Task conflict and team creativity: A question of how much and when.

Bridging the task conflict, team creativity, and project team development literatures, we present a contingency model in which the relationship between task conflict and team creativity depends on the level of conflict and when it occurs in the life cycle of a project team. In a study of 71 information technology project teams in the greater China region, we found that task conflict had a curvilinear effect on team creativity, such that creativity was highest at moderate levels of task conflict. Additionally, we found this relationship to be moderated by team phase, such that the curvilinear effect was strongest at an early phase. In contrast, at later phases of the team life cycle, task conflict was found to be unrelated to team creativity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emulsifier Composition of Solid Lipid Nanoparticles (SLN) Affects Mechanical and Barrier Properties of SLN‐Protein Composite Films

Protein films can be applied to improve food quality and to reduce packaging waste. To overcome their poor water barrier properties, lipids are often incorporated. The function of incorporated lipid depends on the interface between filler and matrix. This study aimed to tailor the properties of a protein–lipid film by designing the oil/water interface to see if the concept of inactive/active filler is valid. Therefore, we varied the emulsifier stabilizing solid lipid nanoparticles (SLN) to promote (via β‐lactoglobulin) or to minimize (via Tween 20) interactions between particle surface and protein. SLN were incorporated into protein films and film properties were determined. Addition of SLN led to significantly decreased water vapor permeability (WVP) of protein films. However, WVP was mainly affected by the emulsifiers and not by the lipid. Protein‐stabilized SLN (BS) replaced a lacking protein in the protein network and therefore did not influence the mechanical properties of the films at ambient temperature. BS‐composite films were temperature sensitive, as lipid and sucrose palmitate melted at temperatures above 40 °C. Tween 20‐stabilized SLN (TS) led to reduced tensile strengths, probably due to perturbative effects of TS and plasticizing effects of Tween 20. Dynamic mechanical analysis showed that TS and Tween 20 increased film mobility. Melting of lipid and emulsifiers, and temperature‐dependent behavior of Tween 20 led to a strong temperature dependence of the film stiffness. By designing the interface, particles can be used to tailor mechanical properties of protein films. Tuned edible films could be used to control mass transfers between foods.     

Assimilation of traumatic experiences and physical-health outcomes: Cautions for the Pennebaker paradigm.

This study reports an application of the assimilation model, a theory of psychotherapeutic change, to an analogue study in which 43 students were asked to write for 20 minutes a day for 4 days ("Pennebaker paradigm") about a traumatic experience. Contrary to expectations based on previous research, participants who showed the greatest change in assimilation level and achieved the highest levels of assimilation during the study subsequently had more health-center visits than participants whose assimilation was less. Qualitative exploratory work suggested that there may be negative consequences of exposing traumatic experiences in the absence of supportive therapy to contain and fully integrate the experiences. A more measured approach to the benefits of brief exposition of traumatic experiences may be warranted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

LiTaO3的声学声子测量

一、引言自六十年代后期以来,不少人对LiTaO_3和LiNbO_3的相变问题进行了广泛的研究,采用的手段各异,有红外光谱、喇曼光谱、热中子散射等。有人认为是位移型相变,有人认为属于有序-无序型,还有人认为是二者之结合,但至今尚无一个肯定性的意见。我们希望通过热中子非弹性散射实验,对LiTaO_3相变机制进行研究。作为第一步,先在两个主要对称方向上测量了色散曲线的声学支,并根据小q值处色散曲线的斜率算出了在晶体内的声速,与其它的结果进行了比较。     

古建筑的新生

成立于1988年的Archea建筑设计事务所一直致力于建筑领域的学术研究。建筑设计、城市规划、旧城改造、室内设计，他们的作品获得了意大利及国际的各大建筑奖项，工作室分布在意大利和中国。Archea十分关注知识、设计和文化的融汇和交流，并在自己的建筑项目中力求将传统与现代，审美与实用完美结合。当Nembro市政府决定把一栋老建筑改造为一个图书馆，计划为城市的居民增添一个能够获取教育及信息的公共设施时，     

Oxidation of vanillin by peroxomonosulphate-thermodynamic and kinetic investigation

The oxidation of vanillin by peroxomonosulphate (PMS) in acetic acid–sodium acetate buffered medium was carried out at 308 K. The rate was first order with respect to [vanillin] and [PMS]. The rate increased with increase in pH and the rate was too fast to be measured at pH 5.2. The rate increased with increase in [acetate] and the plot of k_obs versus [acetate] was a straight line with positive intercept. Variation of ionic strength had no effect on the rate of the reaction. Effects of polarity were studied with five different solvents and in all the cases, log k_obs versus 1/? were linear with negative slope. The reaction had been carried out at four different temperatures and the activation and thermodynamic parameters were calculated. The product of oxidation was confirmed as vanillic acid by IR, ¹H NMR and GC-MS spectral analysis. Based on the results obtained a reaction scheme had been proposed and the rate law was derived.     

