Recent applications of gallium and gallium halides as reagents in organic synthesis

This review highlights the application of gallium metal and gallium halides as reagents in organic synthesis. Owing to their unique catalytic properties, gallium trihalides are considered effective Lewis acids which can activate several functional groups under extremely mild conditions. Gallium halides have been successfully employed as Lewis acid catalysts in various organic transformations such as alkylation, allylation, radical reactions, cycloaddition reactions, Friedel-Craft’s reactions and various coupling reactions. This review seeks to update organic chemists about the potential application of gallium halides in the synthesis of a wide variety of chemical building blocks

Hearty miR-363 controls HAND1 in cardiac cell specification

MicroRNAs regulate target gene expression post-transcriptionally in a myriad of cell types and play critical roles in diverse physiological and pathological processes, including cardiomyocyte development, differentiation, and regeneration. The recent publication in Stem Cell Research and Therapy by Wagh and colleagues reports a novel regulatory role for miR-363 in cardiomyocyte specification. By employing microRNA expression profiling and functional knockdown studies on human embryonic stem cell-derived cardiomyocytes, the authors identified miR-363 as an upstream negative regulator of left ventricular specification transcription factor HAND1

A Review on Characterization of Hybrid Fibre Reinforced Polymer Composite

Fibre reinforced polymer composite are well recognized materials for automobile, aerospace, packaging and construction industries due to its properties such as light weight, low cost and high specific strength. Hybridization of fibres has become very popular technique to increase the properties of single fibre reinforced polymer composite. This paper presents review  on mechanical properties, thermal properties, water absorption properties, dynamic mechanical analysis and tribological behaviour of hybrid fibre reinforced polymer composite. Finding of this study shows that hybridization can improved mechanical, thermal and dynamic mechanical property, and decrease water absorption property and wear rate

Influence of Concentrations of Alkali Treatment on Mechanical and Dynamic Mechanical Properties of Hemp/Polyester Composite

In present work, hemp fibres were subjected to alkali treatments at various concentrations (5, 10 15 wt.%) to prepare its polyester based composites.  Hemp fibre reinforced polyester composites were prepared by hand lay-up technique followed by static compression keeping constant 25 wt.% of fibres content in order to study influence of alkali treatment concentrations on its mechanical and dynamic mechanical properties. Mechanical properties of prepared composites were  studied in terms of tensile strength and modulus, and flexural strength and modulus whereas dynamic mechanical properties were studied in terms of storage modulus (), damping (), glass transition temperature (Tg) and effectiveness constant of reinforcement ().  The results indicated that mechanical and dynamic mechanical properties were found to increase  due to alkali treatment up to 5%  concentration and then decrease.

Effect of Sisal Fibre Loading on Wear and Friction Properties of Jute Fibre Reinforced Epoxy Composite

This paper presents an experimental study on wear and frictional properties of developed hybrid sisal/jute fibre reinforced epoxy composite. Composite are fabricated by hand lay-up technique keeping constant 30 wt. % of fibre content. Wear and frictional properties of hybrid composite is carried out at different operating parameters such as applied load (10-30 N), sliding speed (1-3m/s) and constant sliding distance 1000 m. Alkali treatment of fibres is used to increase the percentage reduction of wear rate and friction coefficient.  The experimental results show that increase in specific wear rate and coefficient of friction is found on increasing the applied load and sliding speed.

Effects of treatments on the properties of polyester based hemp composite

The aim of present study is to enhance the properties of polyester based hemp composites by using different treatments.The effect of different treatments, such as alkali and benzoylation (chemical treatments), and sodium bicarbonate(ecofriendly treatment), on water absorption, and mechanical & dynamic mechanical properties of hemp/polyestercomposites has been studied. The composites are prepared by hand lay-up technique using constant (15 wt. %) fibrescontent. Water absorption properties are investigated in terms of maximum water uptake, and sorption, diffusion &permeability coefficients. Dynamic mechanical properties, such as storage modulus E', glass transition temperature g T & damping Tan , and mechanical properties such as tensile strength & modulus, flexural strength & modulus,and impact strength are also investigated. The results suggest a significant effect of chemical treatment in terms of increasein mechanical and dynamic mechanical properties, and decrease in water absorption properties. The benzoylation treatmentshows the better impact among all three chemical treatments

Mechanical and Water Absorption Properties of Hybrid Sisal/Glass Fibre Reinforced Epoxy Composite

Our environment is being pullulated due to the great use of synthetic fibre as reinforcement for polymer composites. Natural fibres may be better choice for replacement of synthetic fibre for polymer composite to reduced environment burden. Hybrid sisal/glass fibre reinforced epoxy composites are prepared by hand lay-up technique using different weight fractions (10, 20, 30 and 40 %) with 10 mm length of fibres. Mechanical and water absorption properties of prepared composites are investigated. This study shows that the addition of glass fibre into sisal fibre reinforced composite has increased its mechanical properties. Statistical analysis is also carried out using T-test and ANOVA and found significant variation among composites