Comments on `Evaluating distance spectra and performance bounds oftrellis codes on channels with intersymbol interference'

It is shown that the method presented by C. Schlegel (see ibid., vol.37, no.3, p.627-34, May 1991) for evaluating the distance spectra of trellis codes on channels with intersymbol interference is incorrect. A counterexample is presented along with comments on the feasibility of correcting the method     

The MiniWiD-COATER: II. Comparison of acid resistance of enteric-coated bisacodyl pellets coated with different polymers

Neutral pellets were loaded with bisacodyl and enteric-coated with hydroxypropyl methylcellulose acetate succinate (HPMCAS), carboxymethyl ethylcellulose (CMEC), cellulose acetate trimellitate (CAT), and poly(ethylacrylate, methacrylic acid) (Eudragit L 30 D) in a miniature fluid-bed pan coater called MiniWiD. Gastric juice resistance was tested by dissolution using USP Apparatus 2 (paddle) in 0.1 N hydrochloric acid under sink conditions over 6 hours. As a measure of enteric coating quality the USP specifications were used meaning that no more than 10 % of the drug should be released within 2 hours.

Organic-solvent based films of HPMCAS, CMEC and CAT at a coating level of 18 to 25 % provided gastroresistance for more than 6 hours. Aqueous suspensions of HPMCAS and CMEC as well as the ammonium salt aqueous solutions of CAT produced films with a short gastroresistance of below 0.6 hours. By doubling the coating level of water-based HPMCSD films the protection was prolonged to 3.4 h.

Enteric coatings were obtained from all aqueous latex dispersions of Eudragit L 30 D at a coating level of 24 %. The alteration of coating temperature between 25 and 45 °C had no significant effect on the release rates, whereas the variation of type and amount of plasticizer led to a different release rate after 2 hours. Best protection was obtained using films plasticized with 20 % of dibutyl phthalate (DBP) allowing a release of only 4 % of the drug in 6 hours although the application temperature was 15 °C below the minimum film-forming temperature (MFT). All coatings dissolved in artificial intestinal fluid within 15 minutes.     

Electrochromic effects from a simple commercial polymer membrane

A simple commercial polyester polymer membrane has been found to exhibit an intense electrochromic effect. Most polymers which undergo electrochromic effects contain either transition metals or extensive conjugated systems. We have found that a simple commercial polyester membrane when coated with gold and polarised to −4 V (versus Ag) in aprotic organic solvents displays an electrochromic colour change from a colourless to an intense red state.     

Microstructure Refinement of Sintered Alumina by a Two-Step Sintering Technique

For a few oxide ceramics, the use of an initial precoarsening step prior to densification (referred to as two-step sintering) has been observed to produce an improvement in the microstructural homogeneity during subsequent sintering. In the present work, the effect of a precoarsening step (50 h at 800°C) on the subsequent densification and microstructural evolution of high-quality alumina (Al2O3) powder compacts during constant-heating-rate sintering (4°C/min to 1450°C) was characterized in detail. The data were compared with those for similar compacts that were sintered conventionally (without the heat treatment step) and used to explore the mechanism of microstructural improvement during two-step sintering. After the precoarsening step, the average pore size was larger, but the distribution in pore sizes was narrower, than those for similar compacts that were sintered conventionally to 800°C. In subsequent sintering, the microstructure of the precoarsened compact evolved in a more homogeneous manner and, at the same density, the amount of closed porosity was lower for the compacts that were sintered by the two-step technique, in comparison to the conventional heating schedule. Furthermore, a measurably higher final density, a smaller average grain size, and a narrower distribution in grain sizes were achieved with the two-step technique. The microstructural refinement that was produced by the two-step sintering technique is explained in terms of a reduction in the effects of differential densification and the resulting delay of the pore channel pinch-off to higher density.     

Scanning electrochemical microscopy of living cells. 3. Rhodobacter sphaeroides.

The scanning electrochemical microscope (SECM) was used to probe the redox activity of individual purple bacteria (Rhodobacter sphaeroides). The approaches developed in our previous studies of mammalian cells were expanded to measure the rates and investigate the pathway of transmembrane charge transfer in bacteria. The two groups of redox mediators (i.e., hydrophilic and hydrophobic redox species) were used to shuttle the electrons between the SECM tip electrode in solution and the redox centers inside the cell. The analysis of the dependencies of the measured rate constant on formal potential and concentration of mediator species in solution yielded information about the permeability of the outer cell membrane to different ionic species and intracellular redox properties. The maps of redox reactivity of the cell surface were obtained with a micrometer or submicrometer spatial resolution.     

Interpersonal Style and Japanese American Organizational Involvement

This paper reports on an initial effort to develop survey items that measure Japanese American interpersonal style. Based upon the theoretical work of Miyamoto. Fugita, and Kashima (2002) it was hypothesized that Japanese American interpersonal style is an important factor in their forming large numbers of voluntary organizations both historically and contemporarily. A survey was administered to 344 Japanese Americans living in the Seattle, WA and San Jose, CA areas. An initial pool of 16 items yielded a 10-item measure with three subscales that was related to involvement in Japanese American organizations and other indicators of ethnic community participation.

     

Case Study: Sediment Control at Water Intake for Large Thermal-Power Station on a Small River

A large thermal-power station drawing water from a small alluvial river had a chronic problem with alluvial-bed sediment buildup at the station’s river-water intake structure. The problem required expensive corrective dredging and adversely affected the station’s fuel-consumption efficiency. This case-study paper describes how the sediment problem was successfully controlled by means of modifications to the area in front of the intake and the upstream riverbank. The modifications comprised erosion-promoting vanes and a skimming wall, together with realignment of the riverbank upstream of the intake. A hydraulic model was used to aid the design of the modifications. Installation of the modifications required construction techniques that enabled the intake and power station to continue operating while the modifications were being installed.     

Understanding marriage and marital distress: Do milliseconds matter?

This article addresses concerns raised about F. D. Fincham, P. C. Garnier, S. Gano-Phillips, and L. N. Osborne's (1995) study by placing it in the context of current marital research. Studies of marriage-related cognitions have centered on the content of cognitions and have ignored the cognitive processes that give rise to them. Therefore, little is known about spousal cognitions that are unavailable for self-report or about the role of cognitive processes in initiating, maintaining, or alleviating marital distress. Reaction time has the potential to be one of several variables that can be used to investigate such processes. The challenge faced by marital researchers is to incorporate the information-processing paradigm into their work, thereby integrating it with broader literatures in cognitive psychology and social cognition. Failure to do so will leave marital researchers with an incomplete picture of marriage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)