Control energy consumption and system performance in vector control of voltage source converters

Power electronics plays an important role in the control and conversion of modern electric power systems. In particular, to integrate various renewable energies using DC transmissions and to provide more flexible power control in AC systems, significant efforts have been made in the modulation and control of power electronics devices. Pulse width modulation (PWM) is a well developed technology in the conversion between AC and DC power sources, especially for the purpose of harmonics reduction and energy optimization. As a fundamental decoupled control method, vector control with PI controllers has been widely used in power systems. However, significant power loss occurs during the operation of these devices, and the loss is often dissipated in the form of heat, leading to significant maintenance effort. Though much work has been done to improve the power electronics design, little has focused so far on the investigation of the controller design to reduce the controller energy consumption (leading to power loss in power electronics) while maintaining acceptable system performance. This paper aims to bridge the gap and investigates their correlations. It is shown a more thoughtful controller design can achieve better balance between energy consumption in power electronics control and system performance, which potentially leads to significant energy saving for integration of renewable power sources.

Killing Themselves Slowly: India and China's Bad Habits

The world has experienced a public-health miracle in the past half century, as cleaner water, new health technologies, better diet and a host of other improvements have sharply reduced mortality and extended life expectancy in poor countries by as much as 20 years. A substantial portion of those gains has been realized through improvements in infant and child survival. However, the increase in income that was both a cause and effect of this miracle brought with it a new and ironic threat: a steep rise in non-communicable diseases (NCDs) like heart ailments and cancer.

The stability of alcohol consumption between age 16 and 26: Evidence from a National Birth Cohort Study

This study examined the association between moderate drinking at age 16 (adolescence) and alcohol consumption at age 26 (young adulthood), whilst controlling for possible confounding effects at the individual and family level (assessed at birth and age 10). Using the British Cohort Study (BCS70), 6515 respondents provided data on their adolescent alcohol consumption and other behaviours. Of these, 4392 also completed the survey at age 26. Consumption patterns established in adolescence persisted, to a large degree, into early adulthood. Those adolescents who drank moderately in adolescence drank significantly less in adulthood than those adolescents who drank to heavy or hazardous levels. Implications for health promotion strategies and guidance are discussed.

Participating in a fruit and vegetable intervention trial improves longer term fruit and vegetable consumption and barriers to fruit and vegetable consumption: a follow-up of the ADIT study

BACKGROUND: Fruit and vegetable (FV) based intervention studies can be effective in increasing short term FV consumption. However, the longer term efficacy of such interventions is still unclear. The aim of the current study was to examine the maintenance of change in FV consumption 18-months after cessation of a FV intervention and to examine the effect of participating in a FV intervention on barriers to FV consumption.

METHODS: A follow-up of a randomised controlled FV trial in 83 older adults (habitually consuming ≤2 portions/day) was conducted. At baseline, participants were assigned to continue consuming ≤2 portions FV/day or consume ≥5 portions FV/day for 16-weeks. We assessed FV intake and barriers to FV consumption at baseline, end of intervention and 18-months post-intervention.

RESULTS: At 18-months, mean FV intakes in both groups were greater than baseline. The 5 portions/day group continued to show greater increases in FV consumption at 18-months than the 2 portions/day group (p < 0.01). At 18-months, both groups reported greater liking (p < 0.01) and ease in consuming FV (p = 0.001) while difficulties with consuming FV decreased (p < 0.001). The 2 portions/day group reported greater awareness of FV recommendations at 18-months (p < 0.001).

CONCLUSIONS: Participating in a FV intervention can lead to longer-term positive changes in FV consumption regardless of original group allocation.

TRIAL REGISTRATION: Clinical Trials.gov NCT00858728 .

