Ramandeep Kaur

Bio: Ramandeep Kaur is an academic researcher from Punjabi University. The author has contributed to research in topics: Wavelength-division multiplexing & Band gap. The author has an hindex of 14, co-authored 92 publications receiving 643 citations.

Physical, structural, optical and gamma ray shielding behavior of (20+x) PbO – 10 BaO – 10 Na2O – 10 MgO – (50-x) B2O3 glasses

Abstract: Glass samples of composition (20 + x) PbO – 10 BaO – 10 Na2O – 10 MgO – (50-x) B2O3 (x = 0, 5, 10, 15 and 20 mol%) have been prepared by melt quenching technique. Density, molar volume, average boron-boron separation, ion concentration, polaron radius, inter-nuclear distance, field strength, oxygen packing density and oxygen molar volume have been determined to study the physical properties of the glasses. The presence of no sharp peak in the XRD spectra confirms the amorphous nature of the glasses. The structural properties of these glasses have been investigated using Fourier Transform Infrared (FTIR) spectroscopic techniques. The direct and indirect band gap energies, refractive index, dielectric constant, optical dielectric constant, molar fraction, reflection loss and metallization have been also investigated from the UV-VIS spectra. Besides, the radiation attenuation features for the prepared glasses have been calculated using XCOM program. The mass attenuation coefficient values and effective atomic numbers are found to increase with an increase in the PbO content. The radiation shielding study revealed that Pb40B30 and Pb20B50 glasses have the lowest and highest values of mean free path and half value layer values. This indicates that the Pb40B30 glass has the highest photon shielding competence.

Physical, structural, optical and thermoluminescence behavior of Dy2O3 doped sodium magnesium borosilicate glasses

Abstract: The rare earth doped borosilicate glass materials of composition (60 − x) B2O3 − 20 SiO2 − 10 Na2O − 10 MgO − x Dy2O3 have been prepared by melt quenching method. X-ray diffraction confirms the amorphous nature of the present glasses. FTIR spectra reveal the structure of the present glasses. The density, molar volume, average molecular weight, ion concentration, polaron radius and field strength have been determined. The optical parameters like optical band gap, refractive index, dielectric constant, optical dielectric constant, molar polarizability, reflection loss, molar refractivity, metallization and Urbach energy were also calculated. The glow curve behavior of all the present glass samples irradiated with 50 Gy, 100 Gy, 500 Gy, 1 kGy, 5 kGy and 10 kGy gamma ray doses has been investigated in temperature range 50–400°C. The TL dose response shows that the sample having 0.6 mol% doping of Dy3+ was best suitable for dosimetric applications.

Studies on the structural, optical and radiation shielding properties of (50 – x) PbO – 10 WO3–10 Na2O – 10 MgO – (20 + x) B2O3 glasses

Abstract: Heavy metal oxide glasses of composition (50 – x) PbO – 10 WO3–10 Na2O – 10 MgO – (20 + x) B2O3 (where x = 0, 5, 10, 15 and 20 mol%) have been fabricated using melt quenching technique. The X-ray diffraction (XRD) spectra confirm the amorphous nature of the glasses. The Fourier Transform Infrared Spectroscopy (FTIR) throws the light on the various structural properties of the glasses. UV – Visible spectra has been recorded in the range 190–1100 nm. The direct and indirect band gap energies increase from 2.695–2.805 eV and 3.126–3.237 eV as percentage of lead decreases. This value of indirect band gap is further used to calculate the other optical parameters such as refractive index, dielectric constant, optical dielectric constant, reflection loss, molar refractivity, metallization and molar polarizability. Besides, the mass attenuation coefficients have been obtained in the energy range of 0.01–10 MeV using MCNPX code and XCOM program. The obtained results are found to be in agreement. These values are further used to calculate the effective atomic numbers and half value layers of the present glasses. All the shielding parameters are found to depend on the chemical composition and energy of the gamma radiations. But the PB50B20 glass sample is found to possess the highest effective atomic number and the lowest value half value layer. The PB50B20 glass sample (contains 50 mol% PbO) owns the best gamma shielding characteristics.

Optical band gap tuning of Ag doped Ge2Sb2Te5 thin films

Abstract: Thin films of (Ge2Sb2Te5)100−xAgx (x = 0, 1, 3, 5 and 10) were deposited using thermal evaporation technique. X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy was used to confirm the amorphous nature, uniformity and chemical compositions of deposited films respectively. Transmission spectra divulged the highly transparent nature of films in near infra red region. The average transmission in near infra red region and optical band gap (estimated by Tauc’s plot) was increased with Ag doping upto x = 3 while it decreased for higher values of x. The increase in transmission and optical band gap was attributed to the reduction in density of localized states and vacancies. However, the decrease in the transmission and optical band gap is due to the increase in distortion of the host Ge2Sb2Te5 lattice because Ag is doped at the expense of Ge, Sb and Te. The increased optical band gap could be utilized to reduce threshold current which enhances switching speed in phase change materials.

Pharmaceuticals of Emerging Concern in Aquatic Systems: Chemistry, Occurrence, Effects, and Removal Methods.

Abstract: In the last few decades, pharmaceuticals, credited with saving millions of lives, have emerged as a new class of environmental contaminant. These compounds can have both chronic and acute harmful effects on natural flora and fauna. The presence of pharmaceutical contaminants in ground waters, surface waters (lakes, rivers, and streams), sea water, wastewater treatment plants (influents and effluents), soils, and sludges has been well doccumented. A range of methods including oxidation, photolysis, UV-degradation, nanofiltration, reverse osmosis, and adsorption has been used for their remediation from aqueous systems. Many methods have been commercially limited by toxic sludge generation, incomplete removal, high capital and operating costs, and the need for skilled operating and maintenance personnel. Adsorption technologies are a low-cost alternative, easily used in developing countries where there is a dearth of advanced technologies, skilled personnel, and available capital, and adsorption appears to be the most broadly feasible pharmaceutical removal method. Adsorption remediation methods are easily integrated with wastewater treatment plants (WWTPs). Herein, we have reviewed the literature (1990-2018) illustrating the rising environmental pharmaceutical contamination concerns as well as remediation efforts emphasizing adsorption.

Current Opinion in Colloid and Interface Science

Abstract: The author greatly acknowledges the financial support from the Spanish Ministry of Economy and Competitiveness (CTQ2014-52687-C3-1-P project) and Marie Sklodowska Curie Initial Training Networks (FP7-PEOPLE-2013-ITN, BIBAFOODS project). The author also acknowledges support from Generalitat de Catalunya (2014SGR1655 and TECCIT15-1-0009) and Centro de Investigacion Biomedica en Red de Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN).