F-15 flight flutter test program

The modes to be observed during the F-15 flight flutter test program were selected on the basis of the results of analytical studies, wind tunnel tests, and ground vibration tests. The modes (both symmetrical and antisymmetrical) tracked on this basis were: fin first bending, fin torsion, fin tip roll, stabilator bending, stabilator pitch, boom lateral bending, boom torsion, boom vertical bending, wing first bending, wing second bending, wing first torsion, outer wing torsion, and aileron rotation. Data obtained for these various modes were evaluated in terms of damping versus airspeed at 1525 m (5000 ft), damping versus altitude at the cross-section Mach numbers (to extrapolate to the damping value to be expected at sea level), and flutter boundaries on the basis of flutter margin of various modal pairs representing potential flutter mechanisms. Results of these evaluations are summarized in terms of minimum predicted flutter margin for the various mechanisms

Sibling Violence: The Missing Piece in Family Violence Policy

Social work has played an integral role in the conceptualization and implementation of policy aimed at prevention and intervention of various forms of family violence. Seminal federal policies to address child abuse and neglect (Child Abuse Prevention and Treatment Act), elder abuse (Elder Justice and Older Americans Acts), and intimate partner violence (Violence Against Women and Family Violence Prevention and Services Acts) all focus on specific types of violence in the family. To date, however, there are no federal policies specifically addressing physical and/or emotional sibling violence (Perkins, Coles, & O’Connor, 2017; Perkins & O’Connor, 2016). This article examines the exclusion of policy addressing physical and emotional sibling violence considering other family violence policies. Along with prevalence, consequences, and associative factors connected to sibling violence, definitional issues that impede the creation of policy to address this form of family violence are highlighted. Children as a marginalized population, deserving the attention of social workers through policy advocacy will be discussed as well as psychoeducation and interprofessional collaboration that may facilitate the creation of policies aimed at addressing this form of family violence

Correlations in a Confined gas of Harmonically Interacting Spin-Polarized Fermions

For a fermion gas with equally spaced energy levels, the density and the pair correlation function are obtained. The derivation is based on the path integral approach for identical particles and the inversion of the generating functions for both static responses. The density and the pair correlation function are evaluated explicitly in the ground state of a confined fermion system with a number of particles ranging from 1 to 220 and filling the Fermi level completely.Comment: 11 REVTEX pages, 3 postscript figures. Accepted for publication in Phys. Rev. E, Vol. 58 (August 1, 1998

Density and Pair Correlation Function of Confined Identical Particles: the Bose-Einstein Case

Two basic correlation functions are calculated for a model of $N$ harmonically interacting identical particles in a parabolic potential well. The density and the pair correlation function of the model are investigated for the boson case. The dependence of these static response properties on the complete range of the temperature and of the number of particles is obtained. The calculation technique is based on the path integral approach of symmetrized density matrices for identical particles in a parabolic confining well.Comment: 8 pages (REVTEX) + 6 figures (postscript

Confined Harmonically Interacting Spin-Polarized Fermions in a Magnetic Field: Thermodynamics

We investigate the combined influence of a magnetic field and a harmonic interparticle interaction on the thermodynamic properties of a finite number of spin polarized fermions in a confiment potential. This study is an extension using our path integral approach of symmetrized density matrices for identical particles. The thermodynamical properties are calculated for a three dimensional model of N harmonically interacting spin polarized fermions in a parabolic potential well in the presence of a magnetic field. The free energy and the internal energy are obtained for a limited number of particles. Deviations from the thermodynamical limit become negligible for about 100 or more particles, but even for a smaller number of fermions present in the well, scaling relations similar to those of the continuum approximation to the density of states are already satisfied.Comment: 7 pages REVTEX and 8 postscript figures, accepted in Phys. Rev.

Thermodynamic identities and particle number fluctuations in weakly interacting Bose--Einstein condensates

We derive exact thermodynamic identities relating the average number of condensed atoms and the root-mean-square fluctuations determined in different statistical ensembles for the weakly interacting Bose gas confined in a box. This is achieved by introducing the concept of {\it auxiliary partition functions} for model Hamiltonians that do conserve the total number of particles. Exploiting such thermodynamic identities, we provide the first, completely analytical prediction of the microcanonical particle number fluctuations in the weakly interacting Bose gas. Such fluctuations, as a function of the volume V of the box are found to behave normally, at variance with the anomalous scaling behavior V^{4/3} of the fluctuations in the ideal Bose gas.Comment: 5 pages, 1 figur

The Impact of COVID-19 on Family Violence in Immigrant Communities in the United States

