AN EXPERIMENTAL STUDY OF SUPERCRITICAL FLUID DRYING OF Y-BA-CU OXIDES POWDER FROM AQUEOUS ALCOHOL SUSPENSION USING CARBON DIOXIDE

In order to prepare fine Y-Ba-Cu oxides, a suspension of oxide was synthesized by simultaneous hydrolization of 2-propanol solution of yttrium triisopropoxide - barium diisopropoxide - copper diisopropoxide. The suspension could not be dried by the freeze-drying method because the freezing point of aqueous alcohol solvent in the suspension was so low: therefore, supercritical fluid drying was used. Although the diameters of dried powders were larger than expected, the powders containing no BaCO₃ were obtained.

The results from this experiment suggest that the supercritical fluid drying method is useful for drying a suspension prepared by the alkoxide method.     

A direct computation of state deadbeat feedback gains

A method for computing a feedback gain that achieves state deadbeat control is given. From systems given in the staircase form, this method derives the deadbeat gain in a numerically reliable way. It is shown that the gain turns out to be LQ optimal for some weightings     

Impaired motor coordination in mice lacking prion protein

1. Prion protein (PrPC) is a host-encoded glycoprotein constitutively expressed on the neuronal cell surface. Accumulation of its protease-resistant isoform is closely related to pathologic changes and prion propagation in the brain tissue of a series of prion diseases. However, the physiological role of PrPC remains to be elucidated. 2. After long-term observation, we noted impaired motor coordination and loss of cerebellar Purkinje cells in the aged mice homozygous for a disrupted PrP gene, a finding which strongly suggests that PrPC plays a role in the long-term survival of Purkinje cells. 3. We also describe the resistance of the PrP null mice to the prion, indicating the requirement of PrPC for both the development of prion diseases and the prion propagation.     

Clinical evaluation of hepatic bruit audible in patients with alcoholic hepatitis]

Human exposure to methylating agents appears to be widespread, as indicated by the frequent occurrence of methylated DNA adducts in human DNA. The high incidence of methylated DNA adducts even in humans thought not to have suffered extensive exposure to environmental methylating agents implies that chemicals of endogenous origin, probably N-nitroso compounds such as the strongly carcinogenic N-nitrosodimethylamine (NDMA), may be primarily responsible for their formation and raises the question of the carcinogenic risks associated with such exposure. In addition to accumulation of DNA damage, other factors (such as induced cell proliferation) appear to be important in determining the probability of induction of mutation or cancer by NDMA, implying that high to low dose risk extrapolations should not be based on the assumption of dose- or even adduct-linearity. Comparative studies of the accumulation and repair of methylated adducts in humans and animals treated with methylating cytostatic drugs do not reveal significant species differences. Based on this and the dosimetry of adduct accumulation in rats chronically exposed to very low doses of NDMA, it is suggested that the exposure needed to account for the levels of adducts found in human DNA may be of the order of hundreds of micrograms NDMA (or equivalent) per day, a level of exposure which may well represent a significant carcinogenic hazard for man.     

A method for designing CDO conformed to investment parameters

We propose a method for designing CDOs (Collateralized Debt Obligation) that meets investor needs regarding CDO attributes. It is demonstrated that adjusting the attributes (credit capability and issue amount) of CDOs to investors' preferences causes a capital loss risk that the agent takes. We formulate a CDO optimization problem by defining an objective function using the above risk and setting constraints that arise from investor needs and a risk premium that is paid for the agent. Our prototype experiment, in which fictitious underlying obligations and investor needs are given, verifies that CDOs can be designed without opportunity loss and dead stock loss, and that the capital loss is not more than a thousandth part of the amount of annual payment under guarantee for small and medium‐sized enterprises by a general credit guarantee institution. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(4): 20– 28, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20581     

Novel aprotic polar polymers 2. Miscibility of aliphatic polysulfoxides

Summary Miscibility of aliphatic polysulfoxides (1, 2) with other commodity polymers was examined by comparing glass transition temperature(s) (T_gs) of the mixture of these polymers with T_gs of the original polymers by differential scanning calorimetry. It was found that the aliphatic polysulfoxides had good miscibility with poly(2-methyl-2-oxazoline) or/and poly(N-vinylpyrrolidone). Received: 25 December 1997/Revised version: 23 February 1998/Accepted: 25 February 1998     

