275 research outputs found

    Preparation of Biomass-Derived Furfuryl Acetals by Transacetalization Reactions Catalyzed by Nanoporous Aluminosilicates

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    Nanoporous aluminosilicate materials efficiently catalyze the formation of furaldehyde dimethyl acetal directly from methanol in high yields and in short reaction times. The facile nature of this reaction has led to the development of a telescoped protocol in which the acyclic acetal is produced in situ and subsequently functions as a substrate for a transacetalization reaction with glycerol to produce the corresponding dioxane and dioxolane products, which are potentially useful biofuel additives. These products are generated in high yield without the requirement for high reaction temperatures of prolonged reaction times, and the aluminosilicate catalysts are operationally simple to produce, are effective with either purified furaldehyde or crude furaldehyde, and are fully recyclable

    Changes in 10-12 year old's fruit and vegetable intake in Norway from 2001 to 2008 in relation to gender and socioeconomic status - a comparison of two cross-sectional groups

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    Background Norwegian children and adolescents eat less than half of the recommended 5 portions of fruit and vegetables (FV) per day. Gender and socioeconomic disparities in FV consumption shows that boys and children of lower socioeconomic status (SES) eat less FV than girls and high SES children. We also know that accessibility and preferences has been identified as two important determinants of FV intake. The objectives of this study were to compare FV intake among Norwegian 6th and 7th graders in 2001 and 2008, to explore potential mediated effects of accessibility and preferences on changes in FV over time, to explore whether these changes in FV intake was moderated by gender and/or SES and whether a moderated effect in FV intake was mediated by accessibility and preferences of FV. Methods The baseline survey of the Fruits and Vegetables Make the Marks project was conducted in 2001 at 38 randomly chosen schools in two Norwegian counties. A second survey was conducted at the same schools in 2008. A total of 27 schools participated in both surveys (2001 n = 1488, 2008 n = 1339). FV intake was measured by four food frequency questions (times/week) in a questionnaire which the pupils completed at school. SES was based on parents' reports of their own educational level in a separate questionnaire. The main analyses were multilevel linear regression analyses. Results A significant year*parental educational level interaction was observed (p = 0.01). FV intake decreased among pupils of parents with lower educational level (13.9 vs. 12.6 times/week in 2001 and 2008, respectively), but increased among pupils of parents with higher education (14.8 vs. 15.0 times/week, respectively). This increasing SES disparity in FV intake was partly mediated by an increasing SES disparity in accessibility and preferences over time, wherein children with higher educated parents had a steeper increase in accessibility and preferences over time than children with lower educated parents. The year*sex interaction was not significant (p = 0.54). Conclusions This study shows an increase in SES disparities in 6th and 7th graders FV intake from 2001 to 2008, partly mediated by an increasing SES disparity in accessibility and preferences of FV

