An attempt to stabilize nilvadipine solid dispersion by the use of ternary systems

Firstly, we investigated the physical stability of nilvadipine (NIL)/crospovidone (cl-PVP) solid dispersion during storage (40°C, 75% relative humidity) with powder x-ray diffraction, differential scanning calorimetry (DSC) and dissolution test. These studies indicated that recrystallization occurred during storage and that the dissolution of NIL greatly decreased, compared with that of the initial finding. Secondly, to improve the amorphous form physical stability of NIL, methylcellulose (MC) was added to NIL/cl-PVP solid dispersions as a dispersion carrier and NIL/cl-PVP/MC ternary solid dispersion systems were obtained by the solvent method. Powder x-ray diffraction and DSC studies indicated that the amorphous form physical stability of NIL clearly improved in the NIL/cl-PVP/MC solid dispersion systems during storage. Moreover, the dissolution properties of NIL/cl-PVP/MC solid dispersion systems were characterized by cl-PVP markedly enhancing the dissolution of NIL and MC inhibiting the change of the dissolution of NIL during storage. Finally, we obtained an ideal solid dispersion that was accompanied by a consistently higher rate of dissolution.     

A genetic network programming with learning approach for enhanced stock trading model

In this paper, an enhancement of stock trading model using Genetic Network Programming (GNP) with Sarsa Learning is described. There are three important points in this paper: First, we use GNP with Sarsa Learning as the basic algorithm while both Technical Indices and Candlestick Charts are introduced for efficient stock trading decision-making. In order to create more efficient judgment functions to judge the current stock price appropriately, Importance Index (IMX) has been proposed to tell GNP the timing of buying and selling stocks. Second, to improve the performance of the proposed GNP-Sarsa algorithm, we proposed a new method that can learn the appropriate function describing the relation between the value of each technical index and the value of the IMX. This is an important point that devotes to the enhancement of the GNP-Sarsa algorithm. The third point is that in order to create more efficient judgment functions, sub-nodes are introduced in each node to select appropriate stock price information depending on the situations and to determine appropriate actions (buying/selling). To confirm the effectiveness of the proposed method, we carried out the simulation and compared the results of GNP-Sarsa with other methods like GNP with Actor Critic, GNP with Candlestick Chart, GA and Buy&Hold method. The results shows that the stock trading model using GNP-Sarsa outperforms all the other methods.     

Numerical analysis of sleeve monopole in parallel‐plate waveguide

A monopole with double sleeves, which consists of a resonant loading and a conventional sleeve monopole, is experimentally investigated. The loaded monopole is put vertically in a parallel‐plate waveguide and driven by a coaxial feeder. The new structure exhibits a remarkably broad impedance bandwidth. In this paper, a modal expansion technique is used to numerically evaluate the impedance characteristics of the monopole by modeling the fields between the plates using cylindrical harmonic functions. A Fourier least‐square integration is applied to finding the expansion coefficients by the boundary and continuity conditions. Prior to modeling the proposed sleeve monopole, the developed analysis scheme is examined for its convergence and accuracy. Calculated results are validated by the measurements. For the optimum design at 5.8 Ghz, we investigate the effects of the structure parameters on the impedance characteristics. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 86–98, 2001.     

Thermal management with self-rewetting fluids

The present paper describes the results of a series of microgravity experiments on thermal management device, actually wickless heat pipes, with using the so-called “self t-rewetting fluids” (dilute aqueous solutions of high carbon alcohols) as a working fluid. Although most of liquids show a decrease in the surface tension with increasing temperature, self-rewetting fluids show exceptionally an increase in the surface tension with increasing temperature. This particular characteristic allows for a spontaneous liquid supply to hotter interface by the thermocapillary flow. When liquid/vapor phase change takes place, furthermore, additional Marangoni effect due to concentration gradient by the preferential evaporation of alcohol-rich composition in the aqueous solutions is induced. A considerably strong liquid inflow to dry patch or thin film is therefore expected at three-phase interline or liquid/vapor interface. One of the most promising applications of the self-rewetting fluids in space is wickless heat pipes in which condensate spontaneously returns to evaporation region by enhanced Marangoni effect. Demonstrational experiments on the fluid behavior in a transparent glass tube wickless heat pipe were conducted in JAMIC, and spontaneous liquid return velocities were measured. The present authors then performed parabolic flight experiments on heat transfer characteristics of prototype wickless copper heat pipes, and the performance was compared with ordinary heat pipe having wick structure and with other working fluid.     

