2,084 research outputs found

    Equilibrium constant determination for bisulfite addition to aromatic aldehydes

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    Equilibrium constants for bisulfite addition to benzaldehyde and its derivatives were determined by a spectrophotometric method developed by Kokesh and Hall. The concentration of the benzaldehyde derivative was monitored by UV as aliquots of a bisulfite solution are added to a buffered solution of the aldehyde. Additional data on Ī”HĀ° and Ī”SĀ° for the reactions were derived from the temperature variation of the equilibrium constants. For benzaldehyde, the reaction had an equilibrium constant at 25Ā°C of 6.2 x 103 M-1, a Ī”HĀ° of -54.3 kJ/mol, and a Ī”SĀ° of -111 J/MolĀ·K. o-Tolualdehyde exhibited a lower Keq of 2.4 x 103 M-1, Ī”HĀ° of -39.5 kJ/mol and Ī”SĀ° of -67.3 J/MolĀ·K. Similarly, the reaction with o-anisaldehyde had a Keq of 2.6 x 103 M-1, Ī”HĀ° of -38.2 kJ/mol and Ī”SĀ° of -62.9 J/MolĀ·K. The reaction involving salicyladehyde exhibited a much lower Keq of 6.9 x 102 M-1, and Ī”HĀ° of -38.5 kJ/Mol and Ī”SĀ° of -76.1 J/MolĀ·K

    Analytical Evaluation on Hysteresis Performance of Circular Shear Panel Damper

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    The idea of adding metallic energy dissipaters to a structure to absorb a large part of the seismic energy began four decades ago. There are several types of metal-based devices conceived as dampers for the seismic energy absorber whereby damages to the major structural components could be minimized for both new and existing structures. This paper aimed to develop and evaluate structural performance of both stiffened and non stiffened circular shear panel damper for passive seismic energy protection by inelastic deformation. Structural evaluation was done using commercially available nonlinear FE simulation program. Diameter-to-thickness ratio is employed as main parameter to investigate the hysteresis performance of stiffened and unstiffened circular shear panel. Depending on these parameters three different buckling mode and hysteretic behavior was found: yielding prior to buckling without strength degradation, yielding prior to buckling with strength degradation and yielding with buckling and strength degradation which forms pinching at initial displacement. Hence, the hysteresis behavior is identified, specimens which deform without strength degradation so it will be used as passive energy dissipating device in civil engineering structures

    Analytical Evaluation on Hysteresis Performance of Circular Shear Panel Damper

    Get PDF
    The idea of adding metallic energy dissipaters to a structure to absorb a large part of the seismic energy began four decades ago. There are several types of metal-based devices conceived as dampers for the seismic energy absorber whereby damages to the major structural components could be minimized for both new and existing structures. This paper aimed to develop and evaluate structural performance of both stiffened and non stiffened circular shear panel damper for passive seismic energy protection by inelastic deformation. Structural evaluation was done using commercially available nonlinear FE simulation program. Diameter-to-thickness ratio is employed as main parameter to investigate the hysteresis performance of stiffened and unstiffened circular shear panel. Depending on these parameters three different buckling mode and hysteretic behavior was found: yielding prior to buckling without strength degradation, yielding prior to buckling with strength degradation and yielding with buckling and strength degradation which forms pinching at initial displacement. Hence, the hysteresis behavior is identified, specimens which deform without strength degradation so it will be used as passive energy dissipating device in civil engineering structures

