This paper presents the potential application of soft magnetic composite (SMC) material in low speed, directly driven, axial-flux permanent magnet (PM) wind generators. Comparative design studies are ...conducted on PM wind generators of different configurations with both lamination cores and SMC core. Finite element analysis is used to enhance the design precision, from which analytical formulas are modified. Through careful design an axial-flux PM wind generator with slotted SMC core is built and tested, demonstrating the advantages of better performance, reduced size and weight, low part count and low cost.
Macrostructures of spray-formed 13 vol.% SiC reinforced 7075 aluminum metal matrix composites (MMCs) were studied. The workability of spray-formed MMCs was studied, which was compared with that of ...conventional continuously-cast 7075 aluminum alloy. Upset forming was employed to study the workability, for which the strain, strain rate, and temperature were varied. The effects of lubrication were studied. The evolving morphologies during upsetting were investigated together with the surface defects. The relationships between true strain and true stress were studied, and the strain rate sensitivities, m, were calculated. Macrostructural evolution during upset forming was characterized. The forming limit diagram of strain paths during deformation were plotted and analyzed.
We have compared the p and p angular distributions in 117 x 10(6) Xi- -->Lambdapi- -->ppi-pi- and 41 x 10(6) Xi+ -->Lambda pi+ -->p pi+pi+ decays using a subset of the data from the HyperCP ...experiment (E871) at Fermilab. We find no evidence of CP violation, with the direct-CP-violating parameter AXiLambda identical with (alphaXialphaLambda-alpha Xialpha Lambda)/(alphaXialphaLambda+alphaXialphaLambda)=0.0+/-5.1(stat)+/-4.4(syst) x 10(-4).
To examine the etiological association of genetic instability in lung tumorigenesis, we investigated the frequency of microsatellite instability (MI) of eight dinucleotide repeat markers in 68 ...patients with non-small cell lung cancer. Twenty-eight patients (41.2%) evidenced instability in multiple tested microsatellite markers ranging from 3-7 and were defined as MI-positive patients. MI occurred more frequently in patients suffering from squamous cell lung carcinoma (P = 0.004). We examined the association between MI and expression of hMLH1 mismatch repair protein by immunohistochemical analysis of hMLH1 protein in paraffin-embedded tumors from 64 patients. Twenty MI-positive patients (76.9%) had no expression of hMLH1 protein. The data showed that MI was associated with altered hMLH1 expression (P = 0.03). To examine the role of genetic instability in the previous identified small intragenic deletion of the p53 gene, we explored the association between MI and p53 gene mutations. All patients, except one, containing small intragenic deletion in p53 gene showed MI (P = 0.018). In addition, we found that MI was not associated with the prognosis. Our data suggest that MI plays a significant role in non-small cell lung cancer tumorigenesis in Taiwan and that MI is associated with the altered expression of hMLH1 mismatch repair protein. In addition, MI may be involved in frequent small intragenic deletions of p53 gene.
5′-Adenylylsulfate (APS) reductase (EC 1.8.99.-) catalyzes the reduction of activated sulfate to sulfite in plants. The evidence presented here shows that a domain of the enzyme is a glutathione ...(GSH)-dependent reductase that functions similarly to the redox cofactor glutaredoxin. The APR1 cDNA encoding APS reductase from Arabidopsis thaliana is able to complement the cysteine auxotrophy of an Escherichia coli cysH 3′-phosphoadenosine-5′-phosphosulfate (PAPS) reductase mutant, only if the E. coli strain produces glutathione. The purified recombinant enzyme (APR1p) can use GSH efficiently as a hydrogen donor in vitro, showing a KmGSHof ≈ 0.6 mM. Gene dissection was used to express separately the regions of APR1p from amino acids 73-327 (the R domain), homologous with microbial PAPS reductase, and from amino acids 328-465 (the C domain), homologous with thioredoxin. The R and C domains alone are inactive in APS reduction, but the activity is partially restored by mixing the two domains. The C domain shows a number of activities that are typical of E. coli glutaredoxin rather than thioredoxin. Both the C domain and APR1p are highly active in GSH-dependent reduction of hydroxyethyldisulfide, cystine, and dehydroascorbate, showing a KmGSHin these assays of ≈ 1 mM. The R domain does not show these activities. The C domain is active in GSH-dependent reduction of insulin disulfides and ribonucleotide reductase, whereas APR1p and R domain are inactive. The C domain can substitute for glutaredoxin in vivo as demonstrated by complementation of an E. coli mutant, underscoring the functional similarity between the two enzymes.
