Jessore University of Science & Technology

About: Jessore University of Science & Technology is a based out in . It is known for research contribution in the topics: Adsorption & Population. The organization has 811 authors who have published 974 publications receiving 10471 citations.

Surface plasmonic properties in graphene for the variation of chemical potential

Abstract: Graphene which is an outstanding discovery in the area of nano-science shows remarkable electronic and optic properties. In terahertz frequency the surface plasmon wave is formed in graphene, where the fundamental properties of graphene can be controlled by using chemical potential. In this paper, the fundamental parameters of graphene such as relative permittivity, refractive index, propagation constant, resonant plasmon frequency, absorption coefficient, skin depth, modal wave vector are characterized by varying chemical potential. The maximum & minimum permittivity found as 3.6846 + 1.9473i and 1.6398 + 0.3659i; for the terahertz application the maximum & minimum frequencies found are 133 THz & 90 THz respectively. Graphene can be used in the field of plasmonic based devices because of its lowest dissipative loss at the terahertz frequency.

Biosorption of Reactive Red 120 Dye from Aqueous Solutions by using Mahagoni (Swietenia mahagoni) Wood and Bark Charcoal: Equilibrium, and Kinetic Studies

Abstract: This study analyzed the potential use of Mahagoni wood charcoal (MWC) and Mahagoni bark charcoal (MBC) as biosorbent for reactive red 120 (RR 120) dye removal from aqueous solutions. The effect of different operating parameters such as contact time (1–210 min), pH (3–11), adsorbent dose (1–20 g/L), and initial RR 120 concentration (5–70 mg/L) on adsorption processes was studied under batch adsorption experiments. The maximum removal of RR 120 by MWC (78%) and MBC (88%) was achieved when the optimum conditions were initial RR 120 concentration (5 mg/L), pH (3), adsorbents dose (10 g/L) and equilibrium contact time (150 min). The RR 120 adsorption data of MWC and MBC were better described by the Langmuir and Freundlich isotherm models, respectively. The MWC and MBC showed maximum adsorption capacities of 3.806 and 5.402 mg/g, respectively. Kinetic adsorption data of all adsorbents (MWC and MBC) followed the pseudo-second-order model and this adsorption process was controlled by chemisorption with multi-step diffusion. A lower desorption rate advocated that both strong and weak binding forces could exist between RR 120 molecules and adsorbents. The study results revealed that the utilization of either MWC and or MBC as an adsorbent for treating RR 120 is effective and environmentally friendly.

OPTOELECTRONIC STUDY OF DOUBLE PEROVSKITE Rb2SnBr6: A FIRST PRINCIPLES CALCULATIONS

Abstract: The aim of this research work is to investigate the structural, mechanical, electronic and optical properties of double perovskite Rb2SnBr6 by density functional theory (DFT) calculations. The calculated lattice parameter is in sensible agreement with the on the market experimental information. From Paugh’s ductility index (B/G), it shows that Rb2SnBr6 is brittle at ambient conditions. The Zener anisotropy factor confirms the anisotropic nature of this compound. The calculated energy band structures indicate that Rb2SnBr6 is a direct band gap semiconductor, with the band gap of 1.228 eV using PBE potentials. In this work, the optical properties such as dielectric constants, refractive index, conductivity, extinction coefficient, loss function, and reflectivity have been studied and reported for radiation up to 20 eV. It is found that the reflectivity is about 50% in the ultraviolet (UV) region regions up to ~11 eV of incident radiation.

Transport of photosystem II (PS II)–inhibiting herbicides through the vadose zone under sugarcane in the Wet Tropics, Australia

Abstract: The usage of Photosystem II (PS II)–inhibiting herbicides, identified as a risk to ecosystem health and resilience, has been reduced in agricultural activities adjacent to the Great Barrier Reef, Australia over the past 10 years. Two PS II herbicides (diuron and hexazinone) and three metabolites (desethyl atrazine, hydroxyatrazine and DCPMU) were recently detected at low concentrations in the regional aquifer of the South Johnstone River sub-basin, in the Wet Tropics, Australia. This study presents results from monitoring 12 PS II herbicides in soil profile, porewater sampled through the vadose zone monitoring system, and groundwater from bores. Among the 12 PS II herbicides, only hexazinone and metribuzin were applied relatively recently, in November 2014. Hexazinone exhibited substantial transport through the vadose zone, with decreasing concentration with depth, and eventually disappeared over-time. Metribuzin was not detected in the groundwater, in soil profile or through the vadose zone. Diuron was detected in the soil profile, through the vadose zone and in bores at the site. Its two metabolites—1-(3,4-dichlorophenyl)-3-methylurea (DCPMU) and 3,4-dichloroaniline—were detected in the deepest port at 4 m, indicating the transformation of diuron into these metabolites and potential leaching. The other nine PS II herbicides were not detected in the soil profile, through the vadose zone or in bores at the site. Some of the PS II herbicides were detected in the soil profile and beyond the root zone, depending on their application record and persistence in the environment. Therefore, the data shows that the herbicides are long lived at low concentrations. However, herbicide concentrations in subsoil, vadose zone and groundwater are low (less than environmental guideline values) and are detected at much lower concentrations than in surface runoff.