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991.
Rob Aalbers Eline van der Heijden Jan Potters Daan van Soest Herman Vollebergh 《Energy Economics》2009,31(3):431-442
We evaluate the impact of technology adoption subsidies on investment behavior in an individual choice experiment. In a laboratory setting professional managers are confronted with an intertemporal decision problem in which they have to decide whether or not to search for, and possibly adopt, a new technology. Technologies differ in the per-period benefits they yield, and their purchase price increases with the per-period benefits provided. We introduce a subsidy on the more expensive technologies (that also yield larger per-period benefits), and find that the subsidy scheme induces agents to search for and adopt these more expensive technologies even though the subsidy itself is too small to render these technologies profitable. We speculate that the result is driven by the positive connotation (affect) that the concept ‘subsidy’ invokes. 相似文献
992.
de Bruin Marijn; Viechtbauer Wolfgang; Hospers Harm J.; Schaalma Herman P.; Kok Gerjo 《Canadian Metallurgical Quarterly》2009,28(6):668
Objective: Clinical trials of behavioral interventions seek to enhance evidence-based health care. However, in case the quality of standard care provided to control conditions varies between studies and affects outcomes, intervention effects cannot be directly interpreted or compared. The objective of the present study was to examine whether standard care quality (SCQ) could be reliably assessed, varies between studies of highly active antiretroviral HIV-adherence interventions, and is related to the proportion of patients achieving an undetectable viral load (“success rate”). Design: Databases were searched for relevant articles. Authors of selected studies retrospectively completed a checklist with standard care activities, which were coded to compute SCQ scores. The relationship between SCQ and the success rates was examined using meta-regression. Main Outcome Measures: Cronbach’s alpha, variability in SCQ, and relation between SCQ and success rate. Results: Reliability of the SCQ instrument was high (Cronbach’s alpha = .91). SCQ scores ranged from 3.7 to 27.8 (total range = 0–30) and were highly predictive of success rate (p = .002). Conclusions: Variation in SCQ provided to control groups may substantially influence effect sizes of behavior change interventions. Future trials should therefore assess and report SCQ, and meta-analyses should control for variability in SCQ, thereby producing more accurate estimates of the effectiveness of behavior change interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
993.
Maria Helena Santos Rafael M. Silva Vitor C. Dumont Juliana S. Neves Herman S. Mansur Luiz Guilherme D. Heneine 《Materials science & engineering. C, Materials for biological applications》2013,33(2):790-800
Bovine pericardium is widely used as a raw material in bioengineering as a source of collagen, a fundamental structural molecule. The physical, chemical, and biocompatibility characteristics of these natural fibers enable their broad use in several areas of the health sciences. For these applications, it is important to obtain collagen of the highest possible purity. The lack of a method to produce these pure biocompatible materials using simple and economically feasible techniques presents a major challenge to their production on an industrial scale. This study aimed to extract, purify, and characterize the type I collagen protein originating from bovine pericardium, considered to be an abundant tissue resource. The pericardium tissue was collected from male animals at slaughter age. Pieces of bovine pericardium were enzymatically digested, followed by a novel protocol developed for protein purification using ion-exchange chromatography. The material was extensively characterized by electrophoresis, scanning electron microscopy, energy dispersive X-ray spectroscopy, and infrared spectroscopy. The results showed a purified material with morphological properties and chemical functionalities compatible with type I collagen and similar to a highly purified commercial collagen. Thus, an innovative and relatively simple processing method was developed to extract and purify type I collagen from bovine tissue with potential applications as a biomaterial for regenerative tissue engineering. 相似文献
994.
