Metallo-Anti-aromatic Al4Na4 and Al4Na3- compounds: A theoretical investigation

We propose a theoretical investigation in this paper to understand the bonding and structural properties of neutral Al4Na4 and anion Al4Na3- clusters. We show that the Al4 species in Al4Na4 and Al4Na3- clusters is a rectangular planar structure with alternate pi-bonds and hence satisfying the basic criteria for anti-aromaticity. We prove that the Al4Na4 and Al4Na3- clusters are metallo-anti-aromatic compounds

Structural, electronic and bonding properties of zeolite Sn-Beta: A periodic density functional theory study

The structural, electronic and the bonding properties of the Sn-BEA are investigated by using the periodic density functional theory. Each of the 9 different T-sites in the BEA were substituted by the Sn atom and all the 9 geometries were completely optimized using the plane wave basis set in conjunction with the ultra-soft pseudopotential. On the basis of the structural and the electronic properties, it has been demonstrated that the substitution of the Sn atom in the BEA framework is an endothermic process and hence the incorporation of the Sn in the BEA is limited. The lowest unoccupied molecular orbitals (LUMO) energies have been used to characterize the Lewis acidity of each T-site. On the basis of the relative cohesive energy and the LUMO energy, T2 site is shown to be the most favorable site for the substitution of Sn atom in the BEA framework.Comment: 17 pages, 5 figures, 2 Table

Influence of Dam and Foundation Discountinuities Using Discountinuum Approach — A Case Study

Dam-foundation interaction plays an important role in the design and analysis of concrete gravity dams as has been reviewed from the failures of dams in the literature. The objective of the study is to understand the behavior of a concrete gravity dam taking into account the effect of dam and foundation discontinuities using three-dimensional Distinct Element Code. Different models have been formulated considering the complexities involved in the modeling of the dam structure, dam-foundation system and the results have been compared. Modeling the dam with the discontinuity in the form of crack which runs through the concrete section has a complex phenomenon taking place at the interface where sliding and rotation deformation contribute to the overall stability. Modeling dam with discontinuities in the dam monoliths proved to be more realistic in the analysis of dam than considering a monolith dam with no dam discontinuities. Significant relative displacements between the monoliths and the permanent relative displacement at the end of seismic input have been observed at the discontinuities in this case. Modeling the foundation rock discontinuities represent the field conditions in the analysis more realistically. It is clearly indicated from the study that the interaction between dam monoliths and discontinuities in the foundation rock mass provide more realistic dam response

Role of frequency volume chart for the assessment of urinary incontinence in men

Background: This study was conducted to evaluate the role of FVC (frequency volume chart) in the male patient with urinary incontinence. That will definitely help to evaluate patient’s objective lower urinary tract symptoms including incontinence and guide to manage those symptoms. But there are less number of reported studies showing role of FVC in men with urinary incontinence.Methods: Male patient (19-60 years) presenting with incontinence symptoms from 1st February 2018 to 30th July 2018, were enrolled in the study. They were asked to record the time and volume of each oral fluid intake, voided volume for 3 consecutive days and put tick in the column of incontinence in the FVC if present.Results: Total 205 male patients presented with incontinence symptoms were evaluated, they were divided into 3 age groups (19-32, 33-46 and 47-60 years). Mean incontinence were found 2.65 (19-32 years). 2.99 (33-46 years) and 3.13 (47-60 years). In 47-60 years group total oral fluid intake is positively correlated with frequency (p 0.05) and frequency with incontinence (p >0.05) were not statistically significant in any age groups.Conclusions: The FVC is the registration of voiding parameters by patient in his own environment. Assessment of lower urinary tract symptoms based on a history alone is not accurate, value of FVC are found to be consistent and accurate, so it will guide us to initiate management in male with urinary incontinence and also help to assess treatment responsiveness

Phase transitions in Lu2_2Ir3_3Si5_5

We report the results of our investigations on a polycrystalline sample of Lu$_2$Ir$_3$Si$_5$ which crystallizes in the U$_2$Co$_3$Si$_5$ type structure (Ibam). These investigations comprise powder X-ray diffraction, magnetic susceptibility, electrical resistivity and high temperature (120-300 K) heat capacity studies. Our results reveal that the sample undergoes a superconducting transition below 3.5 K. It also undergoes a first order phase transition between 150-250 K as revealed by an upturn in the resistivity, a diasmagnetic drop in the magnetic susceptibility and a large anomaly (20-30 J/mol K) in the specific heat data. We observe a huge thermal hysteresis of almost 45 K between the cooling and warming data across this high temperature transition in all our measurements. Low temperature X-ray diffraction measurements at 87 K reveals that the compound undergoes a structural change at the high temperature transition. Resistivity data taken in repeated cooling and warming cycles indicate that at the high temperature transition, the system goes into a highly metastable state and successive heating/cooling curves are found to lie above the previous one and the resistance keeps increasing with every thermal cycle. The room temperature resistance of a thermaly cycled piece of the sample decays exponentialy with time with a decay time constant estimated to be about 10$^4$ secs. The anomaly (upturn) in the resistivity and the large drop (almost 45%) in the susceptibility across the high temperature transition suggest that the observed structural change is accompanied or induced by an electronic transition.Comment: 7 figures, 1 table and 18 reference

Assessment of Groundwater Potential Zone in Paschim Medinipur District, West Bengal – A Meso-scale study using GIS and Remote Sensing Approach

The investigation of groundwater in hard rock terrains is a complex task. To overcome this complexity, the integrated approach based on advanced applications of remote sensing and GIS lends itself to evaluate groundwater prospective zone based on multi-criteria evaluation approach (e.g. seasonal land use/land cover and vegetation, hydro-geology, geomorphology, soil, drainage density, monsoon and post monsoon water level and elevation). A probability weightage index overlay method was adopted that allows a linear combination of probability weights of each thematic map with the individual impact value using Bayesian statistics. These capability values are then multiplied with the respective probability weight of each thematic map. The result shows groundwater potentiality of Paschim Medinipur is stretched along the eastern part and in small pockets in northern and southern part. The hydrologic parameters-based groundwater potential zone map also indicated, 8.08% of the study area was classified as having very high potential, 11.99% high potential and 17.72% moderate potential. The groundwater abstractions structures feasible in each of the various potential zones have also been suggested. This study also provides a methodological approach for an evaluation of the water resources in hard rock terrain and enables an opening of the scope for further development and management practices. Keywords: Remote Sensing, GIS, probability weightage index , Groundwater potentialit