3,530 research outputs found

    Experimental Investigation on the Impact Resistance of Laminated Glass with Various Glass Make-ups

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    Laboratory testing data concerning the full sized laminated glass panel with different glass make-ups under impact is limited. An experimental investigation on the impact resistance of LG panels under hard body impact is reported in this paper. A test approach namely, mean minimum breakage velocity approach, is adopted to capture the minimum impact energy that triggers each glass breakage. The crack morphology of glass panels is firstly investigated. Results indicate that the intersection angle of the radial crack edges increases when the strengthening level of glass decreases. The impact resistance is then revealed by investigating the effects caused by three design variables, i.e., the glass types, interlayer thickness and interlayer types. It reveals that the configuration with inner HS glass and outer FT glass panel can provide better impact resistance, and performs better in keeping initial stiffness under repeated impacts with higher impact velocity. In the contrast, placing HS glass in the both side may weaken the impact resistance. A 1.52 mm PVB interlayer can provide better impact resistance and higher initial stiffness when compared to a thicker interlayer, it is more likely to produce stiffness degradation between consecutive breakages as well. The difference of SGP LG and PVB LG in MMBV is found to be negligible, however, SGP LG exhibits evidently higher initial pre breakage stiffness and remains greater post breakage strength

    Performance-Based Plastic Design Method for Steel Concentrically Braced Frames Using Target Drift and Yield Mechanism

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    Under severe earthquakes, steel concentrically braced frames (SCBFs) will experience large  inelastic deformations in an uncontrolled manner. According to the energy-work balance concept, a performance-based plastic design (PBPD) methodology for steel concentrically braced frames was presented here. This method uses pre-selected target drift and yield mechanism as key performance limit states. The designed base shear for selected hazard levels was derived based on work-energy balance equations. Plastic design was performed to design bracing members and connection nodes in order to achieve the expected yield mechanism and behavior. The method has been successively applied to design a six-storey steel concentrically braced frame. Results of inelastic dynamic analyses showed that the story drifts were well within the target values, thus to meet the desired performance requirements. The proposed method provided a basis for performance-based plastic design of steel concentrically braced frames

    The contribution of distant sources to the observed flux of ultra high-energy cosmic rays

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    Ultra-high-energy (UHE) cosmic rays (CRs) interact with cosmic background radiation through hadronic processes, and the Universe would become 'opaque' to UHE CRs of energies ∼(1018-1020) eV over about several tens of Mpc, setting the Greisen-Zatsepin-Kuz'min (GZK) horizon. We demonstrate that a non-negligible fraction of the UHE CRs arriving on Earth could originate from beyond the GZK horizon when heavy nuclear CRs, and the population and evolution of UHE CR sources are taken into account. We show how the multi-particle CR horizon is modified by different source populations, and discuss how this leads to the natural emergence of an isotropic flux component in the observed UHE CR background. This component would coexist with an anisotropic foreground component contributed by nearby sources within the GZK horizon

    Advances in the application of action learning in nursing practice

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    AbstractIn this paper, we elucidate the concept and characteristics of action learning as well as summarize the reflexivity, cooperativeness, and subjectivity of this approach. Furthermore, we describe the effects and limitations of action learning when applied in nursing management, nursing education, and clinical practice, among various fields

    Strong decays of the ϕ(2170)\phi(2170) as a fully-strange tetraquark state

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    We study strong decays of the ϕ(2170)\phi(2170), along with its possible partner X(2436)X(2436), as two fully-strange tetraquark states of JPC=1J^{PC} = 1^{--}. We consider seven decay channels: ϕη\phi \eta, ϕη\phi \eta^\prime, ϕf0(980)\phi f_0(980), ϕf1(1420)\phi f_1(1420), h1(1415)ηh_1(1415) \eta, h1(1415)ηh_1(1415) \eta^\prime, and h1(1415)f1(1420)h_1(1415) f_1(1420). Some of these channels are kinematically possible, and we calculate their relative branching ratios through the Fierz rearrangement. Future experimental measurements on these ratios can be useful in determining the nature of the ϕ(2170)\phi(2170) and X(2436)X(2436). The ϕ(2170)\phi(2170) has been observed in the ϕf0(980)\phi f_0(980), ϕη\phi \eta, and ϕη\phi \eta^\prime channels, and we propose to further examine it in the h1(1415)ηh_1(1415) \eta channel. Evidences of the X(2436)X(2436) have been observed in the ϕf0(980)\phi f_0(980) channel, and we propose to verify whether this structure exists or not in the ϕη\phi \eta, ϕη\phi \eta^\prime, h1(1415)ηh_1(1415) \eta, and h1(1415)ηh_1(1415) \eta^\prime channels.Comment: 10 pages, 3 figures, 1 table, suggestions and comments are welcom

