′ and 3′ RACE analysis revealed a cDNA sequence of 1896 base pairs (bp) comprising a 5′ UTR of 49 bp, 3′ UTR of 509 bp and an open reading frame (ORF) of 1338 bp specifying a protein of 445 amino acids. Bioinformatics analysis showed that the deduced peptide sequence included all the characteristic features of microsomal fatty acyl desaturases, including N-terminal cytochrome b5 domain containing the haem binding motif H-P-G-G, fatty acyl (FA) desaturase domain, three histidine boxes and transmembrane regions. P. hypophthalmus ∆6 desaturase peptide sequence shares high similarity with Pangasius larnaudii (95%) and Clarias macrocephalus (90%). The predicted secondary and tertiary protein structures revealed that desaturase protein contains mostly α-helix followed by random coils and strands. Tissue distribution analysis showed that Δ6 fads is mainly expressed in brain followed by liver, heart, gill and muscle. Since α-linolenic acid is a substrate for the Δ6 FADS enzyme, various concentrations of this fatty acid (0.5, 1, 1.5 and 2 g kg − 1 ) were administered to experimental fish through feed to find out its effect on the expression of Δ6 fads . Results showed that the liver Δ6 fads gene expression is up-regulated in fish fed with experimental diets ( p Statement of relevance The fatty acid composition of fish depends on both dietary fatty acid input and endogenous HUFA biosynthesis capacity. Fatty acyl desaturases (fads) introduce double bonds in selected positions of the acyl chains. Particularly, Δ6 FADS are the first enzymes involved in the biosynthesis of long-chain HUFA from the C18 n-3 and n-6 precursors, which is a rate limiting step. The extent to which fish can desaturate/elongate C18 FAs to HUFAs varies with species. Hence it is important to study the relationships between LC-PUFA biosynthesis pathways and the habitat and feeding habit of fish species, which will provide the basis for understanding the regulatory mechanisms controlling LC-PUFA biosynthesis pathways. The present study reports the full-length cDNA cloning, tissue distribution and nutritional regulation of Δ6 fads-like gene from freshwater catfish, P. hypophthalmus . This is the first report on cloning and expression analysis of Δ6 fads-like gene from any freshwater catfish.

Endosulfan is an organochlorine pesticide commonly found in aquatic environments that has been found to reduce thermal tolerance of fish. Lipotropes such as the food additive, Lecithin has been shown to improve thermal tolerance in fish species. This study was conducted to evaluate the role of lipotropes (lecithin) for enhancing the thermal tolerance of Chanos chanos reared under sublethal low dose endosulfan-induced stress. Two hundred and twenty-five fish were distributed randomly into five treatments, each with three replicates. Four isocaloric and isonitrogenous diets were prepared with graded levels of lecithin: normal water and fed with control diet (En0/L0), endosulfan-treated water and fed with control diet (En/L0), endosulfan-treated water and fed with 1% (En/L1%), 1.5% (En/L 1.5%) and 2% (En/L 2%) lecithin supplemented feed. The endosulfan in treated water was maintained at the level of 1/40th of LC50 (0.52ppb). At the end of the five weeks, critical temperature maxima (CTmax), lethal temperature maxima (LTmax), critical temperature minima (CTmin) and lethal temperature minima (LTmin) were Determined. There was a significant (P0.01) effect of dietary lecithin on temperature tolerance (CTmax, LTmax, CTmin and LTmin) of the groups fed with 1, 1.5 and 2% lecithin-supplemented diet compared to control and endosulfan-exposed groups. Positive correlations were observed between CT max and LTmax (R(2)=0.934) as well as between CTmin and LTmin (R(2)=0.9313). At the end of the thermal tolerance study, endosulfan-induced changes in cellular stress enzymes (Catalase, SOD and GST in liver and gill and neurotansmitter enzyme, brain AChE) were significantly (p0.01) improved by dietary lecithin. We herein report the role of lecithin in enhancing the thermal tolerance and protection against cellular stress in fish exposed to an organochlorine pesticide.

Carbon Nanotubes (CNTs) are the allotropes of carbon which belong to the fullerene structural family. These are cylindrical structures with at least one end closed with a buckyball structure hemisphere. They are few nano meter in diameter and have tensile strength of ∼63 GPa and young's modulus of ∼1TPa. On the basis of structures carbon nanotubes can be classified as Single-walled (SWNT), Multi-walled (MWNT), Polymerized SWNT, Nanotorus and Nanobuds. Carbon Nanotubes can behave as metal or as a semiconductor depending on the nature of its helix. They are good thermal conductors along their axis but act as insulators in the lateral direction. Major manufacturing techniques employed for fabrication of CNTs are Arc discharge, Laser Ablation and Chemical vapor deposition. Carbon Nanotubes are extending our ability to fabricate devices such as molecular probes, pipes, wires, bearings, springs, gears and pumps

