Magnetic field induced topological nodal-lines in triplet excitations of frustrated antiferromagnet CaV4_4O9_9

Magnetic field induced multiple non-Dirac nodal-lines are found to emerge in the triplet dispersion bands of a frustrated spin-1/2 antiferromagnetic model on the CaVO lattice. Plaquette and bond operator formalisms have been employed to obtain the triplet plaquette and bond excitations for two different parameter regimes in the presence of nearest and next-nearest-neighbor Heisenberg interactions based on the plaquette-resonating-valence-bond and dimerized ground states, respectively. In the absence of magnetic field a pair of six-fold degenerate nodal-loops with distinct topological feature is noted in the plaquette excitations. They are found to split into three pairs of two-fold degenerate nodal-loops in the presence of magnetic field. In the other parameter regime, system hosts two-fold degenerate multiple nodal-lines with a variety of shapes in the triplon dispersion bands in the presence of magnetic field. Ground state energy and spin gap have been determined additionally for the two regimes. Those nodal-lines are expected to be detectable in neutron scattering experiment on the frustrated antiferromagnet, CaV$_4$O$_9$.Comment: 15 pages, 17 figure

Thermally stable multipartite entanglements in the frustrated Heisenberg hexagon

Thermally stable quantum states with multipartite entanglements led by frustration are found in the antiferromagnetic spin-1/2 Heisenberg hexagon. The model has been solved exactly to obtain all analytic expressions of eigenvalues and eigenfunctions. Detection and characterizations for various types of entanglements have been carried out in terms of concurrence and entanglement witnesses based on several thermodynamic observables. Variations of entanglement properties with respect to temperature and frustration are discussed. Even though the frustration opposes the bipartite entanglement, it favors the multipartite entanglement. Entangled states exhibit robustness against the thermal effects in the presence of frustration and they are found to survive at any temperature.Comment: 25 pages, double space, single column, 5 figure

Enhancement the security of WSN using ALARM protocol to Prevention from Reply Attack

The wireless Ad hoc network is the self configuring type of network. In self configuring type of networks mobile nodes can leave or join the network when they want .In such type of networks many inside and outside attacks are possible. Inside and outside attacks are broadly classified as active and passive attacks. To prevent inside and outside attacks trust relationship between the mobile nodes must be maintained. The trust relationship between the mobile nodes is provided by mutual authentication. ALARM is the protocol for providing trust relationship between the mobile nodes. In this protocol the clocks of the mobile nodes are weakly synchronized by using GPS. In such case reply attack is possible. To prevent reply attack clocks of the mobile nodes must be strongly synchronized. In our new proposed technique, we are enhancing t the ALARM protocol to provide strong clock synchronization between the mobile nodes. Our new technique will be based on the NTP (network time protocol). Keywords— ALARM, Attacks, clock Synchronization, GPS, NT

Rajbanshi Women and Empowerment: Through the Lens of Gender and Development Rubric

Empowerment is the process by which the powerless gain greater control over the circumstances of their lives It includes both control over resources physical human intellectual financial and over ideology believes values and attitudes 1 The status of women in a society is measured in terms of educational level income level employment health status decision making right autonomy as well as the various roles played by them in the family society and the community Indian women s status role and their problems are linked to the history and traditional social system of the country Women constitute half of the population yet they are not treated on par with men in many aspects of life In our country and world wide women usually have been linked to home and hearth This has usually resulted in their economic dependence social neglect and political ignorance which in their turn have prevented women from empowering themselve

Design and Implementation of Different Multipliers Using VHDL

Low power consumption and smaller area are some of the most important criteria for the fabrication of DSP systems and high performance systems. Optimizing the speed and area of the multiplier is a major design issue. However, area and speed are usually conflicting constraints so that improving speed results mostly in larger areas. In our project we try to determine the best solution to this problem by comparing a few multipliers. This project presents an efficient implementation of high speed multiplier using the shift and add method, Radix_2, Radix_4 modified Booth multiplier algorithm. In this project we compare the working of the three multiplier by implementing each of them separately in FIR filter

Solvothermal synthesis of CdO and CuO nanocrystals

Nanocrystals of CdO have been obtained by the decomposition of the cupferron complex in the presence of tri-n-octylphosphine oxide (TOPO) under solvothermal conditions. The precursor:TOPO ratio plays an important role in determining the size of the nanocrystals. The nanocrystals have been characterized by electron microscopy, absorption spectroscopy and fluorescence spectroscopy, besides X-ray diffraction. The CdO nanocrystals are single crystalline and show evidence for quantum confinement. CuO nanocrystals could also be prepared by the decomposition of the cupferronate under solvothermal conditions, the particle size being controlled by the initial precursor concentration

Transport of aerosols and nanoparticles through respirators and masks

In several countries wearing multiple surgical masks or N95 respirators was mandatory in public during the COVID pandemic. In this study, we investigated the transportation and filtering mechanism of heterogeneous nanoparticles and viruses through surgical masks and N95 respirators. We conducted experiments in vitro using aerosol spray paints containing nanoparticles and validated the findings in vivo on a human volunteer. Scanning electron microscopy was employed to analyse the transportation and distribution of nanoparticles in different mask layers and on pristine silicon substrates placed on human skin. We provide analytical insights into the pressure distribution and fluid velocity profiles within the complex polymer network. Remarkably, our results showed that both single surgical masks and N95 respirators demonstrated similar efficiency in filtering colloidal and jet-stream nanoparticles in the air. These comprehensive findings have significant implications for policymakers in defining regulations for airborne pandemics and air pollution control