    Co-Variation of Tonality in the Music and Speech of Different Cultures

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    Whereas the use of discrete pitch intervals is characteristic of most musical traditions, the size of the intervals and the way in which they are used is culturally specific. Here we examine the hypothesis that these differences arise because of a link between the tonal characteristics of a culture's music and its speech. We tested this idea by comparing pitch intervals in the traditional music of three tone language cultures (Chinese, Thai and Vietnamese) and three non-tone language cultures (American, French and German) with pitch intervals between voiced speech segments. Changes in pitch direction occur more frequently and pitch intervals are larger in the music of tone compared to non-tone language cultures. More frequent changes in pitch direction and larger pitch intervals are also apparent in the speech of tone compared to non-tone language cultures. These observations suggest that the different tonal preferences apparent in music across cultures are closely related to the differences in the tonal characteristics of voiced speech

    Identification and pharmacokinetics of saponins in Rhizoma Anemarrhenae after oral administration to rats by HPLC-Q-TOF/MS and HPLC-MS/MS

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    Rhizoma Anemarrhenae is a well-known herbal medicine with saponins as its commonly regarded major bioactive components. It is essential to classify the properties of saponins which are associated with their toxicity and efficacy. In this study, 25 compounds were identified by HPLC-Q-TOF/MS in the extract of Rhizoma Anemarrhenae and 8 saponins were detected in rat plasma by HPLC-MS/MS after oral administration of this extract. These were neomangiferin, mangiferin, timosaponin E1, timosaponin E, timosaponin B-II, timosaponin B-III, timosaponin A-III and timosaponin A-I. A sensitive and accurate HPLC-MS/MS method was developed and successfully applied to a pharmacokinetic study of the abovementioned eight saponins after oral administration of the Rhizoma Anemarrhenae extract to rats. The method validation, including specificity, linearity, precision, accuracy, recovery, matrix effect and robustness, met the requirements of the intended use. The pharmacokinetic parameter, Tmax value, ranged from 2 to 8 h for these eight saponins whereas their elimination half-life (t1/2) ranged from 4.06 to 9.77 h, indicating slow excretion. The plasma concentrations of these eight saponins were all very low, indicating a relatively low oral bioavailability. All these results provide support for further clinical studies

    Factors predictive of papillary thyroid micro-carcinoma with bilateral involvement and central lymph node metastasis: a retrospective study

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    <p>Abstract</p> <p>Background</p> <p>The optimal resection extent for papillary thyroid microcarcinoma (PTMC) remains controversial. The objective of the study was to investigate risk factors of bilateral PTMC and central lymph node metastasis (CLNM) to guide surgical strategies for PTMC patients.</p> <p>Methods</p> <p>We retrospectively reviewed 211 PTMC patients who underwent total thyroidectomy (TT) and 122 clinical lymph node-negative (cN0) cases that underwent prophylactic central lymph node dissection (CLND) between 2010 and 2011. The frequency, pattern, and predictive factors for bilateral PTMC and CLNM in these patients were studied using univariate and multivariate analysis with respect to the following variables: age, gender, extrathyroidal extension (ETE), T stage, with Hashimoto thyroiditis (HT), tumor size and multifocality based on final pathology, and preoperative evaluation using ultrasonography (US).</p> <p>Results</p> <p>Fifty-four of 211 (25.6%) patients had bilateral PTMC. In multivariate analysis, multifocality (<it>P</it> < 0.001, OR = 23.900) and tumor size ≥7 mm (<it>P</it> = 0.014, OR = 2.398) based on US were independent predictive factors for bilateral PTMC which was also independently associated with multifocality (<it>P</it> < 0.001, OR = 29.657) and tumor size ≥7 mm (<it>P</it> = 0.005, OR = 2.863) based on final pathology. Among 122 cN0 patients who underwent prophylactic CLND, we found 49.2% of patients had CLNM. CLNM was independently associated with men, age <50 years and tumor size ≥7 mm based on final pathology or preoperative US.</p> <p>Conclusions</p> <p>TT should be considered for PTMC patients who are found multifocality and tumor size ≥7 mm based on preoperative US. CLND need be considered in cN0 patients who are men, aged <50 years or tumor size ≥7 mm based on preoperative US.</p

    High-efficiency in vitro and in vivo detection of Zn2+ by dye-assembled upconversion nanoparticles

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    10.1021/ja5115248Journal of the American Chemical Society13762336-234
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