1,659 research outputs found

    A study on the level of stress and the influence of socio-demographic factors on stress level among the working women in the state of Kerala

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    Women play vital roles in the process of decision making both in work place and family. Indian culture considers women as care takers of the family members. In contrary to the traditional notions, women are moving from home maker’s par name to working women. More number of women is entering into workforce that is very much challenging and innovative. Aforementioned state gives a double role to most of the women as working women and house wives without any interval. Here a study is undertaken on the level of stress of women who are in the dual standards of family and profession. The study tries to identify the stressful life faced by women in the society. The result indicates that financial position of the family, travelling time and mode of travelling affect the intensity of stress among the working women. It provides us an opportunity to give suggestions to women in facing and challenging critical situations of their lives effectively. Keywords: Stress, Working women, Socio-demographi

    A comprehensive review on bonding between monolithic ceramics and tooth structure with different adhesive agents.

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    Reliable bonding between the prepared tooth and monolithic ceramics can be achieved by various luting agents available on the market. The selection of luting agent and cementation technique plays an important role in the success of the restoration. With the advent of resin-based adhesive systems as luting agents, clinicians\u27 perspectives have changed to a more conservative approach. Recent systems, chemically adhere the crowns to the prepared tooth structure showing higher bond strength. To reach the aesthetic demands of the patients, all-ceramic restorations were considered over metal-ceramic crowns. Few all-ceramic crowns are brittle, the strength is dependent on the chemical structure and method of fabrication. While some all-ceramic restorations gain strength after cementation. Thus, the choice of luting agent used in cementing all-ceramic crowns is crucial. Even though many luting agents are being introduced no single luting agent fulfilled all the requirements. Among them, adhesive cements showed greater bond strength and enhanced the retention of minimal preparation, which are less retentive. Traditional non-adhesive agents can be used in retentive preparations that bond through mechanical means rather than the chemical bond seen in newer adhesive cements. Also, surface treatments of zirconia showed greater bond strengths irrespective of the luting agent being used. These include air abrasion, acid etching, applying silane couplers, and primers that increase the surface area for adhesion. The use of all-ceramic restorations, the need for surface treatments, types of surface treatments, adhesion and adhesive agents, and evidence from current in vitro research on monolithic ceramics and tooth adhesion were all discussed in this review

    The Wolf of SUTD (TWOS): A dataset of malicious insider threat behavior based on a gamified competition

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    In this paper we present open research questions and options for data analysis of our previously designed dataset called TWOS: The Wolf of SUTD. In specified research questions, we illustrate the potential use of the TWOS dataset in multiple areas of cyber security, which does not limit only to malicious insider threat detection but are also related to authorship verification and identification, continuous authentication, and sentiment analysis. For the purpose of investigating the research questions, we present several state-of-the-art features applicable to collected data sources, and thus we provide researchers with a guidance how to start with data analysis. The TWOS dataset was collected during a gamified competition that was devised in order to obtain realistic instances of malicious insider threat. The competition simulated user interactions in/among competing companies, where two types of behaviors (normal and malicious) were incentivized. For the case of malicious behavior,we designed two types of malicious periods that was intended to capture the behavior of two types of insiders – masqueraders and traitors. The game involved the participation of 6 teams consisting of 4 students who competed with each other for a period of 5 days. Their activities were monitored by several data collection agents and producing data for mouse, keyboard, process and file-system monitor, network traffic, emails, and login/logout data sources. In total, we obtained 320 hours of active participation that included 18 hours of masquerader data and at least two instances of traitor data. In addition to expected malicious behaviors, students explored various defensive and offensive strategies such as denial of service attacks and obfuscation techniques, in an effort to get ahead in the competition. The TWOS dataset was made publicly accessible for further research purposes. In this paper we present the TWOS dataset that contains realistic instances of insider threats based on a gamified competition. The competition simulated user interactions in/among competing companies, where two types of behaviors (normal and malicious) were incentivized. For the case of malicious behavior, we designed sessions for two types of insider threats (masqueraders and traitors). The game involved the participation of 6 teams consisting of 4 students who competed with each other for a period of 5 days, while their activities were monitored considering several heterogeneous sources (mouse, keyboard, process and file-system monitor, network traffic, emails and login/logout). In total, we obtained 320 hours of active participation that included 18 hours of masquerader data and at least two instances of traitor data. In addition to expected malicious behaviors, students explored various defensive and offensive strategies such as denial of service attacks and obfuscation techniques, in an effort to get ahead in the competition. Furthermore, we illustrate the potential use of the TWOS dataset in multiple areas of cyber security, which does not limit to malicious insider threat detection, but also areas such as authorship verification and identification, continuous authentication, and sentiment analysis. We also present several state-of-the-art features that can be extracted from different data sources in order to guide researchers in the analysis of the dataset. The TWOS dataset is publicly accessible for further research purposes. © 2018, Innovative Information Science and Technology Research Group. All rights reserved

