Effect of temperature and moisture on high pressure lipid/oil extraction from microalgae

Commercially viable carbon–neutral biodiesel production from microalgae has potential for replacing depleting petroleum diesel. The process of biodiesel production from microalgae involves harvesting, drying and extraction of lipids which are energy- and cost-intensive processes. The development of effective large-scale lipid extraction processes which overcome the complexity of microalgae cell structure is considered one of the most vital requirements for commercial production. Thus the aim of this work was to investigate suitable extraction methods with optimised conditions to progress opportunities for sustainable microalgal biodiesel production. In this study, the green microalgal species consortium, Tarong polyculture was used to investigate lipid extraction with hexane (solvent) under high pressure and variable temperature and biomass moisture conditions using an Accelerated Solvent Extraction (ASE) method. The performance of high pressure solvent extraction was examined over a range of different process and sample conditions (dry biomass to water ratios (DBWRs): 100%, 75%, 50% and 25% and temperatures from 70 to 120 ºC, process time 5–15 min). Maximum total lipid yields were achieved at 50% and 75% sample dryness at temperatures of 90–120 ºC. We show that individual fatty acids (Palmitic acid C16:0; Stearic acid C18:0; Oleic acid C18:1; Linolenic acid C18:3) extraction optima are influenced by temperature and sample dryness, consequently affecting microalgal biodiesel quality parameters. Higher heating values and kinematic viscosity were compliant with biodiesel quality standards under all extraction conditions used. Our results indicate that biodiesel quality can be positively manipulated by selecting process extraction conditions that favour extraction of saturated and mono-unsaturated fatty acids over optimal extraction conditions for polyunsaturated fatty acids, yielding positive effects on cetane number and iodine values. Exceeding biodiesel standards for these two parameters opens blending opportunities with biodiesels that fall outside the minimal cetane and maximal iodine values.

Fire performance and design of cold-formed steel wall systems

Traditionally, the fire resistance rating of Light gauge steel frame (LSF) wall systems is based on approximate prescriptive methods developed using limited fire tests. These fire tests are conducted using standard fire time-temperature curve given in ISO 834. However, in recent times fire has become a major disaster in buildings due to the increase in fire loads as a result of modern furniture and lightweight construction, which make use of thermoplastics materials, synthetic foams and fabrics. Therefore a detailed research study into the performance of load bearing LSF wall systems under both standard and realistic design fires on one side was undertaken to develop improved fire design rules. This study included both full scale fire tests and numerical studies of eight different LSF wall systems conducted for both the standard fire curve and the recently developed realistic design fire curves. The use of previous fire design rules developed for LSF walls subjected to non-uniform elevated temperature distributions based on AISI design manual and Eurocode 3 Parts 1.2 and 1.3 was investigated first. New simplified fire design rules based on AS/NZS 4600, North American Specification and Eurocode 3 Part 1.3 were then proposed with suitable allowances for the interaction effects of compression and bending actions. The importance of considering thermal bowing, magnified thermal bowing and neutral axis shift in the fire design was also investigated and their effects were included. A spread sheet based design tool was developed based on the new design rules to predict the failure load ratio versus time and temperature curves for varying LSF wall configurations. The accuracy of the proposed design rules was verified using the fire test and finite element analysis results for various wall configurations, steel grades, thicknesses and load ratios under both standard and realistic design fire conditions. A simplified method was also proposed to predict the fire resistance rating of LSF walls based on two sets of equations developed for the load ratio-hot flange temperature and the time-temperature relationships. This paper presents the details of this study on LSF wall systems under fire conditions and the results.

