M. Muruganandam; P.C. Mukesh Kumar
Abstract
Much research works are being carried out in applications of nanofluids at different engineering fields as they have improved thermal conductivity. However, the effective applications of nanofluids have limitations such as poor stability, sedimentation, erosive wear and potential health risk. In heat ...
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Much research works are being carried out in applications of nanofluids at different engineering fields as they have improved thermal conductivity. However, the effective applications of nanofluids have limitations such as poor stability, sedimentation, erosive wear and potential health risk. In heat transfer application point of view, stability of nanoparticles plays a major functionin enhancing heat transfer. In this experimental investigation, the stability of Multi-walled Carbon Nano Tube (MWCNT)/water nanofluids with surfactant and without surfactant has been carried out by keeping the nanofluids at static condition and at constant temperature at different time interval. The nanofluids were prepared by means of the use of Multi-walled Carbon Nano Tube (MWCNT) as base materials and distilled water as base fluids at 0.1%, 0.3%, 0.5% and 0.7% volume concentration with 0.02% and 0.05% sodium dodecyl butane sulfonate (SDBS) as surfactant and without the surfactant two-step method is used to put together the nanofluids underneathattention. The stability analysis ofpreparednanofluids are studied with the UV-Vis. spectrophotometer, measure of zeta potential value , and photograph capturing techniques by keeping the nanofluids under static condition for The MWCNT nanofluids have been characterized with the sample ofjust after preparation after 30days of preparation and after 60 days.It is studied that the nanofluids with surfactant showed better stability than the nanofluids without surfactant. Found that the nanofluids at 0.7% volume concentration with surfactant showed good stability with negligible visual sedimentation even after 60 days than the nanofluids without surfactant. Therefore the MWCNT/water nanofluids are the potential heat transfer fluids to apply in heat transfer field.Copyright © VBRI Press.
Claudio Scarponi
Abstract
The purpose of the paper is the description of the main applications of the so-called “Green Composites”, composed by natural fibers, such as hemp and flax, embedded by bio-polymers and the contribution of such materials to the reduction of the environmental pollution. Since the Kyoto Conference ...
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The purpose of the paper is the description of the main applications of the so-called “Green Composites”, composed by natural fibers, such as hemp and flax, embedded by bio-polymers and the contribution of such materials to the reduction of the environmental pollution. Since the Kyoto Conference at the end of 90’s of the last century, there is higher and higher attention to the concepts of sustainability. The market of composite materials based on synthetic resins and synthetic fibers, such as glass and carbon fibers, is huge. Billions of tons worldwide are used in the fields of civil constructions, marine constructions, sport goods, automotive, aerospace constructions. After a short description of the most interesting bio-polymers and natural fibers of interest worldwide, the paper describes the products developed nowadays and future possibilities for more applications, with care to future applications in aeronautical constructions.
M. K. Gupta; Kunwar Rohit
Abstract
In present work, epoxy based glass composite is prepared using hand lay-up method followed by static compression with varying numbers of woven glass layers. Dynamic mechanical properties of prepared glass composites are studied in terms of storage modulus (E'), loss modulus (E''), damping (Tand) and ...
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In present work, epoxy based glass composite is prepared using hand lay-up method followed by static compression with varying numbers of woven glass layers. Dynamic mechanical properties of prepared glass composites are studied in terms of storage modulus (E'), loss modulus (E''), damping (Tand) and glass transition temperature (Tg) as a function of temperature. The results indicated that value of E' and Tg increases whereas value of Tand decreases as increase in temperature. In addition, value of Tg obtained from Tand curve is found lower than that obtained from peak of E'' curve. The present glass composites are suitable for constructions, automobiles and aerospace industries due to its better dynamic mechanical properties and thermal stability. Copyright © 2017 VBRI Press.