    Electron and ion stagnation at the collision front between two laser produced plasmas

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    We report results from a combined optical interferometric and spectrally resolved imaging study on colliding laser produced aluminium plasmas. A Nomarski interferometer was used to probe the spatio-temporal distribution of electron densities at the collision front. Analysis of the resulting interferograms reveals the formation and evolution of a localized electron density feature with a well-defined profile reminiscent of a stagnation layer. Electron stagnation begins at a time delay of 10 ns after the peak of the plasma generating laser pulse. The peak electron density was found to exceed 10^19 cm^−3 and the layer remained well defined up to a time delay of ca 100 ns. Temporally and spectrally resolved optical imaging was also undertaken, to compare the Al^+ ion distribution with that of the 2D electron density profile. This revealed nascent stagnation of singly charged ions at a delay time of 20 ns. We attribute these results to the effects of space charge separation in the seed plasma plumes

    Emission features of femtosecond laser ablated carbon plasma in ambient helium

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    We investigated the optical emission features of plasmas produced by 800 nm, 40 fs ultrafast laser pulses on a carbon target in the presence of ambient helium or nitrogen gases at varied pressures. Fast photography employing intensified charge coupled device, optical emission spectroscopy, and temporally spatially resolved optical time of flight emission spectroscopy were used as diagnostic tools. Spatio-temporal contours of excited neutral, ionic, as well as molecular carbon species in the plume were obtained using time of flight emission spectroscopy. These contours provided detailed account of molecular species evolution and expansion dynamics and indicate that three-body recombination is a major mechanism for carbon dimers generation in ultrafast laser ablation plumes in the presence of ambient gas. A systematic comparison of the emission features from ns and fs laser ablation carbon plumes as well as their expansion in ambient helium is also given. C 2 vibrational temperatures were estimated during carbon plasma expansion with lower values in ambient helium compared to nitrogen and showed decreasing values with respect to space and ambient gas pressure. V C 2013 AIP Publishing LLC. [http://d

    Helium bubble formation in ultrafine and nanocrystalline tungsten under different extreme conditions

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    We have investigated the effects of helium ion irradiation energy and sample temperature on the performance of grain boundaries as helium sinks in ultrafine grained and nanocrystalline tungsten. Irradiations were performed at displacement and non-displacement energies and at temperatures above and below that required for vacancy migration. Microstructural investigations were performed using Transmission Electron Microscopy (TEM) combined with either in-situ or ex-situ ion irradiation. Under helium irradiation at an energy which does not cause atomic displacements in tungsten (70 eV), regardless of temperature and thus vacancy migration conditions, bubbles were uniformly distributed with no preferential bubble formation on grain boundaries. At energies that can cause displacements, bubbles were observed to be preferentially formed on the grain boundaries only at high temperatures where vacancy migration occurs. Under these conditions, the decoration of grain boundaries with large facetted bubbles occurred on nanocrystalline grains with dimensions less than 60 nm. We discuss the importance of vacancy supply and the formation and migration of radiation-induced defects on the performance of grain boundaries as helium sinks and the resulting irradiation tolerance of ultrafine grained and nanocrystalline tungsten to bubble formatio

    Debris and Radiation-Induced Damage Effects on EUV Nanolithography Source Collector Mirror Optics Performance

