Mechanisms of char production from oxidized cellulose

A multi-technique approach, incorporating nuclear magnetic resonance (NMR), elemental analysis, differential scanning calorimetry (DSC), thermogravimetric analysis and surface area determination, has been used to investigate the formation of chars by oxidized cellulose. It was found that oxidation of the cellulose tends to increase the surface area of the resulting char. NMR, elemental analysis and DSC show how cellulose oxidation tends to increase aromaticity and cross-linking. This, in turn, decreases diffusion rates of volatiles out of the oxidized cellulose during pyrolysis, giving denser carbons and higher BET surface areas.     

Use of GafChromic film to diagnose laser generated proton beams

A calibration of three types of GafChromic radiochromic film (HS, MD-55, and HD-810) was carried out on the Crocker Nuclear Laboratory's 76 in. cyclotron at UC Davis over doses ranging from 0.001 to 15 kGy. The film was digitized with a scanning microdensitometer with which it was scanned twice with two different filters to increase the film's effective dynamic range. We demonstrate how this calibrated film can be used to measure the spectrum and total energy of a laser generated proton beam. This technique was applied to an experiment on the 10 J, 100 fs Callisto laser at Lawrence Livermore National Laboratory. The resulting proton spectrum was compared to that obtained by simultaneous measurement of Ti nuclear activation; the two methods give the same proton beam slope temperature and agree in number of protons to within 27%.     

The YouthMood Project: A cluster randomized controlled trial of an online cognitive behavioral program with adolescents.

The aim in the current study was to investigate the effectiveness of an online, self-directed cognitive–behavioral therapy program (MoodGYM) in preventing and reducing the symptoms of anxiety and depression in an adolescent school-based population. A cluster randomized controlled trial was conducted with 30 schools (N = 1,477) from across Australia, with each school randomly allocated to the intervention or wait-list control condition. At postintervention and 6-month follow-up, participants in the intervention condition had significantly lower levels of anxiety than did participants in the wait-list control condition (Cohen’s d = 0.15–0.25). The effects of the MoodGYM program on depressive symptoms were less strong, with only male participants in the intervention condition exhibiting significant reductions in depressive symptoms at postintervention and 6-month follow-up (Cohen’s d = 0.27–0.43). Although small to moderate, the effects obtained in the current study provide support for the utility of universal prevention programs in schools. The effectiveness of booster sessions should be explored in future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Case for Undergraduate Study of Disasters

Literature on disasters provides the focus for student-based learning exercises in civil and architectural engineering at Queen's University, Belfast, which have been ongoing since 1994. Incorporating these studies in the early part of the curriculum helps students to reorientate from their previous mainly science-based study by gaining some knowledge of the roles, responsibilities, priorities, and work practices of engineers in a way that would not be possible through lectures. In view of the influence of disasters on engineering thinking and work practice, they should have a much larger influence than they currently do on curriculum development.     

Strain measurement standards—an outline

Strain measurement techniques are being used more frequently today to check that manufactured components are at a safe stress level in service. Designers are also requiring strain gauge tests on prototypes to confirm that the theoretical calculations are realistic and designs are economic.
Against this background the measurement engineer finds himself under pressure to produce test results quickly and sometimes to justify them. Strain measurement standards would have an important role in convincing customers that tests have been carried out in an approved manner and could be the measurement engineer's defence in the case of disputed results.
A suggested range of standards and codes of practice is described, from the anticipated BSI Standard on Strain Gauge Calibration to a proposed standard on strain gauge application and possible specifications on instrumentation for static and dynamic measurement. The need for strain measurement technician training and possible participationin the National Testing Laboratory Accreditation Scheme, NATLAS, is also discussed.     

