Effects of grazing flow on the steady-state flow resistance and acoustic impedance of thin porous-faced liners

The effects of grazing flow on the steady state flow resistance and acoustic impedance of seven Feltmetal and three Rigimesh thin porous faced liners were studied. The steady-state flow resistance of the ten specimens was measured using standard fluid mechanical experimental techniques. The acoustic impedance was measured using the two microphone method. The principal findings of the study are that the effects of grazing flow were measured and found to be small; small differences were measured between steady-state and acoustic resistance, and a semi-empirical model was derived that correlated the steady-state resistance data of the seven Feltmetal liners and the face sheet reactance of both the Feltmetal and Rigimesh liners

Fluid mechanical model of the acoustic impedance of small orifices

A fluid mechanical model of the acoustic behavior of small orifices is presented which predicts orifice resistance and reactance as a function of incident sound pressure level, frequency, and orifice geometry. Agreement between predicted and measured values is excellent. The model shows the following: (1) The acoustic flow in immediate neighborhood of the orifice can be modeled as a locally spherical flow. Within this near field, the flow is, to a first approximation, unsteady and incompressible. (2) At very low sound pressure levels, the orifice viscous resistance is directly related to the effect of boundary-layer displacement along the walls containing the orifice, and the orifice reactance is directly related to the inertia of the oscillating flow in the neighborhood of the orifice. (3) For large values of the incident acoustic pressure, the impedance is dominated by nonlinear jet-like effects. (4) For low values of the pressure, the resistance and reactance are roughly equal

Fluid mechanical model of the Helmholtz resonator

A semi-empirical fluid mechanical model of the acoustic behavior of Helmholtz resonators is presented which predicts impedance as a function of the amplitude and frequency of the incident sound pressure field and resonator geometry. The model assumes that the particle velocity approaches the orifice in a spherical manner. The incident and cavity sound fields are connected by solving the governing oscillating mass and momentum conservation equations. The model is in agreement with the Rayleigh slug-mass model at low values of incident sound pressure level. At high values, resistance is predicted to be independent of frequency, proportional to the square root of the amplitude of the incident sound pressure field, and virtually independent of resonator geometry. Reactance is predicted to depend in a very complicated way upon resonator geometry, incident sound pressure level, and frequency. Nondimensional parameters are defined that divide resonator impedance into three categories corresponding to low, moderately low, and intense incident sound pressure amplitudes. The two-microphone method was used to measure the impedance of a variety of resonators. The data were used to refine and verify the model

Sound propagation in choked ducts

The linearized equations describing the propagation of sound in variable area ducts containing flow are shown to be singular when the duct mean flow is sonic. The singularity is removed when previously ignored nonlinear terms are retained. The results of a numerical study, for the case of plane waves propagating in a one-dimensional converging-diverging duct, show that the sound field is adequately described by the linearized equations only when the axial mean flow Mach number at the duct throat M sub th 0.6. For M sub th 0.6, the numerical results showed that acoustic energy flux was not conserved. An attempt was made to extend the study to include the nonlinear behavior of the sound field. Meaningful results were not obtained due, primarily, to numerical difficulties

Emotional distress may increase risk for self-medication and lower risk for mood-related drinking consequences in adolescents

The current study examines indicators of emotional distress and coping that may define sub-populations of adolescents at risk for two potential affect-related mechanisms underlying substance misuse: self-medication and mood-related drinking consequences. Although theory and empirical evidence point to the salience of affect-related drinking to current and future psychopathology, we have little knowledge of whether or for whom such mood-related processes exist in adolescents because few studies have used methods that optimally match the phenomenon to the level of analysis. Consequently, the current study uses multi-level modeling in which daily reports of negative mood and alcohol use are nested within individuals to examine whether adolescents with more emotional distress and poorer coping skills are more likely to evidence self-medication and moodrelated drinking consequences. Seventy-five adolescents participated in a multi-method, multi-reporter study in which they completed a 21-day experience sampling protocol assessing thrice daily measures of mood and daily measures of alcohol use. Results indicate that adolescents reporting greater anger are more likely to evidence self-medication. Conversely, adolescents displaying lower emotional distress and more active coping are more likely to evidence mood-related drinking consequences. Implications for identifying vulnerable sub-populations of adolescents at risk for these mechanisms of problematic alcohol use are discussed.peer-reviewe

