Strange hadronic stellar matter within the Brueckner-Bethe-Goldstone theory

In the framework of the non-relativistic Brueckner-Bethe-Goldstone theory, we derive a microscopic equation of state for asymmetric and $\beta$-stable matter containing $\Sigma^-$ and $\Lambda$ hyperons. We mainly study the effects of three-body forces (TBFs) among nucleons on the hyperon formation and the equation of state (EoS). We find that, when TBFs are included, the stellar core is almost equally populated by nucleons and hyperons. The resulting EoS, which turns out to be extremely soft, has been used in order to calculate the static structure of neutron stars. We obtain a value of the maximum mass of 1.26 solar masses (1 solar mass $M_o \simeq 1.99 \cdot 10^{33} g$). Stellar rotations increase this value by about 12%.Comment: 4 pages, Latex, 2 figures included. To appear in the Proceedings of '' Bologna 2000 - Structure of the Nucleus at the Dawn of the Century'', May 29- June 3, 2000, Bologna, Ital

Ionization by bulk heating of electrons in capacitive radio frequency atmospheric pressure microplasmas

Electron heating and ionization dynamics in capacitively coupled radio frequency (RF) atmospheric pressure microplasmas operated in helium are investigated by Particle in Cell simulations and semi-analytical modeling. A strong heating of electrons and ionization in the plasma bulk due to high bulk electric fields are observed at distinct times within the RF period. Based on the model the electric field is identified to be a drift field caused by a low electrical conductivity due to the high electron-neutral collision frequency at atmospheric pressure. Thus, the ionization is mainly caused by ohmic heating in this "Omega-mode". The phase of strongest bulk electric field and ionization is affected by the driving voltage amplitude. At high amplitudes, the plasma density is high, so that the sheath impedance is comparable to the bulk resistance. Thus, voltage and current are about 45{\deg} out of phase and maximum ionization is observed during sheath expansion with local maxima at the sheath edges. At low driving voltages, the plasma density is low and the discharge becomes more resistive resulting in a smaller phase shift of about 4{\deg}. Thus, maximum ionization occurs later within the RF period with a maximum in the discharge center. Significant analogies to electronegative low pressure macroscopic discharges operated in the Drift-Ambipolar mode are found, where similar mechanisms induced by a high electronegativity instead of a high collision frequency have been identified

High dispersive and monolithic 100% efficiency grisms

We present a type of grism, a series combination of transmission grating and prism, in which we reduce the number of diffraction orders and achieve a configuration with very high angular dispersion. The grism can be fabricated from a single dielectric material and requires no metallic or dielectric film layers for high transmission diffraction efficiency. One can reach 100% in the -1st transmission diffraction order and the equal damage threshold as the dielectric bulk material. We realized such an element in fused silica with an efficiency of more then 99%. The bevel backside reflection is reduced by a statistical antireflective structure, so we measured an efficiency of the entire grism of 95% at a single wavelength

Effects of the Zanzibar School-Based Deworming Program on Iron Status of Children.

We evaluated the effects of the Zanzibar school-based deworming program on the iron status of primary school children. Parasitologic and nutritional assessments were carried out at baseline, 6 mo, and 12 mo in 4 nonprogram schools (n = 1002), 4 schools in which students received twice-yearly deworming (n = 952), and 4 schools in which students received thrice-yearly deworming (n = 970) with 500 mg generic mebendazole. Schools were randomly selected for evaluation and allocated to program groups. Relative to no treatment, thrice-yearly deworming caused significant decreases in protoporphyrin concentrations and both deworming regimens caused marginally significant increases in serum ferritin concentrations. The average annual changes in protoporphyrin concentrations were -5.9 and -23.5 micromol/mol heme in the control and thrice-yearly deworming groups, respectively (P < 0.001). The average changes in ferritin concentration were 2.8 and 4.5 microg/L, respectively (P = 0.07). Deworming had no effect on annual hemoglobin change or prevalence of anemia. However, the relative risk of severe anemia (hemoglobin < 70 g/L) was 0.77 (95% confidence limits: 0.39, 1.51) in the twice-yearly deworming group and 0.45 (0.19, 1.08) in the thrice-yearly deworming group. The effects on prevalence of high protoporphyrin values and incidence of moderate-to-severe anemia (hemoglobin < 90 g/L) were significantly greater in children with > 2000 hookworm eggs/g feces at baseline. We estimate that this deworming program prevented 1260 cases of moderate-to-severe anemia and 276 cases of severe anemia in a population of 30,000 schoolchildren in 1 y. Where hookworm is heavily endemic, deworming programs can improve iron status and prevent moderate and severe anemia, but deworming may be needed at least twice yearly

Opinion dynamics driven by leaders, media, viruses and worms

A model on the effects of leader, media, viruses, and worms and other agents on the opinion of individuals is developed and utilized to simulate the formation of consensus in society and price in market via excess between supply and demand. Effects of some time varying drives, (harmonic and hyperbolic) are also investigated. Key words: Opinion; Leader; Media; Market; Buyers; Sellers; ExcessComment: 14 pages, 7 figures (14, total) Will be published in IJMP

3P_2-3F_2 pairing in neutron matter with modern nucleon-nucleon potentials

We present results for the $^3P_2 - ^3F_2$ pairing gap in neutron matter with several realistic nucleon-nucleon potentials, in particular with recent, phase-shift equivalent potentials. We find that their predictions for the gap cannot be trusted at densities above $\rho\approx 1.7\rho_0$, where $\rho_0$ is the saturation density for symmetric nuclear matter. In order to make predictions above that density, potential models which fit the nucleon-nucleon phase shifts up to about 1 GeV are required.Comment: Revtex style, 19 pages, 6 figures inlude