Variational derivation of equation for generalized pair correlation function

The wavefunction of a system is explicitly written down in a fully anti-symmetric way between a fermion pair and a medium, and the equations for each one of them are derived from the variation of total energy for bound systems and by forming appropriate scalar products for continuum states. High-energy particles, such as protons, electrons, and nuclei impinging upon spacecraft, produce secondary radiations. In order to protect the internal environment of spacecraft from these radiations, their intensities are determined in many instances theoretically, and an appropriate program has been developed in the High Energy Science Branch. The purpose of this research is to investigate the problem of indistinguishability of an incident projectile with one of the same in a target

Applications of Quantum Theory of Atomic and Molecular Scattering to Problems in Hypersonic Flow

The general status of a grant to investigate the applications of quantum theory in atomic and molecular scattering problems in hypersonic flow is summarized. Abstracts of five articles and eleven full-length articles published or submitted for publication are included as attachments. The following topics are addressed in these articles: fragmentation of heavy ions (HZE particles); parameterization of absorption cross sections; light ion transport; emission of light fragments as an indicator of equilibrated populations; quantum mechanical, optical model methods for calculating cross sections for particle fragmentation by hydrogen; evaluation of NUCFRG2, the semi-empirical nuclear fragmentation database; investigation of the single- and double-ionization of He by proton and anti-proton collisions; Bose-Einstein condensation of nuclei; and a liquid drop model in HZE particle fragmentation by hydrogen

Radiations from hot nuclei

The investigation indicates that nuclei with excitation energy of a few hundred MeV to BeV are more likely to radiate hot nuclear clusters than neutrons. These daughter clusters could, furthermore, de-excite emitting other hot nuclei, and the chain continues until these nuclei cool off sufficiently to evaporate primarily neutrons. A few GeV excited nuclei could radiate elementary particles preferentially over neutrons. Impact of space radiation with materials (for example, spacecraft) produces highly excited nuclei which cool down emitting electromagnetic and particle radiations. At a few MeV excitation energy, neutron emission becomes more dominant than gamma-ray emission and one often attributes the cooling to take place by successive neutron decay. However, a recent experiment studying the cooling process of 396 MeV excited Hg-190 casts some doubt on this thinking, and the purpose of this investigation is to explore the possibility of other types of nuclear emission which might out-compete with neutron evaporation

Nanoscale surface relaxation of a membrane stack

Recent measurements of the short-wavelength (~ 1--100 nm) fluctuations in stacks of lipid membranes have revealed two distinct relaxations: a fast one (decay rate of ~ 0.1 ns^{-1}), which fits the known baroclinic mode of bulk lamellar phases, and a slower one (~ 1--10 \mu s^{-1}) of unknown origin. We show that the latter is accounted for by an overdamped capillary mode, depending on the surface tension of the stack and its anisotropic viscosity. We thereby demonstrate how the dynamic surface tension of membrane stacks could be extracted from such measurements.Comment: 4 page

Caractérisation physico-chimique des eaux résiduaires de tannerie: cas de l’usine TAN ALIZ à Ouagadougou / Burkina Faso

Les activités de tannage consistent en la transformation de la peau animale en cuir par élimination des lipides et des poils. Deux procédés sont utilisés pour cela : le tannage au chrome et le tannage végétal. Danscette optique, les industries de tannerie emploient plusieurs réactifs chimiques et produisent d’énormes quantités d’eaux résiduaires et de déchets solides. Nous nous intéressons dans cette étude à l’analyse des eaux usées sortant de TAN ALIZ, une unité industrielle de tannerie de la ville de Ouagadougou, afin de déterminer si leurs rejets dans la nature après traitement ne constituent pas une pollution pour l’environnement. Cette étude, qui a été effectuée durant la période de juillet à septembre 2010, fait apparaître que: les nitrates et les sulfates ne constituent pas de pollution du milieu naturel ; les phosphates, le chrome VI, les Matières enSuspension (MES), la conductivité électrique ont des teneurs dépassant les normes admises. Ces eaux constituent donc une pollution pour la nature ; la Demande Biochimique en Oxygène (DBO5) présente des valeurs largement supérieures à 30 mg/L, norme OMS confirmant l’existence d’une pollution organique.Mots clés : TAN ALIZ, MES, Chrome VI, DBO

Variations of the 10 um Silicate Features in the Actively Accreting T Tauri Stars: DG Tau and XZ Tau

