Evaluation of a high temperature solar thermal seasonal borehole storage

A solar thermal system with seasonal borehole storage for heating of a residential area in Anneberg, Sweden, approximately 10 km north of Stockholm, has been in operation since late 2002. Originally, the project was part of the EU THERMIE project “Large-scale Solar Heating Systems for Housing Developments” (REB/0061/97) and was the first solar heating plant in Europe with borehole storage in rock not utilizing a heat pump. Earlier evaluations of the system show lower performance than the preliminary simulation study, with residents complaining of a high use of electricity for domestic hot water (DHW) preparation and auxiliary heating. One explanation mentioned in the earlier evaluations is that the borehole storage had not yet reached “steady state” temperatures at the time of evaluation. Many years have passed since then and this paper presents results from a new evaluation. The main aim of this work is to evaluate the current performance of the system based on several key figures, as well as on system function based on available measurement data. The analysis show that though the borehole storage now has reached a quasi-steady state and operates as intended, the auxiliary electricity consumption is much higher than the original design values largely due to high losses in the distribution network, higher heat loads as well as lower solar gains.

Testing Seasonal Unit Roots in Data at Any Frequency, an HEGY approach

This paper generalizes the HEGY-type test to detect seasonal unit roots in data at any frequency, based on the seasonal unit root tests in univariate time series by Hylleberg, Engle, Granger and Yoo (1990). We introduce the seasonal unit roots at first, and then derive the mechanism of the HEGY-type test for data with any frequency. Thereafter we provide the asymptotic distributions of our test statistics when different test regressions are employed. We find that the F-statistics for testing conjugation unit roots have the same asymptotic distributions. Then we compute the finite-sample and asymptotic critical values for daily and hourly data by a Monte Carlo method. The power and size properties of our test for hourly data is investigated, and we find that including lag augmentations in auxiliary regression without lag elimination have the smallest size distortion and tests with seasonal dummies included in auxiliary regression have more power than the tests without seasonal dummies. At last we apply the our test to hourly wind power production data in Sweden and shows there are no seasonal unit roots in the series.

Testing for Seasonal Unit Roots when Residuals Contain Serial Correlations under HEGY Test Framework

This paper introduces a corrected test statistic for testing seasonal unit roots when residuals contain serial correlations, based on the HEGY test proposed by Hylleberg,Engle, Granger and Yoo (1990). The serial correlations in the residuals of test regressionare accommodated by making corrections to the commonly used HEGY t statistics. Theasymptotic distributions of the corrected t statistics are free from nuisance parameters.The size and power properties of the corrected statistics for quarterly and montly data are investigated. Based on our simulations, the corrected statistics for monthly data havemore power compared with the commonly used HEGY test statistics, but they also have size distortions when there are strong negative seasonal correlations in the residuals.

Sensory adaptability of foods with added Lupin (Lupinus angustifolius) kernel fibre using pre-set criteria

Fiber-enriched white bread, muffin. pasta, orange juice, and breakfast bar were prepared with lupin (Lupin us angusti/olius) kernel fiber. Consumer panelists (n = 44) determined that all these fiber-enriched foods, except orange juice, fulfilled pre-set acceptability criteria. Fiber enrichment did not change overall acceptability (p> 0.05) of the bread and pasta, but reduced overall acceptability (p < 0.05) of the muffin, orange juice, and breakfast bar. In all fiber-enriched products, flavor was the attribute most highly correlated with overall acceptability (p < 0.05). The lupin kernel fiber used in this study therefore appears to have potential as a 'nonintrusive' ingredient in some processed cereal-based foods_ For other applications, fiber modification appears worthy of investigation to accomplish 'nonintrusive' fiber enrichment.

Calcium chemistry of Blue Lake, Mt Gambier, Australia, and relevance to remarkable seasonal colour changes

Calcium speciation and other water quality variables in the Blue Lake, Mt Gambier, Australia, were monitored between August 1999 and August 2000 in order to test previously proposed mechanisms for the seasonal colour changes of this lake. The concentration of calcite was found to be highest in winter when the lake appears grey, and lowest in summer when the lake appears blue. A potential component of the colour change mechanism is therefore identified in which the lake is grey in winter because of non-selective scattering of light by calcite particles, and blue in summer because of the absence of absorbing or scattering impurities.