Bulldog mothers, rabid worker-bees, and white ravens: women's gender dissent in late Soviet Russia

This thesis conceptualizes gender dissent and explores proposed examples of it among women in late Soviet Russia. Through surveying theories of dissent/resistance and gender under a postmodernist lens, I conclude that people may use gender to dissent against political organizations and/or social norms through subverting, disobeying, and/or using for their own purposes norms of gender. In late Soviet Russia, two systems of gender norms existed, one the official order elaborated by the state and the other the societal one based more on traditional, prerevolutionary Russian values; these two orders simultaneously conflicted with, interfered with, and upheld each other. Women were therefore able to dissent against the regime, society, or both by subtly fighting against these varied norms. Through a review of primary and secondary sources, I found that women were expected to adhere to a set of contradictory gender “rules”: working outside the home, believing themselves equal to men, having children, being married, housekeeping and raising children, upholding communist morality, participating in society, having certain characteristics such as modesty, passivity, and an understanding of human nature and emotions, being self-sacrificing, and taking care of their appearances. Through a study of Russian women’s memoirs written during or about the period between 1964 and 1985, I concluded that women could dissent against these norms in several broad categories including identity, sexuality, and “femininity” or the lack thereof. The women generally dissented very subtly, often by using one gender discourse to support behavior that infringed upon another gender order, and were not consistently “dissentive” in their discourse or actions. I found broad participation in gender dissent among the sample of women studied, and while my results are not generalizable, my data revealed that gender dissent as a concept is traceable in late Soviet Russia.http://www.ester.ee/record=b4613827*es

Exploring the Strategies of Translating Cultural References in Kurdish Subtitling

The current study investigates the strategies of translating cultural references applied in the Kurdish subtitles of the American movie entitled ‘Scent of a Woman’. This research also determines the parameters that affect the application of translation strategies in the Kurdish subtitles on the movie. In doing so, the English audio scripts (i.e., source text) and their Kurdish subtitles (i.e., target text), were compared and interpreted in accordance with Pedersen’s taxonomy of subtitling strategies and parameters (2011). The results revealed that all the translation strategies proposed by Pedersen (2011) were used in the Kurdish subtitles. However, due to the consideration of the ‘monocultural parameter’, the subtitler most frequently used the strategy of retention in the Kurdish subtitles. On the other hand, he used the strategies of omission and official equivalence least frequently. It is also shown that the parameters affecting the application of subtitling strategies were monocultural, transcultural, infracultural, and polyesemiotics. In sum, the cultural differences between SL and TL made the subtitler adopt justifiable strategies depending on availability of specific parameters

Ethics and mono-disciplinarity: positivism, informed consent and informed participation

There are a number of pressures on researchers in academia and industry to behave unethically or compromise their ethical standards, for instance in order to obtain funding or publish frequently. In this paper a case study of Deaf telephony is used to discuss the pressures to unethical behaviour in terms of withholding information or misleading participants that can result from mono-disciplinary orthodoxies. The Deaf telephony system attempts to automate multiple aspects of relayed communication between Deaf and hearing users. The study is analysed in terms of consequentialist and deontological ethics, as well as multi-loop action learning. Discussion of a number of examples of bad practice is used to indicate both the compatibility of ethical behaviour and good scientific method and that ethical behaviour is a pre-requisite for obtaining meaningful results.Telkom, Cisco, Siemens, THRI

Semiempirical airframe noise prediction model and evaluation with flight data

A semiempirical maximum overall sound pressure level (OASPL) airframe noise model was derived. Noise radiated from aircraft wings was modeled on the trailing edge diffractes quadrupole sound theory. The acoustic dipole sound theory was used to model noise from the landing gear. The model was correlated with maximum OASPL flyover noise measurements obtained for three jet aircraft. One third octave band sound pressure level flyover data was correlated and interpreted