A note on upwinding and anisotropic balancing dissipation in finite element approximations to convective diffusion problems

In one dimension, Petrov—Galerkin nonsymmetric weighting for the convective diffusion equation can be interpreted as an added dissipation. The addition of an appropriate amount of dissipation can therefore give the same oscillation-free solutions as the ‘unwinding’, Petrov—Galerkin, finite element methods. The ‘balancing dissipation’ is optimally chosen so that excessive dissipation does not occur. A scheme is presented for extending this approach to two-dimensional problems, and numerical examples show that the new method can be used with improved computational efficiency.     

Determination of benzimidazole anthelmintics in livestock foods by HPLC

A simple and rapid liquid chromatographic method was developed for the simultaneous determination of twelve benzimidazole anthelmintics in livestock foods using reversed-phase high-performance liquid chromatography with photodiode array detection (PDA). A sample was homogenized with acetonitrile and n-hexane, and centrifuged. The acetonitrile phase was isolated and evaporated. The residue was dissolved in 0.1 mol/L carbonate buffer solution (pH = 9.1), sonicated, and then subjected to clean-up on a Bond Elut LRC-C18 cartridge. The benzimidazole compounds were separated isocratically on a Capcell Pak C18 UG 120 (5 microns, 150 x 4.6 mm i.d.) column and detected by PDA at 295 and 313 nm. Mixtures of acetonitrile and 0.05 mol/L ammonium acetate in mixing ratios of (20:80) and (40:60) were used as the mobile phase, and the flow-rate was 1.0 mL/min at 40 degrees C. The mean recoveries (n = 3) from 0.1-0.5 microgram/g added samples were 72.6-97.2% with coefficients of variation of 0.3-8.5%. The detection limits were 0.01-0.05 microgram/g.     

10-GHz 8.7-ps Pulse Generation From a Single-Mode Gain-Switched AlGaAs VCSEL at 850 nm

We have successfully generated a 10-GHz 8.7-ps pulse train at 850 nm by using a gain switching technique with a high-speed AlGaAs-based vertical-cavity surface-emitting laser (VCSEL). The VCSEL, which operates in a single transverse mode by employing an aluminum oxide aperture, has a modulation bandwidth of 6.3 GHz and a relaxation oscillation frequency at around 11.7 GHz. An error-free 10-Gb/s return-to-zero data modulation was demonstrated by using the generated 10-GHz pulse train.     

Determination of bisphenol A in canned vegetables and fruit by high performance liquid chromatography

A high performance liquid chromatograph y (HPLC) method was developed for the determination of bisphenol A (BPA) that had migrated into canned fruit and vegetables. BPA was extracted with acetonitrile from the solid portion of canned food, and with an OASIS HLB cartridge from the aqueous portion, respectively. Both extracts were cleaned up on a Florisil cartridge. The HPLC separation was carried out on a Wakosil II 3C18 RS column (4.6 × 150mm) with acetonitrile-water (40:60, v/v) as a mobile phase with a flow rate of 0.8 ml/min. BPA was detectable by UV detector at 228 nm and determined with the similarity of chromatographic peak spectrum by multiwavelength detector (similarity index was 0.99 or above). The quantification limits were 10 ng/g for the solid portion and 5 ng/ml for the aqueous portion, respectively. BPA was mainly detected in the solid portion of canned food and found at the maximum level of 11 μg per can. To verify migration into the solid portion of canned food, a partitioning experiment was carried out.     

Study on environmental effect on fatigue and creep-fatigue strength of 316FR stainless steel in sodium at elevated temperature

Low-carbon 316 stainless steel with medium-nitrogen (316FR) is considered as the principal structural material for next generation fast breeder reactor (FBR) plants in Japan. The material strength standard and the creep-fatigue life evaluation method for 316FR have been developed. However, they are based on the results of material tests in air, while actual structural material will be used mainly in liquid sodium environment in the plants. In order to clarify the environmental effect, cyclic bending tests were carried out with and without hold time in sodium. Tested materials were 316FR and conventional 304 and 316 stainless steels. Weld metal of 316FR was also tested. As a result, it was found that fatigue and creep-fatigue lives of 316FR in sodium were larger than those in air and no explicit consideration of the environmental effect is necessary in design. It was also found that the life evaluation method based on the ductility exhaustion concept is applicable to creep-fatigue life assessment in sodium.     

40 Gbit/s return-to-zero transmission over 500 km of standard fibreusing chirped fibre Bragg gratings with small group delay ripples

A 40 Gbit/s return-to-zero transmission has been successfully achieved over 500 km using standard fibres (non-dispersion shifted fibre, singlemode fibre) and chirped fibre Bragg gratings (CFBG). CFBGs were fabricated with small group delay ripples, and error free transmission (BER <1×10^-12) was achieved using these CFBGs for dispersion compensation     

Outcome of parent-mediated treatment of preschoolers with attention deficit disorder with hyperactivity.

Despite the early onset of attention deficit disorder with hyperactivity (ADDH), there is a dearth of treatment studies with preschoolers with this disorder. Forty-six families with ADDH preschoolers were randomly assigned to either an immediate or a delayed group parent training program aimed at improving child compliance. Groups were balanced on demographic variables. Treatment outcome was evaluated by comparing the groups at pre- and posttreatment and 3-month follow-up on measures of parent–child interactions during free play, a compliance task, and parent-supervised activities, as well as on parent-completed Conners Hyperkinesis Index (C. H. Goyette et al; see record 1980-22450-001) scores. Positive treatment effect was obtained on measures of compliance, parental style of interaction, and management skills. These improvements were maintained at 3-month follow-up. Evaluation of treatment effects on nontargeted child behaviors indicated no generalization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A 250-Mb/s/pin, 1-Gb double-data-rate SDRAM with a bidirectionaldelay and an interbank shared redundancy scheme

This paper describes three circuit technologies indispensable for high-bandwidth multibank DRAM's. (1) A clock generator based on a bidirectional delay (BDD) eliminates the output skew. The BDD measures the cycle time as the quantity charged or discharged of an analog quantity, and replicates it in the next cycle. This achieves a 0.18-mm ², two-cycle-lock clock generator operating from 25 to 167 MHz with a 30-ps resolution. (2) A quad-coupled receiver eliminates the internal skew caused by the difference between a rise input and a fall input by 40%. (3) An interbank shared redundancy scheme (ISR) with a variable unit redundancy (VUR) efficiently increases yield in multibank DRAM's. The ISR allows redundancy match circuits to be shared with two or more banks. The VUR allows the number of units replaced to be variable. These circuit technologies achieved a 250-Mb/s/pin, 8-bank, 1-Gb double-data-rate synchronous DRAM     

Optical Fiber Cable Measurements in the Field

The optical fiber cable measurement instruments developed by NTF for field use in the 1.3 μm wavelength are discussed. The properties of a stabilized optical light source for single-mode fiber attenuation measurement, optical time-domain reflectometer using a Q-switched Nd:YAG laser as a light source, and chromatic dispersion measurement instrument are described. From the measurement results, these instruments are revealed to be suitable in constructing and maintaining singlemode fiber optical transmission lines.