A case of multiple colonic liver metastases treated successfully with percutaneous isolated liver chemoperfusion using cisplatin

We herein report a case of multiple colonic liver metastases treated with repeated percutaneous isolated liver chemoperfusion of cisplatin under hepatic venous isolation and charcoal hemoperfusion (HVI.CHP) as an inductive treatment. The patient was a 70-year-old man who underwent curative resections for metachronous rectal and descending colonic cancer in 1979 and 1995, respectively. During outpatient follow-up, he showed increases of serum CEA level. An abdominal CT study demonstrated multiple low-density lesions in the bilateral lobes of the liver, indicating colonic liver metastases. The patient had a total of 2 treatments with percutaneous isolated liver chemoperfusion of cisplatin (total dose, 500 mg) under HVI.CHP. His post-treatment course was uneventful without side effects, including leukopenia and renal dysfunction. Serum CEA levels showed a sharp decrease to 160 ng/ml 3 months after treatment from the pretreatment value of 1,064 ng/ml. CT scan 3 months after treatment revealed remarkable tumor regression along with liquefaction of liver tumors, showing a partial response. These results suggested that repeated percutaneous isolated liver chemoperfusion of cisplatin under HVI.CHP is a potent inductive treatment for patients with multiple colonic liver metastases.     

Fluid flow and heat transfer of natural convection around large horizontal cylinders: Experiments with air

Natural convective flows of air around large horizontal cylinders were investigated experimentally. The main concerns were the turbulent transition mechanisms and the heat transfer characteristics of turbulent flows. The cylinders were heated with uniform heat flux and their diameters were varied from 200 to 1200 mm to enable experiments over a wide range of modified Rayleigh numbers, Ra_D^* = 1.0 × 10⁸ to 5.5 × 10¹¹. The flow fields around the cylinders were visualized with smoke to investigate the turbulent transition mechanisms. The results show that three‐dimensional flow separations occur first at the trailing edge of the cylinder when Ra_D^* exceeds 3.5 × 10⁹, and the separation points shift upstream with increasing Rayleigh numbers. These separations become a trigger to the turbulent transition and transitional and turbulent flows appear downstream of the separations at higher Rayleigh numbers. However, they occupy a relatively small portion of the cylinder surfaces even at the maximum Rayleigh numbers of the present experiments. The local heat transfer coefficients were also measured. The results show that the coefficients are increased significantly in the transitional and turbulent regions compared with the laminar coefficients. Moreover, the present results for air were compared with previous results for water and the effects of Prandtl number on the flow and heat transfer were discussed. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(4): 293–305, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10080     

High-temperature leak-characteristics of PCV hatch flange gasket

Small-model tests were performed to examine the integrity of the containment flange gasket in a severe accident. During a severe accident, containment structures suffer slow pressurization at relatively high temperatures. A realistic understanding of containment performance in such conditions is a major concern in developing an accident management strategy. This paper describes the results of experiments on the sealing capability of flange gaskets at high pressures and high temperatures. Silicone-rubber gaskets, which are used as the sealing material in BWR plant primary containment vessels (PCV) in Japan, were examined in small-model tests. The gaskets show sufficient sealing capability up to 225°C at 20 kgf/cm². When applying the leakage characteristics specified in this paper to codes for severe accidents, the results should be examined carefully based on realistic heattransfer phenomena.     

The development of <100> texture in Fe-Cr-Co-Mo permanentmagnet alloys

The cold-rolled and recrystallization textures of Fe-Cr-Co-Mo permanent magnet alloys are described. The studied composition is Fe-30%Cr-15%Co-3%Mo (in wt.%). The cold-rolled texture can be considered to be {111}<110>, {111}<112>, {100}<110>, and {211}<110>, while the recrystallization texture can be considered to be {111}<100>, {110}<112>, {211}<110>, and {110}<110>. The secondary recrystallization is caused by heat-treating the alloys in the sequence of α, α+γ, α+γ+σ, α phase region. This results in a favorable texture of {110}<110> and <100> direction, aligning along the transverse direction (TD) of the strips. The best magnetic properties obtained in this study were 1.2 T (12.0 kG), iH _c=82.0 kAm^-1 (1025 Oe), and (BH)max= 60.8 kJm^-3 (7.6 MGOe) with TD alloys