Three terminals optoelectronics devices integrated into a silicon on silicon waveguide

In this paper we describe two different kind of optoelectronic devices both based on a three terminals active device and exploit the plasma dispersion effect to achieve the desired working. The first device exploits this effect in order to obtain an optical modulation. The second device is an optoelectronic router based on the mode-mixing principle together with the injection-induced optical phase shift. Both devices are integrated into a Silicon on Silicon optical channel waveguide which can be realized using a standard bipolar process. The possibility of using standard, well-known technology presents several advantages with respect to III–V Optoelectronics. The active three terminal device used is a Bipolar Mode Field Effect Transistor (BMFET). Numerical simulation results are presented on both devices.     

Stochastic analysis in life office management: applications to large annuity portfolios

The paper deals with the riskiness analysis for a large portfolio of life annuities. By means of the limiting distribution of the present value of the portfolio, in the first part of the paper a model for evaluating the investment and the projection risks is presented. In the second part, with regard to the investment risk's effects, the insolvency risk is measured considering the cumulative probability distribution function of the discounted average cost per policy. Copyright © 2003 John Wiley & Sons, Ltd.     

Performance evaluation of fiber Bragg grating sensors by digital holographic technique, strain gauge measurement

In view of the growing interest for non-destructive tests of materials, geodynamical monitoring and in general remote sensing, there is a great effort to bring practical optical sensors from research labs to industrial and environmental applications. In this paper, we employ digital holographic technique as an efficient tool for evaluating the strain measurement capability of fiber Bragg gratings (FBG). A cantilever beam has been employed as a test structure under loading test. The strain measurements results obtained by fiber-based sensors have been compared to those obtained by using full-field digital holographic technique and point-wise strain gauge sensors glued on the same cantilever beam. A simple theoretical model is also presented to interpret and compare the experimental results coming from different techniques.     

Negative-ion fast atom bombardment mass spectrometry in the characterization of deoxyfluorinated sugars

Negative-ion fast atom bombardment mass spectrometry and metastable ion studies were applied to the characterization of three isomeric fluorine-containing sugars. Peculiar fragmentation processes were evidenced for each isomer, enabling their differentiation. Comparison with the behaviour of a non-fluorinated analogue allowed investigation of the role of fluorine in the decomposition processes of these compounds.     

Fast atom bombardment mass spectrometry of new polydentate schiff bases. 2. The case of mono- and bisaldimines containing pyridine groups

The mass spectrometric behaviour of seven polydentate Schiff bases derived from the condensation of formyl or diformyl precursors (2,3-dihydroxy- or 2,5-dihydroxy-benzaldehyde, 3-metoxy- or 3-ethoxy-salicylaldehyde, 3-formyl-salicyclic acid, 4-methoxy- or 4-chloro-2,6-diformylphenol) with 2-aminomethylpyridine have been investigated by fast atom bombardment mass spectrometry and metastable ion studies.     

The chemistry of 2H-3,1-benzoxazine-2,4(1H)-dione (Isatoic Anhydride). 19. Direct formation of 2-aminobenzyl alcohols from the reduction of N-substituted isatoic anhydrides

Isatoic anhydrides 1 are easily reduced with sodium borohydride to o-(substituted-amino)benzyl alcohols 3 in good yield. Sequential reduction of N-(2-nitrobenzyl)isatoic anhydride ( 5 ) with sodium borohydride followed by catalytic hydrogenation of the nitro group affords the naturally occurring 2-(2′-aminobenzylamino)-benzyl alcohol ( 4 ) in 72% yield.     

Novel heterocycles. I. Synthesis and reactions of 6,7-dihydro-1H,3H,5H-pyrido[3,2,l-ij] [3,1]benzoxazine-1,3-dione

6,7-Dihydro-1H,3H,5H-pyrido[3,2,l-ij][3,1 ]benzoxazine-1,3-dione ( 1b ) was synthesized by a new route and its reactions with various nueleophiles are described.     

Rheology of a lyotropic mesophase through a stress-relaxation experiment

We report on the first rheological study of the structural relaxations in a nematic liquid crystalline phase. Linear dynamic and transient shear experiments were applied to a polydomain nematic phase of the CTAB/water system: a liquid crystalline mixture composed of 28 wt% CTAB at 35 degrees C. The decay of the shear modulus, G(t), was analyzed using the CONTIN inverse Laplace transform to obtain a distribution of relaxation times which were compared with ones from the usual fitting procedure based on a generalized Maxwell model. The behavior of the nematic lyotropic structure of the CTAB/water system is characterized by the presence of both slow and fast relaxation times. These were interpreted as being due to a progressive loss of the lyotropic domain orientation and to the breaking/reforming process of the cylindrical aggregates, respectively.     

Fused lactones as a route to functionalized 1-substituted indoles

Indole lactones 8 and 14 were synthesized as a means of functionalizing the 1-isopropyl substituent of the indole nucleus. Lactone 8 , upon reduction with diisobutylaluminum hydride, produces lactol 9 which behaves like a masked hydroxy aldehyde and undergoes a Horner-Emmons reaction with triethyl phosphonoacteate to give α,β-unsaturated ester 3 which possesses a hydroxyl group on the 1-isopropyl moiety.