Detection of low energy solar neutrinos with HPGermanium

The potential of the GENIUS proposal [1] to measure the spectrum of low energy solar neutrinos in real time is studied. The detection reaction is elastic neutrino-electron scattering 9 + e M 9 + e. The energy resolution for detecting the recoil electrons is about 0.3%, the energy threshold is a few keV. The expected number of events for a target of one ton of natural germanium is 3.6 events/day for pp-neutrinos and 1.3 events/day for ⁷Be-neutrinos, calculated in the standard solar model (BP98 [2]). It should be feasible to achieve a background low enough to measure the low energy solar neutrino spectrum.     

[Bis(tetrahydrofuran–O)–bis(1,3–dialkyl–2–diphenylphosphanyl–1,3–diazaallyl)calcium] – Synthesis and Crystal Structures of Calcium Bis[phospha(III)guanidinates] and Investigations of Catalytic Activity

The reaction of [(thf)₄Ca(PPh₂)₂] ( 1 ) with diisopropyl– and dicyclohexylcarbodiimides yields the phospha(III)guanidinates [(thf)₂Ca{RNC(PPh₂)NR}₂] with R = isopropyl ( 2 ) and cyclohexyl ( 3 ). The metathesis reaction of K{RNC(PPh₂)NR} with anhydrous CaI₂ also allows the synthesis of these phospha(III)guanidinate complexes 2 and 3 . For 2 a cis arrangement is observed whereas 3 crystallizes as trans isomer. The phospha(III)guanidinates act as bidentate chelate bases with an average Ca–N distance of 242.5 pm. The C–P bond length between the PPh₂ fragment and the 1,3–diazaallyl unit is with values above 190 pm very large. The complexes 2 and 3 show a moderate catalytic activity in hydrophosphanylation reactions of dialkylcarbodiimides with diphenylphosphane.     

Asymptotic partition of energy in micropolar mixture theory of porous media

The aim of this paper is to study the asymptotic partition of the energy associated with the solution of the initial-boundary value problem who describes the behavior of binary homogeneous micropolar mixtures of an isotropic micropolar elastic solid with an incompressible micropolar viscous fluid. Some Lagrange-Brun identities are established. Using the Cesáro means of various parts of total energy, the relations that describe the asymptotic behavior of mean energies are established. The author acknowledges support from the Romanian Ministry of Education and Research through CEEX program, contract CERES-2-CEx06-11-12/25.07.2006.     

Analysis of the neutralino system in supersymmetric theories

Charginos and neutralinos in supersymmetric theories can be produced copiously at colliders and their properties can be measured with high accuracy. Consecutively to the chargino system, in which the SU(2) gaugino parameter , the higgsino mass parameter and can be determined, the remaining fundamental supersymmetry parameter in the gaugino/higgsino sector of the minimal supersymmetric extension of the Standard Model, the U(1) gaugino mass , can be analyzed in the neutralino system, including its modulus and its phase in CP–noninvariant theories. The CP properties of the neutralino system are characterized by unitarity quadrangles. Analytical solutions for the neutralino mass eigenvalues and the mixing matrix are presented for CP–noninvariant theories in general. They can be written in compact form for large supersymmetric mass parameters. The closure of the neutralino and chargino systems can be studied by exploiting sum rules for the pair-production processes in collisions. Thus the picture of the non–colored gaugino and higgsino complex in supersymmetric theories can comprehensively be reconstructed in these experiments. Received: 24 August 2001 / Published online: 21 November 2001     

Stability and robustness properties of a class of discrete–time residual generators

The aim of this paper is to present a design methodology for an observer–based fault detection filter. This approach allows to compute a filter gain such that both fault detection and disturbance attenuation requirements are accomplished. The developments are based on H_∞ optimization in the discrete–time framework. The existence conditions for the observer–based detection filter are expressed in terms of feasibility of a system of matrix inequalities. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Development of a high-speed spectrophotometer for transient measurement of pulverized-coal flame radiation emission

A high-speed spectrophotometer system was developed for the transient measurement of pulverized-coal flame radiation. The system is a grating spectrograph with a single detector instead of a detector array. The position of the four-sided rotatable mirror determines the wavelength of the measured spectral radiation intensity, and the plane grating is mounted in a new arrangement. The system allows repeated measurement of radiation intensity spectra at wavelengths of 2.4–4.0 μm within a period of 1 or less. A desktop combustion system with the ability to vary parameters influencing the combustion of pulverized coal has been designed and assembled.

Experiments performed include steady-state measurement of radiation from a constant-intensity light source and transient measurement of radiation from a pulverized-coal flame.

Preliminary measurements showed that this spectrophotometer is capable of obtaining the desired measurements. Transient measurement of the flame radiation of pulverized coal performed on samples of Yugoslav pulverized coals produced data that comply well with results of other authors.     

An optimized method to extract poplar leaf proteins for two‐dimensional gel electrophoresis guided by analysis of polysaccharides and phenolic compounds

Commonly used methods for protein extraction from plant leaves, such as extraction with phenol or a combination of trichloroacetic acid and acetone, were ineffective for four tested cultivars of poplar. Moreover, multiple protocols for 2DE of the extracted proteins gave different results when protein profiles of relatively closely related plants were compared. Given that polycyclic compounds strongly hinder 2DE, we analyzed the impact of polyphenols and polysaccharides present in the plant tissues used for protein extraction, on the quality of 2DE protein profiles. Analysis of content of polyphenols and polysaccharides in leaves of poplar cultivars showed that even small differences in concentrations of analyzed metabolites accompany large differences between poplar cultivars when considering the susceptibility of samples to protein extraction for 2DE. High‐quality 2DE results were correlated with decreased amounts of polyphenols. Additional analysis using MS/MS suggested that only levels of total phenolics affected the results of 2DE. Soluble total nonstructural carbohydrates also had a negative effect, but the level of starch was not important. Finally, we present an optimized method for extraction of proteins from poplar leaves, which enables reliable comparative analysis of four different poplar cultivars, that is, “Eridano,” “Villafranca,” “NE‐42,” and “Luisa Avanzo,” which have not yet been used for the proteomic studies.     

Stability analysis of whirl flutter in rotor-nacelle systems with freeplay nonlinearity

Nonlinear Dynamics - Tiltrotor aircraft are growing in prevalence due to the usefulness of their unique flight envelope. However, aeroelastic stability—particularly whirl flutter...