Partial Seeding Policy for Controlling the Crystal Quality in Batch Cooling Crystallization

Partial seeding, in which the nuclei originating from seed crystals grow to yield the product crystals, was simulated and optimized for controlling the batch cooling crystallization process of L-arginine. The product quality was evaluated by the coefficient of variation (CV) of the crystal size distribution. First, the optimum seed amount for partial seeding was estimated by simulation. Then, the simulated values of the optimum seed amount and the resulting local minimum CV were correlated with the seed crystal size and the cooling rate. The correlation can be utilized for estimating the seed amount in the case that the seed crystals are added in a slurry. Finally, these simulated values were compared to the measured ones. Consequently, the optimum seed amount was suggested to be reasonably predicted.     

Modeling and Growth Kinetics of Antisolvent Crystallization Applied to the Pharmaceutical Industry

With the aim of simulating the product crystal size, which is one of the important physical properties for active pharmaceutical ingredients, an antisolvent crystallization model is proposed, including only six experimentally determined kinetic parameters to develop a concise model. As a first step, the methodology to assess the growth rate parameters, which are some of the six kinetic parameters, is discussed. An approach for appropriately treating the size distribution data obtained by means of the laser diffraction/scattering method is suggested. The determined growth rate parameters could be used to simulate the crystal size indicating that the simulation by crystallization modeling is a practical application for the pharmaceutical industry.     

Electrocaloric Refrigeration using Multi-Layers of Electrocaloric Material Films and Thermal Switches

The electrocaloric effect in thin films of electrocaloric material has the potential to be used for efficient cooling systems. We numerically calculated the effect of the parameters in electrocaloric refrigeration with multi-layers of electrocaloric material films and thermal switches by changing the contact thermal conductance to improve thermal performance. It was found that the average heat transfer efficiency was 10% and the average heat flux transferred to the cold side of the system was 2.4 × 10⁴ W/m² for the standard conditions of a frequency of 100 Hz and a temperature difference between the hot side and the cold side of the system of 20 K. The average heat flux transferred to the cold side of the system was maximum when the thickness of the electrocaloric material was 70 µm and thickness of the heat storage material 100 µm. The average heat transfer efficiency was maximum at the two layers of the electrocaloric material.     

Flame retardancy in fabric consisting of cellulosic fiber and modacrylic fiber containing fine‐grained MoO3 particles

Flame retardancy of fabrics consisting of modacrylic fiber containing with various dispersed metal compounds and cellulosic fiber has been investigated by means of flame test (ISO15025 procedure A) and limiting oxygen index (LOI). It has been found that excellent flame retardancy is achieved by fine‐grained MoO₃ particles. The afterflame time in flame test and the LOI value are improved with decreasing particle size of MoO₃. The flame retardancy of MoO₃ (particle size; 0.1 µm) is comparable to that of Sb₂O₃. On the other hand, significant improvement in flame retardancy is not observed for other metal compounds although some metal oxides and a hydroxide in the present study are known as flame retardant or smoke suppressing agent in halogen containing polymer in previous studies. In order to clarify the mechanism of the observed flame retardancy by the addition of fine‐grained MoO₃, we have carried out X‐ray fluorescence spectrometry (XRF) measurement of the fabric specimen after the flame test and thermogravimetric analysis (TGA) of various types of samples. These analytical data indicated that MoO₃ works as halogen synergist in solid phase and the char of modacrylic fiber formed by addition of MoO₃ suppresses decomposition of the cotton blended in the fabric in the range of the ignition temperature. Copyright © 2015 John Wiley & Sons, Ltd.     

Effect of marzulene on the restitution of rat gastric mucosa after NaOH-induced injury

BACKGROUND/AIMS: The purpose of this study was to assess the effect of marzulene (L-glutamine plus azulene) on the repair of NaOH-induced gastric mucosal injury in rats. METHODOLOGY: Gastric mucosal injury was induced with intragastric instillation of 3.0 ml of 5% NaOH for 1 minute. From 2 days after the operation, the rats were orally given chow pellets containing 0%, 0.25%, or 0.5% of marzulene for 25 weeks. RESULTS: Oral administration of marzulene at both dosages significantly increased the mucosal heights of the fundic and antral mucosa at week 25. Marzulene also increased the labeling indices of the fundic and antral epithelial cells, but not the mucosal blood flow. CONCLUSIONS: These findings indicate that marzulene stimulates repair mechanisms of rat gastric mucosa after NaOH injury. This effect of marzulene may be associated with a stimulation of gastric epithelial cell proliferation.     

Variable-length lapped transforms with a combination of multiple synthesis filter banks for image coding.

A class of lapped transforms for image coding, which are characterized by variable-length synthesis filters, is introduced. In this class, the synthesis filter bank (FB) is first defined with an arbitrary combination of finite impulse response synthesis filters of perfect reconstruction FBs. An analysis FB is then obtained using direct matrix inversion or iterative implementation of Neumann series expansion. Moreover, to improve compression, we introduce a unitary transform that follows the analysis FB. This class enables a greater freedom of design than previously presented variable-length lapped transforms. We illustrate several design examples and present experimental results for image coding, which indicate that the proposed transforms are promising and comparable with conventional subband transforms including wavelets.     

Circularly polarized rectangularly bent slot antennas backed by arectangular cavity

Rectangularly bent slot antennas backed by a rectangular cavity for circular polarization are proposed. Characteristics of three types of cavity-backed rectangularly bent slot antennas for circular polarization-the single square loop slot, the two-element square loop slot, and the two-arm square spiral slot antenna-are analyzed numerically. The generalized network formulation based on the equivalence principle is given in terms of the method of moments. The magnetic currents on the thin rectangularly bent slots in the presence of the backing cavity are obtained and used to calculate the input impedance, radiation pattern, and axial ratio. Experimental results on the input impedance, radiation pattern, and axial ratio are in good agreement with calculated data     

Real-time optical monitoring of ligand-mediated internalization of alpha1b-adrenoceptor with green fluorescent protein

The study of G protein-coupled receptor signal transduction and behavior in living cells is technically difficult because of a lack of useful biological reagents. We show here that a fully functional alphalb-adrenoceptor tagged with the green fluorescent protein (alphalbAR/GFP) can be used to determine the molecular mechanism of intemalization of alphalbAR/ GFP in living cells. In mouse alphaT3 cells, alpha1bAR/GFP demonstrates strong, diffuse fluorescence along the plasma membrane when observed by confocal laser scanning microscope. The fluorescent receptor binds agonist and antagonist and stimulates phosphatidylinositol/Ca2+ signaling in a similar fashion to the wild receptor. In addition, alpha1bAR/ GFP can be internalized within minutes when exposed to agonist, and the subcellular redistribution of this receptor can be determined by measurement of endogenous fluorescence. The phospholipase C inhibitor U73,122, the protein kinase C activator PMA, and inhibitor staurosporine, and the Ca2+-ATPase inhibitor thapsigargin were used to examine the mechanism of agonist-promoted alphalbAR/GFP redistribution. Agonist-promoted internalization of alphalbAR/GFP was closely linked to phospholipase C activation and was dependent on protein kinase C activation, but was independent of the increase in intracellular free Ca2+ concentration. This study demonstrated that real-time optical monitoring of the subcellular localization of alphalbAR (as well as other G protein-coupled receptors) in living cells is feasible, and that this may provide a valuable system for further study of the biochemical mechanism(s) of agonist-induced receptor endocytosis.     

Two rectangular loops fed in series for broadband circular polarization and impedance matching

Two rectangular wire loops above an infinite ground plane are investigated for broadband circular polarization and impedance matching. Each rectangular loop is connected to each end of a short dipole fed by a coaxial cable through the ground plane. One gap on each loop is introduced to get circular polarization and the gap position controls the sense of circular polarization. The position of the gap, the length of the short dipole, the height of the loop above the ground plane and the shape of the rectangle are very important to get a good axial ratio (AR) and voltage standing-wave ratio (VSWR). The AR bandwidth (/spl les/3 dB) and the VSWR bandwidth (/spl les/2) are 18% and 22%, respectively. The measured and computed results are in good agreement.