Applications of graphene nanomaterials in energy storage—A state-of-art short review

The study presents the usage behavior of graphene in the energy field. Graphene has been comprehensively studied in the energy-related application due to higher conductivity and mechanical flexibility. The architecture of graphene permits it to strengthen and facilitate its application in the energy arena. Herein, the application of graphene in various energy storages such as fuel cells, dye-sensitized solar cells, batteries, nuclear power plants, and thermoelectric has been studied neatly. Graphene reacts towards these substances chemically, mechanically, and electrically to a great extend and appears with the excellent output of these objects. In the future graphene could be applied to the others field of energy and science successfully

Cotton waste research follows the effect of pre-treatment and the observation of physical appearance

This paper aims to evaluate the waste cotton quality and its commercialization. The recycled cotton demand seems to be increased day by day: although the lower quality of the resulting items is the biggest barrier to cotton recycling. A thorough analysis of recycled cotton processes is therefore necessary from separation/shredding to completion. To that end, textile wastes made of pre-consumer cotton were systematically collected from the spinning mill. After pretreatment of cotton waste cellulose by caustic soda, alkali, and detergent in 100°C temperature for 30 minutes have produced white clean cotton. Following the next process by sodium hydroxide and isopropyl alcohol must produce Carboxymethyl Cellulose (CMC). CMC has big use in Textile printing, finishing, and warp sizing even in Ice-cream and food baking industry. Recent success stories will be addressed with the steady cotton processing to altering the properties of cell wall cotton and cotton fiber. The prospects of conducting experiments of waste cotton and checking the properties of treated cotton have a great value in the production of commercial products and the results relived that the value addition of waste cotton is a very easy method

Internal energy analysis with nanofluids in header and riser tube of flat plate solar collector by CFD modelling

In this study, Computational Fluid Dynamics (CFD) modelling of internal energy with different nanofluids (TiO2 and crystal nano cellulose) studied. The modelling was three dimensional under Viscous Laminar model. The base fluid for nanoparticles was 60% water+40% ethylene glycol along with individual water and ethylene glycol fluids. Volume fraction of nanofluids was 0.5% and single-phase model used. The diameter of inlet and outlet was fixed of individual model and three kinds of designing model used here. The diameter of both header and riser tubes varied whereas the number of tubes varied only for riser. The results revealed that diameter and number of tubes (riser) do not affect on the internal energy. Since internal energy only depends on different properties of the inside fluids

CFD modelling of different properties of nanofluids in header and riser tube of flat plate solar collector

This paper aimed to evaluate the state of three different flow parameters of nanofluids and hybrid nanofluids flowing through inside header and riser tube of flat plate solar collector. This research work studied with Computational fluid dynamics (CFD) modelling method using nanofluids (Al2O3, TiO2, ZnO) and hybrid nanofluids (Al2O3+TiO2, TiO2+ZnO, ZnO + Al2O3). The modelling was three dimensional under k-epsilon turbulence model, which was set with Standard and Standard Wall Functions. Besides, Absolute reference frame and calculative intensity percentage was fixed. The base fluid was water as well as volume fraction of nanofluids and hybrid nanofluids was 0.1%. Single-phase viscous model with energy equation used. Three types of design models (Model A, B and C) used with fixed inlet and outlet diameter. The number of header tubes fixed with two, but the number of riser tube varied such as two, seven and twelve. Maximum dynamic pressure increased in model B for both nanofluid and hybrid nanofluid of about 48% and 16% respectively. Velocity magnitude enhanced in maximal for both nanofluid and hybrid nanofluid in model B. Besides, highest turbulence kinetic energy achieved in model A (5.5%) for nanofluids and in model B (18%) for hybrid nanofluids. Model B perform better comparing with model A and model C

Improvement in the performance of solar collectors with nanofluids - A state-of-the-art review

The upward energy demand along with the depletion of conventional energy sources demands improved utilization of renewable energy resources. Among many energy resources, solar energy is the most appropriate alternative to conventional energy sources owing to its inexhaustibility and green property. Solar collectors are the devices which convert the solar radiation into heat or energy. Solar collector’s efficiency should be improved by nanofluids. The importance and significance of nanofluid on the performance of solar collectors especially on thermal properties are extensively described here. Six types of solar collector’s viz. flat plate, evacuated tube, direct absorber, parabolic trough, solar dish, and photovoltaic thermal solar collector performance has been extensively reviewed here. The nanomaterials such as TiO2, CuO, ZnO, Al2O3, and MWCNTS in base fluids with polymer dispersant or surfactants forming nanofluids for the mentioned types of solar collectors are compiled. Further, the quantification of the improvement in solar collector performance utilizing these nanofluids as working fluid is compiled. Recent problems of these nanofluids performance in the solar collectors are included and a future recommendation of research based on these problems is also covered