Investigation of the effect of the measurement with the abrupt noise and the number of approximated terms in conductional boundary estimation problem

A direct error vector analysis of inverse heat conduction problem is presented to detect the measured noise. Based on the reverse matrix approach that the inverse problem is solved directly in a linear domain, and the error vector is formulated from the difference between the measured temperature and the estimated temperature. There is no prior knowledge on the exact solution while the error vector is constructed. The error vector is used to investigate the consistence of the measured data in the domain and lead to detect the noise data. Furthermore, the proper number of the undetermined variable is able to suggest based on the mean value of the error vector and the value of the condition number of the reverse matrix. In the first example, a test problem with the measurement noise is presented. The estimated result is influent by the noise globally. The result shows that the value of error vector is changed significantly at the coordinate of the measurement noise appeared. In other words, the error vector analysis is able to identify the noise data. In the second example, the proper number of series expansion terms is investigated. From the result, it shows that the number of expansion terms with the small mean value and condition number can better approximate to the unknown condition. It means that the proposed method is able to suggest a proper number of expansion terms when the function of the recovered boundary is unknown.     

Selective reduction of peptide isothiazolidin-3-ones

Isothiazolidinones are a rare but potentially important chemical moiety in biochemistry. We report the identification of several thiol, phosphinate, and carbon nucleophiles that form covalent adducts by addition to the sulfenamide sulfur. This reduction is selective for isothiazolidinones over similar peptide disulfides. We synthesized a coumarin-based thioacid nucleophile which shows a marked fluorescence increase after addition to an isothiazolidinone sulfenamide bond. [structure: see text]     

Studies on quinazolinones. 2. Synthesis of 2-(4-benzylpiperazin-1-ylmethyl)-2,3-dihydro-5H-oxazolo[2,3–6]quinazolin-5-one and -2,3-dihydro-5H-thiazolo[2,3-b]quinazolin-5-one

To search for novel antihypertensive heterocycles in the condensed quinazoline series, two representative compounds were synthesized via a suitable reaction sequences. Treating anthranilonitrile with allyl isocyanate gave 2-(allylureido)benzonitrile ( 10 ) in a quantitative yield. Compound 10 was cyclized to 3-allylquinazoline-2(1H, 4(3H)-dione ( 11 ). Bromination of 11 in carbon tetrachloride converted it into the corresponding 3-(2,3-dibromopropyl) derivative ( 12 ) in 92% yield. Ring closure of 12 was effected by the action of alkali to afford 2-bromomethyl-2,3-dihydro-5H-oxazolo[2,3-b]quinazolin-5-one ( 13 ). The title compound, 2-(4-benzylpiperazin-1-ylmethyl)-2,3-dihydro-5H-oxazolo[2,3-b]quinazolin-5-one ( 7 ) could be obtained by a reaction of either 12 or 13 with 1-benzylpiperazine respectively. Starting from the readily available 3-allyl-2H-thioxoquinazolin-4(3H)-one ( 16 ) via the analogous reactions gave the 2-bromomethyl-2,3-dihydro-5H-thiazolo[2,3-b]-quinazolin-5-one ( 19 ) in good yield. However, the reaction of 19 with 1-benzylpiperazine provided another target compound, 2-(4-benzylpiperazin-1-ylmethyl)-2,3-dihydro-5H-thiazolo[2,3-b]quinazolin-5-one ( 8 ) only in poor yield (8%). As major product, the dehydrobrominated compound, 2-methylene-2,3-dihydro-5H-thiazolo[2,3-b]quinazolin-5-one ( 22 ) was isolated. A preliminary pharmacological evaluation revealed that both compounds 7 and 8 are devoid of the antihypertensive activity.     

Symmetry and bifurcation in vestibular system

The vestibular system in almost all vertebrates, humans included, controls balance by employing a set of six semicircular canals, three in each inner ear, to detect angular accelerations of the head. Signals from the canals are transmitted to neck motoneurons and activate eight corresponding muscle groups. These signals may be either excitatory or inhibitory, depending on the direction of acceleration. McCollum and Boyle have observed that in the cat the network of neurons concerned possesses octahedral symmetry, a structure deduced from the known innervation patterns (connections) from canals to muscles. We re-derive the octahedral symmetry from mathematical features of the probable network architecture, and model the movement of the head in response to the activation patterns of the muscles concerned. We assume that connections among neck muscles can be modeled by a ‘coupled cell network’, a system of coupled ODEs whose variables correspond to the eight muscles, and that network also has octahedral symmetry. The network and its symmetries imply that these ODEs must be equivariant under a suitable action of the octahedral group. Using results of Ashwin and Podvigina, we show that with the appropriate group actions, there are six possible spatiotemporal patterns of time-periodic states that can arise by Hopf bifurcation from an equilibrium corresponding to natural head motions. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Finite temperature formalism for composite quantum particles

