Comparative Study of Bituminous Mixes Modified by EVA and Crumb Rubber

A good wearing course play very important role for the protection of flexible pavement. Bitumen wearing course in the hot climate area not been performing good on heavy traffic volume highways with life of wearing course not exceeding four years due the brittleness caused by oxidation of binder. Use of bituminous mixes modified by Ethylene vinyl acetate and crumb rubber in the construction of flexible pavement is gaining importance because of many reasons. EVA and Crumb rubber is non biodegradable materials. Addition of this type of materials in the bituminous mixes increase the strength and life of flexible pavement. Conventional bitumen does not have attraction with water. When bitumen is used in flexible pavement during and after rainy season there is possibility of formation of potholes. Bitumen is not good with high air voids, due to which cracks are developed in the flexible pavement. The present work is carried out to find solutions on potholes and cracks formation in case of flexible pavement by the replacement of bitumen by EVA and crumb rubber in various percentages like 2 %, 4%, 6% by the weight in 60/70 grade bitumen. DOI: 10.17762/ijritcc2321-8169.150516

“STRUCTURAL PROPERTIES OF HOLMIUM DOPED COBALT FERRITE BY STANDARD CERAMIC TECHNIQUE”

Objective: Compositions of CoHoxFe2-xO4 (x = 0.00 and 0.02) was prepared by standard ceramic technique using AR grade CoO2, Ho2O3 and Fe2O3. The samples were characterized by X-ray diffraction technique and the analysis of XRD patterns reveals the formation of single phase cubic spinel structure. The structural parameters like lattice constant (a), x- ray density(dx), bulk density (dB), particle size (t) and porosity (P), tetrahedral and octahedral bondlength (dAX and dBX), the tetrahedral edge (dAXE), and the shared and unshared octahedral edge (dBEX and dBXEU) can be calculated were calculated form XRD data and effect of Ho3+ doped cobalt ferrite was studied. Thus, the rare earth Ho3+ doped cobalt ferrite strongly influences the physical properties of cobalt ferrite. Materials and Methods: Present series was prepared by standard ceramic technique using AR grade CoO2, Ho2O3 and Fe2O3. Results: The XRD pattern shows that both the samples possess single phase cubic spinel structure. No extra peak of Ho3+ is observed for x =0.02 sample. Lattice constant, X-ray density of Ho3+ doped cobalt ferrite is increases than that of pure cobalt ferrite. Conclusion: The rare earth Ho3+ doped cobalt ferrite strongly influences the physical properties of cobalt ferrite

Institutional Repositories in India: A preliminary study

This preliminary study investigates various aspects of institutional repositories (IR’s) developed in India. The present study has identified the existence of 16 functional IRs some of which were not registered in any of the directories such as ROAR, Open DOAR. The study explores the timeline involved in planning, pilot testing, to system implementation of IR, exploratory activities conducted before implementing IR, its anticipated benefits

Synthesis of Nanostructured Tin Oxide (SnO2) Powders and Thin Films Prepared by Sol-Gel Method

Nanocrystalline SnO2 powder was successfully prepared by using simple sol-gel technique. The sol-gel obtained was washed and calcinated at 400 C to obtain the SnO2 nano-powder. The structural property of (SnO2) nanocrystalline powder was investigated by using X-ray diffraction (XRD) technique. The optical properties were studied using Uv-Vis Spectroscopy, by recording the absorbance and transmittance spectra. The XRD pattern of the as-prepared sample demonstrated the formation of a rutile structure of SnO2 nanocrystallites. The Scanning Electron Microscopic (SEM) analysis showed a homogeneous distribution of quite small grains over scanned area. The Uv-Vis absorbance spectra also showed a characteristic peak of absorbance at 312 nm corresponding to SnO2. The energy band gap measurement for nanocrystalline SnO2 thin film was done from the graph of variation of (hν)2 versus hν. The measured value of optical bandgap energies for SnO2 thin film is 3.78 eV. The results show that the transmittance of the synthesized SnO2 film is 78 % in the spectral range 350 nm to 800 nm

Synthesis of Nanostructured Tin Oxide (SnO2) Powders and Thin Films Prepared by Sol-Gel Method

Nanocrystalline SnO2 powder was successfully prepared by using simple sol-gel technique. The sol-gel obtained was washed and calcinated at 400 C to obtain the SnO2 nano-powder. The structural property of (SnO2) nanocrystalline powder was investigated by using X-ray diffraction (XRD) technique. The optical properties were studied using Uv-Vis Spectroscopy, by recording the absorbance and transmittance spectra. The XRD pattern of the as-prepared sample demonstrated the formation of a rutile structure of SnO2 nanocrystallites. The Scanning Electron Microscopic (SEM) analysis showed a homogeneous distribution of quite small grains over scanned area. The Uv-Vis absorbance spectra also showed a characteristic peak of absorbance at 312 nm corresponding to SnO2. The energy band gap measurement for nanocrystalline SnO2 thin film was done from the graph of variation of (hν)2 versus hν. The measured value of optical bandgap energies for SnO2 thin film is 3.78 eV. The results show that the transmittance of the synthesized SnO2 film is 78 % in the spectral range 350 nm to 800 nm

Spray Deposited Nanocrystalline ZnO Transparent Electrodes: Role of Precursor Solvent

Nanocrystalline ZnO thin films were deposited by intermittent spray pyrolysis using different alcoholic and aqua-alcoholic precursor solvents. The XRD analysis reveals the polycrystallinity of hexagonal wurtzite type ZnO films with preferred c-axis orientation along [002] direction. The polycrystallinity increased due to use of aqua-alcoholic precursor solvent. The crystallite size was found to vary from 41.7 nm to 59.4 nm and blue shift in band-gap energy (3.225 eV to 3.255 eV) was observed due to aqua-alcoholic to alcoholic precursor solvent transition. The films deposited using alcoholic precursor solvent exhibited high transmittance (> 92 %) with low dark resistivity (10 – 3 Ω·cm) as compared to aqua-alcoholic precursor solvent. The effect of precursor solvent on resistivity, carrier concentration (η – /cm3), carrier mobility (μ – cm2V – 1s – 1), sheet resistance (Ω/) and figure of merit (ΦTC) is also reported. We recommend ethanol or methanol as a superior precursor solvent over aqua-alcoholic precursor solvent for deposition of device quality ZnO thin films

Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by Fermi and Swift during the LIGO-Virgo Run O3b

We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC-2020 March 27 17:00 UTC). We conduct two independent searches: A generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate. © 2022. The Author(s). Published by the American Astronomical Society

Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run

Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search, we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets. © 2022. The Author(s). Published by the American Astronomical Society

Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at √S^{S}NN = 5.02 TeV

The second-order Fourier coefficients (υ$_{2}$) characterizing the azimuthal distributions of Υ(1S) and Υ(2S) mesons produced in PbPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV are studied. The Υmesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb$^{-1}$. The scalar product method is used to extract the υ$_{2}$ coefficients of the azimuthal distributions. Results are reported for the rapidity range |y| < 2.4, in the transverse momentum interval 0 < p$_{T}$ < 50 GeV/c, and in three centrality ranges of 10–30%, 30–50% and 50–90%. In contrast to the J/ψ mesons, the measured υ$_{2}$ values for the Υ mesons are found to be consistent with zero