Solution phase synthesis of amyloid-cleaving catalysts, two [1,3,5]triazine based compounds

Solution phase synthetic method for amyloid-cleaving catalysts was developed, which bears triazine core, scaffold with bulky and that have various solubility properties; Co(III) complex of cyclen (1,4,7,10-tetraazacyclododecane) for catalytic group, and two imaging agents for binding group. This synthetic method was identified by H-NMR, C-NMR for intermediates and MS for the last products. The yields by this method surpassed solid phase synthesis and took much lower labor, expense, and time. The products which were synthesized by solution phase synthetic method showed good catalytic activities.     

Daily planning and scheduling system for the EDS process in a semiconductor manufacturing facility

Operations management in a complex manufacturing environment is practiced hierarchically: production planning and scheduling in sequence since the integrated approach is not efficient and practical. Production targets and allocation to the equipment are determined in the planning procedure by considering the only the critical factors, and the detailed scheduling is determined with more information needed to accomplish the production targets provided in the planning step. There is always, therefore, a gap between the planning and scheduling procedure, and some control parameters or factors are used to control those gaps. In this paper an approach connecting two procedures is suggested, which can be applied in the EDS (electrical die sorting) or the probe process in the semiconductor manufacturing. The EDS process requires very flexible operation management since the manufacturing processing time is relatively short and the supply of upstream fabrication and the demand of downstream assembly have to be met simultaneously. Daily planning and scheduling procedure are modeled to minimize the tester change-over within the daily target. Because of the relatively long setup change-over time, daily planning and scheduling have to be performed so that the time needed for the device and probe card change is minimized as possible. Mathematical programming is suggested for the problem, and the modified model is developed which can be solved in a practical computational time on a daily base. The scheduling heuristic with the planning data obtained from the suggested model, is designed, and their performance is evaluated through the computational experiment.     

Far-field time-domain calculation from aperture radiators using theFDTD method

It is often desirable to determine the far-field radiation pattern from an aperture in a metal plate. The use of time-domain methods, like the finite-difference time-domain (FDTD) method, is problematic because of the necessity of modeling the entire space of interest. This is often circumvented by using the equivalence principle to determine the far field by equivalent currents generated in the near field. However, these transformations are often mathematically complex. This paper presents an extremely simple formulation for calculating the time-domain fields from some types of aperture radiators. By using wavelet analysis, the pertinent parameters can be compressed and stored to be used later to resynthesize the radiated fields     

Frequency-Selective Predistortion Linearization of RF Power Amplifiers

This paper presents a frequency-selective RF vector predistortion linearization system for RF multicarrier power amplifiers (PAs) affected by strong differential memory effects. Differential memory effects can be revealed in two-tone experiment by the divergence for increasing tone-spacing of the vector Volterra coefficients associated with the lower and upper intermodulations tones. Using large-signal vector measurement with a large-signal network analyzer, a class-AB LDMOS RF PA is demonstrated to exhibit a strong differential memory effect for modulation bandwidth above 0.3 MHz. New frequency-selective RF and baseband predistortion linearization algorithms are proposed to separately address the linearization requirements of the interband and inband intermodulation products of both the lower and upper sidebands. Theoretical verification of the algorithms are demonstrated with Matlab simulations using a Volterra/Wiener PA model with memory effects. The baseband linearization algorithm is next implemented in a field-programmable gate array and experimentally investigated for the linearization of the class-AB LDMOS PA for two carrier wideband code-division multiple-access signals. The ability of the algorithm to selectively linearize the two interband and four inband intermodulation products is demonstrated. Adjacent channel leakage ratio of up to 45 dBc for inband and interband are demonstrated experimentally at twice the typical fractional bandwidth.     

Decay of capacitance on ceasing formation of anodic oxide films on tantalum

The decrease with time in the capacitance of anodic oxide films on tantalum after ceasing film growth by reducing the field in the oxide was investigated. No dependence was observed of the amount and rate of change in relative dielectric permittivity on the initial current density. The kinetics of this effect are therefore different from those for the decay of the latent ionic conductivity.     