The pit initiation mechanism on passive iron under both open-circuit and controlled potential conditions

The pit initiation mechanism on passive iron has been studied under open-circuit conditions and under anodic and cathodic polarization. In each case, an indispensable condition for pit initiation is that the passive film is thinned before pitting occurs, and at the most weak points on the passive film arises pitting. Under open-circuit conditions and under cathodic polarization, the pitting potential is determined by a coupling of the cathodic reduction of the passive film and the anodic dissolution of bare iron. The induction time for pit initiation under anodic polarization conditions is the period necessary for the passive film to reduce to a minimum thickness. The probable process for this is that the chloride ion detaches the iron ion from the passive film to form a chloride-iron complex ion.     

A holonic control system based on a universal learning network

A new control method is presented using the holonic concept on a universal learning network (ULN). The holonic concept was proposed by Arthur Koestler in 1905. Its aim is to harmonize entire systems with partial systems that have hierarchal structures. On the other hand, a ULN that models and controls large-scale complicated systems such as industrial plants and, economic, social, and life phenomena is proposed. In this paper, a holonic control system based on the holonic concept and ULN is presented. From simulation results from a nonlinear crane system, it has been proved that holonic control can harmonize the system rather than optimize it, which used to be the conventional method in control engineering.     

Understanding the mechanism of heat stress tolerance caused by high trehalose accumulation in Saccharomyces cerevisiae using DNA microarray

DNA microarray analysis was performed to examine the stress tolerance mechanism of a Saccharomyces cerevisiae recombinant strain exhibiting high trehalose accumulation and heat stress tolerance. Results suggest that the upregulation of sugar transporter genes is one of the key events for heat stress tolerance of the recombinant strain.     

Power-generating performance of alkali metal thermoelectric converter

The alkali metal thermoelectric converter (AMTEC) utilizing the sodium ion conducting β-alumina is a device to convert heat energy to electric energy directly. It is characterized by high conversion efficiencies, high power densities, no moving parts and low maintenance requirements. Because of these merits, AMTEC is one of the most promising candidates for aerospace power systems, remote power stations and dispersed small-scale power stations. In this paper, the experimental results of the series-connected cells and the theoretical considerations about internal resistances have been reported. For the single cell, the open voltage of 1.37 V and the maximum power of 7.89 W and maximum power density of 0.40 W/cm² at the sodium temperature of 1077 K have been obtained. For the two series-connected cells, the open voltage of 2.60 V and the maximum power of 12.3 W at the sodium temperature of 1016 K have been obtained. This power was about 90 percent of the sum power of two cells. This power decrease is due to the resistance of the current-collecting busbar. It is necessary to optimize the current-collecting busbar considering the electrical resistance and heat conductance.     

Comparative studies of circulating KL-6, type III procollagen N-terminal peptide and type IV collagen 7S in patients with interstitial pneumonitis and alveolar pneumonia

KL-6, a MUC1 mucin preferentially expressed in regenerating type 2 pneumocytes, has been reported to be a sensitive serum marker for evaluating the disease activity of interstitial pneumonitis (IP). Type III procollagen N-terminal peptide (PIIIP) and type IV collagen 7S (7S collagen) have also been reported to be useful in the serological evaluation of the activity. Their levels were measured and their serodiagnostic values were compared simultaneously in patients with IP and alveolar pneumonia. The study population was 45 patients with IP and 12 patients with alveolar pneumonia. Serum KL-6 levels were measured by a specific enzyme immunoassay, and both serum PIIIP and 7S collagen concentrations by their correspondent radioimmunoassay kits. There were no significant difference of serum C-reactive protein level, which was evaluated as an indicator of inflammatory process, between IP and alveolar pneumonia patients. In IP, the abnormally elevated rate of KL-6 [80% (36/45)] was significantly higher than those of PIIIP [40% (18/45)] and 7S collagen [40% (18/45)]. In alveolar pneumonia, the rate of KL-6 [0% (0/12)] was significantly lower than those of PIIIP [33% (4/12)] and 7S collagen [25% (3/12)]. There were no significant correlations among serum levels of the markers. These observations indicate that the serodiagnostic value of KL-6 for IP is superior to that of PIIIP and 7S collagen, and that KL-6 has a characteristic to discriminate IP from alveolar pneumonia.     

A survey of usability capability maturity models: implications for practice and research

Improving the position and effectiveness of user-centred design (UCD) in software and product development is a challenge in many companies. One step towards improvements is to carry out a usability capability maturity (UCM) assessment to evaluate the strengths and weaknesses of a development organisation in UCD. While several diverse UCM models have been introduced, little research has been published in the public domain on these models. The paper aims to fill this gap by analysing the main features of the models. The results show that most models represent different approaches - although some of them have the same roots - meaning that understanding one model is not enough to understand the basics of another model. All models can be used for examining the status of UCD in individual development projects. In addition, models provide various means for assessment of the status of UCD in other organisational areas. The level of documentation of models varies a lot, and very few empirical research results exist. Based on the results, implications for practice and research are suggested.