This Letter provides the missing part of the newly constructed many-body formalism for composite quantum particles: the introduction of a finite temperature. The finite T formalism we propose deeply relies on the existence of a compact closure relation for the (overcomplete) set of N-composite-particle states. As a first application, we here calculate the energy mean value of the exciton gas outside the condensation regime. We show that carrier exchanges increase its temperature dependence compared to elementary bosons, a signature of the degree-of-freedom increase resulting from the particle composite nature.     

Some Optimal Strategies for Bandit Problems with Beta Prior Distributions

A bandit problem with infinitely many Bernoulli arms is considered. The parameters of Bernoulli arms are independent and identically distributed random variables from a common distribution with beta(a, b). We investigate the k-failure strategy which is a modification of Robbins's stay-with-a-winner/switch-on-a-loser strategy and three other strategies proposed recently by Berry et al. (1997, Ann. Statist., 25, 2103–2116). We show that the k-failure strategy performs poorly when b is greater than 1, and the best strategy among the k-failure strategies is the 1-failure strategy when b is less than or equal to 1. Utilizing the formulas derived by Berry et al. (1997), we obtain the asymptotic expected failure rates of these three strategies for beta prior distributions. Numerical estimations and simulations for a variety of beta prior distributions are presented to illustrate the performances of these strategies.     

Purification of Chlorophenol Isomers by Stripping Crystallization Combining Melt Crystallization and Vaporization

Stripping crystallization (SC) was introduced in this work to purify p-chlorophenol from the p-chlorophenol-rich liquid mixture and to purify m-chlorophenol from the m-chlorophenol-rich liquid mixture, respectively. Essentially, SC combines melt crystallization and vaporization to produce the solid product and the vapor from a liquid mixture via a series of three-phase transformations at reduced pressures during the cooling process. At the end of the SC, only the solid product remained while the liquid mixture was almost eliminated and the produced vapor was removed. A set of differential equations based on the mass and energy balances were proposed to determine the incremental variations of the amounts of remaining liquid, produced solid and produced vapor during the batch SC process. The experimental yield and product purity of the final product obtained from the batch SC experiments were compared with those predicted by the model.     

Cross Aldolization Between Benzaldehyde and n-Heptaldehyde to α-Pentylcinnamaldehyde Overcalcined mg-al Hydrotalcites

Calcined Mg-Al hydrotalcites (CHT) with various Mg/Al atomic ratios were prepared and characterized by XRD, BET and TPD of carbon dioxide. The CHT catalysts were utilized for the synthesis of -pentylcinnamaldehyde (-P_c) from benzaldehyde and n-heptaldehyde in a stirred batch autoclave reactor. An increase of Mg/Al atomic ratio of CHT samples results in the apparent enhancement of catalyst basicity with concomitant decrease of surface areas. Both the catalytic activity and the -P_c selectivity increase with the catalyst basicity and the reaction temperature.     

Studies on Polymerization of Vinyl Compounds Initiated by Metal Chelate III. Accelerating Effect of Aniline on the Polymerization of Methyl Methacrylate Initiated by Nickel Chelate of β-Diketone

Aniline markedly accelerated polymerization of methyl methacrylate initiated by metal chelates of β-diketones. The kinetic studies of the polymerizaion of methyl methacrylate initiated by Ni (II) acetyl acetonate in the presence of aniline yielded R_p=[I]^0.55 [A]^0.66 [M]^1.87. The polymerization was of free radical in character. The accelerating effect of aniline was attributed to its reduction activation of the chelate. The activation energy for the overall polymerization was 21.3Kcal/mole, which yielded 33.4Kcal/mole for the activation energy for the initiation.     

Design and Performance Evaluation of Optical Ethernet Switching Architecture with Liquid Crystal on Silicon-Based Beam-Steering Technology

A non-blocking optical Ethernet switching architecture with liquid crystal on a silicon-based beam-steering switch and optical output buffer strategies are proposed. For preserving service packet sequencing and fairness of routing sequence, priority and round-robin algorithms are adopted at the optical output buffer in this research. Four methods were used to implement tunable fiber delay modules for the optical output buffers to handle Ethernet packets with variable bit-rates. The results reported are based on the simulations performed to evaluate the proposed switching architecture with traffic analysis under a traffic model captured from a real-core network.