    Analytical Evaluation on Hysteresis Performance of Circular Shear Panel Damper

    Get PDF
    The idea of adding metallic energy dissipaters to a structure to absorb a large part of the seismic energy began four decades ago. There are several types of metal-based devices conceived as dampers for the seismic energy absorber whereby damages to the major structural components could be minimized for both new and existing structures. This paper aimed to develop and evaluate structural performance of both stiffened and non stiffened circular shear panel damper for passive seismic energy protection by inelastic deformation. Structural evaluation was done using commercially available nonlinear FE simulation program. Diameter-to-thickness ratio is employed as main parameter to investigate the hysteresis performance of stiffened and unstiffened circular shear panel. Depending on these parameters three different buckling mode and hysteretic behavior was found: yielding prior to buckling without strength degradation, yielding prior to buckling with strength degradation and yielding with buckling and strength degradation which forms pinching at initial displacement. Hence, the hysteresis behavior is identified, specimens which deform without strength degradation so it will be used as passive energy dissipating device in civil engineering structures

    Analytical Evaluation on Hysteresis Performance of Circular Shear Panel Damper

    Get PDF
    The idea of adding metallic energy dissipaters to a structure to absorb a large part of the seismic energy began four decades ago. There are several types of metal-based devices conceived as dampers for the seismic energy absorber whereby damages to the major structural components could be minimized for both new and existing structures. This paper aimed to develop and evaluate structural performance of both stiffened and non stiffened circular shear panel damper for passive seismic energy protection by inelastic deformation. Structural evaluation was done using commercially available nonlinear FE simulation program. Diameter-to-thickness ratio is employed as main parameter to investigate the hysteresis performance of stiffened and unstiffened circular shear panel. Depending on these parameters three different buckling mode and hysteretic behavior was found: yielding prior to buckling without strength degradation, yielding prior to buckling with strength degradation and yielding with buckling and strength degradation which forms pinching at initial displacement. Hence, the hysteresis behavior is identified, specimens which deform without strength degradation so it will be used as passive energy dissipating device in civil engineering structures

    The English and Chinese language versions of the Short Form 12-item Health Survey are equivalent

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    Background: The Short Form 12-item Health Survey (SF-12v2) was originally developed in English, but it is also available in Hong Kong (HK) Chinese. While both language versions had their measurement properties well assessed in their respective populations, their measurement invariance in scores has not been examined. Therefore, we aimed to assess their measurement invariance. Methods: We conducted a cross-sectional study on individuals aged 18 years or older at a university campus. Those who were bilingual in English and Chinese were randomly assigned to self-complete either the standard English or the HK Chinese SF-12v2. Measurement invariance of the two components and eight scales of the SF-12v2 was concluded if the corresponding 90% confidence interval (CI) for the difference between the two language versions entirely fell within the minimal clinically important difference of Ā±3 units. Multiple-group confirmatory factor analysis (CFA) was also performed. Results: A total of 1013 participants completed the SF-12v2 (496 in English and 517 in HK Chinese), with a mean age of 22 years (Range 18ā€“58), and 626 participants (62%) were female. There were no significant differences in demographics. Only the physical and mental components and the mental health (MH) scale had their 90% CIs (0.21 to 1.61, āˆ’ 1.00 to 0.98, and āˆ’ 0.86 to 2.84, respectively) completely fall within the Ā±3 units. The multiple-group CFA showed partial strict invariance. Conclusions: The English and HK Chinese versions of the SF-12v2 can be used in studies with their two components and MH scores pooled in the analysis

    Development and applications of laser-induced incandescence

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    Several NASA-funded investigations focus on soot processes and radiative influences of soot in diffusion flames given their simplicity, practical significance, and potential for theoretical modeling. Among the physical parameters characterizing soot, soot volume fraction, f(sub v), a function of particle size and number density, is often of chief practical interest in these investigations, as this is the geometrical property that directly impacts radiative characteristics and the temperature field of the flame and is basic to understanding soot growth and oxidation processes. Diffusion flames, however, present a number of challenges to the determination of f(sub v) via traditional extinction measurements. Laser-induced incandescence (LII) possesses several advantages compared to line-of-sight extinction techniques for determination of f(sub v). Since LII is not a line-of-sight technique, similar to fluorescence, it possesses geometric versatility allowing spatially resolved measurements of f(sub v) in real time in nonaxisymmetric systems without using deconvolution techniques. The spatial resolution of LII is determined by the detector and imaging magnification used. Neither absorption by polycyclic aromatic hydrocarbons (PAH's) nor scattering contributes to the signal. Temporal capabilities are limited only by the laser pulse and camera gate duration, with measurements having been demonstrated with 10 ns resolution. Because of these advantages, LII should be applicable to a variety of combustion processes involving both homogeneous and heterogeneous phases. Our work has focussed on characterization of the technique as well as exploration of its capabilities and is briefly described

