Colorful and transparent poly(vinyl alcohol) composite films filled with layered zinc hydroxide salts,intercalated with anionic orange azo dyes (methyl orange and orange II)

Layered zinc hydroxide salts (zinc LHS) were intercalated with anionic orange azo dyes, namely methyl orange (MO) and orange II (OII), and co-intercalated with hydrated chloride anions. After characterization by X-ray diffraction (XRD), thermal analysis (TGA/DTA), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), the materials were used as fillers for poly(vinyl alcohol) (PVA). Colorful transparent films were obtained by wet casting, revealing good dispersion of the material into the polymer. In the case of zinc LHS/OII, PVA was intercalated between the zinc LHS layers. Evaluation of the mechanical properties of the PVA composite films revealed that the layered colorful materials were able to increase the mechanical properties of the PVA films only when the films were stored under lower relative humidity. As expected, films with higher water content displayed reduced tensile strength and modulus because of the plasticizing effect of water. As for the films stored at 43% relative humidity, more pronounced improvement of modulus was observed for 1 and 4% zinc LHS/OII, and enhanced tensile strength was achieved for 0.5 and 1% zinc LHS/OII. This effect can be attributed to better dispersion of the layered filler and its better adhesion to the PVA matrix.     

Retrofitting the suburbs to increase walking: evidence from a land-use-travel study

This paper reports results from a detailed travel diary survey of 2125 residents in the South Bay area of Los Angeles County - a mature, auto-oriented suburban region. Study areas were divided into four centres, typical of compact development or smart growth, and four linear, auto-oriented corridors. Results show substantial variation in the amount of walking across study areas. Trips are shorter and more likely to be via walking in centres. A key to the centres' increased walking travel is the concentration of local shopping and service destinations in a commercial core. Yet the amount of business concentration that is associated with highly pedestrian-oriented neighbourhoods is from three to four times as large as what can be supported by the local resident base, suggesting that pedestrian-oriented neighbourhoods necessarily import shopping trips, and hence driving trips, from larger surrounding catchment areas. The results suggest both land use and mobility strategies that can be appropriate for suburban regions.     

Discrimination of “Louros” wood from the Brazilian Amazon by near-infrared spectroscopy and machine learning techniques

European Journal of Wood and Wood Products - The integration of near infrared spectroscopy (NIR) with machine learning techniques can be an adequate method for discrimination of wood...     

Recovery of N applied as 15N-manure or 15N-gliricidia biomass by maize,cotton and cowpea

Proper management of N applied in fertilizers is important to optimize crop production and to avoid negative environmental impacts. The best way to study N dynamics in the soil plant system is to use fertilizers labeled with ¹⁵N. Recoveries of nitrogen following fertilization with ¹⁵N-labeled goat (Capra hircus L.) manure and gliricidia (Gliricidia sepium Jacq. Walp) biomass were evaluated in a greenhouse experiment with three successive planting cycles of three crops: maize (Zea mays L.), cotton (Gossypium hirsutum L.), and cowpea (Vigna unguiculata (L.) Walp.). Each 1 kg soil pot received 8 g (equivalent to 20 Mg ha^?1) of either manure (12.3 mg g^?1 of N) or gliricidia (37.8 mg g^?1 of N). Plants were harvested 50 days after germination and real (¹⁵N) and apparent recoveries of the applied N were determined. Biomass and N amounts in the cotton and maize crops in all three cycles were higher with gliricidia application than with manure, except for cotton in the first cycle. The biomass of cowpea was also higher with gliricídia in the first and second cycles but the amount of N was significantly higher only in the second cycle. In the first cycle, the largest recoveries of ¹⁵N were obtained with gliricidia, for all three crops, but in the second and third cycles recoveries were greater with manure, so that the real recoveries of gliricidia and manure were similar (cotton, 35 and 37 %; maize, 27 and 26 %; and cowpea, 41 and 38 % of the applied N, respectively). Estimates of apparent recoveries were different from the real ones and therefore inadequate for cotton and cowpea. The fast release of N from gliricidia prunings and, on the other hand, the strong residual effect of goat manure-N to subsequent cropping cycles should be considered by farmers in their fertilization strategies.     