Carbon content in sputter coated iron catalyst was found to be an important parameter for the successful growth of vertically aligned carbon nanotubes on smooth silicon surfaces by means of thermal ...chemical vapor deposition (CVD). Pre-saturation of iron catalyst nanoparticles with carbon reduced the difference in the induction time for the growth of carbon nanotubes. This allows neighboring carbon nanotubes to support each other from its initial growth phase and thus effectively prevent them from growing into randomly oriented carbon nanotube networks on smooth silicon substrates. Cast iron containing carbon was found to be an effective sputtering target for achieving the growth of vertically aligned carbon nanotubes on smooth silicon surfaces. On the contrast, pure iron sputtering target was found to be ineffective. Correlation of in-situ measured sheet resistance of sputter coated iron catalyst with the alignment of carbon nanotubes revealed the optimal control of the amount of carbon containing iron catalyst coatings for the growth of vertically aligned carbon nanotubes on smooth silicon surfaces. The optimal catalyst coating was when the in-situ measured sheet resistance vs. sputtering time was near the transitional zone between that with rapidly declining sheet resistance and that with slow declining sheet resistance with respect to sputtering time. Co-sputtering of an iron target partially covered by graphite sheets as well as sequential sputtering of pure iron and graphite were also applied to confirm the effectiveness of carbon content in iron coatings for the growth of vertically aligned carbon nanotubes.
The high prevalence of protein-energy malnutrition is a critical issue for patients with end stage renal disease (ESRD) on hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD). ...Levels of plasma and intracellular amino acids are significant indicators of protein metabolism and nutritional status assessment. We measured plasma FAAs in patients on maintenance dialysis and to provide information in monitoring the therapeutic strategy, particularly in AA supplementary therapy or protein restriction.
Fifty-five patients with ESRD were investigated, 25 on HD (male : female
=
14 : 11; 48–67 y) and 30 on CAPD (male : female
=
17 : 13; 45–64 y). The subjects had been on dialysis for an average of 13 months (range, 9 to 22 months). Their plasma FAAs (including their intermediate metabolites) were measured by ion exchange chromatography before and after HD or during CAPD and were compared with data obtained from 20 age- and sex-matched healthy controls.
The total plasma FAA levels (urea and free ammonia, NH
3 were excluded) in pre-HD samples (3911
±
709 μmol/l) was significantly higher than in the other groups (2570
±
378 in control, 3210
±
640 in post-HD, and 3468
±
271 in CAPD samples). The mean plasma FAA concentrations differed significantly between pre-HD and controls and between pre-HD and CAPD samples (
p
<
0.05). No significant differences were found among the other group comparisons. Comparing individual FAA concentrations, only citrulline differed significantly among all groups (
p
<
0.05), whereas serine, glutamine, β-alanine, β-aminoisobutyric acid, and γ-aminobutyric acid were not different. Concentrations of some FAAs involved in the urea cycle, e.g., arginine, aspartic acid, citrulline, and ornithines, and solutes urea and NH
3, were significantly increased. Ratios of tyrosine
/
phenylalanine and valine
/
glycine ratios were markedly reduced in all patients on dialysis compared with controls.
FAAs either from dietary uptake or protein catabolism are substantially retained in the plasma of patients with ESRD, possibly producing higher levels of the waste products (urea and NH
3) through the urea cycle and ammonia metabolism in liver. Maintenance dialysis can effectively eliminate excess FAAs in plasma, as there was a 17.9% reduction post-HD. The abnormalities in FAA metabolism found in patients with ESRD necessitate careful consideration of dialysis and dietary measures.
General theory of interdiffusion growth in diffusion couples Chen, Y.C; Zhang, Y.G; Chen, C.Q
Materials science & engineering. A, Structural materials : properties, microstructure and processing,
03/2004, Volume:
368, Issue:
1
Journal Article
Peer reviewed
This paper shows that it is possible to treat solid-phase growth thoroughly with methods of fluid mechanics. Based on the concept ‘flow point’ borrowed from fluid mechanics, the general equations are ...derived to describe atomic interdiffusion in diffusion couples. Two types of phase growth, i.e. volume and interface growths, are mathematically defined as the growing expansion of flow points within interdiffusion field and the creation of flow points at interphase interface, respectively. Mathematical discussions on the thickness–time dependence also indicate that phase growth in diffusion couples can be really interface-controlled when the interface coefficient is much smaller than the characteristic diffusion coefficient. It is also shown that with certain conditions Darken's equations can be strictly deduced from the general equations and Darken's equations should be only applicable for the binary interdiffusion system, in which system no new phase should be created. Furthermore, the Kirkendall velocity expressed by one of the Darken's equations should be defined as the velocity of flow point within that system.
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