Impact of a Short-Pulse High-Intense Proton Irradiation on High-Performance Perovskite Solar Cells

This work investigates the radiation resistance of high-performance multi-component perovskite solar cells (PSCs) for the first time under extreme short-pulse proton irradiation conditions. The devices are subjected to high-intensity 170 keV pulsed (150 ns) proton irradiation, with a fluence of up to 10¹³ p cm^−2, corresponding to ≈30 years of operation at low Earth orbit. A complex material characterization of the perovskite active layer and device physics analysis of the PSCs before and after short-pulse proton irradiation is conducted. The obtained results indicate that the photovoltaic performance of the solar cells experiences a slight deterioration up to 20 % and 50 % following the low 2 × 10¹² p cm⁻² and high 1 × 10¹³ p cm⁻² proton fluences, respectively, due to increased non-radiative recombination losses. The findings reveal that multi-component PSCs are immune even to extreme high-intense short-pulse proton irradiation, which exceeds harsh space conditions, including intense coronal ejection events usually associated with solar flares.     

Separation of strontium from low level radioactive waste solutions using hydrous manganese dioxide composite materials

⁹⁰Sr is one of the major isotopes present in the low level radioactive liquid waste (LLW) generated during operation of nuclear reactors and spent fuel reprocessing plants. A composite ion exchange material consisting of hydrous manganese oxide and poly methyl methacrylate (PMMA) was developed for removal of strontium from aqueous radioactive waste. The prepared composite material showed very good strontium adsorption properties in aqueous solutions. Sorption of strontium on the composite material as a function of pH, equilibration time and strontium ion concentrations were studied. The process of sorption of strontium from solution was analysed using different isotherm models like Langmuir, D-R and Freundlich. Four different error functions were employed to find out the most suitable isotherm model to represent the experimental data and it was found that Freundlich model best fits the sorption of strontium on the composite material. Analysis of the data obtained from the sorption kinetics studies showed that the data fitted better to the pseudo-second order kinetic model. Lab scale column performance study of the composite material revealed that the material could be effectively used in column operations to remove strontium from LLW solutions.     

Do noncontingent vouchers increase drug use?

Data from 2 contingency management trials, targeting opiate or cocaine use, were used to investigate whether noncontingent vouchers inadvertently reinforce drug use. The control group in each trial received noncontingent vouchers matched in value and frequency to those received by experimental groups, but independent of urinalysis. Vouchers were offered thrice weekly for 8 weeks (opiates) or 12 weeks (cocaine). Both dose-response and temporal associations of noncontingent voucher receipt with drug-positive urines were assessed. Drug use was unrelated to frequency of noncontingent voucher delivery and noncontingent voucher receipt when being drug positive was unassociated with risk of subsequent drug use, with one exception: cocaine use in the cocaine study (relative risk = 1.05, 95% confidence interval: 1.01-1.09). Overall, results do not indicate a causal relationship between noncontingent voucher receipt and increased drug use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sparse interpolation of multivariate rational functions

Consider the black box interpolation of a τ-sparse, n-variate rational function f, where τ is the maximum number of terms in either numerator or denominator. When numerator and denominator are at most of degree d, then the number of possible terms in f is O(dⁿ) and explodes exponentially as the number of variables increases. The complexity of our sparse rational interpolation algorithm does not depend exponentially on n anymore. It still depends on d because we densely interpolate univariate auxiliary rational functions of the same degree. We remove the exponent n and introduce the sparsity τ in the complexity by reconstructing the auxiliary function’s coefficients via sparse multivariate interpolation.The approach is new and builds on the normalization of the rational function’s representation. Our method can be combined with probabilistic and deterministic components from sparse polynomial black box interpolation to suit either an exact or a finite precision computational environment. The latter is illustrated with several examples, running from exact finite field arithmetic to noisy floating point evaluations. In general, the performance of our sparse rational black box interpolation depends on the choice of the employed sparse polynomial black box interpolation. If the early termination Ben-Or/Tiwari algorithm is used, our method achieves rational interpolation in O(τd) black box evaluations and thus is sensitive to the sparsity of the multivariate f.     

Prédiction de l'intention créatrice à l'aide du modèle du comportement plainifié d'Ajzen.

Employed I. Ajzen's (1988) planned behavior model to predict creative intent. 291 undergraduates filled out questionnaires regarding 3 prototypical creative behaviors: writing and directing a play, building furniture from waste materials, and developing an individual style of interpreting music. Intent, attitude, subjective standards, and perception of control were measured for each behavior. Hierarchical multiple regression analysis result show that all of the predictor variables, except attitude toward theater behavior, contributed significantly to the prediction of intent. In considering basic impacts, perception of control plays the most significant role of prediction of intent. Perception of control also interacts either with standards or with attitude to increase explained variance of intent by 1–3%. Results support the relevance of the planned behavior model in the prediction of intent to endorse prototypical creative behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention soutenue et motivation : une approche chronopsychologique.