Protein-energy malnutrition exists and is associated with negative outcomes in morbidly obese hospital patients

Prevalence of protein-energy malnutrition (PEM), food intake inadequacy and associated health-related outcomes in morbidly obese (Body Mass Index ≥ 40 kg/m2) acute care patients are unknown. This study reports findings in morbidly obese participants from the Australasian Nutrition Care Day Survey (ANCDS) conducted in 2010. The ANCDS was a cross-sectional survey involving acute care patients from 56 Australian and New Zealand hospitals. Hospital-based dietitians evaluated participants’ nutritional status (defined by Subjective Global Assessment, SGA) and 24-hour food intake (as 0%, 25%, 50%, 75%, and 100% of the offered food). Three months later, outcome data, including length of stay (LOS) and 90-day in-hospital mortality, were collected. Of the 3122 participants, 4% (n = 136) were morbidly obese (67% females, 55 ± 14 years, BMI: 48 ± 8 kg/m2). Eleven percent (n = 15) of the morbidly obese patients were malnourished, and most (n = 11/15, 73%)received standard hospital diets without additional nutritional support. Malnourished morbidly obese patients had significantly longer LOS and greater 90-day in-hospital mortality than well-nourished counterparts (23 days vs. 9 days, p = 0.036; 14% vs. 0% mortality, p = 0.011 respectively). Thirteen morbidly obese patients (10%) consumed only 25% of the offered meals with a significantly greater proportion of malnourished (n = 4, 27%) versus well-nourished (n = 9, 7%) (p = 0.018). These results provide new knowledge on the prevalence of PEM and poor food intake in morbidly obese patients in Australian and New Zealand hospitals. For the first time internationally, the study establishes that PEM is significantly associated with negative outcomes in morbidly obese patients and warrants timely nutritional support during hospitalisation.

Decriminalization of Health and Safety at Work in Australia

ABOUT THE BOOK As the title Safety or Profit? suggests, health and safety at work needs to be understood in the context of the wider political economy. This book brings together contributions informed by this view from internationally recognized scholars. It reviews the governance of health and safety at work, with special reference to Australia, Canada, Sweden, and the United Kingdom. Three main aspects are discussed. The restructuring of the labor market: this is considered with respect to precarious work and to gender issues and their implications for the health and safety of workers. The neoliberal agenda: this is examined with respect to the diminished power of organized labor, decriminalization, and new governance theory, including an examination of how well the health-and-safety-at-work regimes put in place in many industrial societies about forty years ago have fared and how distinctive the recent emphasis on self-regulation in several countries really is. The role of evidence: there is a dearth of evidence-based policy. The book examines how policy on health and safety at work is formulated at both company and state levels. Cases considered include the scant regard paid to evidence by an official inquiry into future strategy in Canada; the lack of evidence-based policy and the reluctance to observe the precautionary principle with respect to work-related cancer in the United Kingdom; and the failure to learn from past mistakes in the Deepwater Horizon disaster in the Gulf of Mexico. Intended Audience: Researchers; policymakers, trade union representatives, and officials interested in OHS; postgraduate students of OHS; OHS professionals; regulatory and socio-legal scholars.

Introduction : studying Indonesian media worlds at the intersections of area and cultural studies

When preparing this special issue,1 our discussions with the editorial board of the International Journal of Cultural Studies (IJCS) included a moment of simultaneous surprise and reflection, which we would like to use as a starting point for our introduction to the articles appearing here. This occurred during communications about the number and length of the articles required for a special issue. The board’s representative stipulated that a specific number of articles were to be written by Indonesian scholars. The request surprised us. We had neither discussed nor anticipated ethnic or national quotas for authorial participation. But although the request caught us off guard it also stimulated us to think about the two disciplinary terrains traversed in the articles to follow.

Effect of moderate- and high-intensity acute exercise on appetite in obese individuals

Purpose The effect of acute exercise, and exercise intensity, on appetite control in obese individuals requires further study. The aim of this study was to compare the effects of acute isocaloric bouts (250 kcal) of high-intensity intermittent cycling (HIIC) and moderate-intensity continuous cycling (MICC) or short-duration HIIC (S-HIIC) (125 kcal) and a resting control condition on the appetite hormone responses, subjective feelings of appetite, energy intake (EI), and food reward in overweight/obese individuals. Methods This study is a randomized crossover study on 12 overweight/obese volunteers. Participants were assigned to the control, MICC, HIIC, and S-HIIC conditions, 1 wk apart, in a counterbalanced order. Exercise was performed 1 h after a standard breakfast. An ad libitum test lunch was served 3 h after breakfast. Fasting/postprandial plasma samples of insulin, acylated ghrelin, polypeptide YY3–36, and glucagon-like peptide 1 and subjective feelings of appetite were measured every 30 min for 3 h. Nutrient and taste preferences were measured at the beginning and end of each condition using the Leeds Food Preference Questionnaire. Results Insulin levels were significantly reduced, and glucagon-like peptide 1 levels significantly increased during all exercise bouts compared with those during rest. Acylated ghrelin plasma levels were lower in the MICC and HIIC, but not in S-HIIC, compared with those in control. There were no significant differences for polypeptide YY3–36 plasma levels, hunger or fullness ratings, EI, or food reward. Conclusions Our findings suggest that, in overweight/obese individuals, isocaloric bouts of moderate- or high-intensity exercise lead to a similar appetite response. This strengthens previous findings in normal-weight individuals that acute exercise, even at high intensity, does not induce any known physiological adaptation that would lead to increased EI.

