Growth and characterization of TiO2 nanotubes from sputtered Ti film on Si substrate

In this paper, we present the synthesis of self-organized TiO₂ nanotube arrays formed by anodization of thin Ti film deposited on Si wafers by direct current (D.C.) sputtering. Organic electrolyte was used to demonstrate the growth of stable nanotubes at room temperature with voltages varying from 10 to 60 V (D.C.). The tubes were about 1.4 times longer than the thickness of the sputtered Ti film, showing little undesired dissolution of the metal in the electrolyte during anodization. By varying the thickness of the deposited Ti film, the length of the nanotubes could be controlled precisely irrespective of longer anodization time and/or anodization voltage. Scanning electron microscopy, atomic force microscopy, diffuse-reflectance UV–vis spectroscopy, and X-ray diffraction were used to characterize the thin film nanotubes. The tubes exhibited good adhesion to the wafer and did not peel off after annealing in air at 350 °C to form anatase TiO₂. With TiO₂ nanotubes on planar/stable Si substrates, one can envision their integration with the current micro-fabrication technique large-scale fabrication of TiO₂ nanotube-based devices.     

Optimization and limitations of known DEMO divertor concepts

In this work we will introduce and discuss improvements for two types of DEMO divertors based on known designs: (i) gas cooled designs and (ii) liquid coolant concepts. In a first step, the advantages and disadvantages of gas cooling as well as the necessity of a jet impingement to increase the heat transfer coefficients will be discussed. Further discussion deals with the pros and cons of liquid coolant concepts, like for example, liquid metal or water cooling.Thereafter, we will present two rather contrary DEMO divertor concepts which are based on today's knowledge on refractory materials science, fabrication and joining technology. The first improved concept uses water flowing through steel pipes, typically made of Eurofer steel. It is well known that using Eurofer at low temperatures is critical due to its severe embrittlement under neutron irradiation. Here we make a proposal how it could be possible to use the Eurofer steel anyway: the solution could consist in a limited operation period followed by an annealing cycle at 550 °C for a few hours during any maintenance shut down phases. The second design is based on the known helium cooling concept using jet impingement. Drawbacks of the actual He-cooled divertor design are small scale parts as well as the necessary high helium inlet temperature of about 600–800 °C which leads to the question: How can we deal with such high helium temperatures? This paper shows a solution for large scale components as well as a new thermal management for the helium outlet gas that we call ‘cooling of the coolant’.Both concepts are discussed in terms of materials selection due to material limits and joining technology with a special focus on the material issue using already existing and available materials.     

Sleep does not enhance motor sequence learning.

Improvements in motor sequence performance have been observed after a delay involving sleep. This finding has been taken as evidence for an active sleep consolidation process that enhances subsequent performance. In a review of this literature, however, the authors observed 4 aspects of data analyses and experimental design that could lead to improved performance on the test in the absence of any sleep consolidation: (a) masking of learning effects in the averaged data, (b) masking of reactive inhibition effects in the averaged training data, (c) time-of-day and time-since-sleep confounds, and (d) a gradual buildup of fatigue over the course of massed (i.e., concentrated) training. In 2 experiments the authors show that when these factors are controlled for, or when their effects are substantially reduced, the sleep enhancement effect is eliminated. Whereas sleep may play a role in protection from forgetting of motor skills, it does not result in performance enhancement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Restraint-free care. Part 1: Legal and regulatory mandates. Part 2: Creating a restraint-free environment

In response to the revised 1996 Joint Commission of Accreditation of Healthcare Organization's restraint standards, many facilities are assessing and revising their current practice. Part 1 discusses the regulatory, legal and ethical dimensions of patient restraints. Part 2 describes one hospital's approach to promoting a restraint-free environment. As a result of this hospital's assessment, restraint use decreased 25% in intubated patients; 50% in nonintubated patients.     

Health Assessment of Polycyclic Aromatic Hydrocarbon Mixtures: Current Practices and Future Directions

The U.S. EPA's Integrated Risk Information System (IRIS) program has initiated a health assessment for polycyclic aromatic hydrocarbon (PAH) mixtures. The IRIS program develops EPA consensus scientific positions on potential human health effects from chronic exposure to chemicals. Currently, the IRIS database contains health assessments for the toxic effects of exposure to coke oven emissions, creosote, diesel emissions, and 15 individual PAH compounds. As a whole, these assessments do not consider issues related to the environmental occurrence of PAH compounds as complex mixtures. Risk assessment of PAH mixtures has been hindered by a lack of information on the composition and toxicity of specific mixtures, the components that contribute most to toxicity, and the interactions and differences in mode of action between components. The state-of-the-science has advanced considerably in the past decade and will play a key role in the development of the health assessment. Consideration of these issues led to an EPA-sponsored Workshop on Approaches to PAH Health Assessment in October 2001. The current practices of the EPA regarding the health assessment of PAH compounds and future directions of the agency are discussed in this article.     

Die unterschiedliche Bedeutung der Fettsäuren in ihrer fungistatischen Wirkung

Significance of Fatty Acids in Their Fungistatic Action The fungistatic action of saturated and unsaturated fatty acids, halogenated fatty acids and esters as well as sulfurcontaining derivatives is reviewed. Fungistatic agents, known since a long time, are propionic acid, caprylic acid and its salts as well as undecylenic acid and its salts. The recently known fatty acid derivatives having fungistatic action are morpholine and piperidine compounds of long chain fatty acids and the new class of aminimides of fatty acids with 14–16 C atoms.     

European cross-cutting research on structural materials for Generation IV and transmutation systems

It has been internationally recognized that materials science and materials development are key issues for the implementation of innovative reactor systems such as those defined in the framework of the Generation IV and advanced fuel cycle initiatives. In Europe, materials studies are considered within the Strategic Research Agenda of the Sustainable Nuclear Energy Technology Platform. Moreover, the European Commission has recently launched a 7th Framework Programme Research Project, named ‘Generation IV and Transmutation Materials’, that has the objective of addressing materials issues which are cross-cutting for more than one type of innovative reactor systems. The present work has been prepared with the aim of describing the rationale, the objectives, the work plan and the expected results of this research project.     

Study of Cd-free buffer layers using Inx(OH,S)y on CIGS solar cells

The alternative buffer layer material In_x(OH,S)_y was deposited on Cu(In,Ga)Se₂ (CIGS) thin films by chemical-bath-deposition (CBD). The impurities in In_x(OH,S)_y buffer layers and their atomic concentration were characterized by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) analyses. In addition, AES was used to depth profile the samples. The band-gap energy of the deposited In_x(OH,S)_y was determined from optical absorption data. Both the dark- and photo-current-voltage (I–V) characteristics of the CIGS solar cells with In_x(OH,S)_y buffer layers were measured, and the results were compared to the CIGS cells deposited with CBD CdS buffer layers.     

Priming and habituation for faces: Individual differences and inversion effects.

Immediate repetition priming for faces was examined across a range of prime durations in a threshold identification task. Similar to word repetition priming results, short duration face primes produced positive priming whereas long duration face primes eliminated or reversed this effect. A habituation model of such priming effects predicted that the speed of identification should relate to the prime duration needed to achieve negative priming. We used face priming to test this prediction in two ways. First, we examined the relationship between priming effects and individual differences in the target duration needed for threshold performance. Second, we compared priming of upright and inverted faces. As predicted, the transition from positive to negative priming as a function of prime duration occurred more slowly for inverted faces and for individuals with longer threshold target durations. Additional experiments ruled out alternative explanations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)