Discusses the effects of motivation on ability to sustain attention. We emphasize the fact that motivation should be considered a masking factor in ultradian rhythmicities of cognitive efficiency. In the first part of this article, several studies are listed. These studies attempted to show behavioral fluctuations when sustained attention is required. The inconsistency of the results brought forth by such studies is pointed out. In the second part of the article, the question of the status granted to motivation in chronopsychological studies, where motivation is manipulated in several ways, is discussed. Interpretations are revisited in terms of intrinsic and/or extrinsic motivation concepts. Some of these chronopsychological studies used only extrinsic motivation whereas others created conditions in which intrinsic motivation was favoured (for example, knowledge of results, which appears to be a prominent masking factor). Finally, we propose several hypotheses in order to support the assumption of a stabilizing effect provided by intrinsic motivation. We conclude by insisting upon the necessity of involving participants in tasks requiring complex cognitive activity, which contrasts with the monotonous and too simple tasks used frequently in chronopsychological studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of sunflower-seed oil and linseed oil on tissue lipid metabolism, gene expression, and milk fatty acid secretion in Alpine goats fed maize silage–based diets

Lipid in the diet is known to enhance milk fat secretion and alter milk fatty acid composition in lactating goats. In the current experiment, the contribution of peripheral tissue and mammary gland lipid metabolism to changes in milk fat composition from plant oils was examined. Fourteen Alpine goats in midlactation were used in a 3 × 3 Latin square design with 28-d experimental periods. Treatments comprised maize silage–based diets containing no additional oil (M), sunflower-seed oil (MSO; 6.1% of diet DM), or linseed oil (MLO; 6.2% of diet DM). Compared with the control, milk yield was greater in goats fed MSO (3.37 and 3.62 kg/d, respectively), whereas MLO enhanced milk fat content (+3.9 g/kg), resulting in a 14% increase in milk fat secretion. Both MSO and MLO increased milk lactose secretion by 12 and 8%, respectively, compared with M. Relative to the control, plant oils decreased C10 to C16 secretion (32 and 24%, respectively, for MSO and MLO) and enhanced C18 output in milk (ca. 110%). Diets MSO and MLO increased cis-9 18:1 secretion in milk by 25 and 31%, respectively, compared with M. The outputs of trans-11 18:1 and cis-9, trans-11 18:2 in milk were increased 8.34- and 6.02-fold for MSO and 5.58- and 3.71-fold for MLO compared with M, and MSO increased trans-10 18:1 and trans-10, cis-12 18:2 secretion. Plant oils decreased milk fat cis-9 14:1/14:0; cis-9 16:1/16:0; cis-9 18:1/18:0; and cis-9, trans-11 18:2/trans-11 18:1 concentration ratios but had no effect on mammary stearoyl-CoA desaturase mRNA or activity. Furthermore, changes in milk fatty acid secretion were not associated with alterations in mammary acetyl-CoA carboxylase mRNA and activity, abundance of mRNA encoding for lipoprotein lipase and fatty acid synthase, or malic enzyme and glycerol-3-phosphate dehydrogenase activity in mammary tissue. Mammary lipoprotein lipase activity was increased with MSO relative to MLO. Treatments had no effect on glucose-6-phosphate dehydrogenase, malic enzyme, glycerol-3-phosphate dehydrogenase activity, or mRNA abundance and/or activity of lipoprotein lipase, acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase in liver or adipose tissue. In conclusion, inclusion of sunflower-seed oil and linseed oil in maize silage–based diets alters milk fatty acid secretion in goats via mechanisms independent of changes in mammary, hepatic, or adipose tissue lipogenic gene expression. Furthermore, data provided indications that the regulation of mammary lipogenic responses to plant oils on starch-rich diets differs between the caprine and bovine.     

Variability and molecular typing of Streptococcus thermophilus strains displaying different proteolytic and acidifying properties

Proteolytic and acidifying properties of Streptococcus thermophilus strains isolated from yoghurt or cheeses were evaluated. Among 30 strains tested, 12 exhibited cell envelope-associated proteinase activity (PrtS⁺), three displayed a slight PrtS activity (PrtS^+/?) and 15 were PrtS^?, despite the presence of the corresponding gene (prtS) in eight of them. Sequencing of the prtS gene in four PrtS^? and one PrtS⁺ strains revealed that the absence of PrtS activity in the PrtS^? strain probably results from an alteration of the prtS regulation. The strains displaying the highest acidifying capacities were all PrtS⁺. All but one PrtS⁺ strains were phylogenetically close, as shown by the sequencing of their rDNA internal transcribed spacer (ITS) 16S-23S. More specifically, the high proteolytic and acidifying capacities are associated with the presence of a type II-ITS.     

Differential sensitization, retention, and generalization of habituation in two response systems in the blowfly (Calliphora vomitoira).

Conducted 3 experiments with 95 blowflies to elicit a cardiac disturbance and a motor response by the same moving visual stimulus. In Exp I, the habituation of these responses developed at an equal rate during stimulus repetition. After a rest period, whereas habituation of motor responses was completely retained, a substantial recovery of cardiac responses was observed. The use of distributed trials in Exp II helped to dissociate the influence of sensitization and habituation processes on the behavioral outcome. Habituation of motor responses, in addition to a longer retention, appeared to be more easily generalized after a spatial displacement of the stimulus in Exp III. Data support the hypothesis that habituation processes develop independently in different response systems, even if they have the same sensory input. The faster reversibility of habituation of cardiac responses is discussed, with reference to a preparatory function for locomotor behavior. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)