Evaluation of a gas in vitro system for predicting methane production in vivo

Methane production from ruminant livestock varies with the diet as a result of factors such as dry matter intake, diet composition, and digestibility. To estimate the effect of dietary composition and feed additives, CH₄ production can be measured in vitro as a first step because large numbers of samples can be incubated and analyzed at the same time. This study evaluated a recently developed in vitro method for prediction of in vivo CH₄ production by examining the relationship between predicted and observed CH₄ production values. A total of 49 different diets (observations), used in previous 13 in vivo studies, were selected to include diets varying in nutrient composition. Methane production was measured in all in vivo studies by respiration chambers or the GreenFeed system (C-Lock Inc., Rapid City, SD). Overall, the in vitro system predicted CH₄ production well (R² = 0.96), but the values obtained were slightly underestimated compared with observed in vivo values (mean 399 L/d compared with 418 L/d: root mean square prediction error = 51.6 L/d or 12.3% of observed mean). Further analysis of the effect on residuals showed no significant relationship between CH₄ production and most factors known to affect CH₄ production such as dry matter intake, digestibility, and dietary concentrations of fat and starch. However, some factors included in the model were not well predicted by the system, with residuals negatively related to neutral detergent fiber concentration and positively related to concentrate proportion. The in vitro system can thus be useful for screening diets and evaluation of feed additives as a first step that can be best interpreted when feeding cows at maintenance level.     

Interruptions in the wild: portraying the handling of interruptions in manufacturing from a distributed cognition lens

This paper presents a study examining interruptions in the wild by portraying the handling of interruptions in manufacturing from a distributed cognition lens. By studying how interruptions occur and are handled in the daily activities of a work team at a large foundry for casting heavy diesel engines, we highlight situations when the propagation, transformation, and representation of information are not supported by prescribed work processes and propose recommendations for how this can be amended. The study was conducted by several visits to the aforementioned factory with cognitive ethnography as the basis for the data collection. The focus was on identifying interruptions and analysing these through a distributed cognition framework as an initial step towards studying interruptions in a manufacturing environment. The key findings include the identification of three, previously undefined, types of interruptions and the conclusion that interruptions do indeed affect the distributed workload of the socio-technical system and thus the overall production performance at the casting line.

     

The New ChemPren Process for the Conversion of Waste Plastic to Chemicals and Fuel

A new technology, ChemPren, is being developed for the catalytic conversion of mixed municipal waste plastic to valuable chemicals and fuel. ChemPren provides a sustainable, clean energy solution to society’s challenge of addressing the 100+ million tons of waste plastic generated annually worldwide. Currently only 7 % is recycled, with the remaining 93+ million being discarded to landfills or burned without useful energy generation.

     

Effects of additives on the performance of two-component waterborne polyurethane coatings

The effects of various additives and solvents on a coating’s performance in a two-component waterborne polyurethane coating system are studied using a statistical experimental design method. Using a blocked arrangement of fractional factorial design matrices, six different independent variables, including the use of different additives, catalysts, as well as solvents at different levels, were examined for their effects on various coating performance parameters, such as gloss, hardness, viscosity, and chemical resistance. Statistical analysis revealed several significant effects of these additives on the coating performances. Most importantly, several two-factor interactions between additives were also found to significantly influence the performance properties of the coating. These interactions could be very difficult to detect using traditional one-at-a-time experimental approaches. The information obtained from this study could be used for designing coating systems with superior performance properties. Presented at the 26th International Waterborne, High-Solids and Powder Coatings Symposium, February 10–12, 1999, New Orleans, LA. Coatings and Colorants Division, 100 Bayer Rd., Pittsburgh, PA 15205-9741.     

Do interactions between personality and social-environmental factors explain smoking development in adolescence?

This study examined if the effects of peer smoking, family smoking, and parenting on smoking development during adolescence are moderated by personality characteristics of adolescents. Longitudinal data were obtained from 428 adolescents (aged M = 13.4, SD = .50) and their parents. Latent Growth Curve models assessed the development of smoking as a function of predictors and if effects of smoking-specific parenting and exposure to smoking were moderated by adolescents’ Big Five personality dimensions. Findings revealed that having peers who smoked was associated with an increased likelihood of being a smoker at baseline. Further, significant interactions revealed that adolescents lower in agreeableness were more likely to be a smoker at baseline if they had an older sibling who smoked or if their parents engaged in frequent smoking-related discussions with them and that effective smoking-specific conversation was more strongly related to smoking at baseline among adolescents who were highly emotionally stable. No interactions predicted growth in smoking over time yet significant main effects showed that growth in smoking was associated with higher levels of extraversion, lower levels of emotional stability, and less effective parental smoking-specific communication. This study highlights the relevance of personality-target interventions and policy programs directed at parents and peers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Too much of a good thing: Underprovision versus overprovision of partner support.

We examined whether support underprovision (receiving less support than is desired) and support overprovision (receiving more support than is desired) should be examined as qualitatively distinct forms of inadequate support in marriage. Underprovision of partner support, overprovision of partner support, and marital satisfaction were assessed 5 times over the first 5 years of marriage in a sample of newlywed husbands and wives (N = 103 couples), and were analyzed via actor-partner interdependence modeling (APIM) and growth curve analytic techniques. Increases in underprovision and overprovision of support were each uniquely associated with declines in marital satisfaction over the first 5 years of marriage; however, overprovision of support was a greater risk factor for marital decline than underprovision. Further, when examining support from a multidimensional perspective, overprovision was at least as detrimental, if not more detrimental, than underprovision for each of 4 support types (i.e., informational, emotional, esteem, and tangible support). The present study is the first to examine the utility of differentiating between underprovision and overprovision of partner support. Theoretical, empirical, and clinical implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self‐Assembly of a Donor‐Acceptor Dyad Across Multiple Length Scales: Functional Architectures for Organic Electronics

Molecular dyads based on polycyclic electron donor (D) and electron acceptor (A) units represent suitable building blocks for forming highly ordered, solution‐processable, nanosegregated D‐A domains for potential use in (opto)electronic applications. A new dyad, based on alkyl substituted hexa‐peri‐hexabenzocoronene (HBC) and perylene monoimide (PMI) separated by an ethinylene linker, is shown to have a high tendency to self‐assemble into ordered supramolecular arrangements at multiple length scales: macroscopic extruded filaments display long‐range crystalline order, nanofiber networks are produced by simple spin‐coating, and monolayers with a lamellar packing are formed by physisorption at the solution‐HOPG interface. Moreover, highly uniform mesoscopic ribbons bearing atomically flat facets and steps with single‐molecule heights self‐assemble upon solvent‐vapor annealing. Electrical measurements of HBC‐PMI films and mesoscopic ribbons in a transistor configuration exhibit ambipolar transport with well balanced p‐ and n‐type mobilities. Owing to the increased level of order at the supramolecular level, devices based on ribbons show mobility increases of more than one order of magnitude.