AN EFFICIENT SEQUENTIAL DESIGN FOR SENSITIVITY EXPERIMENTS

In sensitivity experiments, the response is binary and each experimental unit has a critical stimulus level that cannot be observed directly. It is often of interest to estimate extreme quantiles of the distribution of these critical stimulus levels over the tested products. For this purpose a new sequential scheme is proposed with some commonly used models. By using the bootstrap repeated-sampling principle, reasonable prior distributions based on a historic data set are specified. Then, a Bayesian strategy for the sequential procedure is provided and the estimator is given. Further, a high order approximation for such an estimator is explored and its consistency is proven. A simulation study shows that the proposed method gives superior performances over the existing methods.     

Synthesis and bio‐evaluation of Tc‐99 m‐labeled fatty acid derivatives for myocardial metabolism imaging

¹¹C, ¹⁸F and ¹²³I fatty acids are used for myocardial imaging, and ^99mTc‐labeled fatty acids are more desirable substitutes than other radiolabeled fatty acids. In the work reported, [^99mTc]‐CpTT‐10‐oxo‐FPA ( 1c ), [^99mTc]‐CpTT‐12‐oxo‐FPA ( 2c ), [^99mTc]‐CpTT‐14‐oxo‐FPA ( 3c ) and [^99mTc]‐CpTT‐16‐oxo‐FPA ( 4c ) were prepared with 60.76–70.92% of radiochemical yield and purity of more than 95%. These radiotracers ( 1c , 2c , 3c , 4c ) were chemically stable when incubated in Sprague Dawley rat serum for 3 h at 37 °C. Tissue distribution studies in female mice indicated that 2c had high initial heart uptake (8.84%ID g^?1 at 1 min post‐injection) and 4c had long retention in the heart (1.45%ID g^?1 at 30 min post‐injection). Metabolite analysis showed 4c could be metabolized to 5c via β‐oxidation with loss of two ? CH₂? in the myocardium, the radiometabolite being excreted via urine. However, low heart uptake suggested that 4c cannot be used as a diagnostic imaging agent. Copyright © 2016 John Wiley & Sons, Ltd.     

Simultaneous Determination of Multicomponents in Air Toxic Organic Compounds Using Artificial Neural Networks in Ftir Spectroscopy

The application of Artificial Neural Networks (ANNs) for nonlinear multivariate calibration using simulated FTIR data was demonstrated in this paper. Neural networks consisting of three layers of nodes were trained by using the back-propagation learning rule. Since parameters affect the performance of the network greatly, simulated data were used to train the network in order to get a satisfactory combination of all parameters. The mixtures of four air toxic organic compounds whose FTIR spectra are overlapped were chosen to evaluate the calibration and prediction ability of the network. The relative standard error (RSD%), the percent standard error of prediction samples (%SEP) and the percent standard error of calibration samples (%SEC) are used for evaluating the ability of the neural network.     

Convenient Synthesis of Dicyclohexyldithiophosphinic Acid

Dicyclohexyldithiophosphinic acid was synthesized by a three-step strategy through the Grignard reaction of PSCl₃ with cyclo-C₆H₁₁MgBr and the P-P bond-cleavage reaction of the intermediate. The ¹H NMR data of ammonium dicyclohexyldithiophosphinate 4 and dicyclohexyldithiophosphinic acid 5 were characterized by ¹H-¹H correlation spectra.     

Polycarbonate nanoparticles spray coated on silicon substrate using micro-electromechanical-systems-based high-frequency ultrasonic nozzle

Mono-disperse polycarbonate (PC) nanoparticles 20 nm in diameter was spray coated on silicon substrate using a novel high-frequency ultrasonic nozzle. Specifically, Bisphenol-A polycarbonate with a molecular weight (M_w) of approximately 6.4 × 10⁴ g/mol was first dissolved in pyridine. The resulting solution was sprayed into surfactant-containing de-ionized (DI) water using a 300 kHz silicon-based multiple-Fourier horn nozzle (MFHN). As pyridine was extracted into the water, PC nanoparticles formed but remained dispersed. This suspension of PC nanoparticles was then sprayed onto a silicon substrate using a 500 kHz 3-Fourier horn nozzle. Scanning electron microscopy (SEM) of the dried substrate revealed that PC nanoparticles were spread uniformly with no aggregation.     

A note on spherically symmetric isentropic compressible flows with density-dependent viscosity coefficients

In this note, by constructing suitable approximate solutions, we prove the existence of global weak solutions to the compressible Navier–Stokes equations with density-dependent viscosity coefficients in the whole space or exterior domain, when the initial data are spherically symmetric. In particular, we prove the existence of spherically symmetric solutions to the Saint-Venant model for shallow water in the whole space (or exterior domain).     

GPU accelerated simulations of 3D deterministic particle transport using discrete ordinates method

Graphics Processing Unit (GPU), originally developed for real-time, high-definition 3D graphics in computer games, now provides great faculty in solving scientific applications. The basis of particle transport simulation is the time-dependent, multi-group, inhomogeneous Boltzmann transport equation. The numerical solution to the Boltzmann equation involves the discrete ordinates (S_n) method and the procedure of source iteration. In this paper, we present a GPU accelerated simulation of one energy group time-independent deterministic discrete ordinates particle transport in 3D Cartesian geometry (Sweep3D). The performance of the GPU simulations are reported with the simulations of vacuum boundary condition. The discussion of the relative advantages and disadvantages of the GPU implementation, the simulation on multi GPUs, the programming effort and code portability are also reported. The results show that the overall performance speedup of one NVIDIA Tesla M2050 GPU ranges from 2.56 compared with one Intel Xeon X5670 chip to 8.14 compared with one Intel Core Q6600 chip for no flux fixup. The simulation with flux fixup on one M2050 is 1.23 times faster than on one X5670.     

Performance of non-thermal DBD plasma reactor during the removal of hydrogen sulfide

Destruction of hydrogen sulfide using dielectric barrier discharge plasma in a coaxial cylindrical reactor was carried out at atmospheric pressure and room temperature. Three types of DBD reactor were compared in terms of specific energy density (SED), equivalent capacitances of the gap (Cg) and the dielectric barrier (Cd), energy yield (EY), and H₂S decomposition. In addition, byproducts during the decomposition of H₂S and destruction mechanism were also investigated. SED for all the reactors depended almost linearly on the voltage. In general, Cg decreased with increasing voltage and with the existence of pellet material, while Cd displayed the opposite trend. The removal efficiency of H₂S increased substantially with increasing AC frequency and applied voltage. Longer gas residence times also contributed to higher H₂S removal efficiency. The choice of pellet material was an important factor influencing the H₂S removal. The reactor filled with ceramic Raschig rings had the best H₂S removal performance, with an EY of 7.30 g/kWh. The likely main products in the outlet effluent were H₂O, SO₂, and SO₃.     

Synthesis of spinel CuCo2O4 nanoparticles and its application in p-nitrophenol reduction

Journal of Sol-Gel Science and Technology - CuCo2O4 spinel nanoparticles were successfully preparedvia a sol–gel method, which were firstly employed in catalytic reduction of p-nitrophenol to...