Performance of juvenile Murray cod, Maccullochella peelii peelii (Mitchell), fed with diets of different protein to energy ratio

The results of a 56-day experiment on juvenile Murray cod, Maccullochella peelii peelii, an Australian native fish with a high aquaculture potential, of mean weight 14.9 ± 0.04 g, fed with five experimental diets, one a series of 40% protein content and lipid levels of 10, 17 and 24% (P40L10, P40L17 and P40L24), and another of 50% protein and 17 and 24% (P50L17 and P50L24) lipid are presented. The specific growth rate (SGR) (% day−1) of fish maintained on different diets ranged from 1.18 to 1.41, and was not significantly different between dietary treatments, except P40L10 and the rest. However, there was a general tendency for SGR to increase with increasing dietary lipid content at both protein levels. The food conversion ratio (FCR) for the 40% protein series diets were poorer compared with those of the 50% protein diets, and the best FCR of 1.14 was observed with the P50L17 diet. The protein efficiency ratio (PER), however, was better in fish reared on low protein diets. The net protein utilization (NPU) also did not differ significantly (P > 0.05) in relation to dietary treatment. As in the case of PER the highest NPU was observed in Murray cod reared on diet P40L24 and the lowest in fish fed with diet P50L24. The carcass lipid content reflected that of the diets, when significant increases in the lipid content was observed in relation to dietary lipid content at both protein levels. However, body muscle lipid content did not increase with increasing dietary lipid content, and was significantly lower than in the whole body. The fatty acids found in highest concentration amongst the saturates, monoenes and polyunsaturates (PUFAs) were 16 : 0, 18 : 1n-9 and 22 : 6n-3, respectively, and each of these accounted for more than 60% of each of the group's total. The muscle fatty acid content was affected by the dietary lipid content; for example the total amount (in μg mg−1 lipid) of monoenes ranged from 72 ± 5.1 (P40L10) to 112 ± 10 (P40L24) and 112 ± 2.8 (P50L17) to 132 ± 11.8 (P50L24) and the n-6 series fatty acids increased with increasing dietary lipid content, although not always significant. Most notably, 18 : 2n-6 increased with the dietary lipid level in both series of diets.

Mixing vector construction for single channel semi-blind source separation using empirical mode decomposition

The Empirical Mode Decomposition (EMD) method is a commonly used method for solving the problem of single channel blind source separation (SCBSS) in signal processing. However, the mixing vector of SCBSS, which is the base of the EMD method, has not yet been effectively constructed. The mixing vector reflects the weights of original signal sources that form the single channel blind signal source. In this paper, we propose a novel method to construct a mixing vector for a single channel blind signal source to approximate the actual mixing vector in terms of keeping the same ratios between signal weights. The constructed mixing vector can be used to improve signal separations. Our method incorporates the adaptive filter, least square method, EMD method and signal source samples to construct the mixing vector. Experimental tests using audio signal evaluations were conducted and the results indicated that our method can improve the similar values of sources energy ratio from 0.2644 to 0.8366. This kind of recognition is very important in weak signal detection.

Minimizing energy consumption of yarn winding in ring spinning

Ring spinning has been and will continue to be an important system for making staple yarns from different fibers in the textile industry. But high power consumption and low productivity remain the two outstanding problems with ring spinning. Based on an analysis of power distribution during yarn winding in ring spinning, models for the ratio of energy consumption to yarn production over a full yarn package are established. Spindle speed, yarn count, and package diameter are the three key parameters affecting this ratio. The effects on energy consumption of these parameters are discussed through a case study. The energy-to-production ratio increases with increased package diameter but decreases with increased spindle speed and/or yarn count (tex). The results will help guide spinners in minimizing energy consumption in ring spinning.

Recent studies on yarn tension and energy consumption in ring spinning

High energy consumption remains a key challenge for the widely used ring spinning system. Tackling this challenge requires a full understanding of the various factors that contribute to yarn tension and energy consumption during ring spinning. In this paper, we report our recent experimental and theoretical research on air drag, yarn tension and energy consumption in ring spinning. A specially constructed rig was used to simulate the ring spinning process; and yarn tension at the guide-eye was measured for different yarns under different conditions. The effect of yarn hairiness on the air drag acting on a rotating yarn package and on a ballooning yarn was examined. Models of the power requirements for overcoming the air drag, increasing the kinetic energy of the yarn package (bobbin and wound yarn) and overcoming the yarn wind-on tension were developed. The ratio of energy-consumption to yarn-production over a full yarn package was discussed. A program to simulate yarn winding in ring spinning was implemented, which can generate the balloon shape and predict yarn tension under a given spinning condition. The simulation results were verified with experimental results obtained from spinning cotton and wool yarns.