    PEMETAAN DISTRIBUSI PAPARAN RADIOISOTOP PADA DAERAH PERSAWAHAN DI OESENA AKIBAT KONTAMINASI DARI SUMBER RADIOISOTOP

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    Abstrak Telah dilakukan penelitian di wilayah persawahan Desa Oesena Kecamatan Amarasi Kabupaten Kupang mengenai paparan radioisotop alam. Tujuan penelitian ini memetakan distribusi paparan radioisotop pada wilayah persawahan yang diduga terkontaminasi radioisotop dari bukit setan. Metode penelitian yang digunakan terdiri dari observasi, mapping, dan analisis interpretasi data. Data yang diperoleh dalam penelitian di lapangan adalah nilai cacah radiasi permenit(cpm), elevasi dan data lintang bujur, data-data ini yang kemudian digunakan untuk membuat peta distribusi. Peta dibuat menggunakan software surfer 11. Hasil penelitian menunjukkan nilai cacah radiasi tertinggi adalah 33 cpm dan terendah adalah 8 cpm. Setelah dipetakan diketahui luas wilayah dengan nilai cacah tinggi pada 2 wilayah yaitu 736 m2 dari luas keseluruhan 33.024 m2 pada wilayah A dan 128 m2 dari luas keseluruhan 21.168 m2 pada wilayah B, dengan akumulasi tertinggi wilayah A berada pada bagian barat, dan wilayah B berada pada bagian timur. Cacah radiasi pada lokasi persawahan masih berada pada batas toleransi sesuai standar bahaya minimum (33 cpm) sesuai yang diperbolehkan. Kata kunci : Radioisotop, Cpm. Abstract Has conducted research in the area of the rice field at Oesena Village, Sub-district of Amarasi, Kupang Regency, Nusa Tenggara Timur. for exposure to natural radioisotopes. The aims of research to map the distribution of the radioisotope in the rice-fields exposure suspected to be contaminated radioisotope of the hill demons. The method used consists of observation, mapping, and analysis of data interpretation. The data obtained in research in the field is the value of the radiation count per minute (cpm), elevation and latitude and longitude of data, these data are then used for producing a map of the distribution. The results showed the highest radiation count value is 33 cpm and the lowest is 8 cpm. Having mapped the known area of high count value in two areas, namely 736 m2 of total area 33.024 m2  and 128 m2 of total area of 21.168 m2, with the highest accumulation region 1 is located in the western part, and a second region located on the eastern side. Chopped radiation on the location of rice fields are still within the tolerance limits according to the standard minimum hazard (33 cpm) as allowed. Keywords : Radioisotopes, Cpm

    Study protocol: can a school gardening intervention improve children's diets?

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    BACKGROUND: The current academic literature suggests there is a potential for using gardening as a tool to improve children's fruit and vegetable intake. This study is two parallel randomised controlled trials (RCT) devised to evaluate the school gardening programme of the Royal Horticultural Society (RHS) Campaign for School Gardening, to determine if it has an effect on children's fruit and vegetable intake. METHOD/DESIGN: Trial One will consist of 26 schools; these schools will be randomised into two groups, one to receive the intensive intervention as "Partner Schools" and the other to receive the less intensive intervention as "Associate Schools". Trial Two will consist of 32 schools; these schools will be randomised into either the less intensive intervention "Associate Schools" or a comparison group with delayed intervention. Baseline data collection will be collected using a 24-hour food diary (CADET) to collect data on dietary intake and a questionnaire exploring children's knowledge and attitudes towards fruit and vegetables. A process measures questionnaire will be used to assess each school's gardening activities. DISCUSSION: The results from these trials will provide information on the impact of the RHS Campaign for School Gardening on children's fruit and vegetable intake. The evaluation will provide valuable information for designing future research in primary school children's diets and school based interventions. TRIAL REGISTRATION: ISRCTN11396528

    Short term electricity demand forecasting using partially linear additive quantile regression with an application to the unit commitment problem

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    Abstract Short term probabilistic load forecasting is essential for any power generating utility. This paper discusses an application of partially linear additive quantile regression models for predicting short term electricity demand during the peak demand hours (i.e. from 18:00 to 20:00) using South African data for January 2009 to June 2012. Additionally the bounded variable mixed integer linear programming technique is used on the forecasts obtained in order to find an optimal number of units to commit (switch on or off. Variable selection is done using the least absolute shrinkage and selection operator. Results from the unit commitment problem show that it is very costly to use gas fired generating units. These were not selected as part of the optimal solution. It is shown that the optimal solutions based on median forecasts ( Q 0.5 quantile forecasts) are the same as those from the 99th quantile forecasts except for generating unit g 8 c , which is a coal fired unit. This shows that for any increase in demand above the median quantile forecasts it will be economical to increase the generation of electricity from generating unit g 8 c . The main contribution of this study is in the use of nonlinear trend variables and the combining of forecasting with the unit commitment problem. The study should be useful to system operators in power utility companies in the unit commitment scheduling and dispatching of electricity at a minimal cost particularly during the peak period when the grid is constrained due to increased demand for electricity

