Analysis of the opportunities and challenges of solar water heating system (SWHS) in India: Estimates from the energy audit surveys & review

A solar water heating system (SWHS) is a device that makes available the thermal energy of the incident solar radiation for use in various water heating applications. SWHS largely depends on the performance of the collector's efficiency at capturing the incident solar radiation and transferring it to the water. With today's SWHS, water can be heated up to temperatures of 60–80 °C. Heated water is collected in a tank insulated to prevent heat loss. Circulation of water from the tank through the collectors and back to the tank continues automatically due to the thermosiphon principle. The hot water generated finds many end-use applications in domestic, commercial, and industrial sectors. India has the highest energy intensities in Asia. Very little investment and priority are being given to increase of the efficiency. On the other hand, the India has a high potential for developing energy production from renewable energy sources (RES): solar, water, wind and biomass. However, these potentials are not studied and exploited enough and the present situation for their utilization is not so good. Although energy is a critical foundation for economic growth and social progress of any country, there are many constraints for RES development in all of them (political, technological, financial, legislative, educational, etc.). Obviously, defining development strategies and new support measures is necessary since renewable energy sources can make an important contribution to the regional energy supply and security. The main purpose of this paper is to explore the solar water heating system (opportunities) in India.     

Electron Beam Irradiation to Recrosslink Devulcanized Sulfur Cured Rubber Blended Polypropylene

This study aims to investigate the effect electron beam (EB) irradiation on the polypropylene/devulcanized sulfur cured rubber (PP‐DVC) compound. The PP‐DVC compounds were compounded using twin‐screw extruder and then compression molded into required shapes before irradiation begins. The gel content of all irradiated PP‐DVC compounds gradually increased with higher irradiation dose indicated that the presence of DVC plays an important role in crosslinking enhancement. The mechanical properties of PP‐DVC compounds were observed marginally higher at low irradiation dosages (≤50 kGy). However, higher irradiation dosages up to 200 kGy cause adverse effect to the PP‐DVC compounds. In addition, the application of low irradiation dosage could enhance the dispersion of DVC particles at 20 phr composition in PP matrix. This also found that the scanning electron microscopy (SEM) observation where the DVC particles dispersed better in PP matrix compared to that of nonirradiated samples. Further increment in irradiation dosages up to 200 kGy reduced the crystallinity caused by chain scissoring process could rupture the crystalline structure in PP matrix. It was also found that the wavenumber of the C? H and CH₂ groups for irradiated samples reduced at high irradiation dosages due to the formation of carbonyl group. POLYM. ENG. SCI., 59:1017–1027, 2019. © 2019 Society of Plastics Engineers     

Heterogeneity in phenotypic and genotypic characteristics among strains of Hafnia alvei

Hafnia alvei is an emerging human pathogen associated with sporadic cases and outbreaks of diarrhea. Bangladeshi isolates of H. alvei possess the Escherichia coli attaching and effacing (eaeA) gene and demonstrate an attaching and effacing phenotype. In the present study we examined 11 Canadian H. alvei isolates and strain 19,982 from Bangladesh to determine if the formation of attaching and effacing lesions is a property shared among multiple isolates. Attaching and effacing lesions were detected by induction of tyrosine kinase protein phosphorylation and cytoskeletal rearrangements in infected tissue culture epithelial cells with immunofluorescence microscopy and by the examination of infected cells with transmission electron microscopy. The presence of the eaeA gene was examined by PCR and colony blot hybridization. Profiles of outer membrane protein extracts, chromosomal macrorestriction fragments, and plasmids were also examined. Accumulation of host phosphotyrosine proteins and rearrangement of the cytoskeletal protein alpha-actinin were both observed in HEp-2 cells infected with H. alvei 19,982. In contrast, none of the other 11 clinical H. alvei isolates demonstrated either of these responses, nor did they form attaching and effacing lesions under electron microscopy. Consistent with the absence of the attaching and effacing phenotype, these clinical isolates did not possess the eaeA gene. The outer membrane protein profiles of all the Canadian isolates were identical but differed from that of H. alvei 19,982. Pulsed-field gel electrophoresis and plasmid profile analyses of the clinical H. alvei isolates differed substantially from those of the Bangladeshi strain. These results indicate that there is heterogeneity among H. alvei strains with respect to signal transduction, attaching and effacing adhesion, outer membrane constituents, and genotype. Epidemiological studies on enteropathogenic H. alvei thus need to go beyond simple species designations and require specific identification of the virulent clones.     