Under-reporting of energy intake in the 1997 national nutrition survey

Aims To estimate the level of under-reporting of energy intake by gender, age, ethnicity and body size (normal, overweight, obese) in the 1997 National Nutrition Survey (NNS97) in New Zealand.
Methods Data were from 4,258 participants (1,808 men and 2,450 women aged 15 years and over) who completed the 24-hour diet recall; the primary methodology used in the NNS97. Under-reporting was assessed using the ratio of reported energy intake to estimated resting metabolic rate (EI: RMRest). Cut-off limits were used to identify percentages of under-reporters in the various subgroups.
Results Mean EI: RMRest was 1.40 for all participants (1.51 for men, 1.30 for women, p<0.001) with older age being associated with lower EI: RMRest (p<0.001). There were no significant differences in mean EI: RMRest between ethnic groups for men.
Mean EI: RMRest for women were: Maori 1.46, European 1.29, and Pacific 1.37 (p<0.01). A larger body size was associated with a significantly lower EI: RMRest especially for women.
Percentages of ‘definite’ under-reporters (individual EI: RMRest <0.9) were as follows: men 12%, women 21%; Europeans 16%, Maori 23% and Pacific 26%; normal weight (11%), overweight (19%) and obese (27%) participants; and from 10% in the youngest to 23% in the oldest age group (p<0.001 for all results).
Conclusion In this study, in agreement with the literature, women, older people and obese people under-reported more than men, younger people and non-obese people. Possible ethnic differences in under-reporting rates need further study. Care is needed in interpreting the energy intake data from the NNS97.

Identifying the energy gap: magnitude and determinants of 5-year weight gain in midage women

Objective: The aims of this study were to estimate average yearly weight gain in midage women and to identify the determinants of weight gain and gaining weight at double the average rate.
Research Methods and Procedures: The study sample comprised 8071 participants (45 to 55 years old) in the Australian Longitudinal Study on Women's Health who completed mailed surveys in 1996, 1998, and 2001.
Results: On average, the women gained almost 0.5 kg per year [average 2.42 kg (95% confidence interval, 2.29 to 2.54) over 5 years]. In multivariate analyses, variables associated with energy balance (physical activity, sitting time, and energy intake), as well as quitting smoking, menopause/hysterectomy, and baseline BMI category were significantly associated with weight gain, but other behavioral and demographic characteristics were not. After adjustment for all of the other biological and behavioral variables, the odds of gaining weight at about twice the average rate (>5 kg over 5 years) were highest for women who quit smoking (odds ratio = 2.94; 95% confidence interval, 2.17, 3.96). There were also independent relationships between the odds of gaining >5 kg and lower levels of habitual physical activity, more time spent sitting, energy intake (but only in women with BMI > 25 at baseline), menopause transition, and hysterectomy.
Discussion: The average weight gain equates with an energy imbalance of only about 10 kcal or 40 kJ per day, which suggests that small sustained changes in the modifiable behavioral variables could prevent further weight gain.

Energy absorption and crushing behaviour of foam-filled aluminium tubes

The crushing behaviour and energy absorption of foam filled aluminium tubular structures were investigated using the quasi-static compressive tests. The crushing behaviour of the tubular structures changed due to foam filling. The energy absorption of the foam filled tubular structures was improved significantly. Foam filling caused an interaction effect between the tube and the foam during progressive crushing, leading to an increase in the mean crushing load compared to that of the foam or tube itself. This interaction effect might be affected by several parameters such as the density of the foam, the properties of both the foam material and tube material, and the thickness and outer diameter of the tube. In particular, the interaction effect essentially depended on the ratio of the mean crushing force of the foam to that of the tube.

Donor-п-acceptor conjugated copolymers for photovoltaic applications : tuning the open-circuit voltage by adjusting the donor/acceptor ratio

A class of new conjugated copolymers containing a donor (thiophene)−acceptor (2-pyran-4-ylidene-malononitrile) was synthesized via Stille coupling polymerization. The resulting copolymers were characterized by 1H NMR, elemental analysis, GPC, TGA, and DSC. UV−vis spectra indicated that the increase in the content of the thiophene units increased the interaction between the polymer main chains to cause a red-shift in the optical absorbance. Cyclic voltammetry was used to estimate the energy levels of the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) and the band gap (Eg) of the copolymers. The basic electronic structures of the copolymers were also studied by DFT calculations with the GGA/B3LYP function. Both the experimental and the calculated results indicated an increase in the HOMO energy level with increasing the content of thiophene units, whereas the corresponding change in the LUMO energy level was much smaller. Polymer photovoltaic cells of a bulk heterojunction were fabricated with the structure of ITO/PEDOT/PSS (30 nm)/copolymer−PCBM blend (70 nm)/Ca (8 nm)/Al (140 nm). It was found that the open-circuit voltage (Voc) increased (up to 0.93 V) with a decrease in the content of thiophene units. Although the observed power convention efficiency is still relatively low (up to 0.9%), the corresponding low fill factor (0.29) indicates considerable room for further improvement in the device performance. These results provided a novel concept for developing high Voc photovoltaic cells based on donor-π-acceptor conjugated copolymers by adjusting the donor/acceptor ratio.

