Does the Youth Corrections System Work? Tracking the Effectiveness of Intervention Efforts With Delinquent Boys in State Custody.

This study adopted a systemic approach to studying intervention efforts with delinquent youth, examining the association between several youth corrections programs and adult criminal outcomes. Two studies were designed to use juvenile and adult court records to evaluate the effectiveness of treatment programs provided to delinquent youth in state custody. The results of Study 1 suggested that court-recorded delinquent charges can be used to estimate delinquency severity. The results of Study 2 presented a discouraging but not entirely unexpected illustration of the effectiveness of intervention efforts among delinquent youth. It was found that time spent in juvenile detention facilities, work programs, and group homes was associated with negative adult criminal outcomes. No links between time spent in youth corrections programs and positive outcomes were identified. Implications for future program evaluation efforts are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of the repartition of monomers between sol and gel fractions in copolycondensate glycerol/azelaic acid by radioassay

The distribution of the monomers between sol and gel fractions, theoretically forecasted from network formation theory, is experimentally determined in glycerol/azelaic acid system with tritium labeled glycerol by radioassay.Presented at the 7th Discussion Conference IUPAC Polymer Networks, Karlovy Vary, CSSR, September 15–19, 1980     

Polyurethane/poly(hydroxyethyl methacrylate) semi-interpenetrating polymer networks for biomedical applications

The thermodynamic miscibility, morphology, phase distribution, mechanical properties, surface properties, water sorption, bacterial adhesion and cytotoxicity of semi-interpenetrating polymer networks (semi-IPNs) based on crosslinked polyurethane (PU) and poly(hydroxyethylmethacrylate) (PHEMA) were studied to give an insight into their structure and properties. The free energies of mixing of the two polymers in semi-IPNs have been determined and it was shown that the values are positive and depend on the amount of PHEMA. This demonstrates that the components are immiscible, the extent of which is dependent upon variations in composition. The morphology of the semi-IPNs was analyzed with scanning electron microscopy and tapping mode atomic force microscopy (TMAFM). The micrographs of the semi-IPNs and TMAFM phase images indicated that distinct phase separation at the nanometer scale is observed. The mechanical properties reflect the changes in structure of semi-IPNs with composition. The stress at break increases from 3.4 MPa to 23.9 MPa, and the Young’s modulus from 12.7 MPa up to 658.5 MPa with increasing amounts of PHEMA, but strain at break has a maximum at 40.4% PHEMA. The bacterial adhesion and cytotoxicity data suggest that semi-IPNs with PHEMA content above 22% may be used for biomedical material applications.     

Verunreinigung von Haselnüssen und Schokolade durch Mineralöl aus Jute- und Sisalsäcken

Before spinning, jute and sisal fibres are treated with a batching oil commonly consisting of a raw mineral oil fraction. Such oil is transferred to foods packed into jute or sisal bags, i.e. primarily cocoa beans, hazelnuts, coffee, almonds, oil seeds, and rice. Concentrations in the foods easily exceed 100 mg/kg. Chocolate may be affected several-fold: cocoa beans as well as hazelnuts and almonds may be contaminated.     

Mapping a keystone shrub species,huckleberry (Vaccinium membranaceum), using seasonal colour change in the Rocky Mountains

Black huckleberries (Vaccinium membranaceum) provide a critical food resource to many wildlife species, including apex omnivores such as the grizzly bear (Ursus arctos), and play an important socioeconomic role for many communities in western North America, especially indigenous peoples. Remote sensing imagery offers the potential for accurate landscape-level mapping of huckleberries because the shrub changes colour seasonally. We developed two methods, for local and regional scales, to map a shrub species using leaf seasonal colour change from remote sensing imagery. We assessed accuracy with ground-based vegetation surveys. The high-resolution supervised random forest classification from one-meter resolution National Agricultural Imagery Program (NAIP) imagery achieved an overall accuracy of 75.31% (kappa = 0.26). The approach using multi-temporal 30-meter Landsat imagery similarly had an overall accuracy of 79.19% (kappa = .31). We found underprediction error was related to higher forest cover and a lack of visible colour change on the ground in some plots. Where forest cover was low, both models performed better. In areas with <10% forest cover, the high-resolution classification achieved an accuracy of 80.73% (kappa = 0.48), while the Landsat model had an accuracy of 82.55% (kappa = 0.47). Based on the fine-scale predictions, we found that 94% of huckleberry shrubs identified in our study area of Glacier National Park, Montana, USA are over 100 meters from human recreation trails. This information could be combined with productivity and phenology information to estimate the timing and availability of food resources for wildlife and to provide managers with a tool to identify and manage huckleberries. The development of the multi-temporal Landsat models sets the stage for assessment of impacts of disturbance at regional scales on this ecologically, culturally, and economically important shrub species. Our approach to map huckleberries is straightforward, efficient and accessible to wildlife and environmental managers and researchers in diverse fields.     

