MR. A. A. CAMPBELL SWINTON, in his letter on the above subject in NATURE of December 18, states that “it is hopeless to expect to be able to effect anything of this nature with the heat-engine, for with this we should scarcely reach the 2 per cent, efficiency nearly attained by vegetation.”

Power from the Sun

A novel manufacturing method based on Vacuum Assisted Resin Transfer Molding (VARTM) was devised to incorporate carbon nanoparticles for the enhancement of thermal properties of multiscale laminates. Several graphene-based nanomaterials including graphene oxide (GO), reduced graphene oxide (rGO), graphene nanoplatelets (GNPs) and multi-walled carbon nanotubes (MWCNTs) were used to modify the epoxy matrix and the surface of glass fibers. The thermal, rheological and morphological properties of the resulting glass fiber-reinforced multiscale composites were investigated. The thermal properties of the epoxy/nanoparticle composites were studied through thermal conductivity measurements, differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). The thermal characterization results showed that the introduction of GNPs, GO, rGO, and MWCNTs enhanced thermal conductivity. Compared with the neat epoxy/fiberglass composite control results, improvement in thermal conductivity of fiberglass/epoxy modified with MWCNTs 0.3%, GNPs 1%, GO 2% and rGO 0.042% were 8.8%, 12.6%, 8.2% and 4.1%, respectively. It was concluded that for the same volume fraction of nanoparticles, the thermal conductivity improvement in graphene nanoplatelets-modified composites is more pronounced compared with other nanoparticles. A better dispersion of nanoparticles and a better interfacial interaction between nanoparticles and epoxy are essential in enhancing the thermal conductivity of nanocomposite materials.

Thermal properties of doubly reinforced fiberglass/epoxy composites with graphene nanoplatelets, graphene oxide and reduced-graphene oxide

Development and curing potential of epoxy/starch-functionalized graphene oxide nanocomposite coatings

The present work present numerical and experimental investigations to study the performance of a small-scale parabolic trough solar concentrator integrated with thermal energy storage system. A new design of receiver which uses the phase change material to store the thermal energy is built. A parabolic-trough solar concentrator was proposed and constructed using a concentric absorber tube with phase change material. The absorber is considered as a temporary thermal heat storage component. The heat storage-recovery mechanism will act as a thermal compensator that allows the parabolic trough solar concentrator to stabilizing energy output during the absence of intense radiation or for short time cloudy conditions. The PCM used a binary salt composed of a mixture of 60% NaNO3 and 40% KNO3, filling the annular space of the absorber tube. Solar energy is converted to heat, stored in the phase change material and is discharged to cold water, which is the final heat transfer fluid in the inner pipe of the receiver. The simultaneous testing of the receiver with and without phase change material is investigated. A commercial computational fluid dynamics model of the whole system is presented and numerical results are compared to experimental results, which were conducted with and without phase change material in the receiver tube. The maximum outlet water temperature achieved using phase change material in the receiver tube is about 16.80% and 14.86% higher than the simple tube for 21 July and 21 October respectively. The daily thermal efficiency of the parabolic trough solar concentrator increases by 6.56% and 8.32 respectively for a both days using a receiver with a phase change material concentric tube. The phase change material showed good heat retention of 2 h to 1 h 40 min for water inlet temperature 30°C and 40°C respectively.

Experimental and numerical study of a solar collector using phase change material as heat storage

Graphene and graphene oxide functionalisation with silanes for advanced dispersion and reinforcement of PMMA-based bone cements

Graphene is emerged as a highly sought after reinforcing filler for epoxy matrix in view of its superior electrical, mechanical and thermal properties. Dispersion of low concentration of graphene c...

