Quantum size effects in layered VX2 (X=S, Se, Te) materials: Manifestation of metal to semimetal or semiconductor transition

Most of the 2D transition metal dichalcogenides (TMDC) are nonmagnetic in pristine form. However, 2D pristine VX2 (X=S, Se, Te) materials are found to be ferromagnetic. Using spin polarized density functional theory (DFT) calculations, we have studied the electronic, magnetic and surface properties of this class of materials in both trigonal prismatic 2H- and octahedral 1T-phase. Our calculations reveal that they exhibit materially different properties in those two polymorphs. Most importantly, detailed investigation of electronic structure explored the quantum size effect in 2H-phase of these materials thereby leading to metal to semimetal (2H-VS2) or semiconductor (2H-VSe2, 2H-VTe2) transition when downsizing from bilayer to corresponding monolayer.Comment: 18 pages, 12 figures, 3 table

First principles design of divacancy defected graphene nanoribbon based rectifying and negative differential resistance device

We have elaborately studied the electronic structure of 555-777 divacancy (DV) defected armchair edged graphene nanoribbon (AGNR) and transport properties of AGNR based two-terminal device constructed with one defected electrode and one N doped electrode, by using density functional theory and non-equilibrium Green's function based approach. The introduction of 555-777 DV defect into AGNRs, results in a shifting of the {\pi} and {\pi}* bands towards the higher energy value which indicates a shifting of the Fermi level towards the lower energy. Formation of a potential barrier, very similar to that of conventional p-n junction, has been observed across the junction of defected and N doped AGNR. The prominent asymmetric feature of the current in the positive and negative bias indicates the diode like property of the device with high rectifying efficiency within wide range of bias voltages. The device also shows robust negative differential resistance (NDR) with very high peak-to-valley ratio. The analysis of the shifting of the energy states of the electrodes and the modification of the transmission function with applied bias provides an insight into the nonlinearity and asymmetry observed in the I-V characteristics. Variation of the transport properties on the width of the ribbon has also been discussed.Comment: 28 Pages, 12 Figures and 1 tabl

Structure and function in the sieve tube - An electron microscopic study

This thesis starts with a brief historical background to the modern study of translocation and discusses how different hypotheses of its mechanism have emerged and taken their present shape. This is followed by a review of the literature on the ultrastructure of the phloem tissue (especially the sieve tubes) down to the present year, with an emphasis on the state of the normal functioning sieve plate. At the moment a strong difference of opinion exists about this: The Californian School have argued the view that the sieve plate pores are normally 'open', while the contrary view has been maintained as energetically in London. The work reported consists of an investigation mainly of the sieve tube ultrastructure of Helianthus annuus hypocotyl and Saxifraga sarmentosa stolon. Material of these excised in 1 mm slices by twin cuts direct into fixative invariably showed the pores filled with slime fibrils. No open pores were ever encountered. The pores sometimes had callose cylinders and were sometimes without, but this seemed to make no difference to the degree of compaction. In a second approach the plant axes were plunged into boiling water. Subsequent excision, fixing and e.m. examination indicated that the pores were filled with coagulated slime. This indicates that the filling of the pores is not an enzymatic reaction artefact. It also discounts the view that it is due to turgor release. Finally material was wilted for several hours prior to surgery and fixation, contrary to the findings of the Californian school, the pores still appeared filled. The slime fibrils of both species have the typical banded structure and tend to 'crystallise' in the pores or when close together. Tubular material was rarely found, but membranous aggregates of several types were frequent. Low power surveys embracing several sieve tubes at once revealed a similar polarisation state in all; and photomontages of whole sieve tubes indicated the relationships of the centre and plate regions of functioning elements. On the whole, the work reported does not support the pressure-flow hypothesis, nor the transcellular streaming theory.<p

GSU Event Portal

GSU Event portal is an application which deals with showing any post, ongoing and upcoming events on the website. From the application, user can be able to check all the events going on globally in multiple locations. This application has an option to opt for receiving the recordings of the event when registered and paid for it. This portal will display all the events in different categories such as cultural events, recreational events, ground events. This portal allows users to interact with all other registered members and get updates over the events regularly. This application will have a home page where a panel for navigation will be available for users. Through this they have the various options to go through such as organizers, admin and visitors. organizers can create or edit events, view registrations or payments, etc. The administrator panel allows admin to administer accounts, edit or delete events, review registrations, etc. In the visitor’s console visitors, can set up its profile and payment info, view log of history, etc. This application will help the user to find any kind of events with the help of location, date and name of the project. There will be front page for different types of events. Login page form already registered members and sign up option for new users. Event page to show photos and full details of event and Web map if possible. Booking process will include the payment page and confirmation. The events page will show all the upcoming events and recommended events for you