The COVID-19 pandemic has threatening implications for all individuals; and has been particularly unsettling for immigrants. Given their unique positionality in the U.S., the intersectional discussion about the impact of this pandemic on immigrants and issues of family violence is salient. The position of some groups of immigrant women is even more precarious due to the increased dependency on their spouse/partner for emotional, economic and immigration-related reasons. While immigrants have been on the frontlines as responders for COVID-19, there are limited policies that provide them with healthcare, employment guarantee, or benefits. Further, the immigration restrictions created by the U.S. Government have worsened the position of immigrants. All these stressors create unprecedented challenges for immigrants. Therefore, it is vital to delve into the family dynamics, unique challenges, and potential solutions that can provide support to immigrant families. This commentary highlights the atypical challenges of immigrants in relation to the pandemic and how these challenges may impact the incidence of family violence. Through our discussion, we hope to encourage social work scholars, practitioners, and policy advocates to support and advocate for immigrants; especially, during the new normal under the COVID-19 pandemic

Turbulent convection: comparing the moment equations to numerical simulations

The non-local hydrodynamic moment equations for compressible convection are compared to numerical simulations. Convective and radiative flux typically deviate less than 20% from the 3D simulations, while mean thermodynamic quantities are accurate to at least 2% for the cases we have investigated. The moment equations are solved in minutes rather than days on standard workstations. We conclude that this convection model has the potential to considerably improve the modelling of convection zones in stellar envelopes and cores, in particular of A and F stars.Comment: 10 pages (6 pages of text including figure captions + 4 figures), Latex 2e with AAS Latex 5.0 macros, accepted for publication in ApJ

Protective effect of prostacyclin on postischemic acute renal failure in the rat

Protective effect of prostacyclin on postischemic acute renal failure in the rat. Infusion of prostacyclin (PGI2) reportedly attenuates renal ischemic injury in the dog and the rat. In the dog, PGI2 is a potent renal vasodilator; in the rat a direct action on the renal vasculature is not always apparent. To determine whether or not the protective effect of PGI2 on postichemic ARF was hemodynamically mediated, studies were performed in uninephrectomized Sprague–Dawley rats before and after a 40 minute period of complete renal artery occlusion. In response to the preischemic infusion of PGI2 for 30 minutes at 160 ng/kg body wt/min i.v. (N = 7), MAP and RBF fell to 86 ± 7% (P < 0.0001) and 84 ± 9% (P < 0.05) of baseline values, respectively. RVR initially declined to 81 ± 9% of baseline values (P < 0.025) but returned to 102 ± 13% of baseline values prior to the period of ischemia. Following the period of ischemia, reflow of blood in the rats receiving PGI2 was delayed when compared to rats not receiving PGI2 (N = 1). RBF returned to only 76 ± 19% of the initial values in PGI2-treated rats (P < 0.01) but to 90 ± 12% of the initial values in rats receiving buffer alone (NS). Observations made during the ensuing 48 hours in animals treated with either 80 (N = 8) or 160 ng/kg/body wt/min (N = 7) for 30 minutes before and four hours after the period of ischemia indicated that renal function improved to a greater extent in the PGI2-treated animals than in buffer–treated animals (N = 15) as judged by significantly–greater mean values of V, UOsm, UCr and CCr. On the second day after ischemia, CInwas significantly greater in PGI2-treated animals than in the postischemic animals receiving buffer alone (77 ± 45 vs. 33 ± 20 µl/min/100 g body wt; P < 0.05) despite the fact that no differences were found in the mean values of RBF (3.59 ± 1.08 vs. 3.43 ± 0.32 ml/min/100 body wt. Blinded analysis of the histological sections revealed significantly less evidence of tublar epithelial cell necrosis in the PGI2-treated animals (P < 0.005). The data indicate that the protective effect of PGI2 on the renal response to ischemic injury in the Sprague–Dawley rat is not related to changes in RBF or RVR. Instead, the beneficial effect of PGI2may be a result of cytoprotective properties as has been demonstrated in other tissues

Sneutrino-Antisneutrino Mixing and Neutrino Mass in Anomaly--mediated Supersymmetry Breaking Scenario

In supersymmetric models with nonzero Majorana neutrino mass, the sneutrino and antisneutrino mix, which may lead to same sign dilepton signals in future collider experiments. We point out that the anomaly-mediated supersymmetry breaking scenario has a good potential to provide an observable rate of such signals for the neutrino masses suggested by the atmospheric and solar neutrino oscillations. The sneutrino mixing rate is naturally enhanced by m_{3/2}/m_{\tilde{\nu}}={\cal O}(4\pi/\alpha) while the sneutrino decay rate is small enough on a sizable portion of the parameter space. We point out also that the sneutrino-antisneutrino mixing can provide much stronger information on some combinations of the neutrino masses and mixing angles than neutrino experiments.Comment: Revtex, 13 pages, 2 figure