A Study of the Heat Transfer Characteristics of an FC-72(C6F14) Two-Phase Closed Thermosyphon with Helical Grooves on the Inner Surface

This study is a fundamental work performed to obtain basic information about designing two-phase closed thermosyphons with a working fluid of FC-72 (C₆F₁₄). FC-72 is a kind of alternative refrigerant designed to be chemically safe and more environmentally friendly than any other conventional CFC refrigerants.

To obtain experimental data on operational performances of a FC-72 two-phase closed thermosyphon, an experimental model was designed and manufactured with a micro fin groove copper tube with an outside diameter of 22.2 mm for its container, on which a series of operational performance tests were conducted. Its maximum capacity of heat transport rate was designed to be about 300–400 W. The focus was given to investigate the effects of such parameters as micro fin grooves and fill charge ratios on operational performances of the FC-72 two-phase closed thermosyphon. The experimental data on phase change heat transfer coefficients and heat transport limitations were compared with some corresponding correlations, and a couple of measures that would help to predict operational performances were suggested with some physical explanations.     

INDIRECT INPUT IDENTIFICATION BY MODAL FILTER TECHNIQUE

This paper is a study on modal model method in estimating system inputs from vibration responses, which is one of the indirect input identification methods in frequency domain. The method has advantages over the direct inverse method especially when points of operational inputs are inaccessible for artificial excitation but accessible for response measurement. Systematic procedures of an extended modal model method are proposed and checked by numerical experiments. Mechanisms of error propagation, i.e. how errors in modal parameters such as poles and mode shape vectors affect estimation of the input forces, are illustrated. Then, in order to counteract the error propagation, discrete modal filter approach is used in this paper to compute the inversion of modal matrix in which most serious errors seem to be generated. Further, a reduced form of modified reciprocal modal vector (MRMV) is proposed to estimate multiple inputs, which is shown to have orthogonality errors smaller than by the MRMV filter.     

Effects of Ti thickness on epitaxial CoSi2 growth from Co/Ti bilayer

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

Effect of chromium on the phase evolution and microstructure of ZnO doped with bismuth and antimony

Crystalline phase formation and microstructure of ZnO varistors with a basic composition ZnO–Bi₂O₃–Sb₂O₃ were examined. Addition of chromium oxide to this basic varistor resulted in an α-spinel (α-Zn₇Sb₂O₁₂) phase dissolving a significant amount of Cr, while the β-spinel did not. β-spinel transformed to pyrochlore during cooling, whereas α-spinel hardly transformed to pyrochlore irrespective of the cooling conditions. When Sb₂O₃ was completely replaced by Cr₂O₃, ZnCr₂O₄ was formed instead of spinel. α-spinel particles were 1–2 μm in size and intra- as well as intergranular. ZnCr₂O₄ particles, smaller than 1 μm in size, however, were present as aggregates in the bismuth-rich matrix phase at the grain boundaries. This revised version was published online in November 2006 with corrections to the Cover Date.     

A novel helix termination mutation in keratin 10 in annular epidermolytic ichthyosis, a variant of bullous congenital ichthyosiform erythroderma

Annular epidermolytic ichthyosis is a distinct phenotypic variant of bullous congenital ichthyosiform erythroderma that has recently been described in two separate kindreds. Individuals with this variant present with bullous ichthyosis in early childhood and hyperkeratotic lichenified plaques in the flexural areas and extensor surfaces at later ages. Characteristically, they also develop intermittent bouts of annular and polycyclic, erythematous, scaly plaques on the trunk and proximal extremities. We now describe a third kindred with annular epidermolytic ichthyosis. Molecular analysis of this family revealed a novel mutation resulting in an isoleucine to threonine substitution at residue 107 (codon 446) within the highly conserved helix termination motif at the end of the rod domain of keratin 10.     

CD4-CD8-C.B-17 SCID thymocytes enter the CD4+CD8+ stage in the presence of neonatally grafted T cells

Our previous studies in iron-loaded rat heart cells showed that in vitro iron loading results in peroxidative injury, manifested in a marked decrease in rate and amplitude of heart cell contractility and rhythmicity, which is correctable by treatment with deferoxamine (DF). In the present studies we explored the role of mitochondrial damage in myocardial iron toxicity. Iron loading by 24-hour incubation with 0.36 mmol/L ferric ammonium citrate resulted in a decrease in the activity of nicotinamide adenine dinucleotide (NADH)-cytochrome c oxidoreductase (complex I+III) to 35.3%+/-11.2% of the value in untreated controls; of succinate-cytochrome c oxidoreductase (complex II+III) to 57.4%+/-3.1%; and of succinate dehydrogenase to 63.5%+/-12.6% (p < 0.001 in all cases). The decrease in activity of other mitochondrial enzymes, including NADH-ferricyanide reductase, succinate ubiquinone oxidoreductase (complex II), cytochrome c oxidase (complex IV), and ubiquinol cytochrome c oxidoreductase (complex III), was less impressive and ranged from 71.5%+/-15.8% to 91.5%+/-14.6% of controls. That the observed loss of respiratory enzyme activity was a specific effect of iron toxicity was clearly demonstrated by the complete restoration of enzyme activities by in vitro iron chelation therapy. Sequential treatment with iron and doxorubicin caused a loss of complex I+III and complex II+III activity that was greater than that seen with either agent alone but was only partially correctable by DF treatment. Alterations in cellular adenosine triphosphate measurements paralleled very closely the changes observed in respiratory complex activity. These findings demonstrate for the first time the impairment of cardiac mitochondrial respiratory enzyme activity caused by iron loading at conditions formerly shown to produce severe abnormalities in contractility and rhythmicity.     

PURIFICATION OF THE CELLULAR RECEPTOR OF AN OYSTER JUICE BORNE COLIPHAGE OJ367 FROM THE OUTER MEMBRANE OF ESCHERICHIA COLI HOST

The cellular receptor of an oyster juice borne phage OJ367 was found in the outer membrane (OM) of its host Escherichia coli. The total cell envelope (TCE) was fractionated by differential extraction and it was found that the OM possesses phage neutralization ability. The OM was purified by diethylaminoethyl cellulose column chromatography to screen for the phage recognition moiety. A homogeneous, 39‐kDa OM protein (Omp) with receptor activity was eluted. It was a peptidoglycan (PG)‐associated protein which showed trypsin resistance. Lipopolysaccharide (LPS) had no effect on its receptor activity either when coexisting in the column fractions or when the isolated LPS was mixed with the Omp. Mutants resistant to lysis by phage OJ367 were isolated. The amount of the 39‐kDa and another PG‐associated 37‐kDa protein decreased significantly in the TCE of the mutant. The 39‐kDa Omp may serve as the cellular receptor for adherence of the coliphage, whereas the 37‐kDa protein is also involved in the infection mechanism.