491 research outputs found

    Once despised now desired: innovative land use and management of multilayered Pumice Soils in the Taupo and Galatea areas, central North Island, New Zealand

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    The tour brings together innovative land use change and management associated with dairy farming, and land-based effluent disposal, on weakly weathered and multi-layered, glass-rich, Pumice Soils (Vitrands) in the Taupo and Galatea areas. These changes and their effects, together with environmental and sustainability issues, form a central theme of the trip. Four main stops are planned, two before lunch and two after: (1) plantation pine-to-dairy farm conversion and impacts, the Taupo eruption deposits (AD 232 ± 10) and the Taupo soil, at Tahorakuri; (2) overview of the application of secondary-treated wastewater and nitrogen leaching and uptake, Rotokawa; (3) a sequence of five Holocene tephras and buried soils, including Kaharoa eruption deposits (AD 1314 ± 12) and the Galatea soil, Smeith Farm, Murupara; and (4) enhancing pasture production on ‘new’ soils formed by excavating and mixing (‘flipping’) buried soil horizons (paleosols) on Smeith’s farm. During the trip − which helps mark Waikato University’s 50th anniversary − we will see a spectacular range of volcanic and fluvial landscapes and deposits, together with impacts of tectonism, as we traverse the famous Taupo Volcanic Zone ((TVZ) in the central volcanic region. Landforms and soils dominated by tephras (volcanic ash) become generally younger towards the loci of volcanic activity. Extensive areas of soils have been formed repeatedly from the fragmental eruptive products of the two most frequently active and productive rhyolite (silica-rich) volcanic centres known, namely Taupo and Okataina. Thus soil stratigraphy and upbuilding pedogenesis form a second theme on the trip. The first part of the guidebook thus contains sections including (i) volcanism and its products, (ii) Quaternary volcanism in TVZ including deposits erupted recently from Taupo and Tarawera volcanoes from which Pumice Soils have been formed, (iii) tephra-derived soils including Pumice Soils, their classification, special problems, and (low) fertility, (iv) allophane and its formation, and (v) the interplay between geological and pedological processes relating to tephras (upbuilding pedogenesis). The second part then comprises notes and illustrations pertaining to each stop (note that figure and table numbers are self-contained at each stop, or not used). Broad overviews of the region’s geology are covered by Leonard et al. (2010), and the soils are outlined by Rijkse and Guinto (2010) and S-map. Further compilations of data are available in tour guides by Lowe (2008) and Lowe et al. (2010)

    The SASPREN primary care survey - who consults the family doctor?

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    Objective. To describe selected characteristics of patients consulting general family practitioners in the Western Cape.Design. A cross-sectional survey design was employed in which doctors completed a structured questionnaire during or immediately after each consultation.Setting. Data were collected by family practitioners in private practice who were affiliated to the South African Sentinel Practitioner Research Network (SASPREN).Participants. All patients who had a face-to-face encounter wrth the doctor at his/her surgery. A total of 2 473 such encounters was included. Main outcome measures. Age, sex, race, method of payment and smoking status.Results. Females outnumbered males in all race groups except blacks, where they comprised 48% of patients. Most patients were under the age of 14 years (23.3%) or between 25 and 44 years (33.3%). However, after the demography of the ca1chment population was taken into account, the highest utilisation of general practitioner services was found to be at extremes of age. This utilisation pattern was demonstrated in both sexes and all races. In relation to their distribution in the population. whites and Indians are over~represented in private practice while blacks and coloureds are under-represented. The bulk of patients (67%) pay for general practitioner services via some form of insurance (medical aid or benefit fund). but significant differences exist across race groups. In the case of blacks and Indians, the majority (72% and 64% respectively) of consultations are funded 'out of pocket'. An alamingly high smoking prevalence was found in black and coloured men. In all race/sex groups smoking rates peak between 25 and 44 years. In this age group, 68.6% of black men and 73.3% of coloured men were current smokers.Conclusions. This study provides essential information on patients seen in family practice. Access to family doctor selVices in the Western Cape should be improved for blacks and coIoureds. There is an urgent need for smoking cessation interventions in the region

    Gravity model improvement using GEOS-3 (GEM 9 and 10)

