A simple taste analyzing system design for visual and quantitative analysis of different tastes using multi-array chemical sensors and pattern recognition techniques

In this paper, we describe design of a simple taste analyzing system using sensory system based on a multi-array chemical sensor (MACS) and personal digital assistant (PDA) for visual and quantitative analysis of different tastes using pattern recognition techniques. The sensory system is communicated with PDA, which has several interesting benefits for data analysis and display, via wireless using the Bluetooth. A various pattern recognition techniques are adapted including spider map, principal component analysis (PCA) and fuzzy C-means (FCM) algorithm to classify visually data patterns detected by the sensory system. The proposed techniques can be determined the cluster centers and membership grade of patterns through the unsupervised way. The membership grade of an unknown pattern, which does not shown previously, can be visually and analytically determined. Throughout the experimental trails, the taste analyzing system is demonstrated robust performance through data acquisition via wireless communication and visual and quantitative analysis of different tastes for the liquids. The system, which is implemented as a simple hand-held taste analyzing instrument, can be applicable to on-site taste monitoring.     

Synthesis of functionalized organotrifluoroborates via the 1,3-dipolar cycloaddition of azides

[reaction: see text] We have successfully prepared potassium azidoalkyltrifluoroborates from the corresponding halogen compounds in 94-98% yields through a nucleophilic substitution reaction with NaN(3). In the presence of various alkynes and Cu(I) as a catalyst, these azidotrifluoroborates easily formed 1,4-disubstituted organo-[1,2,3]-triazol-1-yl-trifluoroborates in 85-98% yields. This method was then developed into a facile one-pot synthesis for the preparation of various organo-[1,2,3]-triazol-1-yl-trifluoroborates using haloalkyltrifluoroborates as the starting materials.     

Fluorescent ratiometry of tetrahomodioxacalix[4]arene pyrenylamides upon cation complexation

[structure: see text] C-1,2-alternate tetrahomodioxacalix[4]arene pyreneamides were synthesized. Pb(2+) coordination gave a quenched monomer and excimer fluorescence emission, while upon Ca(2+) ion binding, the receptor provides an enhanced excimer and declined monomer emission with ratiometric response. The excimer emission spectra changes are rationalized by frontier molecular orbitals that the effective Py-Py interaction induces emission intensity increases upon Ca(2+) ion complexation, whereas there is no such interaction observed upon Pb(2+) binding.     

Synthesis of functionalized organotrifluoroborates via halomethyltrifluoroborates

[reaction: see text] Potassium bromo- and iodomethyltrifluoroborates have been prepared via in situ reaction of n-BuLi with dibromo- and diiodomethane, respectively, in the presence of trialkyl borates, followed by treatment with KHF(2). Moreover, a new synthetic method for the preparation of potassium organotrifluoroborates through nucleophilic substitution of the halide in these potassium halomethyltrifluoroborates is described.     

The I2(B) predissociation by solving an inverse atoms-in-molecule problem

The valence electronic states of the iodine molecule are analysed by means of a simple atoms-in-molecule model which accounts for the lowest ²P states of iodine atoms and approximates the spin-orbit interaction by its atomic part. For this model, an inverse problem is solved, i.e. non-relativistic potential energy curves and diabatic couplings are determined by a least-squares fit to known relativistic potential energy curves. The resulting adiabatic wave functions are used to calculate the electronic matrix elements responsible for natural, hyperfine and magnetic predissociation of the iodine molecule in the B0⁺ _u: state. The results are in reasonable agreement with experimental data, being stable enough with respect to the variation of input relativistic potentials. They also indicate the importance of diabatic couplings between the non-relativistic states of the same symmetry.     

On M-hyponormal weighted shifts

Let α≡{α_n}_n=0^∞ be a weight sequence and let W_α denote the associated unilateral weighted shift on . In this paper we prove that if α is eventually increasing, then W_α is M-hyponormal and that if α has exactly two subsequential limits such that the larger one is different from the spectral radius of W_α then W_α is not M-hyponormal.     

Reactions of Magnesium and Titanium Alkoxides. Preparation and Characterization of Alkoxy-Derived Magnesium Titanate Powders and Ceramics

The interaction between magnesium and titanium alkoxides is studied in order to chose the best precursors for synthesis of MgTiO₃. No reaction between magnesium and titanium methoxides and isopropoxides occurs. The solubility diagrams for Mg(OR)₂-Ti(OR)₄-ROH, R = Et,-Bu at 20°C are studied. Magnesium ethoxotitanates of variable composition Mg_nTi_4-n (OEt)_16-2n2nEtOH (n=2.0-0) which are structural analogs of Ti₄(OR)₁₆ (R = Me, Et) are isolated. This is a quite unusual example of statistical distribution of heteroatoms in molecular structures of metal alkoxides. Among the systems of metal alkoxides with simple aliphatic radicals only Mg(OBu)₂-Ti(OBu)₄-BuOH gives a convenient precursor for the synthesis of MgTiO₃. A simple scheme of preparation of magnesium titanate from the alkoxide solutions is suggested. The phase purity of MgTiO₃ is to a considerable extent dependent on the hydrolysis conditions. The alkoxy-derived magnesium titanate is obtained in the form of a uniform fine powder, it can be sintered into dense ceramics in the temperature range of 1140–1220°C which is 150–200°C lower in comparison with the conventional powders.     

Mechanism of action of vitamin K

We have discovered a novel, spontaneous model oxidation that leads to a powerful base capable of carrying out a carbon-carbon bond forming condensation reaction analogous to that observed in the vitamin K-mediated carboxylation of glutamate. The model sequence incorporates a novel base-strength enhancement sequence and it implicates molecular oxygen as the initiating factor in the vitamin K-dependent carboxylation. When the oxygenation is carried out under an atmosphere of (18)O2, two atoms of (18)O are incorporated into the vitamin K oxide product. Selective (18)O labelling defines the carbonyl group next to methyl as the active site of the vitamin K.     

Synthesis of 2,3-disubstituted indole on solid phase by the Fischer indole synthesis

2,3-Disubstituted indoles were synthesized by solid-phase reaction using the Fischer indole synthesis. A "traceless" silicon linker was employed with the silicon-carbon bonding being cleaved with TFA. An oxygen atom was placed into the middle of the spacer/linker so as to enhance solid-phase synthesis by better solvation.