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

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)

Use of the South African Food Composition Database System (SAFOODS) and its products in assessing dietary intake data: Part II

A number of dietary research methodologies are available for the collection of quantitative dietary intake data. The methods most often used in South Africa include the 24-hour dietary recall, the quantitative food frequency questionnaire, and the dietary intake record. To quantify dietary intake, the information typically required includes the energy and nutrient composition of foods commonly consumed in South Africa. The South African Food Composition Database System (SAFOODS) and its products, e.g. the printed tables and software program FoodFinder3, provide the researcher with the tools to convert food intake data into energy and nutrient(s) intake. FoodFinder3 can be used for the nutrient analysis of the data. It also enables the user to export the data to MS Excel for further analysis and for importing the data into other statistical packages. Coding for the type and quantity of food consumed is required however before the data can be electronically analysed. The Food Quantities Manual of the Medical Research Council provides the necessary information for the conversion of food intake data recorded in household measures into grams of food. To ensure that the quality of the dataset is high, several steps have to be undertaken before statistical analysis and reporting of the data can take place. Appropriate statistical methods are required for the analysis of the data as nutrient intake data are often skewed. Using a standardised protocol, validated questionnaires and the South African Food Composition Database (SAFOOD) for the analysis of dietary intake data could make the pooling of data from small scale or regional studies possible. This may impart an impression of energy and nutrient intake at the national level, and could, at least in part, compensate for the absence of regular national surveys

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

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

A numerical analysis of machining induced residual stresses of Grade 5 Titanium Alloy

In general most manufacturing techniques alter the surface integrity of the final component. Surface integrity refers to the surface properties and their influence on the functional performance of manufactured components1. Machining induced residual stress is a surface integrity descriptor that may have a significant influence on the mechanical behavior of metallic parts subjected to dynamic loads2. Most manufacturing processes introduce some form of residual stress to the material. Cutting or more specifically machining involves large plastic deformation and elevated temperatures that may induce significant residual stresses in the surface and near surface region. When turning steel these stresses are largely tensile in nature and extend to a depth of approximately 200 μm1

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

This study determined the contribution of dark-green leafy vegetables (DGLV) to total micronutrient intake of two- to five year-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 ½ 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

Trends in adult tobacco use from two South African demographic and health surveys conducted in 1998 and 2003

Introduction. Since peaking in the early 1990s in South Africa,tobacco use has declined significantly. The reduction has beenattributed to the governmentfs comprehensive tobacco controlpolicies that were introduced at the time.Objective. To assess the pattern of tobacco use in the SouthAfrican Demographic and Health Surveys of 1998 and 2003.Methods. Multi-stage sampling was used to select approximately 11 000 households in cross-sectional national surveys. Face-to-face interviews, conducted with 13 826 adults (41% men) aged .15 years in 1998, and 8 115 (42% men) in 2003, included questions on tobacco use according to the WHO STEP-wise surveillance programme. Logistic regression analysis was used to assess the independent effects of selected characteristics on smoking prevalence.Results. Daily or occasional smoking prevalence among women remained unchanged at 10 - 11%; it decreased among men from 42% (1998) to 35% (2003). The decline for men was significant among the poorest and those aged 25 - 44 years. Strong age patterns were observed, peaking at 35 - 44 years, which was reduced among men in 2003. Higher income and education were associated with low prevalence of smoking, while living in urban areas was associated with higher rates. Black men and women smoked significantly less than otherpopulation groups.Conclusion. Despite decreased smoking rates in some subgroups, a lapse exists in the efforts to reduce tobacco use, as smoking rates have remained unchanged among women, and also among young adults aged 15 - 24 years

On machinability of titanium grade 4 under minimum quantity lubrication assisted high speed machining

Abstract: The wonder metal Titanium and its alloys are prime candidate for various automotive, biomedical and aerospace applications due to their good strength-to-weight ratio, biocompatibility and corrosion resistance. Titanium and its alloys are known as difficult-to-machine materials i.e. their machining is challenging. The experimental work reported in the present paper attempts to enhance the machinability of Titanium Grade 4 under the influence of minimum quantity lubrication at high speed conditions. In this work a total of twenty seven experiments has been conducted based on full factorial design of experiment technique. Cutting speed, feed rate, and depth of cut are varied at three levels each and the values of important MQL parameters are fixed. The effects of machining parameters on surface roughness are discussed. Machining at optimum combination of parameters resulted in precision finish with maximum roughness value 2.16 μm and maximum tool flank wear value 0.201 mm. The research results reveal the superiority of MQL over conventional wet cooling to successfully machine Titanium Grade 4 at high speed conditions with sustainability

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

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