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    The use of collocation permitted GEM 9 to be a larger field than previous derived satellite models, GEM 9 having harmonics complete to 20 x 20 with selected higher degree terms. The satellite data set has approximately 840,000 observations, of which 200,000 are laser ranges taken on 9 satellites equipped with retroreflectors. GEM 10 is complete to 22 x 22 with selected higher degree terms out to degree and order 30 amounting to a total of 592 coefficients. Comparisons with surface gravity and altimeter data indicate a substantial improvement in GEM 9 over previous satellite solutions; GEM 9 is in even closer agreement with surface data than the previously published GEM 6 solution which contained surface gravity. In particular the free air gravity anomalies calculated from GEM 9 and a surface gravity solution are in excellent agreement for the high degree terms

    The contribution of dark-green leafy vegetables to total micronutrient intake of two- to five-year-old children in a rural setting

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    This study determined the contribution of dark-green leafy vegetables (DGLV) to total micronutrient intake of two- to fiveyear- old children residing in two neighbouring rural villages in KwaZulu-Natal where production and consumption of these vegetables were promoted. A repeated cross-sectional study that included five repeated 24 h dietary recalls per study period was done during February (n=79), May (n=74), August (n=75) and November (n=78) of 2005 by interviewing the caregivers. Consumption of spinach (mostly Swiss chard) and imifino (a collective term for various dark-green leaves) complemented each other, with imifino being consumed mostly during the first and last quarter of the year, and spinach (mostly Swiss chard) during the 3rd quarter. The proportion of children who consumed DGLV during the 5 d recall period ranged from 36% (May survey) to 86% (February survey), and the average number of times that children consumed it ranged from 1.4 (May survey) to 2.2 (February survey). The average portion size consumed was approximately œ cup (87 ± 56 g for spinach; 87 ± 38 g for imifino). For children consuming DGLV, these vegetables contributed significantly to dietary intake of calcium (21 to 39% of total intake), iron (19 to 39%), vitamin A (42 to 68%) and riboflavin (9 to 22%).In conclusion, DGLV made a significant contribution towards total nutrient intake of the children for several of the micronutrients. This contribution can potentially be increased should these vegetables be consumed more frequently and by a larger proportion of the children.Keywords: dark-green leafy vegetables, dietary intake, micronutrients, children, rural, South Afric

    Towards energy management during the machining of titanium alloys

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    The manufacturing industry needs to address challenges as regards to the machining process in the multifaceted context of sustainability. The current cost of energy and the reduction in material reserves highlights the need for machining systems to be more energy-efficient. This paper aims to provide a systematic overview of advanced approaches to manage energy and resource efficiency in cutting operations. The research experimentation focuses on the machining of a selected titanium alloy, Ti6Al4V, using carbide cutting tools. Tool wear, chip formation, cutting force and energy use were measured and analysed for selected cutting parameters. The experimental results illustrate the importance of selecting optimum cutting parameters and machining strategy. The results further help to define the boundary conditions for the various input parameters. Future research is also discussed

    Substance misuse in youth admitted to a psychiatric emergency unit

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    Objectives. To investigate the pattern of substance misuse in youth admitted to a psychiatric emergency unit of a 'major hospital, and to compare regular users of cannabis,methaqualone and alcohol with the rest of the sample in terms of selected psychosocial variables.Study population. Consecutive patients aged 25 years or younger admitted to a psychiatric emergency unit over a 3month period.Method. Patients completed a standardised questionnaire .containing questions about their family, social, economic and educational backgrounds. Their current psychiatric folder was examined to ascertain mental state and behaviour on admission as well as previous psychiatric contacts and hospitalisation. Particular attention was paid to the use of cannabis, methaqualone and alcohol For each substance patients were divided into two groups, namely those who did not use the substance or who used it infrequently, and regular users. Unadjusted odds ratios were used to document the relationship between substance use and the selected psychosocial variablesResults. One hundred and fourteen patients were assessed, of which number 61 (53.5%) were male and 98 (86%) were single. The group consisted of 37 blacks (32.5%), 56 coloureds (49.1%) and 21 whites (18.4%)_ Alcohol was . regularly used by 30 patients (263%), cannabis by 29 (25.4%), methaqualone by 11 (9.6%), and any-of these substances by 46 patients (40.4%). Unadjusted odds ratios showed that there was a significant association between regular use of alcohol and cannabis and male gender, dropping out of school, previous psychiatric treatment, and an absence of both depression and suicidal ideation; and between regular cannabis use and bizarre behaviour, auditory hallucinations and disorganised or incoherent speech. Methaqualone use was associated with hostile threats.Conclusions. In the study population substance use was associated with various adverse psychosocial circumstances; these may alert the practitioner to the possibility of substance use. Cannabis misuse was suggested by behavioural, perceptual and speech abnormalities on mental state examination

