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In order to optimize the acoustic properties of a stacked fiber nonwoven, the microstructure of the non-woven is modeled by a macroscopically homogeneous random system of straight cylinders (tubes). That is, the fibers are modeled by a spatially stationary random system of lines (Poisson line process), dilated by a sphere. Pressing the non-woven causes anisotropy. In our model, this anisotropy is described by a one parametric distribution of the direction of the fibers. In the present application, the anisotropy parameter has to be estimated from 2d reflected light microscopic images of microsections of the non-woven.After fitting the model, the flow is computed in digitized realizations of the stochastic geometric model using the lattice Boltzmann method. Based on the flow resistivity, the formulas of Delany and Bazley predict the frequency-dependent acoustic absorption of the non-woven in the impedance tube.Using the geometric model, the description of a non-woven with improved acoustic absorption properties is obtained in the following way: First, the fiber thicknesses, porosity and anisotropy of the fiber system are modified. Then the flow and acoustics simulations are performed in the new sample. These two steps are repeatedc for various sets of parameters. Finally, the set of parameters for the geometric model leading to the best acoustic absorption is chosen.

The commonly reported preponderance of female over male depression in incidence and prevalence studies requires further analysis. One explanation is that the social consequences of expression of depressive symptomatology are different for males and females. A comparison of participants' reactions to male and female case histories of common reactions to stress confirmed the hypothesis. Depression elicited more rejection of males than of females, and the sex difference in rejection of depression was more pronounced than for anxiety or flat affect-detached responses. A discriminant analysis further suggested that depressed males are especially likely to be perceived as impaired in role functioning as compared with depressed females. Results suggest that depressed males are not rejected for expression of emotionality as such. Speculations about the causes and consequences of differential rejection of depression are noted.

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