Injury potential of a three-year-old Hybrid III dummy in forward and rearward facing positions under CMVSS 208 testing conditions

This research focuses on the injury potential of children in forward and rearward facing child restraint seats in frontal collisions. Vehicle crash tests were completed following the guidelines outlined in the Canadian Motor Vehicle Safety Standard 208 using a Hybrid III three-year-old dummy in a convertible forward/rearward facing child restraint seat. The seat was equipped with a five-point restraining system and the experimental test was completed in the forward facing configuration. A numerical model employing a similar set-up as the experimental crash test was developed and numerically simulated using LS-DYNA. To verify the numerical simulations, the head and chest accelerations as well as neck loads and moments were compared to the experimental findings and it was observed that a reasonable correlation between the experimental and numerical observations existed. Further numerical simulations were completed to investigate the influence of positioning the three-year-old dummy in the rearward configuration on the head and neck injury potential during frontal crash. Through an analysis of injury criteria, using neck loads and head accelerations, it was observed that the rearward facing child dummy sustained significantly lower levels of neck injury criteria while exhibiting similar levels of the head injury criteria as the forward facing child dummy.     

Adolescents in the City: Material and Social Living Conditions in Johannesburg–Soweto, South Africa

Urban populations are growing rapidly in developing countries. As a result, challenges to the well-being of adolescents are increasing in priority. This paper describes the material and social living conditions of 5,367 young adolescents, in Johannesburg–Soweto, South Africa in 2002–2003. The majority of children in South Africa’s urban hub have adequate access to basic services. However, social conditions are a key concern—lack of financial support by parents; defaulting caregiver roles to grandparents; minimal or no contact with fathers; and poor school performance. Weakened levels of family support in urban environments may negatively impact on adolescent development. In the long term, family systems as well as other social networks and institutions need to be strengthened to improve adolescent outcomes.

Enhanced Anthocyanin Extraction from Red Cabbage Using Pulsed Electric Field Processing

Abstract: This study was conducted to evaluate the effect of pulsed electric field (PEF) treatment on anthocyanin extraction from red cabbage using water as a solvent. Mashed cabbage was placed in a batch treatment chamber and subjected to PEF (2.5 kV/cm electric field strength; 15 μs pulse width and 50 pulses, specific energy 15.63 J/g). Extracted anthocyanin concentrations (16 to 889 μg/mL) were determined using HPLC. Heat and light stabilities of the control and PEF-treated samples, having approximately the same initial concentrations, were studied. PEF treatments enhanced total anthocyanin extraction in water from red cabbage by 2.15 times with a higher proportion of nonacylated forms than the control (P < 0.05). The heat and light stabilities of the PEF-treated samples and control samples were not significantly different (P > 0.05). Practical Application: An innovative pretreatment technology, pulsed electric field processing, enhanced total anthocyanin extraction in water from red cabbage by 2.15 times. Manufacturers of natural colors can use this technology to extract anthocyanins from red cabbage efficiently.     

Thermal characteristics of flaxseed (Linum usitatissimum L.) proteins

Thermal characteristics of ion-exchange protein fractions from dehulled delipidated meal of four flaxseed cultivars grown at three locations were evaluated by differential scanning calorimetry (DSC) to examine genotypic and environmental effects. DSC was performed in a “dry” state on four, 0.28, 0.35, 0.45 and 0.50 M NaCl lyophilized protein fractions. Flaxseed proteins exhibited two thermal events between 83 and 115 °C with distinct shoulders present in the 0.45 and 0.50 M fractions of all cultivars. Cultivar and location effects were significant for the first thermal transition (_Td1$T_{{\mathrm{d}}_1}$) of the 0.28 and 0.35 M fractions, and the second transition (_Td2$T_{{\mathrm{d}}_2}$) of the 0.35, 0.45 and 0.50 M fractions. The enthalpy of the first transition ΔH₁ of the 0.35 and 0.50 M fractions was cultivar dependent, while that of the second transition ΔH₂ was cultivar and location specific for the 0.35, 0.45 and 0.50 M fractions. The 0.28 and 0.45 M fractions displayed the lowest and highest thermal transition temperatures, respectively. All protein fractions consisted of reversing and nonreversing thermal events as assessed by modulated DSC. Flaxseed cultivars, when grouped by thermal characteristics of protein fractions, can be differentiated by principal component analysis.     

New potentiometric sensor for the determination of iodine species

The characteristics, performance and application of novel triiodide potentiometric sensor based on ion-pair of Rhodamine B triiodide as a membrane carrier are described. The electrode has a linear dynamic range between 1 × 10^? 6 and 1 × 10^? 1 M, with a Nernstian slope of 68 ± 1 mV pC^? 1 and detection limit of 3.9 × 10^? 7 M. Fast and stable response, good reproducibility, long-term stability, very good selectivity over a large number of common organic and inorganic anions, applicability over a pH range of 2–10 are demonstrated. The proposed sensor has been applied for potentiometric determination of some iodine species.     