    The intake and quality of breakfast consumption in adolescents attending public secondary schools in the North West province, South Africa

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    Objectives: The objectives of the study were to determine the proportion and quality of breakfast intake in adolescents, and to determine the effect of breakfast intake and quality on overall diet quality.Design: A cross-sectional quantitative study design was used.Setting: The setting was seven public secondary schools in Potchefstroom and the surrounding areas in North West province.Subjects: The subjects were randomly selected adolescents in grades 9-11 (n = 244).Outcome measures: A self-administered demographic questionnaire was completed by the adolescents. Single 24-hour recall, using the four-stage multiple-pass method, was conducted to obtain information on breakfast and dietary intake for the day. Breakfast quality was measured by applying a breakfast quality score. The Diet Quality Index Revised was used to assess the quality of the overall diet. Spearman’s rank correlation coefficient was employed to assess an association between the continuous variables. The chi-square or Fisher’s exact test was utilised to assess an association between the categorical variables.Results: The proportion of breakfast intake and skipping was 81% and 19%, respectively. The mean breakfast quality score was moderate (3.1). No significant difference was shown in the diet quality score for the breakfast eaters and skippers. The breakfast quality score was marginally associated with calcium intake (p-value < 0.0001, r = 0.418), phosphorous intake (p-value < 0.0001, r = 0.378) and total diversity score (p-value < 0.0001, r = 0.369).Conclusion: The proportion of breakfast skipping, moderate quality of the breakfast consumed and trend of improved nutrient intake with improved breakfast quality highlights the need for breakfast education and intervention as part of the Integrated School Health Policy.Keywords: adolescent, breakfast, breakfast quality, diet quality, adolescenc

    Recent developments in sustainable manufacturing of gears: a review

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    Abstract: Environment awareness is of the utmost importance to all socially responsible manufacturers. To be competitive on a global scale manufacturing needs to be aligned with various strict environmental regulations. The manufacturing industry at large is striving to improve productivity and product quality while maintaining a clean and sustainable environment. This can only be achieved by adopting sustainable techniques of manufacturing which include minimizing the number of manufacturing steps by employing advanced and alternative methods, environment-friendly lubricants and lubrication techniques while machining, reducing wastage, active waste management and minimizing energy consumption etc. Gear manufacturing industries, the major service providers to all other industrial and manufacturing segments are also focusing on to implement the techniques targeting overall sustainability. Some of the recent developments to achieve sustainability in gear manufacturing can be summarized as reducing the use of mineral-based cutting fluids by employing alternative lubrication techniques i.e. minimum quantity lubrication (MQL) and dry machining, material saving, waste reduction, minimizing energy consumption and maintaining economic efficiency by reducing the number of gear manufacturing stages (eliminating the necessity of finishing processes) by utilizing advanced methods such as gear rolling and wire electric-discharge machining (WEDM), and finally increasing productivity by minimizing tool wear at high gear cutting speeds through the use of alternative tool materials and coatings. This paper reviews and amasses the current state of technology for sustainable manufacturing of gears and also recommends ways to improve the productivity and quality while simultaneously ensuring environmental sustainability

    Distortional Buckling of Cold-formed Stainless Steel Compression Members

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    In this paper the critical local buckling strength of cold-formed stainless steel compression members, with special emphasis on the method developed by Lau and Hancock for distortional buckling is discussed. Cold-formed stainless steel channel and I-section members under axial compression in distortional buckling are analysed. A control experiment is carried out for comparing analytical methods with a finite element method and experimental values

    Poking Holes and Cutting Corners to Achieve Clifford Gates with the Surface Code

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    The surface code is currently the leading proposal to achieve fault-tolerant quantum computation. Among its strengths are the plethora of known ways in which fault-tolerant Clifford operations can be performed, namely, by deforming the topology of the surface, by the fusion and splitting of codes, and even by braiding engineered Majorana modes using twist defects. Here, we present a unified framework to describe these methods, which can be used to better compare different schemes and to facilitate the design of hybrid schemes. Our unification includes the identification of twist defects with the corners of the planar code. This identification enables us to perform single-qubit Clifford gates by exchanging the corners of the planar code via code deformation. We analyze ways in which different schemes can be combined and propose a new logical encoding. We also show how all of the Clifford gates can be implemented with the planar code, without loss of distance, using code deformations, thus offering an attractive alternative to ancilla-mediated schemes to complete the Clifford group with lattice surgery
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