Entropic effects in carbon nanotubes-templated crystallization of Poly(3-alkyl thiophenes,P3HT,P3OT)

A significant increase in polymer crystallinity is reported in composites of carbon-nanotubes (CNT) and Poly(3-octylthiophene-2,5-diyl), P3HT and Poly(3-octylthiophene-2,5-diyl), P3OT; Differential scanning calorimetry (DSC) reveal an increase from about 40% crystallinity of the native P3HT to ∼62% in composites containing 25 wt% MWNT. A similar behavior is observed in P3OT with ∼68% crystallinity, a double crystallization peak and higher melting temperature than the native polymers. The effect is unique to CNT and is not induced by fullerenes or graphene layers. High-resolution transmission electron microscopy, (HRTEM) of CNT-polymer dispersions reveal chains stacked upon the CNT in an elongated, stretched conformation. Following a detailed molecular study by Bernardi et al. and the HRTEM observations the DSC results are attributed to a CNT-mediated entropic effect: due to their intrinsic, 1D cylindrical shape the CNT impose an increased conjugation length on chains adsorbed and stacked upon dispersed CNT. Crystallization thus commences from a heterogeneous mixture of native chains and chains with a longer persistence length (higher effective rigidity) and consequentially a lower effective height of the entropic barrier for crystallization. The findings offer a new insight into the origins of CNT-induced polymer nucleation.     

红色雷司令

首先声明，这绝对不是个玩笑! 其次，红雷司令（Roter Riesling）也并非由享誉全球的德国盖森海姆研究院Gaisenheim Institute培育出的新的克隆品种。相反，这是一个存在了几个世纪的古老品种。据了解，几个世纪来红雷司令葡萄串中常常能发现白色变种，至于为何红皮最终被白皮取而代之，这是个很有意思的问题...     

Effect of NiO on the Phase Stability and Microstructure of Yttria-Stabilized Zirconia

Nickel oxide (NiO) was screen printed onto the surfaces of 3 and 8 mol% yttria-stabilized zirconia (YSZ) dense pre-fired substrates and then heat treated at temperatures from 1350° to 1550°C. The effect of NiO was dependent on the yttria content of the substrate. In 3 mol% YSZ, it was found to alter the phase composition from predominantly tetragonal with a small amount of cubic phase to one consisting of approximately equal amounts of cubic and monoclinic phase. The cubic grains were much larger than the monoclinic ones and contained more nickel. Furthermore, nickel was observed to migrate through the thickness of the tile, a distance of approximately 200 μm. In the 8 mol% YSZ substrates, the phase composition was unaltered, although large grains developed under the printed NiO layer and the nickel migration was confined to the extent of these large grains.     

<Emphasis Type="Italic">Corymbia</Emphasis> Species and Hybrids: Chemical and Physical Foliar Attributes and Implications for Herbivory

Hybridization is an important biological phenomenon that can be used to understand the evolutionary process of speciation of plants and their associated pests and diseases. Interactions between hybrid plants and the herbivores of the parental taxa may be used to elucidate the various cues being used by the pests for host location or other processes. The chemical composition of plants, and their physical foliar attributes, including leaf thickness, trichome density, moisture content and specific leaf weight were compared between allopatric pure and commercial hybrid species of Corymbia, an important subtropical hardwood taxon. The leaf-eating beetle Paropsis atomaria, to which the pure taxa represented host (C. citriodora subsp. variegata) and non-host (C. torelliana) plants, was used to examine patterns of herbivory in relation to these traits. Hybrid physical foliar traits, chemical profiles, and field and laboratory beetle feeding preference, while showing some variability, were generally intermediate to those exhibited by parent taxa, thus suggesting an additive inheritance pattern. The hybrid susceptibility hypothesis was not supported by our field or laboratory studies, and there was no strong relationship between adult preference and larval performance. The most-preferred adult host was the sympatric taxon, although this species supported the lowest larval survival, while the hybrid produced significantly smaller pupae than the pure species. The results are discussed in relation to plant chemistry and physical characteristics. The findings suggest a chemical basis for host selection behavior and indicate that it may be possible to select for resistance to this insect pest in these commercially important hardwood trees.     

Ecological predictors of substance use in middle school students.

The current study examined important predictors of substance use during early adolescence. The authors hypothesized that adolescents' relationships with key adults (i.e., teachers and parents) influence their choices to use substances indirectly through links with their decisions regarding peer groups. A total of 461 middle school students from an affluent suburban community completed self-report measures of authoritative parenting, perceived social support from teachers, affiliation with rule-breaking and substance-using peers, and frequency of alcohol, cigarette, and drug use. Results of structural equation modeling supported the hypothesized model. Authoritative parenting and teacher support accounted for 31% of the variance in affiliation with deviant peers which, in turn, accounted for 27% of the variance in adolescent substance use; direct paths from parenting and teacher support to substance use were not indicated. Implications for school psychologists' involvement in substance use prevention and intervention are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Juvenile transfer to adult courts: A look at the prototypes for dangerousness sophistication-maturity and amenability to treatment through a legal lens.

Juvenile court judges are often required to make distinctions as to whether certain adolescents should remain in the juvenile justice system or be transferred to adult courts. Typically, 3 broad factors weigh into juvenile court judges' decision making: (a) the level of danger the juvenile poses to the community, (b) the level of sophistication-maturity of the juvenile, and (c) the extent to which the juvenile is viewed as treatable. In an earlier study, knowledge of forensic and child psychologists was tapped to elucidate core characteristics related to the transfer process (R. T. Salekin et al, 2001). The current study augments that investigation. Judges provided (a) their perspective regarding the core criteria for dangerousness, sophistication-maturity, and amenability to treatment, and (b) data on the core characteristics of juveniles who were evaluated and subsequently judged to be appropriate for transfer to adult criminal courts. Policy implications for this increasingly critical interface between law and psychology are threefold: (a) Individualized assessments are key; (b) the adoption of a national standard for transfer to adult court is required; and (c) the development of treatment programs to improve the socialization of youth is necessary. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What's on the menu? The influence of menu content on the selection process

This paper focuses on the distinction between the selection process in a computer command menu and in an information retrieval menu. We argue that the cognitive processes involved in these two tasks are different and consequently, that performance cannot be explained by the same factors. Preliminary experimental results are presented to support this claim.     

Preparation and characterization of biodiesel produced from fish oil

This study evaluated the production of biodiesel using fish oil as raw material. Two-stage alkaline-catalysis transesterification was performed with 6/1 molar ratio of methanol to oil at 55°C in the presence of 1 wt. % base amount of potassium hydroxide (KOH). The fuel properties of the biodiesel were further analyzed. The characterizations of the produced biodiesel showed that it met ASTM D 6751 standard with respect to acid number, flash point, water and sediment, free and total glycerin, sulfur content, distillation temperature, etc. It was found that cold soak and oxidative stability were out spec due to the high amount of polyunsaturated fatty acid present in the fish oil. However, through blending with used cooking oil biodiesel, in spec biodiesel fuel could be achieved.