The influence of vehicle aerodynamic and control response characteristics on driver-vehicle performance

The effects of changes in understeer, control sensitivity, and location of the lateral aerodynamic center of pressure (c.p.) of a typical passenger car on the driver's opinion and on the performance of the driver-vehicle system were studied in a moving-base driving simulator. Twelve subjects with no prior experience on the simulator and no special driving skills performed regulation tasks in the presence of both random and step wind gusts

Trions in a periodic potential

The group-theoretical classification of trion states is presented. It is based on considerations of products of irreducible representations of the 2D translation group. For a given BvK period N degeneracy of obtained states is N^2. Trions consist of two identical particles so the symmetrization of states with respect to particles transposition is considered. Completely antisymmetric states can be constructed by introducing antisymmetric spin functions. Two symmetry adapted bases are considered. The third possibility is postponed for the further investigations.Comment: revtex, 5 p., sub. to Physica

Evidence for Quark-Hadron Duality in the Proton Spin Asymmetry A_1

Spin-dependent lepton-nucleon scattering data have been used to investigate the validity of the concept of quark-hadron duality for the spin asymmetry A_1. Longitudinally polarized positrons were scattered off a longitudinally polarized hydrogen target for values of Q^2 between 1.2 and 12  GeV^2 and values of W^2 between 1 and 4  GeV^2. The average double-spin asymmetry in the nucleon resonance region is found to agree with that measured in deep-inelastic scattering at the same values of the Bjorken scaling variable x. This finding implies that the description of A_1 in terms of quark degrees of freedom is valid also in the nucleon resonance region for values of Q^2 above 1.6  GeV^2

Socio-Cultural Factors Influencing Uptake of Skilled Childbirth Services Among Women in Kaiti Division, Makueni District (Kenya)

Each year, over 500,000 women die from the complications of pregnancy and child birth, almost all of them in the developing countries. This trend can be addressed by increasing the rates of skilled care during childbirth. This study therefore sought to establish the socio-cultural factors influencing uptake of skilled childbirth care which has remained low in Kaiti Division. The researchers applied a descriptive cross-sectional study design which involved women of childbearing age (15-49 years). The study was conducted in March 2010 and had a sample size of 246 women which was randomly selected from the estimated target population of 12,077. The researchers applied both quantitative and qualitative approaches. The tests of significance employed included Fisher's exact test, chi-square, test and logistic regression. The study established that the proportion of women attended to by the skilled attendant within various age cohorts was higher (58.9%) amongst the youth/adolescent (15-24 years) (P-value = 0.091> 0.05, c2 10.915 df 6).). Skilled attendance declined among the grand-multiparas (para4 and above) from 7.7% in Para 4-5 to 2% in Para 6+ (P-value = .000<0.05, c2 34.888 df 3; Para 1(p =0.000, OR 28.391), Para 2-3 (p =0.000, OR 7.564), Para 4-5(p=0.030, OR 3.493) Further findings indicated that the principal decision maker (46.7%) on type of assistant in the last delivery was the woman (P-value = 0.000 <0.05, c2 56.076 df 5). However, the husband was the leading (39.5%) decision maker in use of a skilled assistant in the last delivery (p=0.000, OR 15.667). More than two thirds (70.7%) of the respondents who performed a ceremony prayed for safe delivery in their last delivery. The study concluded that women's parity, decision making and religion were significant in use of skilled childbirth services

Liquid-cooled liner for helmets

Liner acts as coolant tubing, manifold, and supporting structures. Fabric of waffle-design is made of several integrated channels (or capillaries) through which coolant liquid can flow. Thin and light-weight liner can be incorporated into any type of helmet or head gear