Influence of covalent and non-covalent modification of graphene on the mechanical, thermal and electrical properties of epoxy/graphene nanocomposites: a review

In this work, high concentration exfoliation (∼0.2 mg/ml) of graphene in ethyl alcohol is achieved in presence of block copolymer of polyethylene oxide–polypropylene oxide–polyethylene oxide (PEO–PPO–PEO) using sonication followed by centrifugation. The obtained graphene solution is used to prepare epoxy nanocomposites. Flexural tests were conducted over epoxy nanocomposites. The 0.018 wt% of PEO–PPO–PEO block copolymer exfoliated graphene in epoxy matrix shows 21.7% and 15.8% enhancement in flexural modulus and flexural strength respectively as compared to pure epoxy. Transmission electron microscopy reveals well dispersion of graphene in epoxy matrix; and fractography of flexural fractured sample shows graphene dispersion restricts the crack propagation. The well-dispersed graphene in epoxy matrix increase the dielectric constant and thermal stability of epoxy nanocomposites. Further, the enhanced graphene dispersion in epoxy nanocomposites reduces the glass transition temperature (Tg). Thus, en...

High concentration exfoliation of graphene in ethyl alcohol using block copolymer surfactant and its influence on properties of epoxy nanocomposites

Concentrating collectors absorbs solar energy and convert it into heat for generating hot water, steam at required temperature, which can be further used for solar thermal applications. The developing countries like India where solar energy is abundantly available; there is need to develop technology for harnessing solar energy for power production, but the main problem associated with concentrating solar power technology is the high cost of installation and low output efficiency. To solve this problem, a prototype cylindrical parabolic solar collector having aperture area of 1.89 m 2 is designed and developed using low cost highly reflecting and absorbing material to reduce initial cost of project and improve thermal efficiency. ASHRAE Standard 93, 1986 was used to evaluate the thermal performance and it was observed that this system can generate hot water at an average temperature of 50 0 C per day with an average efficiency of 49% which is considerable higher than flat plate solar collectors. Hot water produced by this system can be useful for domestic, agricultural, industrial process heat applications. Article History : Received Sept 19, 2015; Received in revised form Dec 23, 2015; Accepted February 2 , 2016; Available online How to Cite This Article : Bhujangrao, K.H. (2016). Design and Development of Prototype Cylindrical Parabolic Solar Collector for Water Heating Application. International Journal of Renewable Energy Development, 5(1), 49-55 http://dx.doi.org/10.14710/ijred.5.1.49-55

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Design and Development of Prototype Cylindrical Parabolic Solar Collector for Water Heating Application

Machine shop layout can be designed and modelled using either traditional or modern techniques. Traditional techniques are time consuming and are not much superior so that manufacturing industry are facing real time problems. Machine shops designed in traditional way facing the problems like unavailability of sufficient space for material handling, back tracking issue and presence of bottleneck etc. Flexsim is a simulation software used to model, visualize, simulateand monitor the Machine locations and flow of activities. In present work a modern approach of modelling a machine layout is done by simulation. Flexsim software is implemented to measure and analyze the performance of machine shop layout by performing 5 iterations. Result of each iteration was recorded and it shows that productivity is improved at fifth iteration.

Optimization of machine shop layout by using flexsim software

Halloysite nanotubes (HNTs) are modified successfully using polyethyleneimine (PEI). The HNTs and HNTs modified using PEI filled 90/10 (wt/wt) polypropylene (PP) and acrylonitrile butadiene styrene...

https://journals.sagepub.com/doi/pdf/10.1177/096369351702600602

Hrushikesh B. Kulkarni

Papers

Influence of covalent and non-covalent modification of graphene on the mechanical, thermal and electrical properties of epoxy/graphene nanocomposites: a review

High concentration exfoliation of graphene in ethyl alcohol using block copolymer surfactant and its influence on properties of epoxy nanocomposites

Design and Development of Prototype Cylindrical Parabolic Solar Collector for Water Heating Application

Optimization of machine shop layout by using flexsim software

Morphological, Thermal and Mechanical Properties of 90/10 (WT %/WT %) PP/ABS Blends and their Polymer Nanocomposites: