1,674 research outputs found

    Scrutinizing the Structural Response of Regular and Irregular Structure (With and Without Shear Wall) Subjected to Seismic and Wind Loading

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    The spectacular increase in population, living in urban areas and their demands leads to housing problem in India. This results in the rise of multi-storey and high-rise building with irregular configuration. Past earthquake occurrences in India reveals that the buildings with irregular configuration are prone to earthquake damage. Therefore, it is obligatory to identify the seismic and wind response of structures with irregular shape in different zones of India. Shear Wall system is one of the most common systems used for lateral load resistance. It is necessary to identify the response of structure in different zones of India with and without Shear Wall. In the present study the main focus is to thoroughly examine and have a comparative study of the behavior of regular and irregular R.C building with and without shear wall for seismic and wind load activities in different zones of India. Analysis has been done in CYPE Software

    Extraction and immediate placement of root analogue zirconia implants: an overview

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    Dental implants constitute a well-established approach for replacement of lost teeth with titanium being the most favored material for implantation. However, titanium has its limitations in esthetically demanding cases and neither the form nor material of such implants has changed much over the past 40 years. Immediate implantation has been introduced to overcome the disadvantages of conventional implantation which in turn has many disadvantages owing to the incongruence of the implant to the extraction socket. Today, there is scientific evidence that zirconia dental implants osseointegrate well and offer many advantages over titanium implants. The successful use of zirconia ceramics in orthopedic surgery led to a demand for dental zirconium-based implant systems. Because of its excellent biomechanical characteristics, biocompatibility, and bright tooth-like color, zirconia (zirconium dioxide, ZrO2) has the potential to become a substitute for titanium as dental implant material. In addition, there are previous reports on the successful use of Zirconia as root-analogue implants by reproducing the contours of the extracted tooth. This article presents an overview of the technique of using root analogue zirconia dental implants as an immediate implantation material which are replicas of the extracted tooth and therefore truly anatomical and socket friendly

    Response surface methodology and artificial neural network-based models for predicting performance of wire electrical discharge machining of inconel 718 alloy

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    This paper deals with the development and comparison of prediction models established using response surface methodology (RSM) and artificial neural network (ANN) for a wire electrical discharge machining (WEDM) process. The WEDM experiments were designed using central composite design (CCD) for machining of Inconel 718 superalloy. During experimentation, the pulse-on-time (TON), pulse-off-time (TOFF), servo-voltage (SV), peak current (IP), and wire tension (WT) were chosen as control factors, whereas, the kerf width (Kf), surface roughness (Ra), and materials removal rate (MRR) were selected as performance attributes. The analysis of variance tests was performed to identify the control factors that significantly affect the performance attributes. The double hidden layer ANN model was developed using a back-propagation ANN algorithm, trained by the experimental results. The prediction accuracy of the established ANN model was found to be superior to the RSM model. Finally, the Non-Dominated Sorting Genetic Algorithm-II (NSGA- II) was implemented to determine the optimum WEDM conditions from multiple objectives

    Comparison of Stability Indices for Critical Line at Different Loading Conditions

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    Modern power systems are operating under much stressed load conditions and also facing the problem of limited capacity of power generating sources. Voltage instability is a quite frequent phenomenon under such situation rendering degradation of power system performance. In order to avoid system voltage collapse and blackouts, power system is to be analyzed in view of voltage stability for a wide range of system conditions. This paper discusses the use of line voltage stability indices termed as fast voltage stability index (FVSI) and line stability index (Lmn) in order to determine the critical line. The line with least stability margin is ranked highest indices value is identified as theoretical line. The performances of the indices are investigated for the IEEE 14 - bus test system at different loading using MATLAB simulations

    Toxicity and Environmental Health Hazards of Petroleum Products in Wells Used for Drinking Water in the Intermountain West

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    Introduction: Groundwater is aprimary source of drinking water for about 50 percent of the population in the U.S. This source of drinking water has been generally regarded as safe from contamination. Several papers indicate that numerous underground storage tanks containing petroleum products may be leaking and contaminating public water supply wells across the U.S. (Matis, 1971; Ferguson, 1979; Woodhull, 1981; Burmaster and Harris, 1982; Lehman, 1984; Dowd, 1984; OTA, 1984). A study conducted by the Utah Cureau of Solid and Hazardous Wastes in 1985 concluded that there are at least 2,314 underground steel tanks, most of which are used to store gasoline and diesel fuel, in Utah which are more than 20 years old and may be leaking. Contamination of well water by petrolium products from leaking underground storage tanks (LUST) is a matter of increasing concern. LUST pose a serious threat to the groundwater and public health. Leaks of petroleum products from LUST at industrial plants, commercial establishments (e.g., automobile service stations), and other operations could be expected to increase the types and concentrations of petroleum products in groundwater used for drinking and exposure of humans to the toxic effects of these chemical compounds. Petroleum products are persistent and highly mobile contaminatns which are difficult to remove from groundwater. In addition, many of these chemicals are known or suspected carcinogens or mutagens which can pose undesireable human health risks (e.g., cancer, birth defects, and other chronic conditions) at 10 ppb and below (Council on Environmental Quality, 1980). There is a need for more research on the types and concentrations of petroleum products (e.g., benzene, toluene, ethylbenzene) found in public water supply wells used for drinking water and the immunotoxic and neurotoxic effects of these organic compounds. The objectives of this research project were: 1. To characterize petroleum products in raw water from wells used for drinking water in selected areas (industrial, commercial, and other) of Utah. 2. To evaluate the toxicity of selected petroleum products in experimental animals, with emphasis on the following: a. Immunotoxic and hypersensitivity effects. b. Neurotoxic and behavioral effects

    Variational structures beyond gradient flows: a macroscopic fluctuation-theory perspective

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    Macroscopic equations arising out of stochastic particle systems in detailed balance (called dissipative systems or gradient flows) have a natural variational structure, which can be derived from the large-deviation rate functional for the density of the particle system. While large deviations can be studied in considerable generality, these variational structures are often restricted to systems in detailed balance. Using insights from macroscopic fluctuation theory, in this work we aim to generalise this variational connection beyond dissipative systems by augmenting densities with fluxes, which encode non-dissipative effects. Our main contribution is an abstract framework, which for a given flux-density cost and a quasipotential, provides a decomposition into dissipative and non-dissipative components and a generalised orthogonality relation between them. We then apply this abstract theory to various stochastic particle systems – independent copies of jump processes, zero-range processes, chemical-reaction networks in complex balance and lattice-gas models

    Prevalence and 1-year incidence of frailty among women with and without HIV in the Women's Interagency HIV Study

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    A previous cross-sectional analysis of 2028 women in the Women’s Interagency HIV Study (WIHS), who were on average 39 years old, found a frailty prevalence of 17% and 10% in women with or at risk for HIV, respectively [1]. To our knowledge, the only two longitudinal studies of frailty among people with HIV were conducted in the Multicenter AIDS Cohort Study (MACS), which includes only men [2,3]. Data on the distribution of frailty components are limited, and have not been reported for HIV-seropositive people in the United State

    Asteroseismology of red giants & galactic archaeology

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    Red-giant stars are low- to intermediate-mass (M≲10M \lesssim 10~M⊙_{\odot}) stars that have exhausted hydrogen in the core. These extended, cool and hence red stars are key targets for stellar evolution studies as well as galactic studies for several reasons: a) many stars go through a red-giant phase; b) red giants are intrinsically bright; c) large stellar internal structure changes as well as changes in surface chemical abundances take place over relatively short time; d) red-giant stars exhibit global intrinsic oscillations. Due to their large number and intrinsic brightness it is possible to observe many of these stars up to large distances. Furthermore, the global intrinsic oscillations provide a means to discern red-giant stars in the pre-helium core burning from the ones in the helium core burning phase and provide an estimate of stellar ages, a key ingredient for galactic studies. In this lecture I will first discuss some physical phenomena that play a role in red-giant stars and several phases of red-giant evolution. Then, I will provide some details about asteroseismology -- the study of the internal structure of stars through their intrinsic oscillations -- of red-giant stars. I will conclude by discussing galactic archaeology -- the study of the formation and evolution of the Milky Way by reconstructing its past from its current constituents -- and the role red-giant stars can play in that.Comment: Lecture presented at the IVth Azores International Advanced School in Space Sciences on "Asteroseismology and Exoplanets: Listening to the Stars and Searching for New Worlds" (arXiv:1709.00645), which took place in Horta, Azores Islands, Portugal in July 201

    Identification of novel peptide motifs in the serpin maspin that affect vascular smooth muscle cell function

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    Maspin is a non-inhibitory member of the serpin family that affects cell behaviours related to migration and survival. We have previously shown that peptides of the isolated G α-helix (G-helix) domain of maspin show bioactivity. Migration, invasion, adhesion and proliferation of vascular smooth muscle cells (VSMC) are important processes that contribute to the build-up of atherosclerotic plaques. Here we report the use of functional assays of these behaviours to investigate whether other maspin-derived peptides impact directly on VSMC; focusing on potential anti-atherogenic properties. We designed 18 new peptides from the structural moieties of maspin above ten amino acid residues in length and considered them beside the existing G-helix peptides. Of the novel peptides screened those with the sequences of maspin strand 4 and 5 of beta sheet B (S4B and S5B) reduced VSMC migration, invasion and proliferation, as well as increasing cell adhesion. A longer peptide combining these consecutive sequences showed a potentiation of responses, and a 7-mer contained all essential elements for functionality. This is the first time that these parts of maspin have been highlighted as having key roles affecting cell function. We present evidence for a mechanism whereby S4B and S5B act through ERK1/2 and AMP-activated protein kinase (AMPK) to influence VSMC responses
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