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    ABSTRACT Exposure of collector mirrors facing the hot, dense pinch plasma in plasma-based EUV light sources to debris (fast ions, neutrals, off-band radiation, droplets) remains one of the highest critical issues of source component lifetime and commercial feasibility of nanolithography at 13.5-nm. Typical radiators used at 13.5-nm include Xe and Sn. Fast particles emerging from the pinch region of the lamp are known to induce serious damage to nearby collector mirrors. Candidate collector configurations include either multi-layer mirrors (MLM) or single-layer mirrors (SLM) used at grazing incidence. Studies at Argonne have focused on understanding the underlying mechanisms that hinder collector mirror performance at 13.5-nm under fast Sn or Xe exposure. This is possible by a new state-of-the-art in-situ EUV reflectometry system that measures real time relative EUV reflectivity (15-degree incidence and 13.5-nm) variation during fast particle exposure. Intense EUV light and off-band radiation is also known to contribute to mirror damage. For example offband radiation can couple to the mirror and induce heating affecting the mirror's surface properties. In addition, intense EUV light can partially photo-ionize background gas (e.g., Ar or He) used for mitigation in the source device. This can lead to local weakly ionized plasma creating a sheath and accelerating charged gas particles to the mirror surface and inducing sputtering. In this paper we study several aspects of debris and radiation-induced damage to candidate EUVL source collector optics materials. The first study concerns the use of IMD simulations to study the effect of surface roughness on EUV reflectivity. The second studies the effect of fast particles on MLM reflectivity at 13.5-nm. And lastly the third studies the effect of multiple energetic sources with thermal Sn on 13.5-nm reflectivity. These studies focus on conditions that simulate the EUVL source environment in a controlled way

    Femtosecond Laser Ablation: Fundamentals and Applications

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    Abstract Traditionally nanosecond laser pulses have been used for Laser-induced Breakdown Spectroscopy (LIBS) for quantitative and qualitative analysis of the samples. Laser produced plasmas using nanosecond laser pulses have been studied extensively since 1960s. With the advent of short and ultrashort laser pulses, there has been a growing interest in the applications of femtosecond and picosecond lasers for analysis of materials using LIBS and LA-ICP-MS. The fundamentals of laser ablation process using ultrashort laser pulses are not still fully understood. Pulse duration of femtosecond laser pulse is shorter than electron-to-ion energy transfer time and heat conduction time in the sample lattice. This results in different laser ablation and heat dissipation mechanisms as compared to nanosecond laser ablation. In this chapter, the focus will be on understanding the basics of femtosecond laser ablation processes including laser target interaction, ablation efficiency, ablation threshold, laser plasma interactions, and plume hydrodynamics. Analytical figures of merit will be discussed in contrast to nanosecond LIBS. Introduction Laser ablation (LA) and laser-produced plasmas (LPP) have been studied extensively for more than 50 years since the discovery of lasers in the 1960s. The physics involved in laser-plasma generation and subsequent evolution is very complex and contains many processes like heating, melting, vaporization, ejection of particles, and plasma creation and expansion. The laser ablation craters and plasmas produced are dependent on laser beam parameters such as pulse duration, energy, and wavelength, along with the target properties and surroundin

    Multiple early introductions of SARS-CoV-2 into a global travel hub in the Middle East

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    International travel played a significant role in the early global spread of SARS-CoV-2. Understanding transmission patterns from different regions of the world will further inform global dynamics of the pandemic. Using data from Dubai in the United Arab Emirates (UAE), a major international travel hub in the Middle East, we establish SARS-CoV-2 full genome sequences from the index and early COVID-19 patients in the UAE. The genome sequences are analysed in the context of virus introductions, chain of transmissions, and possible links to earlier strains from other regions of the world. Phylogenetic analysis showed multiple spatiotemporal introductions of SARS-CoV-2 into the UAE from Asia, Europe, and the Middle East during the early phase of the pandemic. We also provide evidence for early community-based transmission and catalogue new mutations in SARS-CoV-2 strains in the UAE. Our findings contribute to the understanding of the global transmission network of SARS-CoV-2
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