Effect of major lifestyle risk factors, independent and jointly, on life expectancy with and without cardiovascular disease: results from the Consortium on Health and Ageing Network of Cohorts in Europe and the United States (CHANCES)

Seldom have studies taken account of changes in lifestyle habits in the elderly, or investigated their impact on disease-free life expectancy (LE) and LE with cardiovascular disease (CVD). Using data on subjects aged 50+ years from three European cohorts (RCPH, ESTHER and Tromsø), we used multi-state Markov models to calculate the independent and joint effects of smoking, physical activity, obesity and alcohol consumption on LE with and without CVD. Men and women aged 50 years who have a favourable lifestyle (overweight but not obese, light/moderate drinker, non-smoker and participates in vigorous physical activity) lived between 7.4 (in Tromsø men) and 15.7 (in ESTHER women) years longer than those with an unfavourable lifestyle (overweight but not obese, light/moderate drinker, smoker and does not participate in physical activity). The greater part of the extra life years was in terms of "disease-free" years, though a healthy lifestyle was also associated with extra years lived after a CVD event. There are sizeable benefits to LE without CVD and also for survival after CVD onset when people favour a lifestyle characterized by salutary behaviours. Remaining a non-smoker yielded the greatest extra years in overall LE, when compared to the effects of routinely taking physical activity, being overweight but not obese, and drinking in moderation. The majority of the overall LE benefit is in disease free years. Therefore, it is important for policy makers and the public to know that prevention through maintaining a favourable lifestyle is "never too late".

During pregnancy, recreational drug-using women stop taking ecstasy (3,4-methylenedioxy-N-methylamphetamine) and reduce alcohol consumption but continue to smoke tobacco and cannabis

While recreational drug use in UK women is prevalent, to date there is little prospective data on patterns of drug use in recreational drug-using women immediately before and during pregnancy. A total of 121 participants from a wide range of backgrounds were recruited to take part in the longitudinal Development and Infancy Study (DAISY) study of prenatal drug use and outcomes. Eighty-six of the women were interviewed prospectively while pregnant and/or soon after their infant was born. Participants reported on use immediately before and during pregnancy and on use over their lifetime. Levels of lifetime drug use of the women recruited were high, with women reporting having used at least four different illegal drugs over their lifetime. Most users of cocaine, 3,4-methylenedioxy-N-methylamphetamine (MDMA) and other stimulants stopped using these by the second trimester and levels of use were low. However, in pregnancy, 64% of the sample continued to use alcohol, 46% tobacco and 48% cannabis. While the level of alcohol use reduced substantially, average tobacco and cannabis levels tended to be sustained at pre-pregnancy levels even into the third trimester (50 cigarettes and/or 11 joints per week). In sum, while the use of ‘party drugs’ and alcohol seems to reduce, levels of tobacco and cannabis use are likely to be sustained throughout pregnancy. The data provide polydrug profiles that can form the basis for the development of more realistic animal models.

Brand personification and symbolic consumption among ethnic minority teenage consumers: An empirical study

A plethora of evidence suggests that developed societies such as the United Kingdom are becoming increasingly multicultural by the day. Hence, the diversity of consumption in these societies becomes gradually evident in the form of residents’ age, gender, income and ethnicity. Accordingly, this article explores the brand personification and symbolic consumption in respect of London-based Black African teenage consumers. The study is rooted in the interpretive research paradigm with 36 in-depth interviews conducted with the target respondents. The study shows the interactions of personal, social, cultural, psychological and commercial factors in how these young ethnic minority consumers make their consumption decisions, define and manage their various ‘selves’ in the postmodern society. It specifically highlights that they use symbolic consumption to address their need for acceptance in the society. It updates the extant ethnic minority studies and enriches the current understanding about symbolic consumption and brand personification especially with a focus on a specific segment of the society. The managerial implications of the study are highlighted in the article.