    Micro-level economic factors and incentives in Children's energy balance related behaviours findings from the ENERGY European cross-section questionnaire survey

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    <p>Abstract</p> <p>Background</p> <p>To date, most research on obesogenic environments facing school children has focused on physical and socio-cultural environments. The role of economic factors has been investigated to a much lesser extent. Our objective was to explore the association of micro-level economic factors and incentives with sports activities and intake of soft drinks and fruit juice in 10-12 year-old school children across Europe, and to explore price sensitivity in children’s soft drink consumption and correlates of this price sensitivity.</p> <p>Methods</p> <p>Data for the study originate from a cross-sectional survey undertaken in seven European countries (Belgium, Greece, Hungary, Netherlands, Norway, Slovenia and Spain) in 2010 among 10-12 year-old school children and their parents. In total, 7234 child questionnaires and 6002 parent questionnaires were completed. The child questionnaire included questions addressing self-reported weekly intake of soft drinks and fruit juices and time spent on sports activities, perception of parental support for sports activities, use of pocket money for soft drinks and perceived price responsiveness. Parent questionnaires included questions addressing the role of budget and price considerations in decisions regarding children’s sports activities, soft drink consumption, home practices and rules and socio-demographic background variables. Data were analysed using multiple linear regression and discrete-choice (ordered probit) modelling.</p> <p>Results</p> <p>Economic factors were found to be associated with children’s sports participation and sugary drink consumption, explaining 27% of the variation in time for sports activities, and 27% and 12% of the variation in the children’s soft drink and juice consumption, respectively. Parents’ financial support was found to be an important correlate (Beta =0.419) of children’s sports activities. Children’s pocket money was a strong correlate (Beta =21.034) of soft drink consumption. The majority of the responding children reported to expect that significantly higher prices of soft drinks would lead them to buy less soft drinks with their own pocket money, but a majority of parents did not expect higher soft drink prices to reduce their children’s soft drink consumption.</p> <p>Conclusions</p> <p>We conclude that economic factors, especially parents’ financial support and amount of pocket money, appear to be of importance for children’s sports participation and soft drink consumption, respectively.</p

    Reporting accuracy of packed lunch consumption among Danish 11-year-olds differ by gender.

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    Background: Packed lunch is the dominant lunch format in many countries including Denmark. School lunch is consumed unsupervised, and self-reported recalls are appropriate in the school setting. However, little is known about the accuracy of recalls in relation to packed lunch. Objective: To assess the qualitative recall accuracy of self-reported consumption of packed lunch among Danish 11-year-old children in relation to gender and dietary assessment method. Design: A cross-sectional dietary recall study of packed lunch consumption. Digital images (DIs) served as an objective reference method to determine food items consumed. Recalls were collected with a lunch recall questionnaire (LRQ) comprising an open-ended recall (OE-Q) and a pre-coded food group prompted recall (PC-Q). Individual interviews (INTs) were conducted successively. The number of food items was identified and accuracy was calculated as match rates (% identified by DIs and reported correctly) and intrusion rates (% not identified by DIs but reported) were determined. Setting and subjects: Three Danish public schools from Copenhagen. A total of 114 Danish 11-year-old children, mean (SE) age=11.1 (0.03), and body mass index=18.2 (0.26). Results: The reference (DIs) showed that girls consumed a higher number of food items than boys [mean (SE) 5.4 (0.25) vs. 4.6 (0.29) items (p=0.05)]. The number of food items recalled differed between genders with OE-Q recalls (p=0.005) only. Girls&#x2019; interview recalls were more accurate than boys&#x2019; with higher match rates (p=0.04) and lower intrusion rates (p=0.05). Match rates ranged from 67&#x2013;90% and intrusion rates ranged from 13&#x2013;39% with little differences between girls and boys using the OE-Q and PC-Q methods. Conclusion: Dietary recall validation studies should not only consider match rates as an account of accuracy. Intrusions contribute to over-reporting in non-validation studies, and future studies should address recall accuracy and inaccuracies in relation to gender and recall method
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