Influence of the surface conditions on permeation in the deuterium–MANET system

The condition of the surfaces is of crucial importance for the deuterium permeation through materials. In this work a study of the surface constants for the adsorption (σk₁) and release (σk₂) of deuterium under different surface conditions on the martensitic steel DIN 1.4914 (MANET) has been carried out. The growth of an oxide surface layer (Cr₂O₃) of about 25–30 nm in a MANET sample, heat treated in an oxidizing environment, compared to the bare MANET that have a ‘natural' oxide of about 5 nm has provoked a reduction of both the permeation rate and the recombination coefficient (about 3 orders of magnitude). In addition, the permeation governing process has changed from diffusion-limited to surface-limited. The measurements of the permeation rate of deuterium were performed by a gas-phase permeation technique over the temperature range 574–746 K and for deuterium driving pressures in the range from 3 to 10⁵ Pa.     

Health and Indoor Climate Complaints of 7043 office Workers in 61 Buildings in the Netherlands

During the winter of 1988/1989, the relationships between the prevalence of work-related health and indoor climate complaints and a number of building, management, workplace and personal characteristics have been investigated in a study in more than 60 office buildings located throughout the Netherlands. To collect the information, a questionnaire was prepared on health and indoor climate complaints and personal and workplace characteristics. A checklist was used to obtain information on building characteristics More than 7000 questionnaires were completed by the regular users of the buildings investigated. The results showed that the prevalence of symptoms was higher in air-conditioned buildings than in naturally or mechanically ventilated buildings. some other variables were also related with most work-related complaints after adjustment for selected management, personal, workplace and job characteristics. These included gender, work satisfaction in general, presence of allergies and/or respiratory symptoms, and personal control over temperature at the workplace. No differences were found in symptom prevalences between buildings with spray and steam humidification. The combination of air-conditioning and humidification did not lead to further increases in the prevalence of complaints as compared to buildings with only airconditioning or only humidification.     

Preview benefit and parafoveal-on-foveal effects from word n + 2.

Using the gaze-contingent boundary paradigm with the boundary placed after word n, the experiment manipulated preview of word n + 2 for fixations on word n. There was no preview benefit for 1st-pass reading on word n + 2, replicating the results of K. Rayner, B. J. Juhasz, and S. J. Brown (2007), but there was a preview benefit on the 3-letter word n + 1, that is, after the boundary but before word n + 2. Additionally, both word n + 1 and word n + 2 exhibited parafoveal-on-foveal effects on word n. Thus, during a fixation on word n and given a short word n + 1, some information is extracted from word n + 2, supporting the hypothesis of distributed processing in the perceptual span. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

木寡糖的研究进展

木寡糖可以从多种多样含木聚糖的原材料中通过化学法或酶法制得，然后再利用物理化学方法精制。作为食物配料，木寡糖具有许多有利的技术特性，并且具有调节肠功能的能力，能导致生物前效应。除了对肠功能的作用外，其他关于木寡糖的生物活性也作了相关综述，包括木寡糖在生物合成配置方面的作用以及他们的技术特性和市场前景。     

Characterization of CuInS2 thin films for solar cells prepared by spray pyrolysis

We have made a study of the chemical composition, the electrical, the optical and the structural properties of polycrystalline CuInS₂ thin films prepared by spray pyrolysis to be used for thin film solar cells. These films were deposited starting from aqueous solutions with different chemical compositions ([Cu]/[In] and [S]/[Cu] ratios) and at different substrate temperatures. In all cases, the material is p-type with grains preferentially oriented in the (112) direction of the sphalerite structure. The electro-optical properties show a very strong dependence on the [Cu]/[In] ratio in the solution. Films with copper excess have smaller resistivity and better crystallinity than those which are stoichiometric or have indium excess. The results obtained in this work show the possibility of having CuInS₂ thin films with a wide range of resistivity, a fact that could be important for making solar cells based on this material.     

Diurnal and environmental characterization of solar photovoltaic panels using a PC-AT add on plug in card

This article describes the development of an instrumentation system for characterizing photovoltaic panels. It uses an add on card (which contains DAC, ADC and digital input/output ports) in conjunction with a PC-AT. The panels in a field are selected in succession through a set of relays actuated by the digital output port. The selected panel is loaded in discreet steps by a transistor loading circuit which is activated by the digital to analog convertor to trace the most significant portion of the I-V curve. The data shows that the power output is invariably lower than that specified by the manufacturer. The reasons for drop in output have been analyzed. It is shown that these effects can be represented by the curvature of I-V characteristic at the maximum power point (OP). The loss of power due to accumulation of dust and the increase in temperature of the panels can be significant.     

High temperature low cycle fatigue

Fatigue at high temperature is a complex phenomenon as it is influenced by a number of time-dependent processes which become important at elevated temperatures. These processes include creep, oxidation, phase instabilities and dynamic strain ageing (DSA), acting either independently or synergistically influence fatigue behaviour, often lowering the fatigue life. Current design approaches employ linear summation of fatigue and creep damage with suitable factors on permissible damage to take care of uncertainties in interaction between cyclic and time-dependent processes. It is, therefore, important to develop a deeper understanding of the processes that occur during high temperature fatigue so that realistic life predictions could be made. Results on the high temperature fatigue behaviour of austenitic stainless steels, ferritic steels and nickel base alloys are presented here. The important mechanisms of interaction of high temperature time-dependent processes with fatigue under various conditions are discussed in detail. Emphasis is placed on cyclic stress response, fatigue life, deformation substructure and fracture behaviour. This is followed by a review of important life prediction techniques under combined creep-fatigue loading conditions. Life prediction techniques considered here include linear damage summation, strain range partitioning, ductility exhaustion approach, frequency modified and frequency separation methods, techniques based on hysteresis energy and damage rate models, and methods based on crack-cavitation interation models.     

Interference effects from grammatically unavailable constituents during sentence processing.

Evidence from 3 experiments reveals interference effects from structural relationships that are inconsistent with any grammatical parse of the perceived input. Processing disruption was observed when items occurring between a head and a dependent overlapped with either (or both) syntactic or semantic features of the dependent. Effects of syntactic interference occur in the earliest online measures in the region where the retrieval of a long-distance dependent occurs. Semantic interference effects occur in later online measures at the end of the sentence. Both effects endure in offline comprehension measures, suggesting that interfering items participate in incorrect interpretations that resist reanalysis. The data are discussed in terms of a cue-based retrieval account of parsing, which reconciles the fact that the parser must violate the grammar in order for these interference effects to occur. Broader implications of this research indicate a need for a precise specification of the interface between the parsing mechanism and the memory system that supports language comprehension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

AN EXPERIMENTAL INVESTIGATION OF THE GROWTH OF SMALL CORNER FATIGUE CRACKS IN ALUMINIUM 6061-T651

Results of an experimental investigation of the fatigue growth of small corner cracks emanating from small flaws are presented. Growth-arrest behaviour was observed, and increases in crack length during growth periods were of the order of the transverse grain size. For the test material, the corner crack front intersects, on average, only three–six grains in the small crack regime monitored, so only a small number of constrained, interior grains is encountered. It is suggested that the presence of partially constrained surface grains may contribute to the 'anomalous' growth behaviour which has been observed by a number of investigators.
The crack growth histories of the test data presented exhibit considerable scatter. It is shown that a Student's t -test can be used to estimate confidence intervals in order to provide a measure of the observed scatter. The variation in confidence intervals in the transition from small to long fatigue crack growth is discussed.