Alcohol-impaired driving behavior and sensation-seeking disposition in a college population receiving routine care at campus health services centers

Accidents stemming from alcohol-impaired driving are the leading cause of injury and death among college students. Research has implicated certain driver personality characteristics in the majority of these motor vehicle crashes. Sensation seeking in particular has been linked to risky driving, alcohol consumption, and driving while intoxicated. This study investigated the effect of sensation seeking on self-reported alcohol-impaired driving behavior in a college student population while adjusting for demographics, residence and drinking locations. A total of 1587 college students over the age of 18 completed a health screening survey while presenting for routine, non-urgent care at campus heath services centers. Student demographics, living situation, most common drinking location, heavy episodic drinking, sensation-seeking disposition and alcohol-impaired driving behavior were assessed. Using a full-form logistic regression model to isolate sensation seeking after adjusting for covariates, sensation seeking remains a statistically significant independent predictor of alcohol-impaired driving behavior (OR = 1.52; CI = 1.19-1.94; p < 0.001). Older, white, sensation-seeking college students who engage in heavy episodic drinking, live off-campus, and go to bars are at highest risk for alcohol-impaired driving behaviors. Interventions should target sensation seekers and environmental factors that mediate the link between sensation seeking and alcohol-impaired driving behaviors.     

Calculation of the isothermal transformation into two different microstructures from measurements with continuous cooling

With the method described it is possible to use measurements of continuous cooling for the calculation of isothermal transformation diagrams. From the experimental point of view, this is in general easier than the immediate measurement of isothermal transformation. Additionally for steels with a fast transformation rate in the pearlite range it may be difficult or impossible to get a correct measurement of the transformation in the bainite range, due to a pre-transformation in the pearlite range. Using the method described, this difficulty can by avoided. On the other hand, only the knowledge of the isothermal transformation characteristic of a steel permits the calculation of transformation during any time-temperature sequence, for example with industrial equipment.     

A synthetic approach to pyrazole functionalized polystyrene

Summary Polystyrene containing 20 % phenyl rings functionalized with pyrazole was obtained by acylation and subsequent reaction with N,N-dimethylformamid dimethylacetal and hydrazine and characterized by means of NMR and IR spectroscopy and elemental analysis.     

Microwave-assisted sample combustion: a technique for sample preparation in trace element determination

A novel digestion procedure based on sample combustion ignited by microwave radiation is proposed for organic samples. Certified samples of bovine liver, pig kidney, and skim milk were used as examples to demonstrate the performance of the proposed procedure. Cadmium and copper were determined in these samples by electrothermal atomic absorption spectrometry. Samples (between 50 and 250 mg) were wrapped with paper and placed on a homemade quartz holder that was positioned inside to quartz vessels used in a commercial microwave oven. Ammonium nitrate solution was added to the paper, and vessels were pressurized with oxygen to 15 bar. The rotor containing four vessels was placed inside the oven, and microwave radiation was applied for 20 s at 1400 W. Combustion was complete in few seconds, and an additional reflux step, which was optional, was applied. The agreement to the certified values was between 96 and 105% for both analytes. Only with the combustion step, the residual carbon (RC) was below 1.3%. The RC decreased to less than 0.4% when an additional reflux step with concentrated nitric acid was applied.     

Specification and execution of composite trading activities

With the growing number of trading opportunities available online, software tools designed to act on behalf of human traders are increasingly being used to automate trading activities. The next logical step in this evolution is the automation of composite trading activities designed to fulfill complex user goals and requirements. In this paper, we describe a model for specifying composite trading activities involving concurrent and interrelated negotiations with multiple parties and heterogeneous protocols. The model supports the specification of several types of constraints, such as the number of required successful negotiations, the limit price for the items to be traded, and the temporal constraints imposed by all trading parties. In order to guide the execution of the trading activities, we describe a novel planning and execution model for composite trading activities which is designed to maximize the expected utility of the user.