Design characteristics and first experience concerning the new high-resolution powder diffractometer for thermal neutrons at the Swiss spallation neutron source SINQ are summarized. It is based on a ...linear position-sensitive
3
He
detector with 1600 wires and angular separation of 0.1°, permitting also real-time experiments.
Removals of adsorbable organic halides (AOX) achieved by 8 full-scale wastewater treatment systems at pulp mills in North America were surveyed over a 2-year period. AOX removals averaged 46 per cent ...for activated sludge systems and 34 per cent for aerated stabilization systems studied. The best performance was recorded at a sulphite mill activated sludge system which consistently removed 53 per cent of total AOX and 62 per cent of low-molecular-weight AOX in bleaching wastewaters. In some cases, the use of oxygen and peroxide and chlorine dioxide substitution reduced influent AOX loadings, with little effect on treatment plant removal efficiency.
Composite germanium monochromators are in the beginning of their application in neutron diffraction. In order to optimize their properties for high-resolution neutron powder diffraction we ...significantly improved the alignment procedure of the individual wafers used for building the monochromator plates, as we added the tin necessary for soldering with a sputtering technique instead of tin foil spacers. Sputtering could also be replaced by evaporation giving similar results.
The ability of artificial marshes to polish high quality pulp mill effluents was assessed on a pilot scale using areas of 2.6 m2, 15 to 40 cm in depth and employing marl substrate of 1 to 3 cm in ...size. Cordgrass, cattail and reeds were planted and there were controls without vegetation. Initial experiments showed little advantage in exceeding a retention period of 15 h. Average percentage removals of suspended solids, BOD and organic nitrogen were 57, 38 and 29 respectively, with no advantages arising from the use of plants. Removals of ammonia and phosphate were greatly increased by plants. Only 16 per cent of ammonia was removed by the control compared with a range of 63 to 82 by the plants. They also reduced phosphorus by around 20 per cent with the control having virtually no effect. Shallow beds exhibited the greatest efficiency. Annual reed biomass production was estimated at 30 dry tons per acre. A 10 per cent loss of interstitial volume per year was noted. The process should be considered where the reduction of algal nutrients was important. Some factors affecting the design of full scale units are discussed.
Cognitive deficits are a fundamental feature of schizophrenia for which currently no effective treatments exist. This paper examines the possibility to use transcranial direct current stimulation ...(tDCS) to target cognitive deficits in schizophrenia as evidence from studies in healthy participants suggests that tDCS may improve cognitive functions and associated neural processes.
We carried out a systematic review with the following search terms: ‘tDCS’, ‘electric brain stimulation’, ‘schizophrenia’, ‘cognitive’, ‘cognition’ until March 2019. 659 records were identified initially, 612 of which were excluded after abstract screening. The remaining 47 articles were assessed for eligibility based on our criteria and 26 studies were excluded. In addition, we compared several variables, such as online vs. offline-stimulation protocols, stimulation type and intensity on mediating positive vs. negative study outcomes.
The majority of studies (n = 21) identified significant behavioural and neural effects on a range of cognitive functions (versus n = 11 with null results), including working memory, attention and social cognition. However, we could not identify tDCS parameters (electrode montage, stimulation protocol, type and intensity) that clearly mediated effects on cognitive deficits.
There is preliminary evidence for the possibility that tDCS may improve cognitive deficits in schizophrenia. We discuss the rationale and strength of evidence for using tDCS for targeting cognitive deficits in schizophrenia as well as methodological issues and potential mechanisms of action.
Transcranial magnetic stimulation (TMS) evokes neuronal activity in the targeted cortex and connected brain regions. The evoked brain response can be measured with electroencephalography (EEG). TMS ...combined with simultaneous EEG (TMS−EEG) is widely used for studying cortical reactivity and connectivity at high spatiotemporal resolution. Methodologically, the combination of TMS with EEG is challenging, and there are many open questions in the field. Different TMS−EEG equipment and approaches for data collection and analysis are used. The lack of standardization may affect reproducibility and limit the comparability of results produced in different research laboratories. In addition, there is controversy about the extent to which auditory and somatosensory inputs contribute to transcranially evoked EEG. This review provides a guide for researchers who wish to use TMS−EEG to study the reactivity of the human cortex. A worldwide panel of experts working on TMS−EEG covered all aspects that should be considered in TMS−EEG experiments, providing methodological recommendations (when possible) for effective TMS−EEG recordings and analysis. The panel identified and discussed the challenges of the technique, particularly regarding recording procedures, artifact correction, analysis, and interpretation of the transcranial evoked potentials (TEPs). Therefore, this work offers an extensive overview of TMS−EEG methodology and thus may promote standardization of experimental and computational procedures across groups.
•TMS−EEG is a powerful technique for basic research and clinical applications.•The methodological combination of TMS−EEG is challenging.•The lack of standardization may affect reproducibility and limit the comparability of results produced across groups.•This article covers all aspects that should be considered in TMS−EEG experiments.•We provide methodological recommendations for effective TMS−EEG recordings and analysis.
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