Third-sound resonance and thermal resistance in unsaturated helium films

We have obtained a thermodynamic state of thin helium films which permits precision measurements of their properties. Third-sound resonances indicate a transition in the superfluid density of these films. This transition is accompanied by an exponential rise in the thermal resistance of the helium film which indicates the formation of high-energy excitations of 0.08 eV. The dissipation at resonance indicates that thermodynamic fluctuations are the principal mode of third-sound damping.A revised approach to the data in this paper appeared inPhysical Review Letters, Vol. 25, No. 11, page 711ff, September 14, 1970.This research was supported in part by the Advanced Research Projects Agency under Contract SD-131 and in part by the Alfred P. Sloan Foundation.Alfred P. Sloan Fellow.     

Oil palm empty fruit bunch (OPEFB) fiber reinforced PVC/ENR blend-electron beam irradiation

The effect of irradiation on the tensile properties of oil palm empty fruit bunch (OPEFB) fiber reinforced poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends were studied. The composites were prepared by mixing the fiber and the PVC/ENR blend using HAAKE Rheomixer at 150 °C. The composites were then irradiated by using a 3.0 MeV electron beam machine at doses ranging from 0 to 100 kGy in air and room temperature. The tensile strength, Young’s modulus, elongation at break and gel fraction of the composites were measured. Comparative studies were also made by using poly(methyl acrylate) grafted OPEFB fiber in the similar blend system. An increase in tensile strength, Young’s modulus and gel fraction, with a concurrent reduction in the elongation at break (Eb) of the PVC/ENR/OPEFB composites were observed upon electron beam irradiation. Studies revealed that grafting of the OPEFB fiber with methyl acrylate did not cause appreciable effect to the tensile properties and gel fraction of the composites upon irradiation. The morphology of fractured surfaces of the composites, examined by a scanning electron microscope showed an improvement in the adhesion between the fiber and the matrix was achieved upon grafting of the fiber with methyl acrylate.     

Electron beam irradiation of epoxidized natural rubber: FTIR studies

The effect of irradiation on the structure of epoxidized (50 %) natural rubber (ENR50) has been studied using Fourier transform infrared spectroscopy (FTIR). ENR50 was irradiated using a 3.0 MeV electron beam machine with doses ranging from 20 to 200 kGy. The influence of several additives such as trimethylolpropane triacrylate (TMPTA). Irganox®1010, and tribasic lead sulfate on the irradiation‐induced changes of ENR50 is investigated. Upon irradiation, ring opening of epoxide groups, and oxidation and crosslinking of residual double bonds occurred, leading to decreases in the intensities of epoxide and cis double bond bands and an increases in ether, furan and hydroxyl bands. Gel fraction and hardness values have been used to correlate changes in the structure of the rubber upon irradiation. The results show that the increase in gel fraction upon irradiation of pure ENR50 can be associated with irradiation‐induced crosslinking, ring opening side‐chain reactions of oxirane groups and oxidation at the cis‐double bonds. The addition of Irganox®1010 and tribasic lead sulfate inhibits irradiation‐induced reactions in ENR50 to a considerable extent. The importance of TMPTA in preventing intramolecular ring opening side‐chain reactions is also discussed. However, our studies do not reveal the exact nature of the irradiation‐induced reactions involved in ENR. © 2000 Society of Chemical Industry     

Effect of electron beam irradiation on (waste tire dust)‐filled ethylene vinyl acetate in the presence of bisphenol a diglycidyl ether

The effect of bisphenol A diglycidyl ether (BADGE) and electron beam (EB) irradiation on the properties of waste tire dust (WTD) ‐filled ethylene vinyl acetate (EVA) has been studied. The EVA/WTD ratio was fixed to 80:20, whereas the BADGE concentration varied from 1 to 5 wt%. The samples were then irradiated using a 3.0‐MeV EB machine at 50 kGy to 200 kGy at increments of 50 kGy. All the samples were subjected to various mechanical, physical, and thermal tests. Prior to irradiation, the mechanical properties of the composites show a gradual decrease with increasing BADGE concentration. Such observation is attributed to the plasticizing effect of the BADGE, as indicated by the reduction in mixing torque and a 14% increase in the elongation at break with the addition of 5 wt% BADGE. Results of gel fraction indicated that BADGE did not accelerate the irradiation‐induced crosslinking of EVA/WTD composites. The scanning electron micrographs and tan δ curves of EVA/WTD composites showed evidence that the addition of BADGE and EB irradiation of the EVA/WTD improves the compatibility of the composite. The overall results revealed that the irradiated EVA/WTD composite without BADGE gives a better enhancement in mechanical properties compared with the composites incorporated with the BADGE. J. VINYL ADDIT. TECHNOL., 23:172–180, 2017. © 2015 Society of Plastics Engineers     