Reliability and validity of the Yale Global Tic Severity Scale.

To investigate the reliability and validity of the Yale Global Tic Severity Scale (YGTSS), 28 youth aged 6 to 17 years with Tourette's syndrome (TS) participated in the study. Data included clinician reports of tics and obsessive-compulsive disorder (OCD) severity, parent reports of tics, internalizing and externalizing problems, and child reports of depression and anxiety. All children participated in a 2nd YGTSS administration by the same rater 48 days later. Good internal consistency and stability were found for the YGTSS scores. YGTSS scores demonstrated strong correlations with parent-rated tic severity (r = .58-.68). YGTSS scores were not significantly related to measures of clinician ratings of OCD severity (r = .01-.15), parent ratings of externalizing and internalizing behavior (r = -.07-.20), and child ratings of depression (r = .02-.26) and anxiety (r = -.06 -.28). Findings suggest that the YGTSS is a reliable and valid instrument for the assessment of pediatric TS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Organic Photovoltaics with Multiple Donor–Acceptor Pairs

Compared with conventional organic solar cells (OSCs) based on single donor–acceptor pairs, terpolymer‐ and ternary‐based OSCs featuring multiple donor–acceptor pairs are promising strategies for enhancing the performance while maintaining an easy and simple synthetic process. Using multiple donor–acceptor pairs in the active layer, the key photovoltaic parameters (i.e., short‐circuit current density, open‐circuit voltage, and fill factor) governing the OSC characteristics can be simultaneously or individually improved by positive changes in light‐harvesting ability, molecular energy levels, and blend morphology. Here, these three major contributions are discussed with the aim of offering in‐depth insights in combined terpolymers and ternary systems. Recent exemplary cases of OSCs with multiple donor–acceptor pairs are summarized and more advanced research and perspectives for further developments in this field are highlighted.     

DNA-modified nanocrystalline diamond thin-films as stable,biologically active substrates

Diamond, because of its electrical and chemical properties, may be a suitable material for integrated sensing and signal processing. But methods to control chemical or biological modifications on diamond surfaces have not been established. Here, we show that nanocrystalline diamond thin-films covalently modified with DNA oligonucleotides provide an extremely stable, highly selective platform in subsequent surface hybridization processes. We used a photochemical modification scheme to chemically modify clean, H-terminated nanocrystalline diamond surfaces grown on silicon substrates, producing a homogeneous layer of amine groups that serve as sites for DNA attachment. After linking DNA to the amine groups, hybridization reactions with fluorescently tagged complementary and non-complementary oligonucleotides showed no detectable non-specific adsorption, with extremely good selectivity between matched and mismatched sequences. Comparison of DNA-modified ultra-nanocrystalline diamond films with other commonly used surfaces for biological modification, such as gold, silicon, glass and glassy carbon, showed that diamond is unique in its ability to achieve very high stability and sensitivity while also being compatible with microelectronics processing technologies. These results suggest that diamond thin-films may be a nearly ideal substrate for integration of microelectronics with biological modification and sensing.     

Development and analysis of high density poly ethylene (HDPE) nano SiO2 and wood powder reinforced polymer matrix hybrid nano composites

ABSTRACT

The Hybrid composites are the emerging materials which uses two or more reinforced particles or fibres simultaneously. As potential applications of the composites, wood reinforced thermoplastic composites are commercially attractive for high volume applications, but their properties can be enhanced by adding Nano SiO₂ particles. Wood powder and nano SiO₂ were mixed with high density polyethylene as matrix material. Wood powder with fixed 5 wt. % and Nano SiO₂ with varying weight % (3, 5, 7 wt. %) are reinforced in HDPE to manufacture composite materials by compression moulding process. Mechanical properties including tensile strength, flexural strength and Izod impact strength were evaluated and it was revealed that tensile strength and flexural strength were obtained maximum at 5 wt. % of Nano SiO₂ and impact strength was obtained maximum at 3 wt. % of Nano SiO₂.     

A task–technology fit view of learning management system impact

Learning management systems (LMSs) are very widely used in higher education. However, much of the research on LMSs has had a technology focus or has been limited to studies of adoption. In order to take advantage of the potential associated with LMSs, research that addresses the role of LMSs in learning success is needed. Task–technology fit is one factor that has been shown to influence both the use of information systems and their performance impacts. The study described in this paper used the technology-to-performance chain as a framework to address the question of how task–technology fit influences the performance impacts of LMSs. The results provide strong support for the importance of task–technology fit, which influenced perceived impact on learning both directly and indirectly via level of utilization. Whilst task–technology fit had a strong influence on perceived impact of the LMS on learning it only had a weak impact on outcomes in terms of student grades. Contrary to expectations, facilitating conditions and common social norms did not play a role in the performance impacts of LMSs. However, instructor norms had a significant effect on perceived impact on learning via LMS utilization.