SIR optimization in wavelength-hopping time spreading optical code routed networks

In this work, we investigate the performance of a distributed power control algorithm (DPCA) for signal-to-interference (SIR) optimization in wavelength-hopping time spreading code routed networks. These networks are based on 2D codes (time/wavelength) to establish end-to-end optical code paths (OCPs). The SIR model considers multiple access interference (MAI) between OCPs and amplified spontaneous emission (ASE) at cascaded amplified spans. The utilization of power control has a significant impact on both performance and capacity of practical optical networks. The DPCA can be effectively implemented in each node because uses only local parameters or measurements.     

Mass spectrometry fingerprinting of media used for in vitro production of bovine embryos

Using the bovine species as a biological model, direct infusion chip‐based nano‐electrospray ionization mass spectrometry (nano‐ESI‐MS) fingerprinting in the positive ion mode is used to obtain fast chemical profiles of media used for in vitro production of bovine embryos. Nano‐ESI‐MS fingerprinting is useful for characterization and routine quality control requiring no sample pre‐separation, being able to differentiate four different media (IVM, IVF, SOF and HSOF) via principal component analysis (PCA). For media stored at +4°C for up to 45 days, no significant (p > 0.05) variation was observed in cleavage and blastocyst rate development, as well as in the nano‐ESI‐MS chemical profiles. For media exposed to a heat shock (60°C for 3 h), no significant decrease (p > 0.05) in embryo development rates was observed, but nano‐ESI‐MS profiles were quite distant from fresh control media in the PCA. For frozen media (?70°C for 2 months), again no significant variation (p > 0.05) in embryo development was noticed, but nano‐ESI‐MS profiles from all media were significantly affected. These results indicate that nano‐ESI(+)‐MS fingerprinting was able to characterize different media based on their specific chemical profile. The technique seems therefore applicable as a routine quality control assay, detecting, for example, compositional changes after temperature variations that may affect post‐transfer embryo viability. Copyright © 2009 John Wiley & Sons, Ltd.     

Weak basis transformations and texture zeros in the leptonic sector

We investigate the physical meaning of some of the texture zeros which appear in most of the ansatzes on leptonic masses and their mixing. It is shown that starting from arbitrary lepton mass matrices and making suitable weak basis transformations one can obtain some of these sets of zeros, which therefore have no physical content. We then analyse four-zero texture ansatzes where the charged lepton and neutrino mass matrices have the same structure. The four texture zeros cannot be obtained simultaneously through weak basis transformations, so these ansatzes do have physical content. We show that they can be separated into four classes and study the physical implications of each class.     

Microwave-assisted multicomponent synthesis of julolidines using silica-supported calix[4]arene as heterogeneous catalyst

The application of immobilizing calixarene onto the surface of silica using a sol-gel method, as an efficient heterogeneous catalyst (CX4SO₃HSi(n)) for multicomponent Povarov reaction has been described. Catalytic activity of the CX4SO₃HSi(n) for the synthesis of julolidines under greener and environmentally benign conditions in simple and efficient method was explored. Notably, only 0.5 mol% of the catalyst is sufficient to catalyze the Povarov solvent-free reaction under microwave-assistance. Besides, this protocol allows the construction of four new C–C bonds and two C–N bonds in a single step. To the best of our knowledge, this consists the first silica support calix[4]arene as a heterogeneous catalyst for multicomponent synthesis of julolidines.     

One- and two-electron reduction of triarylborane-based helical donor–acceptor compounds

One-electron chemical reduction of 10-(dimesitylboryl)-N,N-di-p-tolylbenzo[c]phenanthrene-4-amine (3-B(Mes)₂-[4]helix-9-N(p-Tol)₂) 1 and 13-(dimesitylboryl)-N,N-di-p-tolyldibenzo[c,g]phenanthrene-8-amine (3-B(Mes)₂-[5]helix-12-N(p-Tol)₂) 2 gives rise to monoanions with extensive delocalization over the annulated helicene rings and the boron p_z orbital. Two-electron chemical reduction of 1 and 2 produces open-shell biradicaloid dianions with temperature-dependent population of the triplet states due to small singlet-triplet gaps. These results have been confirmed by single-crystal X-ray diffraction, EPR and UV/vis-NIR spectroscopy, and DFT calculations.

Stepwise chemical reduction of D–π–A triarylborane-based helicenes gives the corresponding monoanions and dianions with delocalized unpaired electrons. The structures were confirmed by single crystal X-ray diffraction.     

Optimization of an acoustic test chamber involving the fluid-structure interaction by FEM and experimental validation

The aim of this work is to determine the optimal design of two acoustic test chambers using systems of optimization by means of finite elements. In this way, we have modelled a set of tests composed of a source chamber and a receiving chamber according to the basic requirements of the standard rule. The constructive element whose acoustical behaviour is being evaluated is placed between both chambers. Applying the finite element method (FEM), a two-dimensional coupled finite element model with fluid-structure interaction has been made, using finite elements of the fluid-type both for the air and fluid-structure interface, and finite elements of solid-type with its elastic properties for a multilayered wall. The geometry of the chambers has been parameterized as design variables (DVs) and an objective function has been defined from the absolute value of the difference between the transmission loss (TL) values of the laboratory test and the TL of the numerical simulation in order to minimize it. To find an optimal design of the geometry of the acoustic chamber, a new cascade optimization procedure has been successfully developed. Finally, the numerical simulation results are compared with the acoustic laboratory results, and conclusions are exposed.     

Euclidean weights of codes from elliptic curves over rings

We construct certain error-correcting codes over finite rings and estimate their parameters. For this purpose, we need to develop some tools, notably an estimate for certain exponential sums and some results on canonical lifts of elliptic curves. These results may be of independent interest.

     

The sodium salt of diethyl 1H-pyrazole-3,5-dicarboxylate as an efficient amphiphilic receptor for dopamine and amphetamines. crystal structure and solution studies

The sodium salt of the diethyl 1H-pyrazole-3,5-dicarboxylate (2) of amphiphilic character is able to interact with (+)-amphetamine, (+)-methamphetamine, and dopamine, yielding stable complexes. Crystal structure of 2 with (+)-amphetamine leads to a very nice double helical supramolecular structure.     

Gradient ion-pair chromatographic method for the determination of iron N,N'-ethylenediamine-di-(2-hydroxy-5-sulfophenylacetate) by high performance liquid chromatography-atmospheric pressure ionization electrospray mass spectrometry

The most effective remedy for iron deficiency is the use of synthetic iron chelates, specifically chelates derived from polyaminecarboxylic acids as EDDHSA (N,N'-ethylenediamine-di-(2-hidroxy-5-sulfophenylacetic) acid). A gradient ion-pair chromatographic method was developed to quantify the total amount of chelated iron in EDDHSA/Fe3+ fertilizers. Two mobile phases were used containing, respectively, 35 and 75% acetonitrile in a 0.005 M tetrabutylammonium hydroxide aqueous solution at pH 6.0. The stationary phase was a reverse phase C-18 column (150mm x 3.9mm i.d., dp = 5 microm). Two chromatographic peaks appeared and were identified by Electrospray Mass Spectrometry. The first peak corresponds to the monomer of EDDHSA/Fe3+ and the second peak has been assigned to condensation molecules. Quality parameters indicate that the method is suitable for the quantification of iron chelate by EDDHSA fertilizers.