Measuring adhesion forces between model polysaccharide films and PLA bead to mimic molecular interactions in flax/PLA biocomposite

Natural fiber-reinforced polymers or biocomposites are becoming increasingly popular as an environment friendly alternative to traditional glass fiber-reinforced thermoplastics. The mechanical properties of reinforced biocomposites, such as flax/polylactic acid (PLA), are largely governed by the level of interfacial interactions between the two constituents apart from their intrinsic properties. The hierarchical organization of various polysaccharides present in natural fibers results in complex mechanisms at the interface which are still poorly understood and difficult to analyze through a traditional approach that rely on indirect assessments. The possibility of measuring direct adhesion force between individual particles using the colloidal force microscopy has been exploited here by developing an experimental set-up in which a micrometer colloidal PLA bead is brought into close contact with molecularly smooth polysaccharide surfaces that mimic the main constituents of flax fibers, cellulose, hemicellulose, and pectins. Adhesion force measurements performed under ambient and low relative humidity conditions indicate that cellulose/PLA is the weakest interface in the biocomposite. Moreover, the results emphasize the important role of water molecules for the more hydrophilic polymers in flax fibers that takes place in the fundamental forces involved in the adhesion phenomena at the biocomposite interface.     

HPLC-Analytik von ethanolischen Eichenholzextrakten mit UV-, Fluorescenz- und amperometrischer Detektion

Zusammenfassung Jute- und Sisalfasern werden vor dem Verspinnen mit einem Batching-Öl gewalkt, welches bisher normalerweise aus einer ungereinigten Erdölfraktion bestand. Solches Öl wird auf Lebensmittel übertragen, welche in Jute- oder Sisalsäcken transportiert und gelagert werden, also hauptsächlich auf Kakaobohnen, Haselnüsse, Kaffee, Mandeln, Ölsamen und Reis. Konzentrationen können leicht 100 mg/kg überschreiten. Schokoladenprodukte sind davon mehrfach betroffen: sowohl die Kakaobohnen als auch die Haselnüsse und Mandeln können verunreinigt sein.

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Contamination of hazelnuts and chocolate by mineral oil from jute and sisal bags

Before spinning, jute and sisal fibres are treated with a batching oil commonly consisting of a raw mineral oil fraction. Such oil is transferred to foods packed into jute or sisal bags, i.e. primarily cocoa beans, hazelnuts, coffee, almonds, oil seeds, and rice. Concentrations in the foods easily exceed 100 mg/kg. Chocolate may be affected several-fold: cocoa beans as well as hazelnuts and almonds may be contaminated.

     

Phase separation in the polyurethane/poly(2‐hydroxyethyl methacrylate) semi‐interpenetrating polymer networks synthesized by different ways

The thermal, dynamic mechanical analysis, morphology and mechanical properties of semi‐interpenetrating polymer networks based on crosslinked polyurethane (PU) and poly(2‐hydroxyethyl methacrylate) (PHEMA) synthesized by photopolymerization and by thermopolymerization have been investigated. The thermal analysis has evidenced the two glass temperature transitions in the semi‐IPNs and this is confirmed by the thermodynamic miscibility investigation of the systems. The Dynamic Mechanical Analysis spectra have shown that the phase separation is more significant in the thermopolymerized semi‐IPNs: the tan δ peaks of constituent polymers are more distinct and the minimum between the two peaks is deeper. The calculated segregation degree values of semi‐IPN's components are significantly higher for thermopolymerized semi‐IPNs, thereby the process of phase separation in the thermopolymerized semi‐IPNs is more developed. The structures of two series of samples investigated by SEM are completely different. The mechanical properties reflect these changes in structure of semi‐IPNs with increasing amount of PHEMA and with the changing of the method of synthesis. The results suggest that the studied semi‐IPNs are two‐phase systems with incomplete phase separation. The semi‐IPN samples with early stage of phase separation demonstrate higher mechanical characteristics. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Semi‐interpenetrating polymer networks based on polyurethane and poly(vinyl pyrrolidone) obtained by photopolymerization: Structure‐property relationships and bacterial adhesion

A range of semi‐interpenetrating polymer networks (semi‐IPNs) based on polyurethane (PU) and poly(vinyl pyrrolidone) (PVP) have been synthesized and characterized with respect to their thermodynamic characteristics, morphology, mechanical properties, surface properties, water sorption and bacterial adhesion. The free energies of mixing of PU and PVP in semi‐IPNs have been determined by the vapor sorption method and were shown to be positive for all compositions. The surface properties of semi‐IPNs were investigated using the dynamic contact angle analysis. It was shown that the advancing contact angle changes from 83.1° to 65.3° with increasing PVP from 7.05% to 57.38%. Scanning electron microscopy demonstrated that the semi‐IPNs are two‐phase systems with incomplete phase separation. The mechanical properties reflect the changes in structure of semi‐IPNs with increasing of amounts of PVP in the system. Incorporation of PVP into the semi‐IPN with PU restricts the ability of PVP to sorb water. As infection is likely to be caused by bacterial adherence to biomedical implants, the bacterial adhesion data suggests that the semi‐IPNs with PVP content below 22.52% may be useful for biomedical material applications. Polym. Eng. Sci. 44:940–947, 2004. © 2004 Society of Plastics Engineers.