Onome Scott-Emuakpor Tommy George Todd Letcher M.-H. Herman Shen Charles Cross 《Journal of Failure Analysis and Prevention》2012,12(1):109-115
The proposed work analyzes the possibility of improving the capabilities of an energy-based fatigue life prediction method. The improvement being addressed is regarding the variation of empirical monotonic strain energy density calculations and the effects on the energy-based fatigue life prediction capability. Since the prediction method was developed from the concept that the strain energy accumulated during both monotonic failure and an entire fatigue process are equal, meaning the strain energy accumulated during monotonic failure is a physical damage quantity, it was important to understand the variation of monotonic strain energy density. The process for incorporating this variation into the prediction method explores a probabilistic, Three-Sigma analysis that is applicable for all deterministic methods of measuring experimental monotonic strain energy density. The accuracy of the probabilistic energy-based lifing method was admirably assessed by comparison with experimental fatigue life results, between 103 and 105 cycles, conducted on Titanium 6Al–4V specimens at room temperature. 相似文献
995.
Dougan DA; Malby RL; Gruen LC; Kortt AA; Hudson PJ 《Protein engineering, design & selection : PEDS》1998,11(1):65-74
The interactions between the Fab and single-chain Fv (scFv) fragments of an
antibody (NC10) and its antigen, influenza virus neuraminidase, were
analysed in the crystal structures of the Fab-neuraminidase and
scFv-neuraminidase complexes. To investigate the contribution to binding
made by cavities, salt links and hydrogen bonds in the antibody- antigen
interface, 14 single amino acid replacements were made at six contact
residues in the scFv fragment by site-directed mutagenesis. The binding
affinity of each mutant scFv antibody for neuraminidase was determined with
a BIAcore optical biosensor. Four of the mutations resulted in large
changes in the free energy of binding to neuraminidase (deltadeltaG > 1
kcal/mol) and together may account for approximately 70% of the free energy
of binding. Hence these data support the theory that a small number of
residues form the 'functional epitope' and are most important for binding
of NC10 to neuraminidase. The salt link between antibody residue (Asp)H56
and (Lys)N432 from neuraminidase was demonstrated to be important for
affinity, since substitution of (Asp)H56 with Asn caused a large reduction
in the free energy of binding (deltadeltaG = +2.8 kcal/mol). Hydrogen bonds
provided by (Tyr)L32 and (Asp)H56 were also important for binding: mutation
of (Tyr)L32 to Phe resulted in a significant reduction in binding affinity
(deltadeltaG = +1.7 kcal/mol). Disruption of hydrophobic interactions (van
der Waals contacts) led to significant reductions in affinity also
((Tyr)H99 to Ala, deltadeltaG = +1.5 kcal/mol; (Leu)L94 to Ala, deltadeltaG
> +3.0 kcal/mol). An attempt to increase binding affinity by filling a
cavity in the interface with a larger antibody side chain was unsuccessful,
as the free energy gained by new antibody-antigen interactions did not
compensate for the removal of cavity-bound water molecules.
相似文献
996.
Vera Lúcia Othéro de Brito Herman Jacobus Cornelis Voorwald Nasareno das Neves Ivani de S. Bott 《Journal of Materials Engineering and Performance》2001,10(3):249-257
Postweld heat treatment (PWHT) is frequently applied to steel pressure vessels, following the requirements of the ASME code
(section VIII), which establishes the parameters of the PWHT based on the thickness and chemical composition of the welded
section. This work shows the results of an analysis undertaken on a sample of ASTM A537 C1 steel subjected to qualifying welding
procedure tests including PWHT (650°C/5 h). The results obtained showed that this PWHT practice promoted a reduction in the
mechanical properties of the base metal and the heat-affected zone (HAZ). 相似文献
997.
Plasma spray processing is a well-established method for forming protective coatings and free-standing shapes from a wide
range of alloys and ceramics. The process is complex, involving rapid melting and high-velocity impact deposition of powder
particles. Due to the rapid solidification nature of the process, deposit evolution also is complex, commonly leading to ultrafine-grained
and metastable microstruc-tures. The properties of a plasma-sprayed deposit are directly related to this complex microstructure.
