4,217 research outputs found

    Effect of stirring on the safety of flammable liquid mixtures

    Get PDF
    Flash point is the most important variable employed to characterize fire and explosion hazard of liquids. The models developed for predicting the flash point of partially miscible mixtures in the literature to date are all based on the assumption of liquid-liquid equilibrium. In real-world environments, however, the liquid-liquid equilibrium assumption does not always hold, such as the collection or accumulation of waste solvents without stirring, where complete stirring for a period of time is usually used to ensure the liquid phases being in equilibrium. This study investigated the effect of stirring on the flash point behavior of binary partially miscible mixtures. Two series of partially miscible binary mixtures were employed to elucidate the effect of stirring. The first series was aqueous-organic mixtures, including water + 1-butanol, water + 2-butanol, water + isobutanol, water + 1-pentanol, and water + octane ; the second series was the mixtures of two flammable solvents, which included methanol + decane, methanol + 2,2,4-trimethylpentane, and methanol + octane. Results reveal that for binary aqueous-organic solutions the flash-point values of unstirred mixtures were located between those of the completely stirred mixtures and those of the flammable component. Therefore, risk assessment could be done based on the flammable component flash point value. However, for the assurance of safety, it is suggested to completely stir those mixtures before handling to reduce the risk

    Integral and Rxte/Asm Observations on Igr J17098-3628

    Full text link
    To probe further the possible nature of the unidentified source IGR J17098-3628, we have carried out a detailed analysis of its long-term time variability as monitored by RXTE/ASM, and of its hard X-ray properties as observed by INTEGRAL. INTEGRAL has monitored this sky region over years and significantly detected IGR J17098-3628 only when the source was in this dubbed active state. In particular, at \ge 20 keV, IBIS/ISGRI caught an outburst in March 2005, lasting for \sim5 days with detection significance of 73σ\sigma (20-40 keV) and with the emission at << 200 keV. The ASM observations reveal that the soft X-ray lightcurve shows a similar outburst to that detected by INTEGRAL, however the peak of the soft X-ray lightcurve either lags, or is preceded by, the hard X-ray (>>20 keV) outburst by \sim2 days. This resembles the behavior of X-ray novae like XN 1124-683, hence it further suggests a LMXB nature for IGR J17098-3628. While the quality of the ASM data prevents us from drawing any definite conclusions, these discoveries are important clues that, coupled with future observations, will help to resolve the as yet unknown nature of IGR J17098-3628.Comment: 15 pages, 7 figure, accepted in PAS

    Possible hard X-ray shortages in bursts from KS 1731-260 and 4U 1705-44

    Full text link
    Aims: A hard X-ray shortage, implying the cooling of the corona, was observed during bursts of IGR J17473-272, 4U 1636-536, Aql X-1, and GS 1826-238. Apart from these four sources, we investigate here an atoll sample, in which the number of bursts for each source is larger than 5, to explore the possible additional hard X-ray shortage during {\it Rossi X-ray timing explorer (RXTE)} era. Methods: According to the source catalog that shows type-I bursts, we analyzed all the available pointing observations of these sources carried out by the {\it RXTE} proportional counter array (PCA). We grouped and combined the bursts according to their outburst states and searched for the possible hard X-ray shortage while bursting. Results: We found that the island states of KS 1731-260 and 4U 1705-44 show a hard X-ray shortage at significant levels of 4.5 and 4.7 σ\sigma and a systematic time lag of 0.9±2.10.9 \pm 2.1 s and 2.5±2.02.5 \pm 2.0 s with respect to the soft X-rays, respectively. While in their banana branches and other sources, we did not find any consistent shortage.Comment: 5 pages, 4 figures, accepted by A&A as a research not

    Analysis of the effect of Qizhuyigan on liver function in a mouse model of immunological liver injury

    Get PDF
    Purpose: To assess the protective effect of Qizhuyigan capsules containing an  herbal mixture on liver function in a mouse model of immunological liver injury and to explore the mechanism of action.Methods: One hundred and twenty mice were randomly divided into four groups: control, test, bifendate, and Qizhuyigan. Immunological liver injury was induced in all groups except the control group. Mice in the control group and the test group were gavaged with 2.5 g/kg tap water, mice in the bifendate group were gavaged with 12 mg/kg bifendate in water, and mice in the Qizhuyigan group were gavaged with 1,000 mg/kg of an aqueous solution containing the contents of a Qizhuyigan capsule. The gavage continued for 10 days. Changes in liver function-related indices, such as the levels of alanine aminotransferase (ALT), aspartate  aminotransferase (AST), malonaldehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6), were assessed.Results: Compared with the test and bifendate groups, the Qizhuyigan group exhibited lower serum ALT (98.3 U/L ± 8.7 U/L vs. 224.7 U/L ± 18.4 U/L vs. 132.8 U/L ± 9.4 U/L); AST (165.5 U/L ± 12.1 U/L vs. 362.6 U/L ± 16.6 U/L vs. 224.6 U/L ± 12.2 U/L); and MDA levels (12.7 ± 2 μmol/L vs. 31.3 ± 6.60 μmol/L vs. 14.4 ± 2.3 μmol/L); a higher SOD level; and reduced TNF-α and IL-6 levels. The differences of the above indices had statistical significance (p &lt; 0.05).Conclusion: Qizhuyigan exerted a protective effect in a mouse model of immunological liver injury.Keywords: Qizhuyigan capsule, Immunological liver injury, Biochemical parameter

    Study of Fully Homomorphic Encryption over Integers

    Get PDF
    Fully homomorphic encryption has long been regarded as an open problem of cryptography. The method of constructing first fully homomorphic encryption scheme by Gentry is complicate so that it has been considered difficult to understand. This paper explains the idea of constructing fully homomorphic encryption and presents a general framework from various scheme of fully homomorphic encryption. Specially, this general framework can show some possible ways to construct fully homomorphic encryption. We then analyze the procedure how to obtaining fully homomorphic encryption over the integers. The analysis of recrypt procedure show the growth of noise, and the bound of noise in recrypt procedure is given. Finally, we describe the steps of implementation.

    Simulation of Piezoelectric Laminated Smart Structure under Strong Electric Field

    Get PDF
    Applying strong electric field on piezoelectric actuators, on one hand very significant electroelastic material nonlinear effects will occur, on the other hand piezo plates and shells may undergo large displacements and rotations. In order to give a precise prediction of piezolaminated smart structures under large electric field, this paper develops a finite element (FE) model accounting for both electroelastic material nonlinearity and geometric nonlinearity with large rotations based on the first order shear deformation (FSOD) hypothesis. The proposed FE model is applied to analyze a piezolaminated semicircular shell structure
    corecore