Proinov-type relational contractions and applications to boundary value problems

This manuscript deals with proving certain metrical fixed-point findings for a class of generalized contractions involving a couple $(\psi, \varphi)$ of test functions employing a local class of transitive relation. The outcomes investigated herein refine, modify, unify, and sharpen various existing outcomes. To attest the accuracy of our outcomes, we provide a few examples. By means of our outcomes, we impart an explanation of the reality of a solution to a boundary value problem

Newtype single-layer magnetic semiconductor in transition-metal dichalcogenides VX 2 (X = S, Se and Te)

We present a newtype 2-dimensional (2D) magnetic semiconductor based on transition-metal dichalcogenides VX2 (X = S, Se and Te) via first-principles calculations. The obtained indirect band gaps of monolayer VS2, VSe2, and VTe2 given from the generalized gradient approximation (GGA) are respectively 0.05, 0.22, and 0.20 eV, all with integer magnetic moments of 1.0 μB. The GGA plus on-site Coulomb interaction U (GGA + U) enhances the exchange splittings and raises the energy gap up to 0.38~0.65 eV. By adopting the GW approximation, we obtain converged G0W0 gaps of 1.3, 1.2, and 0.7 eV for VS2, VSe2, and VTe2 monolayers, respectively. They agree very well with our calculated HSE gaps of 1.1, 1.2, and 0.6 eV, respectively. The gap sizes as well as the metal-insulator transitions are tunable by applying the in-plane strain and/or changing the number of stacking layers. The Monte Carlo simulations illustrate very high Curie-temperatures of 292, 472, and 553 K for VS2, VSe2, and VTe2 monolayers, respectively. They are nearly or well beyond the room temperature. Combining the semiconducting energy gap, the 100% spin polarized valence and conduction bands, the room temperature TC, and the in-plane magnetic anisotropy together in a single layer VX2, this newtype 2D magnetic semiconductor shows great potential in future spintronics

Label-free visualization of carbapenemase activity in living bacteria

Evaluating enzyme activity intracellularly on natural substrates is a significant experimental challenge in biomedical research. We report a label‐free method for real‐time monitoring of the catalytic behavior of class A, B, and D carbapenemases in live bacteria based on measurement of heat changes. By this means, novel biphasic kinetics for class D OXA‐48 with imipenem as substrate is revealed, providing a new approach to detect OXA‐48‐like producers. This in‐cell calorimetry approach offers major advantages in the rapid screening (10 min) of carbapenemase‐producing Enterobacteriaceae from 142 clinical bacterial isolates, with superior sensitivity (97 %) and excellent specificity (100 %) compared to conventional methods. As a general, label‐free method for the study of living cells, this protocol has potential for application to a wider range and variety of cellular components and physiological processes

DYNAMIC ANALYSIS AND COMPARATIVE STUDY OF PLAN IRREGULAR (C-SHAPED) BUILDING WITH DIFFERENT TYPES OF BRACING SYSTEM

When the multi-storied buildings are constructed a suitable care should be taken while designing, as they are subjected to lateral forces. The behaviour of multi-story building depends upon either in plan or in vertical direction i.e, elevation, is considered as one of the main causes of failure during earthquakes. Thus irregular structures, especially the structures which are located in seismic zones are required a special attention during analysis and design of structure. In this study Plan irregular (C-shaped building) is considered to carry out study. Bracing system is installed to provide strength against lateral loading and the behaviour of the structure in terms of base shear, story drift, stiffness and the lateral displacements are observed. Three different types of bracings X, V and Diagonal are installed in the structure. Total 4 models are analysed for 7 story height level, 4 Models are computed to determine the performance of the structure. One MRF and three models with different bracing system. And the best suitable bracing system for this study. The method used for this study is response spectrum method, to perform dynamic analysis of the structure. </jats:p