This paper examines the solidification dynamics and the resultant microstructures in an effort to estab-lish a processing/microstructure
relationship. Existing models in the literature developed for splat coo-ling have been extended and applied for examining
the rapid solidification process during plasma spraying. Microstructural features of the splats that are produced by individual
impinging droplets are examined through scanning and transmission electron microscopy. The relation of dimensions and mor-phologies
of these individual splats to the consolidated deposit microstructure is considered. In addition, the distinguishing features
in the solidification and microstructural development between air plasma spraying and vacuum plasma spraying are explored,
and a unified model is proposed for splat solidifica-tion and evolution of the microstructure. 相似文献
998.
This paper presents an overview of the possibilities for further development of tools and. approaches for the ecological assessment and management of diffusively contaminated ecosystems. It is based on the results of the “Netherlands Stimulation Programme on Ecosystem-oriented Ecotoxicological Research”, the SSEO programme, which ran from 1998 to 2006, and on opinions of international experts on ecological and ecotoxicological risk-assessment methods and their legal applications. The paper also discusses the pros and cons of the set-up of the SSEO programme.Proper management of diffusively polluted areas has to be based on an integral risk-based and system approach. The approach has to be founded on the relationships between pollution, natural stresses, management measures and the presence and activities of specific species. Furthermore, the relationships between biodiversity in ecosystems and its stability and functioning have to be known. The assessment of aquatic ecosystem quality is now based on the comparisons of the composition of actual species with that of reference species. This type of system does not yet exist for the assessment of soil quality, but it is being developed. It is shown that ecological quality criteria based on a Species Sensitivity Distributions approach are sufficiently conservative to avoid or prevent major ecological impacts of diffuse pollution at concentrations below legal standards.However, a proper quality relationship of biodiversity and ecosystem functioning is lacking in the ecological assessment methods. Future research should focus on the relationship of ecosystem structure (species composition) and ecosystem functioning and on the impact of disturbing the environment and appropriate management measures. 相似文献
999.
Kristof Demeestere Jo Dewulf Bavo De Witte Anne Beeldens Herman Van Langenhove 《Building and Environment》2008
This paper reports the potential of heterogeneous photocatalysis as an advanced oxidation technology for removal of toluene from air using TiO2 as a photocatalyst in building materials. First, the photocatalytic activity of two types of TiO2 containing building materials, i.e. roofing tiles and corrugated sheets, has been investigated at ambient conditions (T=25.0 °C; relative humidity RH=47%; toluene inlet concentration [TOL]in=17–35 ppbv). Toluene removal efficiencies up to 63% were observed at a gas residence time (τ) of 17 s. Second, the effect of RH (1–77%), [TOL]in (23–465 ppmv) and τ (17–115 s) on toluene removal has been systematically investigated using TiO2 containing roofing tiles as photocatalytic building materials. Results revealed lower toluene removal efficiencies at higher RH and [TOL]in, whereas a positive effect was observed with increased τ. Under optimal conditions, toluene removal efficiencies up to 78±2% and elimination rates higher than 100 mg h−1 m−2 roofing tile were obtained. A decline in photocatalytic activity by a factor of 2 was observed after operation at gas residence times shorter than 69 s and [TOL]in higher than 76 ppmv. Washing the building materials with deionized water, simulating rainfall, could partially (i.e. by a factor 1.3) regenerate the catalyst activity. 相似文献
1000.
Zircon, ZrSiO4, is a natural mineral used for various applications as a refractory bulk material. It is an excellent feedstock for the plasma
spraying of protective coatings and free-standing bodies. Zircon decomposes on spraying into t-ZrO2 and glassy SiO2, which can be preserved in deposits by fast cooling. This combination of zirconia and silica exhibits properties such as
a high thermal shock resistance, good corrosion resistance, low wettability, etc. The final properties of deposits can be
further enhanced by the addition of other materials such as alumina. For instance, alumina-zircon plasma-sprayed free-standing
pipes have a low gas permeability. Several technical applications are discussed. 相似文献