“I was proud of myself that I didn’t give up and I did it”: Experiences of pride and triumph in learning science

The role that specific emotions, such as pride and triumph, play during instruction in science education is an under-researched field of study. Emotions are recognized as central to learning yet little is known about the way in which they are produced in naturalistic settings, how emotions relate to classroom learning during interactions, and what antecedent factors are associated with emotional experiences during instruction. Data sources for the study include emotion diaries, student written artifacts, video recordings of class interactions, and interviews. Emotions produced in the moment during classroom interactions are analyzed from video data and audio data through a novel theoretical framework related to the sociology of human emotions. These direct observations are compared with students’ recollected emotional experiences reported through emotion diaries and interviews. The study establishes links between pride and triumph within classroom interactions and instructional tasks during learning episodes in a naturalistic setting. We discuss particular classroom activities that are associated with justified feelings of pride and triumph. More specifically, classroom events associated with these emotions were related to understanding science concepts, social interactions, and achieving success on challenging tasks.

Coverage of international and Pacific news in the Fiji Times and The Australian

The debate over the nature and flow of international news has dominated intellectual debate about journalism practice for some time. Developing countries argued there was an imbalance in the nature and amount of international news concerning them. They argued that the Western media rarely reported on developing countries and when they did, reported predominantly negative news about developing countries. The debate led to calls for a New World Information and Communication Order (NWICO). A number of studies examined its arguments, many finding developing countries were indeed disadvantaged by the Western media. This study compared foreign news coverage in The Australian and The Fiji Times, with special attention on news from the Pacific Islands region. It found the coverage of the Pacific Islands was still grossly inadequate in both newspapers. The coverage consisted of only a small number of stories, which were predominantly negative, surprising especially in the case of The Fiji Times.

Numerical investigation of motion and deformation of a single red blood cell in a stenosed capillary

It is generally assumed that influence of the red blood cells (RBCs) is predominant in blood rheology. The healthy RBCs are highly deformable and can thus easily squeeze through the smallest capillaries having internal diameter less than their characteristic size. On the other hand, RBCs infected by malaria or other diseases are stiffer and so less deformable. Thus it is harder for them to flow through the smallest capillaries. Therefore, it is very important to critically and realistically investigate the mechanical behavior of both healthy and infected RBCs which is a current gap in knowledge. The motion and the steady state deformed shape of the RBCs depend on many factors, such as the geometrical parameters of the capillary through which blood flows, the membrane bending stiffness and the mean velocity of the blood flow. In this study, motion and deformation of a single two-dimensional RBC in a stenosed capillary is explored by using smoothed particle hydrodynamics (SPH) method. An elastic spring network is used to model the RBC membrane, while the RBC's inside fluid and outside fluid are treated as SPH particles. The effect of RBC's membrane stiffness (kb), inlet pressure (P) and geometrical parameters of the capillary on the motion and deformation of the RBC is studied. The deformation index, RBC's mean velocity and the cell membrane energy are analyzed when the cell passes through the stenosed capillary. The simulation results demonstrate that the kb, P and the geometrical parameters of the capillary have a significant impact on the RBCs' motion and deformation in the stenosed section.