Induction of anti-herbivore defences by direct amphipod consumption and water borne grazer cues in macroalgae

Dissertação mest., Estudos Marinhos e Costeiros, Universidade do Algarve, 2007

A fauna do Novo Mundo e o dealbar da alimentação científica na Europa

As preocupações médicas com o equilíbrio alimentar remontam à Antiguidade, mas apenas a partir do século XVII o assunto começou a ser questionado de modo mais científico e preciso. Dois médicos holandeses de renome, Luís Nunes (1553-1645) e Willem Piso (1611-1678), estudaram esta questão e legaram-nos tratados de inquestionável relevância historiográfica. Destacamos, em particular, Ichtyophagia sive de piscium esu commentarius (“Ictiofagia ou comentário sobre uma alimentação piscívora”, Antuérpia, 1616) e De Indiae utriusque re naturali et medica. Libri quatuordecim (“Sobre a Índia e sua história natural e médica”, Amesterdão, 1658). A defesa de uma dieta que inclua o consumo de peixe é transversal aos dois textos, pois ambos fundam um discurso inaugural em defesa de hábitos alimentares equilibrados numa época de profundas mudanças históricas e culturais impostas pelo contacto com as realidades do exótico Novo Mundo. Esta influência é sobretudo evidente na obra de Piso, especialmente nas suas descrições de espécies de peixes endémicas do Brasil.

Gastronomia Algarvia/Dieta Mediterrânica?

The Mediterranean Diet concept was formulated during the sixties, in association with the food consumption pattern of Mediterranean areas that produced olive oil and shared common health styles. These areas, besides their own cultural and religious differences, share common food habits, such as: - The use of olive oil (supplier of monounsaturated fatty acids and antioxidants); - The abundant use of cereals, mainly under the form of excellent quality bread, flour and pasta (providing fibre and energy); - Large and variegate consumption of fruit (fresh and dried), nuts and vegetables (colourful, rich in fibre, antioxidants and other protective materials); - Abundant use of herbs and spices (rich in antioxidants and other protective materials); - Simple culinary methods, using short cooking times and low temperatures (which enhance the preservation of food nutritional and sensorial characteristics). The Mediterranean Diet reflects a set of characteristics that make it internationally recognized as a health promoter eating pattern, where the relation between monounsaturated and saturated fatty acids is highly advantageous for the former, fibre, vitamins and natural antioxidants intake is high, together with a low consumption of animal protein and salt. The obtained results show contents in protein, lipid and carbohydrates very adequate to the “DRI”; The relation between mono and saturated fatty acids (40:9) should be emphasised, together with the high fibre content. Protective nutrients show remarkable results, with a wide variety of vitamins and minerals, in particular Vitamin A, complex B vitamins, biotin, vit. E, folic acid, iron, manganese and selenium, that are widely recognised as important antioxidants and responsible for the good function of the immune system. In conclusion, tomato soup, consumed traditionally as a poor meal, shows to be a health promoter nutritionally complete recipe.

A importância da gastronomia na experiência turística: o caso do Algarve

Dissertação de mestrado em Turismo e Culturas Urbanas, Escola Superior de Gestão, Hotelaria e Turismo, Universidade do do Algarve, 2016

Assessing energy consumption in supply chains

The paper addresses the transport activities and associated energy consumption involved in the production and supply of two products: jeans and yoghurt. In the case of jeans, the analysis is from the locations in which cotton is grown, to retail outlets in the UK; in the case of yoghurt, the analysis is from the supply of milk on farms, to retail outlets in France. The results show that the transport stages from the point of jeans manufacture to UK port are responsible for the greatest proportion of transport energy use per kilogram of jeans in the UK supply chain. In the case of the French yoghurt supply chains, the results indicate that each of the three transport stages from farm to third-party distribution centre consume approximately the same proportion of total freight transport energy. The energy used on the transport stage for yoghurt from third-party distribution centre to retail outlet varies depending on the type of retail outlet served. Far greater quantities of energy are used in transporting jeans than yoghurts from farm/field to retail outlet. This is explained by the distances involved in the respective supply chains. Both case studies demonstrate that the energy used by consumers transporting goods to their homes by car can be as great as total freight transport energy used in the supply chain from farm/field to retail outlet (per kilogram of product transported).