Using the Infrared Spectrograph aboard the Spitzer Space Telescope, we observed multiple epochs of 11 actively accreting T Tauri stars in the nearby Taurus-Auriga star forming region. In total, 88 low-resolution mid-infrared spectra were collected over 1.5 years in Cycles 2 and 3. The results of this multi-epoch survey show that the 10 um silicate complex in the spectra of two sources - DG Tau and XZ Tau - undergoes significant variations with the silicate feature growing both weaker and stronger over month- and year-long timescales. Shorter timescale variations on day- to week-long timescales were not detected within the measured flux errors. The time resolution coverage of this data set is inadequate for determining if the variations are periodic. Pure emission compositional models of the silicate complex in each epoch of the DG Tau and XZ Tau spectra provide poor fits to the observed silicate features. These results agree with those of previous groups that attempted to fit only single-epoch observations of these sources. Simple two-temperature, two-slab models with similar compositions successfully reproduce the observed variations in the silicate features. These models hint at a self-absorption origin of the diminution of the silicate complex instead of a compositional change in the population of emitting dust grains. We discuss several scenarios for producing such variability including disk shadowing, vertical mixing, variations in disk heating, and disk wind events associated with accretion outbursts.Comment: 6 pages, emulate apj format, accepted for publication in ApJ Letter

Pollution des eaux dans le bassin du nakambe: Cas du barrage de Ziga

Le Burkina Faso est drainé essentiellement par quatre (4) grands bassins-versants: le bassin du fleuve Niger, le bassin du fleuve Nakanbé, le bassin du Mouhoun et le bassin de la Comoé. Le Nakanbé est le bassin le plus peuplé. La ville de Ouagadougou est presque entièrement tributaire des eaux de surface de ce bassin. Les problèmes d’approvisionnement en eau potable de la ville ont conduit à l’adoption du projet de barrage de Ziga. D’une capacité nominale de deux cents (200) millions de m3 au plan d’eau normal (P.E.N), cet important ouvrage a pour vocation l’approvisionnement en eau de la ville de Ouagadougou. Les populations riveraines du barrage pratiquent le maraîchage sur les rives et avancent dans le lit du barrage au fur et à mesure que l’eau se retire. Pour lutter contre les insectes et les animaux nuisibles (vers, rats, rats-voleurs, lièvres, perdrix, pintades sauvages, …) qui détruisent leurs légumes, ils emploient des pesticides de synthèse, dont beaucoup sont interdits d’usage. Des fertilisants sont également utilisés. L’objectif de cette étude est de déterminer les perturbations physiques et chimiques subies par l’eau du barrage de Ziga par la mesure des paramètres physicochimiques de l’eau et la détermination des concentrations des résidus de pesticides organochlorés. Douze points de prélèvement d’échantillons ont été identifiés et ceux-ci ont été prélevés au mois de février et de mars 2012 et analysés pendant la même période. L’étude fait apparaître que les perturbations physicochimiques restent limitées et que sur les vingt (20) pesticides organochlorés recherchés, cinq (5) ont été détectés dans les eaux brutes du barrage de Ziga. Il s’agit de l’aldrine, de l’endosulfan sulfate, du alpha endosulfan, du beta HCH et du o,p- DDE.Mots clés: approvisionnement; eau; maraîchage; pesticides; paramètres physicochimique

Analysis of diversity genetic of Moroccan net blotch populations using amplified fragment length polymorphism (AFLP) markers

Net blotch caused by Pyrenophora teres f. teres is the most harmful foliar disease in barley generating significant economic losses in Morocco. Populations of P. teres f. teres were collected from different regions of Morocco. Thirty five (35) P. teres f. teres isolates, single conidial, were isolated and were subjected to molecular study using amplified fragment length polymorphism (AFLP) technique. Out of the fourteen primers combinations tested, four primers combinations were selected to disclose the polymorphism between the different P. teres f. teres isolates. The molecular characterization of these isolates showed high degree of polymorphism reaching 95% and identifying 25 specific genotypes. The genetic variability of the different isolates of P. teres f. teres within and between Moroccan regions was highlighted, disclosing no linkage between the isolates and their geographical origins. This result might be due to informal material flow between regions.Key words: Barley, net blotch, Pyrenophora teres f. teres, amplified fragment length polymorphism (AFLP), genetic diversity