The result of a wall failure in-pile experiment under the EAGLE project

The WF (wall failure) test of the EAGLE program, in which 2 kg of uranium dioxide fuel-pins were melted by nuclear heating, was successfully conducted in the IGR (Impulse Graphite Reactor) of NNC/Kazakhstan. In this test, a 3 mm-thick stainless steel (SS) wall structure was placed between fuel pins and a 10 mm-thick sodium-filled channel (sodium gap). During the transient, fuel pins were heated, which led to the formation of a fuel-steel mixture pool. Under the transient nuclear heating condition, the SS wall was strongly heated by the molten pool, leading to wall failure. The time needed for fuel penetration into the sodium-filled gap was very short (less than 1 s after the pool formation). The result suggests that molten core materials formed in hypothetical LMFBR core disruptive accidents have a certain potential to destroy SS-wall boundaries early in the accident phase, thereby providing fuel escape paths from the core region. The early establishment of such fuel escape paths is regarded as a favorable characteristic in eliminating the possibility of severe re-criticality events. A preliminary interpretation on the WF test results is presented in this paper.     

An investigation of the pH-activity relationships of Cex, a family 10 xylanase from Cellulomonas fimi: xylan inhibition and the influence of nitro-substituted aryl-beta-D-xylobiosides on xylanase activity

The kinetic parameters of Cex, a family 10 xylanase from Cellulomonas fimi, were determined at various pH levels using soluble birchwood xylan (BWX) as a natural polymeric substrate along with three other synthetic aryl-beta-D-xylobioside substrates. Using BWX, a high level of substrate inhibition was observed which increased with decreasing pH. In contrast, typical Michaelis-Menten-type profiles were obtained using the three aryl-beta-D-xylobiosides as substrates. The k(cat) values determined using o-nitrophenyl-beta-D-xylobioside did not change as the pH increased, whereas the k(cat) values obtained with BWX, phenyl-beta-D-xylobioside and p-nitrophenyl-beta-D-xylobioside decreased, suggesting that the presence of an ortho nitro group affects the activity displayed by Cex. These differences were not observed with XynB from Clostridium stercorarium F9, a member of the same family of xylanases as Cex. These results indicate that a careful evaluation is required when employing substituted aryl-beta-D-xylobiosides in the characterization of xylanases.     

A model of stage of change to recommend colonoscopy among urban primary care physicians.

Theory is little used in the prediction of physician cancer screening stage of change. Structural equation modeling was used to evaluate the theoretical predictors of stage of change to recommend colonoscopy among 235 urban physicians. Constructs from the theory of planned behavior, social-cognitive theory, and the transtheoretical model were systematically tested. As predicted, contextual factors, such as the physicians' ages, their race-ethnicities, patient race-ethnicity, and office-related barriers to preventive care were associated with stage of change through self-efficacy, normative beliefs, and negative behavioral beliefs. The findings demonstrate the relevance of these models to studying the behavior of physicians and support the development of interventions that are tailored to normative beliefs and specific physician cognitions for colonoscopy recommendation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanism for change in leakage current waveform on a wet silicone rubber surface-a study using a dynamic 3-D model

This paper describes the results of experiments and simulations made to examine the waveform of leakage current flowing through the surface of HTV (high temperature vulcanized) silicone rubber specimen exposed to clean fog. Water droplets were placed on the surface of specimen energized with AC voltage and investigations of the surface state were done by a high-speed video camera in a wet condition produced by sprayed clean fog. Simultaneously, according to the experimental condition, a dynamic 3-D model was built to calculate the electric field and current density distribution on the specimen surface by a finite element software. A conducting water layer is formed due to the deformation of droplets and the development of dry band arcing. This caused large distortion and nonlinearly which increased the odd harmonic components in the leakage current waveform. This is in good agreement with the simulating calculation. The information from the leakage current frequency characteristic was extracted and correlated with the insulation surface condition. It can be considered as a diagnostic index for electrical characteristics and insulation state of polymer insulators in the wet condition.     

Sinusoidal model based on instantaneous frequency attractors

We propose a sinusoidal synthesis method based on instantaneous frequency (IF) attractors, which correspond to harmonic frequency trajectories. The algorithm is novel in extracting accurate sinusoidal components. Since the continuity of IF attractors is well-defined and simple to detect, the IF attractors can be extracted from audio signals without any explicit constraint or complicated algorithm; therefore, they can be directly applied to sinusoidal synthesis. Accuracy of IF attractor analysis can be further improved by time-warping analysis, which improves resolution for harmonic components whose frequencies that change rapidly. We describe the procedure for sinusoidal synthesis and precise phase estimation along with examples and also evaluate the effect of time-warping on analysis and synthesis of speech.     

