Thermodynamics and performance evaluation of encapsulated PCM-based energy storage systems for heating application in building

This communication presents the comparative study of two different types of thermal management systems for room’s heating applications using calcium chloride hexahydrate as the thermal energy storage material encapsulated in panels and balls. During the daytime, TMS was outside the test room to store the solar heat in TMS. The solar heat made available to charge the PCM from solid to liquid and to warm the test room throughout the observation period during night time. As the room temperature drops significantly during the night time, so as the level of comfort. Both the thermal management systems have been used to heat the test room during night time and the temperature of the test room has been maintained at thermal comfort level without any conventional source of energy, i.e. using passive system. Also the experimental values were compared with those of the theoretical values and are found in good agreement with each other. Thus, it can be concluded that the experimental study carried out for both the thermal management systems have been validated by theoretical approach or vice versa and hence found to be satisfactory towards the successful operation of these systems.     

Electron scattering with LiH molecule including a realistic dipole potential

Various electron scattering processes are examined theoretically for the strongly polar lithium hydride molecule. We have introduced a realistic dipole potential to calculate rotational cross sections of LiH upon electron impact. From the ionization threshold onwards total cross sections for elastic and inelastic scattering are evaluated in the complex molecular potential, and total ionization cross sections are extracted by CSP-ic method developed in recent years. While most of the results are new some indirect comparisons are made to draw conclusions.     

Study of Interaction of Silver Nanoparticles with Bovine Serum Albumin Using Fluorescence Spectroscopy

The interaction between silver nanoparticles (SNPs) and Bovine Serum Albumin (BSA) was investigated at physiological pH in an aqueous solution using fluorescence spectroscopy. The analysis of fluorescence spectrum and fluorescence intensity indicates that SNPs have a strong ability to quench the intrinsic fluorescence of BSA by both static and dynamic quenching mechanisms. Resonance light scattering (RLS) spectra indicated the formation of a complex between BSA and SNP. The number of binding sites ‘n’ and binding constants ‘K’ were determined at different temperatures based on fluorescence quenching. The thermodynamic parameters namely ∆H^°, ∆G^°, ∆S^° were calculated at different temperatures and the results indicate that hydrophobic forces are predominant in the SNP-BSA complex. Negative ∆G^° values imply that the binding process is spontaneous. Synchronous fluorescence spectra showed a blue shift which is indicative of increasing hydrophobicity.     

A scatter search algorithm for the single row facility layout problem

The single row facility layout problem (SRFLP) is the problem of arranging facilities with given lengths on a line, with the objective of minimizing the weighted sum of the distances between all pairs of facilities. The problem is NP-hard and research has focused on heuristics to solve large instances of the problem. In this paper we present a scatter search algorithm to solve large size SRFLP instances. Our computational experiments show that the scatter search algorithm is an algorithm of choice when solving large size SRFLP instances within limited time.     

Nano-composite soda lime silicate glass prepared using silver ion exchange

Commercial soda lime silicate glasses have been subjected to ion exchange at different temperatures ranging from 320 to 500 °C in a molten mixture of AgNO₃ and NaNO₃ with molar ratio of 10:90, 02:98 and 50:50 for different time periods ranging from 40 to 180 min. Optical and structural properties of the ion exchanged glass are measured using UV–Vis–NIR absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, fluorescence spectroscopy and transmission electron microscopy (TEM). Signature of silver nanoparticle formation is obtained from the UV–Vis–NIR spectra, which shows a peak at 425 nm due to surface plasmon resonance (SPR). Replacement of Na⁺ ions by Ag⁺ ions is inferred from FTIR spectra. Fluorescence spectra reveal the formation of Ag⁰ atoms from Ag⁺ ions at higher temperatures. TEM image shows the silver nanoparticles of average size 3.75 nm. At exchange temperature of 500 °C Ag nanoparticles are formed without post-exchange annealing treatment.     

Hyperfine field and relaxation effect in Li−Zn−Ti ferrites

⁵⁷Fe Mössbauer effect studies were made on titanium substituted Li?Zn ferrite with composition Li_0.45+0.5tZn_0.1 Ti_t Fe_2.45–1.5tO₄ (t=0.0 to 1.2) at 300K. The Mössbauer spectra for t≤0.4 show two well defined Zeeman sextets corresponding to the Fe³⁺ ions at tetrahedral (A) and octahedral (B) sites. The spectra for t=0.6, 0.8 and 0.9 show relaxation but can still be resolved into 2 sextets. The spectra for t=1.0, 1.2 show strong ferrimagnetic relaxation with the spectra for t=1.2 exhibiting an additional central doublet. The effect of Ti⁴⁺ substitution on the Isomer shift (I.S), Quadrupole splitting (Q.S.) and nuclear magnetic fields of Li?Zn ferrites have been reported in this paper. The I.S. was found to be independent of substitution level t, while the quadrupole splitting was observed to be negligible. The variation of hyperfine field with t has been explained on the basis of superexchange interaction and cation distribution.     

Frequency distribution for graphite based on the unfolding technique

We have extended the “unfolding technique”, developed in Reactor Physics, to calculate the frequency distribution function for graphite, starting from the measured values of its specific heat at different temperatures. The advantages and limitations of this approach are discussed.