Mechanical,Thermal and Electrical Properties of Ethylene Vinyl Acetate Irradiated by an Electron-Beam

The effects of electron beam irradiation of (ethylene vinyl acetate) EVA containing 18% vinyl acetate was studied. The EVA sample was then irradiated by using 3 MeV electron beam machine at doses ranging from 120 to 360 kGy in air at room temperature and analyzed for mechanical, thermal and electrical properties. It was revealed by DSC analysis that the crystallinity of the electron-beam radiated EVA decreased slightly as verified by a marginal reduction in the densities and heats of melting. Thermal degradation of EVA occurred through two steps as shown by the thermogravimetric curve with maximum rates of 350 and 450°C, respectively. The results obtained from both gel content and hot set tests showed that under the irradiation conditions employed, the EVA sample cross-linked by the electron beam irradiation, and the degree of cross-linking in the amorphous regions was dependent on the irradiation dose. A significant improvement in the tensile strength of the neat EVA samples was obtained upon electron-beam radiation up to 210 kGy with a concomitant decline in elongation of break. Various electrical properties of EVA such as surface and volume resistance, breakdown voltage and dielectric constant were studied as a function of radiation dose. It was revealed that the surface resistance and volume resistivity of the EVA reaches a maximum at a 190 kGy dose of radiation. No considerable change of breakdown voltage and dielectric constant was observed with increasing irradiation dose. These studies suggest that radiation-cured EVA is more thermally and mechanically stable than pure EVA. Similarly, the results from the electrical properties revealed that surface and volume resistance are higher than pure EVA.     

Interactive effects of carbon nanotube and montmorrilonite reinforcement polyvinyl alcohol composite system

This work was conducted to investigate the interactive effect of carbon nanotubes (CNTs) and montmorillonite (MMT) on the mechanical–physical properties of the polyvinyl alcohol (PVOH) nanocomposites. The increasing of CNTs amounts from 0.5 phr to 1 phr has gradually increased tensile strength and Young's modulus of all PVOH/MMT blends due to good interaction effect between MMT and CNTs with PVOH matrix especially for 2 phr MMT added PVOH blends. Besides, the addition of low CNTs amounts (≤1 phr) in PVOH matrix has significantly weakened the hydrogen bonding polymer matrix of all PVOH/MMT blends as evaluated in FTIR analysis. This is attributed to the good of dispersion of low amounts of CNTs could disturb the hydrogen bonding between PVOH molecules and thus induced the strength of O? H stretching in PVOH matrix. However, higher amounts of CNTs (≥1.5 phr) have significantly increased hydrogen bonding in PVOH matrix due to the agglomeration of higher amounts of CNTs particles in PVOH matrix as observed in Fourier transform infrared spectroscopy and scanning electron microscopy analysis. From X‐ray diffraction and transmission electron microscopy observation, the MMT particles were found to effectively exfoliate in PVOH matrix of 2 phr MMT (low amounts) added PVOH/MMT/MCNTs composites, indicates that low MMT amounts could improve the interaction effect between PVOH matrix and CNTs particles. In conclusion, the incorporation of lower amounts of CNTs has effectively improved on the mechanical and physical properties of all PVOH and PVOH/MMT blends. J. VINYL ADDIT. TECHNOL., 26:77–89, 2020. © 2019 Society of Plastics Engineers     

A review of antimicrobial fabric containing nanostructures metal‐based compound

Textile can be a potential microorganism's propagation site because it contacts with human skin endows optimal conditions combination of nutrient sources, temperature, and moisture which provides conducive environment for microorganism growth. Thus, the development of antibacterial textile is crucial to inhibit the growth of microorganisms for protection the health and safety of wearer. This review article focuses on several metal‐based nanoparticles possess biocidal feature namely, Ag, ZnO, Cu based, TiO₂, and other minor metals based such as iron based, CeO₂, Au, SiO₂, Ni, and Pt. The phenomenology of metal nanoparticles associated to the antibacterial effects and possible mechanisms of action against bacteria have been highlighted. This review also discussed the synthesis techniques and effects of incorporation additive materials of those metal‐based nanoparticles to inhibit the growth of microorganisms. J. VINYL ADDIT. TECHNOL., 2017. © 2017 Society of Plastics Engineers