Foods prepared outside the home: association with selected nutrients and body mass index in adult Australians

Objective: To determine the proportion of energy from foods prepared outside the home (FPOH) and the relationships with energy and nutrient intakes and body mass index (BMI).

Design: A nutrition survey of a representative sample of the Australian population aged 18 years and over (n = 10 863). Measure used was a 24-hour dietary recall. Underreporters (energy intake/estimated basal metabolic rate (EI/BMR) <0.9) were excluded from analysis. Daily energy and selected nutrient intakes were calculated using a 1996 nutrient composition database for all foods/beverages during the 24-hour period.

Results: On average FPOH contributed a significant 13% to total energy intake. About a third of the sample had consumed FPOH in the last 24 hours and on average this group consumed a third of their total energy as FPOH. The relative contributions of fat (for men and women) and alcohol (for women) were significantly higher for those in the top tertile of FPOH consumers. The intakes of fibre and selected micronutrients (calcium, iron, zinc, folate and vitamin C) were significantly lower in this group. After adjustment for age and income no relationship between FPOH and BMI was observed.

Conclusions: FPOH make a significant contribution to the energy intake of a third of the Australian population. FPOH contribute to poor nutritional intakes. Altering the supply of FPOH may be an effective means of improving diets at a population level.

The promise of plant based foods - new directions?

The consumption of a plant based diet has important implications for health and the environment, yet little is known about the attitudes of the food industry and media personnel towards plant foods and the barriers they face to the production, retail and promotion of such foods. Therefore, 32 Australian food industry and media representatives participated in individual interviews on plant foods. Participants saw strong health benefits associated with the consumption of plant foods. Barriers to production or retail of plant foods that were identified included drought and lack of grower control over the distribution and marketing of their product. Participants believed that we are in the early stages of learning about consumer attitudes and preferences to plant foods. In addition to the greater financial resources necessary to be able to compete with less healthy foods, better cooperation within and between industry and non-industry groups was identified as a key factor that could help in their endeavours to promote plant foods.

Fattening foods - perceptions and misconceptions: a qualitative and quantitative exploration

Describes adults' perceptions and beliefs about foods that are considered "fattening". Use of qualitative and quantitative methods to determine the prevalence of the perceptions among adults; Range of factors that are considered when judging foods as "fattening"; Limitations in the public's understandings of "fattening foods" which are inconsistent with dietary recommendations.

Energy density of foods and beverages in the Australian food supply: influence of macronutrients and comparison to dietary intake

Objectives: The energy density (ED) of the diet is considered an important determinant of total energy intake and thus energy balance and weight change. We aimed to compare relationships between ED and macronutrient content in individual food and beverage items as well as population diet in a typical Western country. Design: Nutrient data for 3673 food items and 247 beverage items came from the Australian Food and Nutrient database (AusNut). Food and beverage intake data came from the 1995 Australian National Nutrition Survey (a 24-h dietary recall survey in 13 858 people over the age of 2). Relationships between ED and macronutrient and water content were analysed by linear regression with 95% prediction bands. Results: For both individual food items and population food intake, there was a positive relationship between ED and percent energy as fat and negative relationships between ED and percent energy as carbohydrate and percent water by weight. In all cases, there was close agreement between the slopes of the regression lines between food items and dietary intake. There were no clear relationships between ED and macronutrient content for beverage items. Carbohydrate (mostly sucrose) contributed 91, 47, and 25% of total energy for sugar-based, fat-based, and alcohol-based beverages respectively. Conclusions: The relationship between ED and fat content of foods holds true across both population diets and individual food items available in the food supply in a typical Western country such as Australia. As high-fat diets are associated with a high BMI, population measures with an overall aim of reducing the ED of diets may be effective in mediating the growing problem of overweight and obesity.

