Experimental Study of Aerodynamic Damping in Arrays of Vibrating Cantilevers

Cantilever structures vibrating in a fluid are encountered in numerous engineering applications. The aerodynamic loading from a fluid can have a large effect on both the resonance frequency and damping, and has been the subject of numerous studies. The aerodynamic loading on a single beam is altered when multiple beams are configured in an array. In such situations, neighboring beams interact through the fluid and their dynamic behavior is modified. In this work, aerodynamic interactions between neighboring cantilever beams operating near their first resonance mode and vibrating at amplitudes comparable to their widths are experimentally explored. The degree to which two beams become coupled through the fluid is found to be sensitive to vibration amplitude and proximity of neighboring components in the array. The cantilever beams considered are slender piezoelectric fans (approximately 6 cm in length), and are caused to vibrate in-phase and out-of-phase at frequencies near their fundamental resonance values. Aerodynamic damping is expressed in terms of the quality factor for two different array configurations and estimated for both in-phase and out-of-phase conditions. The two array configurations considered are for neighboring fans placed face-to-face and edge-to-edge. It is found that the damping is greatly influenced by proximity of neighboring fans and phase difference. For the face-to-face configuration, a reduction in damping is observed for in-phase vibration, while it is greatly increased for out-of-phase vibration; the opposite effect is seen for the edge-to-edge configuration. The resonance frequencies also show a dependence on the phase difference, but these changes are small compared to those observed for damping. Correlations are developed based on the experimental data which can be used to predict the aerodynamic damping in arrays of vibrating cantilevers. The distance at which the beams no longer interact is quantified for both array configurations. Understanding the fluid interactions between neighboring vibrating beams is essential for predicting the dynamic behavior of such arrays and designing them for practical applications

Differential regulation of TNF-α and IL-1β production from endotoxin stimulated human monocytes by phosphodiesterase inhibitors

The effect of selective PDE-I (vinpocetine), PDE-III (milrinone, CI-930), PDE-IV (rolipram, nitroquazone), and PDE-V (zaprinast) isozyme inhibitors on TNF-α and IL-1β production from LPS stimulated human monocytes was investigated. The PDE-IV inhibitors caused a concentration dependent inhibition of TNF-α production, but only partially inhibited IL-1β at high concentrations. High concentrations of the PDE-III inhibitors weakly inhibited TNF-α, but had no effect on IL-1β production. PDE-V inhibition was associated with an augmentation of cytokine secretion. Studies with combinations of PDE isozyme inhibitors indicated that PDE-III and PDE-V inhibitors modulate rolipram's suppression of TNF production in an additive manner. These data confirm that TNF-α and IL-1β production from LPS stimulated human monocytes are differentially regulated, and suggest that PDE-IV inhibitors have the potential to suppress TNF levels in man

The unintegrated gluon distribution from the CCFM equation

The gluon distribution f(x, k_t^2,mu^2), unintegrated over the transverse momentum k_t of the gluon, satisfies the angular-ordered CCFM equation which interlocks the dependence on the scale k_t with the scale \mu of the probe. We show how, to leading logarithmic accuracy, the equation can be simplified to a single scale problem. In particular we demonstrate how to determine the two-scale unintegrated distribution f(x,k_t^2,mu^2) from knowledge of the integrated gluon obtained from a unified scheme embodying both BFKL and DGLAP evolution.Comment: 16 pages LaTeX, 3 eps figure

Children\u27s and caregivers\u27 perspectives about mandatory reporting of child maltreatment: A meta-synthesis of qualitative studies

Objective To systematically synthesise qualitative research that explores children\u27s and caregivers\u27 perceptions of mandatory reporting. Design We conducted a meta-synthesis of qualitative studies. Data sources Searches were conducted in Medline, Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Criminal Justice Abstracts, Education Resources Information Center, Sociological Abstracts and Cochrane Libraries. Eligibility criteria English-language, primary, qualitative studies that investigated children\u27s or caregivers\u27 perceptions of reporting child maltreatment were included. All healthcare and social service settings implicated by mandatory reporting laws were included. Data extraction and synthesis Critical appraisal of included studies involved a modified checklist from the Critical Appraisal Skills Programme (CASP). Two independent reviewers extracted data, including direct quotations from children and caregivers (first-order constructs) and interpretations by study authors (second-order constructs). Third-order constructs (the findings of this meta-synthesis) involved synthesising second-order constructs that addressed strategies to improve the mandatory reporting processes for children or caregivers-especially when these themes addressed concerns raised by children or caregivers in relation to the reporting process. Results Over 7935 citations were retrieved and 35 articles were included in this meta-synthesis. The studies represent the views of 821 caregivers, 50 adults with histories of child maltreatment and 28 children. Findings suggest that children and caregivers fear being reported, as well as the responses to reports. Children and caregivers identified a need for improvement in communication from healthcare providers about mandatory reporting, offering preliminary insight into child-driven and caregiver-driven strategies to mitigate potential harms associated with reporting processes. Conclusion Research on strategies to mitigate potential harms linked to mandatory reporting is urgently needed, as is research that explores children\u27s experiences with this process

