488 research outputs found

    Dark sector interaction: a remedy of the tensions between CMB and LSS data

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    The well-known tensions on the cosmological parameters H0H_0 and σ8\sigma_8 within the Λ\LambdaCDM cosmology shown by the Planck-CMB and LSS data are possibly due to the systematics in the data or our ignorance of some new physics beyond the Λ\LambdaCDM model. In this letter, we focus on the second possibility, and investigate a minimal extension of the Λ\LambdaCDM model by allowing a coupling between its dark sector components (dark energy and dark matter). We analyze this scenario with Planck-CMB, KiDS and HST data, and find that the H0H_0 and σ8\sigma_8 tensions disappear at 68\% CL. In the joint analyzes with Planck, HST and KiDS data, we find non-zero coupling in the dark sector up to 99\% CL. Thus, we find a strong statistical support from the observational data for an interaction in the dark sector of the Universe while solving the H0H_0 and σ8\sigma_8 tensions simultaneously.Comment: 5 pages, 3 figure

    Observational Constraints on generalized dark matter properties in the presence of neutrinos with final Plank release

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    In this paper, we investigate an extension of standard Λ\LambdaCDM model by allowing: a temporal evolution in the equation of state (EoS) of DM via Chevallier-Polarski-Linder parametrization, and the constant non-null sound speed. We also consider the properties of neutrinos, such as the effective neutrino mass and the effective number of neutrino species as free parameters. We derive the constraints on this scenario by using the data from the Planck-2018 cosmic microwave background (CMB), baryonic acoustic oscillations (BAO), the local value of the Hubble constant from the Hubble Space Telescope (HST), and some large scale structure (LSS) information from the abundance of galaxy clusters. We find constraints on the EoS and sound speed of DM very close to the null value in all cases thus no significant evidence can be stated beyond the standard CDM paradigm, and we conclude that the present observational data favor DM as a pressureless fluid. In all cases, we find the tighter upper bounds on the sum of neutrino masses. The most tight upper bound is mν<0.17\sum m_\nu < 0.17 eV at 95\% CL, imposed with the addition of HST prior in the analysis. We also observe the effects of neutrino properties on the extended DM parameters and also on other parameters. We find significantly lower mean values of σ8\sigma_8 in all cases which are in agreement with the LSS measurements. Thus, the well-known σ8\sigma_8 tension is reconciled in the considered model.Comment: 10 pages, 4 Figure panels. arXiv admin note: text overlap with arXiv:1901.0754

    New Measure Routing Algorithm for PEGASIS Wireless Sensor Network

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    The sensor node spends the maximum energy in data transmission for maintaining this issue we proposed a new routing protocol for sensor nodes in WSN. A sensor network is organized into many sets and all sets collect the data with minimum edge weight in a parallel way so doing this all sets create a minimum edge weight chain. Further, the sets make a head node that is near the base station. All sets have a unique chain in this round after that all set again to select a head node on the basis of high residual energy, less mobility, and minimum distance to the base station that the head node sends the data to the base station. Further, our proposed routing algorithms save energy. We simulated the proposed model in MATLAB all simulation result is better than both routing algorithms

    Cosmic Ray Decreases and Geomagnetic Storms During 1975-1994

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    Solid Waste management from Steel Melting Shop

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    - Production of steel in steel Industry is accomplice for the generation of solid waste materials like sludge, slag, dust etc. In recent days most part of wastes are generated from steelmaking process which is a focus point now-a-days. The solid waste generation, presently in Indian steel industry is in the range of 400 - 500 kg/t of crude steel and recycling rate varies between 40 - 70 % which lead to higher production costs, lower productivity and further environmental degradation. It is very essential not only for recycling of the waste valuable metals and mineral resources but also to protect the environment. I Solid waste management in steel industry is broadly classified in “4 R” i.e. reduce, reuse, recycle and restore the materials. The aim of the paper is to explore the various developments for total recycling of solid waste generated from steel industry, so that the vision for making “clean &amp; green steel with zero waste” can be achieved for survival and growth of steel business in future. Keywords—Steel, Reuse, recycle, solid waste, sustainable development

    WHEEL CHAIR USING VOICE RECOGNITION

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    The wide spread prevalence of lost limbs and sensing system is of major concern in present day due to wars, accident, age and health problems. This Omni-directional wheelchair was designed for the less able elderly to move more flexibly in narrow spaces, such as elevators or small aisle. The wheelchair is developed to help disabled patients by using speech recognition system to control the movement of wheelchair in different directions by using voice commands and also the simple movement of the patient's fingers with keypad control. From previous literature surveys it was observed that the moments of wheels of wheelchair is difficult in diagonals direction, in this proposed system achievement of wheelchair movement in all direction is obtained by using multi-directional Omni-wheels which makes the diagonal moments comparatively flexible
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