Release of embryogenic carrot cells with high regeneration potency from immobilized alginate beads

For the mass-production of regenerated carrot plantlets, embryogenic carrot callus immobilized in calcium alginate gel beads was cultivated in a growth medium and the regeneration frequency of cells released from alginate gel beads was compared with that in a suspension culture. Cells released in the immobilized culture were regenerated at a frequency which was about 1.5 times higher than that obtained in the suspension culture. When CaCl2 was added to the growth medium at 5 mM, repeated batch culture for plantlet production continued for 245 d with no significant decrease in the productivity (1.6 x 10(5) plantlets/l-medium/d).     

Positron emission tomography [15O]water studies with short interscan interval for single-subject and group analysis: influence of background subtraction

Ethanol at concentration of 200 mM induces anesthesia in experimental animals and depresses neurotransmission in isolated spinal cords. To determine whether actions on primary afferent nerve terminals contribute to ethanol's depressant effects on spinal cord, a study was undertaken to test whether ethanol blocks sodium currents (I(Na)) in dorsal root ganglion neurons (DRGn). Whole-cell patch clamp was used to examine I(Na) in DRGn isolated from 1- to 15-day-old rats. At a holding potential of -80 mV ethanol (200 mM) decreased peak tetrodotoxin-resistant (TTX-R) and tetrodotoxin-sensitive (TTX-S) I(Na) by 19.0% +/- 2.7 (mean +/- SEM) and 8.5% +/- 2.2, respectively. Maximal available I(Na) was reduced to 82 +/- 4% (TTX-R) and 93 +/- 1% (TTX-S) of control. Steady-state inactivation curves were shifted in the hyperpolarizing direction by 2.1 +/- 0.2 mV (TTX-R) and 1.1 +/- 0.1 mV (TTX-S). At prepulse potentials of -30 mV (TTX-R) and -70 mV (TTX-S), these shifts contributed an additional 17 +/- 1% (TTX-R) and 7 +/- 1% (TTX-S) reduction in available I(Na). Ethanol thus selectively induced both voltage-independent and voltage-dependent block of TTX-R I(Na) in DRGn. Because DRGn TTX-R sodium channels are associated with small-diameter primary afferent fibers, these results are consistent with a role for ethanol actions on sodium channels in depression of nociceptive-related neurotransmission in spinal cord.     

Acute respiratory distress syndrome due to methicillin-resistant Staphylococcus aureus sepsis in hyper-IgE syndrome

We report the case of a 34 year old woman with acute respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (DIC) due to methicillin-resistant Staphylococcus aureus (MRSA) sepsis with hyperimmunoglobulin E syndrome (HIES). Although chemotactic activity of neutrophils was impaired in this patient, neutrophils accumulated in the lungs as assessed by bronchoalveolar lavage fluid (BALF) counts. In addition to antibiotics and oxygen therapy, the administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) resulted in a remarkable recovery.     

Change in fine structure of nylon 6 gut yarn in twisting,annealing, and untwisting processes. I. Observation by WAXD,SAXD, and EM

To obtain information on the change in fine structure of nylon 6 taking place during practical false-twisting processes, the manner of change in the three elemental processes, i.e., twisting, annealing, and untwisting, was studied. For simplicity, nylon 6 gut yarn was used instead of multifilament yarn. Wide- and small-angle x-ray diffraction (WAXD and SAXD) together with electron microscopy (EM) were used here. The degree of molecular orientation in the crystalline region of the twisted yarn gradually decreases with increase of the twist number (TN) in the region of TN ? 100. The long spacing, determined by SAXD, of the twisted yarn increases with increases in TN. The increase in long spacing cannot be interpreted only by macroscopic strain or elongation of the yarn in the twisting process. This difference seems to arise from the contribution of the decrease of lateral size of lamellae to the average long spacing; therefore the increase in long spacing should be attributed to the elongation of the amorphous region, deduced from the crystallinity measured by WAXD and the long spacing diffraction. The angle between the streak line on the surface of twisted yarn observed by EM and the fiber axis agrees well with the twist angle of the yarn. The crystal lamellae are stacked normal to the streak line at the initial stage, i.e., at a low value of TN, but they begin to deviate from the normal direction with increase in TN, accompanied by their partial destruction. Based on SAXD and density measurements, the internal strain of yarn annealed after twisting is fully relaxed. When the yarn is untwisted after twisting and annealing, the crystal orientation recovers gradually to that of the untreated yarn. The chain axis within the lamellae in the center region of the yarn becomes nearly parallel to the fiber axis, but the chain axis in the outer region does not.