Sensory acceptability of foods containing Australian sweet lupin (Lupinus angustifolius) flour

Foods containing Australian sweet lupin (Lupinus angustifolius) flour (ASLF) were assessed by consumer panelists (n= 54) in comparison to wheat flour (control) and defatted soy flour (DFSF) products. All ASLF products were rated in the acceptable half of the evaluation scale. General acceptability of ASLF chocolate chip cookies and breakfast bars was rated similarly to the control and DFSF variants (P > 0.05). ASLF pasta was rated lower than control but higher than DFSF pasta (P < 0.05), whereas ASLF addition reduced the general acceptability of muffins and bread (P < 0.05) compared with the other variants. Some ASLF products appeared palatable whereas ASLF incorporation rate in others requires reduction.

Seasonal variability in whale encounters in the Western Antarctic Peninsula

Cetacean sighting surveys were conducted as part of nine multidisciplinary research cruises over late summer, autumn and winter of 2 years (2001–2003) during the Southern Ocean Global Ocean Ecosystems (SO GLOBEC) program. Sea-ice cover differed markedly between years, with apparent effects on cetacean distribution. No ice was present until late June in 2001, while the previous winter sea ice never fully retreated (>30% cover) during the 2002 or 2003 summer, thus increasing the proportion of thicker and more complex ice, including multi-year floes. Humpback (237 sightings; 537 individuals) and minke (103 sightings: 267 individuals) whales were the most commonly detected species. Data from seven comparable cruises were used to identify habitat for minke and humpback whales over five geographically distinct spatial divisions in the study area. In all years, both species were predominantly found in near coastal habitat, particularly in the fjords where complex habitat likely concentrated prey. In 2002 and 2003 the presence of sea ice provided additional feeding habitat, and the numbers of minkes (in winter) and humpbacks (late summer and autumn) in the area doubled compared with 2001. Humpbacks in particular were concentrated at the ice boundaries during late summer and autumn, while minke numbers increased in the winter that followed and occupied ice-covered areas along the entire shelf edge. Important resource sites for these species are mainly located in near-coastal areas and are used in all years, but when ice margins exist and intersect with resource sites they attract much larger numbers of animals due to the dynamics between sea ice and prey.

Aggregate planning for seasonal demand : reconciling theory with practice

Purpose: The paper reports on the ramifications for production planning when monthly sales exhibit predictable seasonal highs and lows. The literature first acknowledged and dealt with the (aggregate planning) problem 50 years ago. Nevertheless, there is neither evidence that industry has adopted any of the mathematical techniques that were subsequently developed, nor a convincing explanation as to why not. Hence this research sets out to discover the methods manufacturers use to cope with seasonal demand, and how germane the published algorithms really are.

Design/methodology/approach: Forty-two case studies were compiled by interviewing senior managers and then conducting plant tours. No prior assumptions were made and the list of questions covered the gamut of production planning.

Findings: The main finding is that manufacturers select a straightforward production strategy, right from the outset, so the fundamental cost-balancing format is not relevant. The majority pick a “chase” strategy, since most organizations subscribe to a “just in time” ethos. Whenever a different strategy is preferred the rationale springs from skilled labour considerations or binding facilities constraints. The chosen strategy serves as a road map for resources acquisitions, and the master production schedule is constructed directly. So, the complex issue of how to disaggregate an optimal aggregate plan never even arises. Managers do not seek perfect solutions, but strive to eliminate, or contain, the most significant marginal costs. The nature of the business determines the most appropriate tactics to employ.

Originality/value: These findings break the mould as far as orthodox aggregate planning is concerned and show why theory is at odds with practice, whilst reaffirming the importance of concepts such as “flexibility”, “integration”, and “just-in-time production”.

Beliefs about genetically modified foods : a qualitative and quantitative exploration

This study is aimed to examine consumers' beliefs about genetically modified foods. Ten focus group interviews of community members and a random questionnaire-based mail survey of 500 Australian (Victorian) adults were conducted (58% response). Participants were generally negative about genetically modified foods, with concerns being raised about them being unnatural, difficult to identify, and having unknown long-term health and environmental effects. Many participants were unaware of or disagreed with the benefits of genetically modified foods that are promoted by its advocates and there were some misconceptions present. These findings provide information for both advocates and opponents of genetically modified foods and a basis for future larger-scale research.