Tomography measurements of gas holdup in rotating foam reactors with Newtonian, non-Newtonian and foaming liquids

Rotating solid foam reactors have already proven to show high mass transfer rates and to be a potential alternative to slurry reactors. The rotation of a foam block stirrer results in a high mass transfer and in the development of different reactor sections showing specific hydrodynamics and gas holdup distributions. In order to optimize the reactor system the hydrodynamics in a lab scale reactor are studied using γ-ray tomography, a powerful method to measure the gas holdup in three-phase reactors. The influence of liquid properties, such as viscosity and surface tension, and the rotational speed on the gas/liquid distribution in the different reactor sections is investigated. Especially the viscosity has a strong effect on the entrapment of gas bubbles in the foam block structure, while the surface tension is the dominant parameter in the outer reactor section. The influence of these parameters on the inset of foaming and the collapse of the gas/liquid dispersion is investigated. Conclusions on the mass transfer performance are drawn and recommendations for further optimizations of the reactor design and the operational conditions depending on the liquid properties are developed.     

Optimal placement of probes for dynamic pressure measurements in large-scale fluidized beds

Pressure data sampled at sufficiently high frequency (typically 20 Hz or higher) can yield much information about the hydrodynamic state of a fluidized bed. Since part of the pressure waves travelling through large (industrial) fluidized beds is only detectable in a limited area of the bed, pressure measurements need to be performed at several positions to cover the whole bed. We examine these local pressure waves (caused by, e.g., passing bubbles or coalescing bubbles) in a 0.80 m i.d. bubbling fluidized bed of Geldart B particles. Experiments and simulations are performed to determine the intensity decrease as local pressure waves propagate from their origin. A new spectral method is applied to determine the degree of coherence for pressure signals measured at two different positions in a fluidized bed. For a superficial gas velocity of 5u_mf, local pressure waves can be detected up to a radial distance of about 0.5 m from their origin; this distance is somewhat lower for lower gas velocities. This means that the radial spacing of pressure probes should not exceed 1 m. For large diameter beds with a bed height below 1.5 m, a set of probes at a single level and at several radial positions is sufficient to observe or monitor the dynamic state of the complete bed; the probes should preferably be placed at a height of 30% to 40% of the total bed height.     

Validation of the MODIS bidirectional reflectance distribution function and albedo retrievals using combined observations from the aqua and terra platforms

We evaluate the performance of the MODerate Resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF)/Albedo algorithm using observations from MODIS instruments aboard NASA's Terra (EOS AM-1) and Aqua (EOS PM-1) platforms. This "combined" albedo product is evaluated against continuous field measurements from SURFace RADiation Budget Network (SURFRAD) and Atmospheric Radiation Measurement Southern Great Plains (ARM/SGP) stations, and through an internal analysis of the product's quality assurance (QA) fields. The combined product is compared to the initial MODIS albedo product, which used observations from the Terra satellite only. During the spring and summer months, the combined product showed a slight improvement over the original Terra-only albedo product, with a root mean square error (RMSE) of 0.0130 and a bias of about -0.02. As with the Terra-only product, accuracy drops during the fall and winter months at some sites. Jin et al. found that increased heterogeneity of validation sites during the fall and winter months is partially responsible for this drop in accuracy. The additional data provided by the Aqua platform changes high-quality albedo estimations only slightly, which underscores the stability of the MODIS algorithm. The most significant benefit of the combined product is a near 50% decrease in lower quality backup algorithm retrievals for the entire globe. A decrease in backup algorithm retrievals improves the overall accuracy of the MODIS albedo product, as it reduces algorithm reliance upon an a priori determination of the underlying surface anisotropy that is not entirely data derived.