An explanatory study of 11^{11}Li β\beta decay into 9^9Li and deuteron

The $\beta$-decay of $^{11}$Li into $^9$Li and {\it d} is studied using simple halo wave functions of $^{11}$Li. The sensitivity of the transition probability is elucidated on a description of the halo part and on a choice of the potential between $^9$Li and {\it d} .Comment: 8 pages,revtex,2 figures (available upon request

Four-Probe Measurements of Carbon Nanotubes with Narrow Metal Contacts

We find that electrons in single-wall carbon nanotubes may propagate substantial distances (tens of nanometers) under the metal contacts. We perform four-probe transport measurements of the nanotube conductance and observe significant deviations from the standard Kirchhoff's circuit rules. Most noticeably, injecting current between two neighboring contacts on one end of the nanotube, induces a non-zero voltage difference between two contacts on the other end.Comment: 4 pages, 5 figures; submitte

Theoretical study of one-proton removal from 15O

One-proton removal from 15O at intermediate energies (56 A MeV) is studied in the eikonal approximation of the Glauber model. The production of the 14N core fragment in the ground and excited states is regarded. The calculated proton removal cross section, the 15O interaction cross section, and the longitudinal momentum distribution of the 14N fragments are compared to recent experimental data [1]. [1] H. Jeppesen, R. Kanungo, B. Abu-Ibrahim it et al, Nucl. Phys. A 739, 57 (2004)

Identification of the Content of Biologically Active Substances in Nut Shots

One of ways of the food industry development is a search for non-traditional raw material resources with the high content of physiologically healthy nutrients. A promising way of biologically important raw materials is secondary products of oil production, especially shots. The aim of the research was to determine the content of biologically active substances in nut shots (cedar nut shot (CNS) and walnut shot (WNS)). The quality composition of the phenol nature was established by reactions with 10 % alcohol solutions of FeCl3, NaOH, АlCl3 and cyanidin test. The content of hydroxycinnamic acids (with recalculation for chlorogenic acid) was determined by the spectrophotometric method. The amount of tanning substances – by the method of permanganometry. The analysis of the sum of flavonoids (in recalculation for rutin) was realized by the method of differential spectrophotometry. Carbonic acids were identified by the method of gas-liquid chromatography. There were revealed quality differences in the composition of substances of the phenol nature for CNS and WNS. WNS is characterized by the higher content of hydroxycinnamic acids – in 2,5 times, tanning substances – in 3,1 times and flavonoids – in 60 times, comparing with CNS. The content of unsaturated fats in WNS is 95,79 % of the total number of fats, and in CNS – 80,05 %. The ratio Omega-3/Omega-6 for the fat component of CNS is 1/0,06, and for WNS fats – 1/1,3. WNS comparing with CNS is characterized by the higher content of Malic (in 5,3 times) and fumaric (in 100 times)acid. CNS contains more lemon (in 2,9 times) and succinic (in 2,2 times) acid. That is, identification of the content of some biologically active substances in nut shots allows to recommend them for usage in technologies of food products. It allows to enrich them with phenol compounds, polyunsaturated fats and organic acids

Electron-phonon relaxation and excited electron distribution in zinc oxide and anatase

We propose a first-principle method for evaluations of the time-dependent electron distribution function of excited electrons in the conduction band of semiconductors. The method takes into account the excitations of electrons by external source and the relaxation to the bottom of conduction band via electron-phonon coupling. The methods permits calculations of the non-equilibrium electron distribution function, the quasi-stationary distribution function with steady-in-time source of light, the time of setting of the quasi-stationary distribution and the time of energy loss via relaxation to the bottom of conduction band. The actual calculations have been performed for titanium dioxide in the anatase structure and zinc oxide in the wurtzite structure. We find that the quasi-stationary electron distribution function for ZnO is a fermi-like curve that rises linearly with increasing excitation energy whereas the analogous curve for anatase consists of a main peak and a shoulder. The calculations demonstrate that the relaxation of excited electrons and the setting of the quasi-stationary distribution occur within the time no more than 500 fsec for ZnO and 100 fsec for anatase. We also discuss the applicability of the effective phonon model with energy-independent electron-phonon transition probability. We find that the model only reproduces the trends in changing of the characteristic times whereas the precision of such calculations is not high. The rate of energy transfer to phonons at the quasi-stationary electron distribution also have been evaluated and the effect of this transfer on the photocatalyses has been discussed. We found that for ZnO this rate is about 5 times less than in anatase.Comment: 21 p., 9 figure

Critical Fields and Critical Currents in MgB2

We review recent measurements of upper (Hc2) and lower (Hc1) critical fields in clean single crystals of MgB2, and their anisotropies between the two principal crystallographic directions. Such crystals are far into the "clean limit" of Type II superconductivity, and indeed for fields applied in the c-direction, the Ginzburg-Landau parameter k is only about 3, just large enough for Type II behaviour. Because m0Hc2 is so low, about 3 T for fields in the c-direction, MgB2 has to be modified for it to become useful for high-current applications. It should be possible to increase Hc2 by the introduction of strong electron scattering (but because of the electronic structure and the double gap that results, the scatterers will have to be chosen carefully). In addition, pinning defects on a scale of a few nm will have to be engineered in order to enhance the critical current density at high fields.Comment: BOROMAG Conference Invited paper. To appear in Supercond. Sci. Tec

The LYRA Instrument Onboard PROBA2: Description and In-Flight Performance

The Large Yield Radiometer (LYRA) is an XUV-EUV-MUV (soft X-ray to mid-ultraviolet) solar radiometer onboard the European Space Agency PROBA2 mission that was launched in November 2009. LYRA acquires solar irradiance measurements at a high cadence (nominally 20 Hz) in four broad spectral channels, from soft X-ray to MUV, that have been chosen for their relevance to solar physics, space weather and aeronomy. In this article, we briefly review the design of the instrument, give an overview of the data products distributed through the instrument website, and describe the way that data are calibrated. We also briefly present a summary of the main fields of research currently under investigation by the LYRA consortium