Thermal degradation behavior of inconel 617 alloy

Inconel 617 alloy is a candidate material for potential use as an intermediate heat exchanger (IHX) and as a hot gas duct (HGD) in high-temperature gas-cooled reactors (HTGRs) for H₂ production. This alloy supports severe operating conditions of a pressure over 8 MPa and temperature that exceed 950 °C in He gas with some impurities. In this work, the oxidation behavior of Inconel 617 alloy was studied after exposure at 1050 °C for 2000 h in both air and He atmospheres. The external oxide scale was mainly composed of Cr₂O₃ and small amount of TiO₂. The internal oxide was observed just below the external oxide scale and was distributed on the grain boundaries. The internal oxide was confimed as Al₂O₃. The Cr-depleted zone and internal oxide in both environments became thicker as the exposure time increased. The Cr₂O₃ in air at 2000 h was thinned in terms of its scale by CrO₃ evaporation and delamination. The Cr₂O₃ in He was constantly maintained.     

Electron tomography of large, multicomponent biological structures

Genome-wide scans for linkage of chromosome regions to type 1 diabetes in affected sib pair families have revealed that the major susceptibility locus resides within the major histocompatibility complex (MHC) on chromosome 6p21 (lambda s = 2.5). It is recognised that the MHC contains multiple susceptibility loci (referred to collectively as IDDM1), including the class II antigen receptor genes, which control the major pathological feature of the disease: T lymphocyte-mediated autoimmune destruction of the insulin-producing pancreatic beta cells. However, the MHC genes, and a second locus, the insulin gene minisatellite on chromosome 11p15 (IDDM2; lambda s = 1.25), cannot account for all of the observed clustering of disease in families (lambda s = 15), and the scans suggested the presence of other susceptibility loci scattered throughout the genome. There are four additional loci for which there is currently sufficient evidence from linkage and association studies to justify fine mapping experiments: IDDM4 (FGF3/11q13), IDDM5 (ESR/6q22), IDDM8 (D6S281/6q27) and IDDM12 (CTLA-4/2q33), IDDM4, 5 and 8 were detected by genome scanning, and IDDM12 by a candidate gene strategy. The results suggest that the clustering of type 1 diabetes in families is due to the sharing of alleles at multiple loci, and that the as yet unidentified environmental factors are not causing clustering, but instead appear to influence the overall penetrance of genetically programmed susceptibility. The data are consistent with a polygenic threshold model for the inheritance of type 1 diabetes.     

Nondestructive measurement of the coating thickness for simulated TRISO-coated fuel particles by using phase contrast X-ray radiography

The TRISO-coated fuel particle for a HTGR (high temperature gas-cooled reactor) is composed of a nuclear fuel kernel and outer coating layers. The coating layers consist of a buffer PyC (pyrolytic carbon) layer, an inner PyC (I-PyC) layer, a SiC layer, and an outer PyC (O-PyC) layer. X-ray radiography is one of the nondestructive alternatives to measure a coating thickness without generating a radioactive waste. Phase contrast X-ray radiography technology is more powerful for acquiring a radiograph with clear boundaries, when compared with a conventional X-ray radiography. The contrast can be enhanced for weakly absorbing materials in a phase contrast X-ray radiograph by detecting an intensity variation due to the variation of a phase of the X-rays in the boundary between two objects. Phase contrast X-ray radiograph was acquired from a simulated TRISO-coated fuel particle with a micro-focus X-ray imaging system. The coating thickness was nondestructively measured from the phase contrast X-ray image for the fuel particle.     

CLEAVAGE AUTOMATED: A new combinatorial chemistry tool

Liquid handling systems are in common use throughout the research chemistry industry, for a variety of fluid dispensing applications. However, few manual or automatic systems have been specifically designed for dosing highly corrosive acid/solvent mixes. Even fewer can withstand 60% Trifluoroacetic acid mixes - a standard mixture for cleavage of compound from polystyrene beads. A design is presented of such an automated dosing system. The requirements are to reduce human exposure to chemicals, remove potential for repetitive strain injury, and increase reaction plate throughput. Material choice, the use of process valves, equipment protection, and a novel plate detection system are discussed. Modifications resulting from the prototype test are discussed, along with additional improvements to the system and further research.