Log‐normal distribution for a description of the molecular weight distribution of N‐acetylated chitosans depolymerized with hydrolytic enzyme

N‐acetylated chitosans (NACs) with different degrees of N‐acetylation (DAs) were enzymatically depolymerized at pH 5.1 and 40 °C, and the molecular weight distributions (MWDs) of the depolymerized NACs were then measured by size exclusion chromatography and were fitted by the log‐normal distribution function with two distribution parameters, β and M₀. We discuss also the time‐evolution of the distribution parameters derived from the experimentally obtained MWD as well as the effects of experimental conditions, such as DA and initial NAC concentration (S₀), on the distribution parameters. Copyright © 2003 Society of Chemical Industry     

Classical but effective techniques for estimating cardiovasculardynamics

This article first describes the effectiveness and the limitations of classical approaches based on linear models for the cardiovascular system. The authors then introduce their own work on less-invasive and real-time estimation of cardiac output flow and pump function in the clinical setting. It is shown that system identification techniques using linear models can yield unexpectedly accurate results useful for patient care     

An automatic control algorithm for the optimal driving of theventricular-assist device

This paper presents a new method of keeping one of the most suitable driving conditions for regulating the outflow volume from the ventricular-assist device (VAD). The experimental results from a mock circulatory system have shown that the relationship between the stroke volume and the systolic duration of the VAD can be specified by the combination of characteristic curves of the positive and negative drive pressures. The optimal operating point on the characteristic curve have been defined as the point at which thrombosis on the blood-contacting surface and hemolysis due to mechanical damage can be avoided and at which the driving energy can be minimized. The present analysis has been revealed that the optimal operating point is the vertex of the triangular figure obtained from the characteristic curve. The algorithms for keeping the optimal operating point and for regulating the stroke volume have been also proposed.     

Preparation of hydrophilic polyethylene foam of open cell type by radiation grafting of acrylic acid

Hydrophilic polyethylene foam was synthesized by radiation grafting of acrylic acid onto polyethylene foam of open cell type using monomer solution containing Mohr's salt which inhibits homopolymerization of the monomer. The graft foam was easily dyed by cationic dyes and showed excellent moisture regain. The wicking properties were also excellent and were almost the same as those of commercially available PVA foam. The surface resistivity of 10¹⁶ ohm of the original foam decreased to 10⁶ ohm and half decay time of surface charge decreased from 8000 s to 1 s by the grafting, indicating that the grafted foam has excellent antistatic properties.     

Equilibrium state and crystal growth of (BEDT-TTF)2I3

The equilibrium state and crystal growth of (BEDT-TTF)₂I₃ were investigated. Measurements of the temperature dependence of solubility and analyses of the components in the solution were carried out. The analysis of the solution showed that the crystals decompose into neutral BEDT-TTF and I₂ molecules. As to the polymorphism, it was clarified that the -form is more stable than the -form in the temperature region between 0 and 50 °C. Using these information, we succeed in growing single crystals form BEDT-TTF and I₂ and in control of the crystallizing polymorph. The polymorphic behavior was explained in terms of supersaturation as a driving force of crystal growth.     

Estimation of mixing index and contact number by spot sampling of a mixture in an incompletely mixed state

There are two approaches to the determination of the mixing index based on the contact number. One is based on coordination number sampling, and the other on spot sampling. In this work, the estimation of the mixing index and that of the contact number by spot sampling of a mixture in an incompletely mixed state are examined. General expressions have been derived for the precision of the estimation of the population mean contact number and that for the contact number.     

Fabrication of Highly Porous Alumina Prepared by Gelation Freezing Route with Antifreeze Protein

Macroporous alumina ceramic monolith was fabricated by the novel gelation freezing method with antifreeze protein (AFP). The gelation freezing route with AFP is a simple and efficient way to produce macrocellular ceramics with tailored and uniform pore architecture as well as high porosity.     

Short‐term memory of color sensation is robust against luminance distortion

It is well‐known that past knowledge affects color perception, as for example in the perception of familiar objects having richer colors. Although there have been many studies on human memory function with regard to color perception, it is not clear how color signals are treated in the early stages of human memory formation. Here, we tested whether in early memory color information is conserved without any interaction of other visual information. We found that performance of chromatic discrimination between a memorized color and a test color did not deteriorate under any contrast condition of dynamic luminance masking, and thus concluded that color signals were not disturbed by dynamic luminance signals. The results indicate that chromatic sensation per se is not modified at the early stages of the human memory system. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2011