Electromagnetic forming (EMF) is a non-contact forming technique. It is an impulse or high-velocity forming method using pulsed magnetic field by application of Lorentz’ forces to the work piece preferably made of highly electrically conductive material without having working medium and mechanical contact. Therefore, hollow profiles can be compressed or expanded as well as 2D or 3D sheet metal can be shaped, joined or cut. Electromagnetic forming process has very high strain rate and velocity in comparison to conventional process. Therefore, the Forming limits can be extended for several materials. In this paper, the state of the art of electromagnetic forming is reviewed subjected to following aspects-Research work on parameters related to acting load, Work piece deformation, Interaction between load parameters and work piece deformation, Behaviour of materials, Energy interaction during the process and Research regarding the principle and application of electromagnetic forming. On the basis of this study it is proposed why electromagnetic forming has not been widely initiated in industrial manufacturing processes up to now and how the challenges for its widespread applications can be meet.

Aluminium metal matrix composite is a relatively new material that has proved its position in automobile, aerospace and other engineering design applications due to its wear resistance and substantial hardness. Need for improved tribological performance has led to the design and selection of newer variants of the composite. The present investigation deals with the study of dry sliding wear performance of Al5083-10 wt. % SiC composites fabricated by Ultrasonic assisted stir casting process. Dry sliding wear tests have been carried out by using Pin-on-Disk wear test rate with normal loads of 10N, 20N, 30N, sliding distance 754 m, 1131 m, 1508 m and sliding velocity 0.42 m/s, 0.63 m/s, 0.84 m/s at constant time 30 minutes. Experiments were conducted based on the plan of experiments generated through Taguchi“s technique. A L9 Orthogonal array was selected for analysis of the output. Investigation to find the influence of applied load, sliding speed and sliding distance on wear rate, during wearing process was carried out using ANOVA and regression equation were developed for 10% SiC reinforced Al-5083 AMMCs. Objective of the model was chosen as “smaller the better” characteristics to analyse the dry sliding wear resistance. In this research it is observed that applied load has the highest influence followed by sliding distance and sliding speed. Finally, the experimental results were validated by the confirmation tests.

In the process of rapid prototyping by the method of selective laser sintering, transient temperature has a direct effect upon the sintering performance. In the present work, a model is developed to predict the three-dimensional transient temperature field. It uses the finite element method to model the variation of thermal properties and solid–liquid two-phase interface in sintering the mixture of Al2O3-coated ceramic powder and polystyrene powder. A high-speed charge-coupled device image temperature measurement system is used to obtain real data from laser sintering experiments for comparison. The test results validate the simulation data and imply that the modelling method is useful in predicting the transient sintering temperature when correct thermal properties and key factors of two-phase interface are main concerns. The performance characteristics of the sintering process are predicted by the modelling method.

Endosulfan is an organochlorine pesticide widely used in agriculture and hence finds its way into natural water bodies, thus affecting aquatic life. The purpose of this study was to determine LC50 of endosulfan (99%; α:β ratio of 7:3) in Tilapia, Oreochromis mossambicus and study its effect on anti-oxidative enzymes (superoxide dismutase, glutathione-S-transferase and catalase), immuno-hematological profile (RBC, WBC, Hb, serum protein, albumin-A, globulin-G, A/G ratio, phygocytic activity as indicated by nitroblue tetrazolium reduction, serum cortisol and serum lipid peroxidation) and neurotransmitter acetylcholine esterase enzyme activity. The LC50 value at 96 h and 95% confidence limit for tilapia (46.78 g) was estimated as 3.6 μg/L. Activities of anti-oxidative enzymes, immuno-hematological profile, blood glucose and neurotransmitter activity was significantly influenced (P

The dual-modulus prescaler is a critical block in CMOS systems like high-speed frequency synthesizers. However, the design of high-moduli, high-speed, and low-power dual-modulus prescalers remains a challenge. To face the challenge, this paper introduces the idea of using transmission gates and pseudo-PMOS logic to realize the dual-modulus prescaler. The topology of the prescaler proposed is different from prior designs primarily in two ways: 1) it uses transmission gates in the critical path and 2) the D flip-flops (DFFs) used in the synchronous counter comprise pseudo-PMOS inverters and ratioed latches. A pseudo-PMOS logic-based DFF is introduced and used in the proposed prescaler design. Based on the proposed topology, a dual-modulus divide-by-127/128 prescaler is implemented in 0.35-/spl mu/m CMOS technology. It consumes 4.8 mW from a 3-V supply. The measured phase noise is -143.4 dBc/Hz at 600 kHz. The silicon area required is only 0.06 mm/sup 2/. There are no flip flops or logic gates in the critical path. This topology is suitable for high-speed and high-moduli prescaler designs. It reduces: 1) design complexity; 2) power consumption; and 3) input loading. Measurement results are provided. An improvement in the figure of merit is shown.