    Bioinformatics tools in predictive ecology: Applications to fisheries

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    This article is made available throught the Brunel Open Access Publishing Fund - Copygith @ 2012 Tucker et al.There has been a huge effort in the advancement of analytical techniques for molecular biological data over the past decade. This has led to many novel algorithms that are specialized to deal with data associated with biological phenomena, such as gene expression and protein interactions. In contrast, ecological data analysis has remained focused to some degree on off-the-shelf statistical techniques though this is starting to change with the adoption of state-of-the-art methods, where few assumptions can be made about the data and a more explorative approach is required, for example, through the use of Bayesian networks. In this paper, some novel bioinformatics tools for microarray data are discussed along with their ā€˜crossover potentialā€™ with an application to fisheries data. In particular, a focus is made on the development of models that identify functionally equivalent species in different fish communities with the aim of predicting functional collapse

    Cooperative vocal control in marmoset monkeys via vocal feedback

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    Choi JY, Takahashi DY, Ghazanfar AA. Cooperative vocal control in marmoset monkeys via vocal feedback

    Adaptive School-based Implementation of CBT (ASIC): clustered-SMART for building an optimized adaptive implementation intervention to improve uptake of mental health interventions in schools

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    Abstract Background Depressive and anxiety disorders affect 20ā€“30% of school-age youth, most of whom do not receive adequate services, contributing to poor developmental and academic outcomes. Evidence-based practices (EBPs) such as cognitive behavioral therapy (CBT) can improve outcomes, but numerous barriers limit access among affected youth. Many youth try to access mental health services in schools, but school professionals (SPs: counselors, psychologists, social workers) are rarely trained adequately in CBT methods. Further, SPs face organizational barriers to providing CBT, such as lack of administrative support. Three promising implementation strategies to address barriers to school-based CBT delivery include (1) Replicating Effective Programs (REP), which deploys customized CBT packaging, didactic training in CBT, and technical assistance; (2) coaching, which extends training via live supervision to improve SP competence in CBT delivery; and (3) facilitation, which employs an organizational expert who mentors SPs in strategic thinking to promote self-efficacy in garnering administrative support. REP is a relatively low-intensity/low-cost strategy, whereas coaching and facilitation require additional resources. However, not all schools will require all three strategies. The primary aim of this study is to compare the effectiveness of a school-level adaptive implementation intervention involving REP, coaching, and facilitation versus REP alone on the frequency of CBT delivered to students by SPs and student mental health outcomes. Secondary and exploratory aims examine cost-effectiveness, moderators, and mechanisms of implementation strategies. Methods Using a clustered, sequential multiple-assignment, randomized trial (SMART) design, ā‰„ā€‰200 SPs from 100 schools across Michigan will be randomized initially to receive REP vs. REP+coaching. After 8Ā weeks, schools that do not meet a pre-specified implementation benchmark are re-randomized to continue with the initial strategy or to augment with facilitation. Discussion EBPs need to be implemented successfully and efficiently in settings where individuals are most likely to seek care in order to gain large-scale impact on public health. Adaptive implementation interventions hold the promise of providing cost-effective implementation support. This is the first study to test an adaptive implementation of CBT for school-age youth, at a statewide level, delivered by school staff, taking an EBP to large populations with limited mental health care access. Trial registration NCT03541317 ā€”Registered on 29 May 2018 on ClinicalTrials.gov PRShttps://deepblue.lib.umich.edu/bitstream/2027.42/145606/1/13012_2018_Article_808.pd
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