SCALING IN SITU BIOREMEDIATION PROBLEMS BY APPLICATION OF MULTIPHASE, MULTICOMPONENT TRANSPORT THEORY

A methodology for scaling in situ bioremediation problems is presented. This methodology is based on multiphase, muiticomponent transport theory and employs inspectional analysis and numerical sensitivity studies. A general mathematical model that describes subsurface aerobic biotransformation of organic chemical species in a multiphase setting is first presented. This general model is applied to the specific case of microbial enhanced vapor-vacuum extraction (MEVVE) in a one-dimensional zone of immobile liquids. The resulting simplified MEVVE model considers rate-dependent interphase mass transfer, a flowing gaseous phase, a single hydrocarbon pseudo-component, and either oxygen or hydrocarbon limited microbial activity. By inspectional analysis a set of dimensionless groups are derived that represent the various model parameters. A scries of numerical sensitivity studies are presented that examine the impact of selected dimensionless groups on overall system biotransformation rates. This analysis demonstrates that overall biotranformation rates can be significantly limited not only by insufficient transport of oxygen in the gaseous phase, but also by interfacial mass transfer resistance between nonaqueous phase liquid globules and adjacent fluids. Finally, an examination of the selected dimensionless groups reveals the parameter requirements for properly scaled MEVVE tests. These results indicate the need for further investigation of the importantance of fluid distributions in the pore space and their impact on the design of laboratory and field tests.     

Crystal structure and functional analysis of the HERG potassium channel N terminus: a eukaryotic PAS domain

More and more elderly subjects are offered for pulmonary resection. The object of this study was to review the results of excision for cancer in octogenarians. PATIENTS: 51 consecutive patients (44 men, 7 women) with a mean age of 82 years (80-91) were operated on. 31 lobectomies, 2 bilobectomies, 13 pneumonectomies, 1 segmental resection and 4 exploratory thoracotomies were carried out. 17 tumours were classed as stage I, 15 as stage II and 15 as stage III. RESULTS: 38 patients (75%) had uncomplicated post-operative periods; the predicted factors for complication were the existence of weight loss and alteration of respiratory function. 2 patients (4%) died in the post-operative phase. Neither the type of operation, the staging or the existence of cardiovascular dysfunction had any influence on the post-operative phase. The level of the survival at 3 and 5 years was 39% and 16% respectively. 30% of the late deaths were related to intercurrent events. CONCLUSIONS: Pulmonary excision may be envisaged in an octogenarian who is in good physical and intellectual state with a limited tumour. This surgery in general is applied to a population which probably only marginally consists of octogenarians but the results here justify their inclusion in the indications for selection.     

The regulation of collagen in fetal skin wounds: mRNA localization and analysis

The deposition of collagen in fetal skin wounds has been shown in several animal models. The authors used a radiolabeled RNA antisense probe, complementary to the mRNA for the alpha-1 chain of human procollagen type I, to assess regulation of this collagen species in fetal and adult rabbit wounds. Dorsal skin wounds were placed on fetal and maternal animals at the beginning of the third trimester, and were harvested 3, 5, and 7 days later. In situ RNA/RNA hybridization was performed on suitable specimens, and morphometric analysis was carried out with a computerized LECO image analyzer. Fetal wounds exhibited an inflow of mesenchymal cells that produced collagen type I at levels higher than the surrounding tissue; this activity was highest on days 3 and 5 after wounding. Adult wounds had increased fibroblast presence by day 7, producing collagen type I at levels higher than those of adjacent unwounded tissue. Morphometric analysis of the signal produced by in situ hybridization and of the number of cells producing the signal in a given field showed that fetal wounds appear to produce collagen type I by an increase in the number of cells in the area of the wound--not by induction of the gene for procollagen type I. In contrast, adult wounds had both fibroblast migration and induction of procollagen type I mRNA synthesis. These findings imply multilevel regulation of collagen production in the adult and posttranslational regulation in the fetus.     

Characterization of impurity effects in zinc electrowinning from industrial acid sulphate electrolyte

The individual effects of 15 impurities and their interaction with glue on zinc electrowinning from industrial acid sulphate electrolyte were characterized in terms of deposit morphology and preferred deposit orientation and in terms of current efficiency and zinc deposition polarization behaviour. The current efficiency decreased in a cyclical manner with increasing atomic number of the impurity element in each period of the periodic table. This decrease in current efficiency can be correlated to a corresponding increase in the rate of hydrogen evolution on the impurity metal. The various impurities produced four distinct zinc deposit morphologies and orientations and also produced characteristic changes in the cyclic voltammograms for the zinc deposition.