Sensitization and radiation hardening of the photostimulable X-ray storage phosphor CsBr:Eu2+

The X-ray storage phosphor CsBr:Eu²⁺ in form of needle image plates is believed to be a promising alternative to the granular BaFBr:Eu²⁺ with regard to PSL yield and spatial resolution. Unfortunately, CsBr:Eu²⁺ exhibits poor radiation hardness, which is caused by a migration of europium ions initiated by naturally existing defect centers like (Eu²⁺-V_Cs)-centers and X-ray generated M_Eu-centers. It will be shown that the formation of (Eu²⁺-O²⁻)-dipoles at the expense of (Eu²⁺-V_Cs)-dipoles, incorporated by thermal annealing in O₂-containing and humid atmosphere, does not improve the radiation stability. There is, however, a strong improvement in the radiation hardness by codoping of CsBr:Eu²⁺ with lithium ions, which is accompanied by a complete suppression of the previously observed M_Eu-center formation.     

Effect of chilling on the survival of Bacteroides fragilis

Factors affecting the susceptibility of Bacteroides fragilis subsp. fragilis to low temperature were examined. Predetermined numbers of cells were spread on agar media or suspended in enriched Trypticase soy broth and exposed to low temperature under both aerobic and anaerobic conditions. Exposure of 18-h growth of a freshly isolated B. fragilis strain to 4 degrees C aerobically or anaerobically resulted in a loss of at least 50% viability after 12 h. B. fragilis cells in early growth (6 h) were more tolerant to exposure at 4 degrees C than older cells (18 h). When the freshly isolated strain was repeatedly subcultured in the laboratory it was uniformly more cold tolerant than fresh clinical isolates. The incorporation of 1.0 M sucrose and 5 mM magnesium chloride into liquid media partially alleviated the lethal effects of cold temperature on B. fragilis subsp. fragilis.     

Zum Stand der kontinuierlichen Extraktion von Feststoffen mit überkritischen Gasen

Stage of Continuous Extraction of Solid Material by Overcritical Gases Up to now the extraction of solid material by overcritical gases has mainly been applied in smaller plants to obtain rather expensive valuable ingredients. It has proved because of its know advantages in opposite to the common solvent extraction. Gas extraction of mass products - for example removal of oil from oil seeds - however, seems not to be economic because of the due to the high pressure expensive batch process. In the meantime some apparative trials to carry out a continuous extraction of solid material have become known. Therefore a survey about various systems for continuous solid material transport through containers of different pressure is given. Simultaneously the applicability of these systems to the high pressure extraction is investigated.     

Magnetic Performance of the Main Superconducting Magnets for the LHC

The field strength and homogeneity of all the LHC superconducting magnets were measured as a part of the production control and qualification process that has taken place during the past four years. In addition to field measurements at room temperature performed on the integral of the production, a significant part of the magnets has been subjected to extensive magnetic measurements at cold. The measurements at cryogenic temperatures, generally performed up to excitation currents of 12 kA corresponding to the ultimate LHC energy of 7.6 TeV, were mainly based on static and dynamic field integral and harmonic measurements. This allowed us to study in detail the DC effects from persistent current magnetization and long-term decay during constant current excitation. These effects are all expected to be of relevance for the field setting and error compensation in the LHC. This paper reports the main results obtained during these tests executed at operating conditions. The integrated field quality is discussed in terms of distribution (average and spread) of the field strength and low-order harmonics as obtained for all the main ring magnet families (dipoles, main and matching quadrupoles). The dependence of field quality on coil geometry, magnet and cable manufacturer is analyzed. A projection of the field quality expected for the critical components in the machine is presented.     

Treatment effectiveness of parent management training in Norway: A randomized controlled trial of children with conduct problems.

This study was a randomized control trial (RCT) of Parent Management Training--The Oregon Model (PMTO) in Norway. A sample representing all health regions of Norway and consisting of 112 children with conduct problems and their families participated in the study. Families were randomly assigned to either PMTO or a regular services comparison group. PMTO was delivered via existing children's services, and families were recruited using the agencies' regular referral procedures, making this the first effectiveness study of PMTO and the first RCT of PMTO conducted outside of the United States. Using a multiagent-multimethod approach, results showed that PMTO was effective in reducing parent-reported child externalizing problems, improving teacher-reported social competence, and enhancing parental discipline. Age level and gender modified the effects of PMTO treatment on other outcomes. In a path model, participation in PMTO was associated with improved parental discipline, and effective discipline predicted greater child compliance, fewer child-initiated negative chains, and lower levels of child externalizing problems. Findings are presented along with a discussion of the implications for practice and research and the challenges accompanying effectiveness trials. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Efficient design of spatially symmetric Bragg gratings for add/drop multiplexers

A simple and fast numerical procedure is presented for designing spatially symmetric Bragg gratings with no need for iteratively solving the coupled mode equations. Using a unique relation between the phase and the amplitude of the reflection spectra valid for spatially symmetric gratings, the grating spectra are suitably optimized to fit given specifications. At the end of the design process an inverse-scattering algorithm determines the spatial structure of the corresponding Bragg grating. This method is particularly useful for the design of add/drop multiplexers, where symmetry can be a crucial prerequisite.     

Reduction of 3‐Substituted 1‐Arylcyclobutanols

A useful and specific method for the the title reaction ( 1 → 2 ) involves treatment with NaBH₄ in CF₃COOH whereas other procedures from the literature yield hard‐toseparate mixtures. 1‐Arylcyclohexanols 3 give mainly cyclohexenes with borohydride/trifluoroacetic acid. Their reduction to compounds 4 ,however, is possible with MeSO₃H/NaBH₄.     

A radiant heat flux apparatus for measuring the thermal response of polymeric materials to high temperatures

An efficient and economical experimental apparatus has been designed and built which delivers a known radiant heat flux and simultaneously measures the in-depth temperature profiles in polymeric materials. Test samples are maintained in a controlled environment and are heated radiantly by a silicon carbide heating element capable of producing heat fluxes up to 7.0 cal/cm²-sec. The experimental data produced by this device are extremely accurate and therefore are suitable for use in verification of numerical models. The utility of the apparatus was demonstrated by measuring temperature profiles to approximately 1000°C in a glass-filled phenol-formaldehyde resin.