Mandated reporters\u27 experiences with reporting child maltreatment: A meta-synthesis of qualitative studies

Objective To systematically search for research about the effectiveness of mandatory reporting of child maltreatment and to synthesise qualitative research that explores mandated reporters\u27 (MRS) experiences with reporting. Design As no studies assessing the effectiveness of mandatory reporting were retrieved from our systematic search, we conducted a meta-synthesis of retrieved qualitative research. Searches in Medline (Ovid), Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Sociological Abstracts, Education Resources Information Center, Criminal Justice Abstracts and Cochrane Library yielded over 6000 citations, which were deduplicated and then screened by two independent reviewers. English-language, primary qualitative studies that investigated MRS\u27 experiences with reporting of child maltreatment were included. Critical appraisal involved a modified checklist from the Critical Appraisal Skills Programme and qualitative meta-synthesis was used to combine results from the primary studies. Setting All healthcare and social-service settings implicated by mandatory reporting laws were included. Included studies crossed nine high-income countries (USA, Australia, Sweden, Taiwan, Canada, Norway, Finland, Israel and Cyprus) and three middle-income countries (South Africa, Brazil and El Salvador). Participants: The studies represent the views of 1088 MRS. Outcomes Factors that influence MRS\u27 decision to report and MRS\u27 views towards and experiences with mandatory reporting of child maltreatment. Results Forty-four articles reporting 42 studies were included. Findings indicate that MRS struggle to identify and respond to less overt forms of child maltreatment. While some articles (14%) described positive experiences MRS had with the reporting process, negative experiences were reported in 73% of articles and included accounts of harm to therapeutic relationships and child death following removal from their family of origin. Conclusions The findings of this meta-synthesis suggest that there are many potentially harmful experiences associated with mandatory reporting and that research on the effectiveness of this process is urgently needed

Mandated reporters' experiences with reporting child maltreatment: a meta-synthesis of qualitative studies.

OBJECTIVE: To systematically search for research about the effectiveness of mandatory reporting of child maltreatment and to synthesise qualitative research that explores mandated reporters' (MRs) experiences with reporting. DESIGN: As no studies assessing the effectiveness of mandatory reporting were retrieved from our systematic search, we conducted a meta-synthesis of retrieved qualitative research. Searches in Medline (Ovid), Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Sociological Abstracts, Education Resources Information Center, Criminal Justice Abstracts and Cochrane Library yielded over 6000 citations, which were deduplicated and then screened by two independent reviewers. English-language, primary qualitative studies that investigated MRs' experiences with reporting of child maltreatment were included. Critical appraisal involved a modified checklist from the Critical Appraisal Skills Programme and qualitative meta-synthesis was used to combine results from the primary studies. SETTING: All healthcare and social-service settings implicated by mandatory reporting laws were included. Included studies crossed nine high-income countries (USA, Australia, Sweden, Taiwan, Canada, Norway, Finland, Israel and Cyprus) and three middle-income countries (South Africa, Brazil and El Salvador). PARTICIPANTS: The studies represent the views of 1088 MRs. OUTCOMES: Factors that influence MRs' decision to report and MRs' views towards and experiences with mandatory reporting of child maltreatment. RESULTS: Forty-four articles reporting 42 studies were included. Findings indicate that MRs struggle to identify and respond to less overt forms of child maltreatment. While some articles (14%) described positive experiences MRs had with the reporting process, negative experiences were reported in 73% of articles and included accounts of harm to therapeutic relationships and child death following removal from their family of origin. CONCLUSIONS: The findings of this meta-synthesis suggest that there are many potentially harmful experiences associated with mandatory reporting and that research on the effectiveness of this process is urgently needed

A Magnetic Transition Probed by the Ce Ion in Square-Lattice Antiferromagnet CeMnAsO

We examined the magnetic properties of the square-lattice antiferromagnets CeMnAsO and LaMnAsO and their solid solutions La1-xCexMnAsO by resistivity, magnetic susceptibility, and heat capacity measurements below room temperature. A first-order phase transition is observed at 34.1 K, below which the ground-state doublet of the Ce ion splits by 3.53 meV. It is likely that Mn moments already ordered above room temperature are reoriented at the transition, as reported for related compounds, such as NdMnAsO and PrMnSbO. This transition generates a large internal magnetic field at the Ce site in spite of the fact that simple Heisenberg interactions should be cancelled out at the Ce site owing to geometrical frustration. The transition takes place at nearly the same temperature with the substitution of La for Ce up to 90%. The Ce moment does not undergo long-range order by itself, but is parasitically induced at the transition, serving as a good probe for detecting the magnetism of Mn spins in a square lattice.Comment: 11 pages, 5 figures, to be published in J. Phys. Soc. Jp