Three of a kind? The special case of Australia's Island Councils

In common with many other countries, Australian local government policymakers have focussed heavily on improving financial sustainability and operational efficiency through structural change and other modes of systemic reform. However, this system-wide approach cannot adequately deal with small island councils due to their sui generis characteristics. In an effort to fill this gap in the literature, this article examines the financial sustainability of Australia’s three island councils – Flinders, Kangaroo and King – over the period 2008–2013 in order to determine whether alternative organisational arrangements may be better suited to their unique circumstances. In so doing, our study contributes to the literature by providing the first empirical analysis of the financial viability of Australia’s island councils while considering the need for an alternative organisation entity in an effort to enhance their long-term financial sustainability.

Prediction of shrinkage and porosity during drying: Considering both material properties and process conditions

Drying of food materials offers a significant increase in the shelf life of food materials, along with the modification of quality attributes due to simultaneous heat and mass transfer. Shrinkage and variations in porosity are the common micro and microstructural changes that take place during the drying of mostly the food materials. Although extensive research has been carried out on the prediction of shrinkage and porosity over the time of drying, no single model exists which consider both material properties and process condition in the same model. In this study, an attempt has been made to develop and validate shrinkage and porosity models of food materials during drying considering both process parameters and sample properties. The stored energy within the sample, elastic potential energy, glass transition temperature and physical properties of the sample such as initial porosity, particle density, bulk density and moisture content have been taken into consideration. Physical properties and validation have been made by using a universal testing machine ( Instron 2kN), a profilometer (Nanovea) and a pycnometer. Apart from these, COMSOL Multiphysics 4.4 has been used to solve heat and mass transfer physics. Results obtained from models of shrinkage and porosity is quite consistent with the experimental data. Successful implementation of these models would ensure the use of optimum energy in the course of drying and better quality retention of dried foods.

Residents’ experiences of privacy and comfort in multi-storey apartment dwellings in subtropical Brisbane

Dwellings in multi-storey apartment buildings (MSAB) are predicted to increase dramatically as a proportion of housing stock in subtropical cities over coming decades. The problem of designing comfortable and healthy high-density residential environments and minimising energy consumption must be addressed urgently in subtropical cities globally. This paper explores private residents’ experiences of privacy and comfort and their perceptions of how well their apartment dwelling modulated the external environment in subtropical conditions through analysis of 636 survey responses and 24 interviews with residents of MSAB in inner urban neighbourhoods of Brisbane, Australia. The findings show that the availability of natural ventilation and outdoor private living spaces play important roles in resident perceptions of liveability in the subtropics where the climate is conducive to year round “outdoor living”. Residents valued choice with regard to climate control methods in their apartments. They overwhelmingly preferred natural ventilation to manage thermal comfort, and turned to the air-conditioner for limited periods, particularly when external conditions were too noisy. These findings provide a unique evidence base for reducing the environmental impact of MSAB and increasing the acceptability of apartment living, through incorporating residential attributes positioned around climate-responsive architecture.

The nutritional profile of baby and toddler food products sold in Australian supermarkets

Background/Aims To examine the nutritional profile of baby and toddler foods sold in Australia. Methods Nutrient information for baby and toddler foods available at Australian supermarkets was collected between August and December 2013. Levels of declared energy, total fat, saturated fat, total sugar, sodium and estimated added sugar were examined, as well as the presence of additional micronutrients on the label. The Health Star Rating (HSR) system was used to determine nutritional quality. The range of products on offer was also examined by product type and by the age category for which the product was marketed. Results Of the 309 products included, 29 % were fortified. On a per 100 g basis, these 309 products provided a mean (±SD) of 476 ± 486 kJ, 1.6 ± 2.4 g total fat, 10.7 ± 12.2 g total sugar, 2.7 ± 7.4 g added sugar, and 33.5 ± 66.5 mg sodium. Fruit-based products or products with fruit listed as an ingredient (58 %) were the predominant product type. On the nutrition label, 42 % displayed at least one additional micronutrient while 37 % did not display saturated fat. The most common HSR was four stars (45 %) and 6? months was the most commonly identified targeted age group (36 %). Conclusions The majority of baby and toddler foods sold in Australian supermarkets are ready-made fruit-based products aimed at children under 12 months of age. Baby and toddler foods are overlooked in public policy discussions pertaining to population nutrient intake but their relatively high sugar content deriving from fruits requires close attention to ensure these foods do not replace other more nutrient dense foods, given children have an innate preference for sweet tastes.