Solar energy use for energy savings in dairy processing plants

New Zealand is one of the world’s largest producers of dairy products and has a climate with high levels of solar radiation; however, the use of solar energy in the dairy processing industry has received limited attention. An examination of historical records found that the annual peak in New Zealand milk production and processing occurs at a time when solar radiation levels are increasing markedly. An F-Chart analysis was used to simulate the performance of large-area arrays of solar collectors and to determine their suitability for heating and cooling in a dairy processing environment. For the study four types of solar collectors were analysed: glazed flat plates, evacuated tubes, evacuated tubes with CPC reflectors and a building-integrated solar collector under development at the University of Waikato (UoW). It was found that of these echnologies, both flat plate and evacuated tubes with CPC reflectors could make useful heating and cooling contributions. Furthermore, the solar fraction was determined mainly by the collector area to storage volume ratio. Finally, it was found that the UoW building-integrated solar collector could make a significant contribution to energy use in dairies and may be an attractive future technology for the industry.

Nanoelectrodes : energy conversion and storage

Nanosized materials are known to take on peculiar properties compared to the bulk material. Their electronic and mechanical properties are known to improve e.g. higher electrical conductivity and greater strength. Their electrochemical redox properties can change dramatically, e.g. in the case of Ag°, the E° value for Ag° → Ag+ + e can change by up to half a volt as the particle size decreases. Nanodimensional materials also have an extraordinarily high surface area to volume ratio. All of these properties would bring beneficial effects if they could be retained when the material is assembled into a structure capable of being used as an electrode – nanostructured electrodes.

Here we consider selected examples illustrating the importance of nanostructured electrodes in energy conversion (organic solar cells and fuel cells) and storage (batteries and capacitors). These examples involve the use of inorganic as well as organic conducting and semiconducting materials.

Bipolar disorder and adiposity : a study using whole body dual energy X-ray absorptiometry scans

Objective: Previous research has demonstrated a relationship between adiposity and bipolar disorder, although data are derived predominantly from patient samples and use indirect methods of assessing adiposity. This study investigated the association between bipolar disorder and several indices of adiposity, including body fat mass as measured by dual energy X-ray absorptiometry (DXA), in a community-based sample.

Methods: In this study, 21 women with bipolar disorder and 523 healthy controls were drawn from an age-stratified, random, community-based sample of women (20–93 years) participating in the Geelong Osteoporosis Study. Bipolar disorder was diagnosed utilising a semi-structured clinical interview. Anthropometric measurements (weight, height, waist and hip circumference) were taken and fat mass was determined from whole body DXA scans (Lunar DPX-L).

Results: Those with bipolar disorder tended to have greater adiposity. Age-adjusted mean (95% CI) values for bipolar versus controls according to adiposity indices were weight 75.6 (68.9–82.3) versus 72.6 (71.3–74.0) kg, waist circumference 89.8 (84.1–95.6) versus 87.3 (86.1–88.5) cm, waist:hip ratio 0.85 (0.82–0.87) versus 0.84 (0.83–0.84), body mass index 27.6 (25.1–30.1) versus 27.5 (27.0–28.0) kg/m2, fat mass 31.4 (26.5–36.3) versus 28.6 (27.5–29.5) kg and %body fat 40.4 (36.9–43.9) versus 38.0 (37.3–38.7)%; all p > 0.05. Further adjustment for height, smoking, alcohol, psychotropic medication, energy intake or physical activity did not influence these patterns.

Conclusion: Although a pattern suggestive of greater adiposity among those with bipolar disorder was observed, no significant differences were detected. We cannot exclude the possibility of a type II error. Further research with a larger sample may produce more conclusive results.

Backward modelling and look-ahead fuzzy energy management controller for a parallel hybrid vehicle

This paper focuses on a parallel hybrid electric vehicle. It first develops a model for the vehicle using the backward-looking approach where the flow of energy starts from wheels and spreads towards engine and electric motor. Next, a fuzzy logic-based strategy is developed to control the operation of the vehicle. The objectives of the controller include managing the energy flow from engine and electric motor, controlling transmission ratio, adjusting speed, and sustaining battery's state of charge. The controller examines current vehicle speed, demand torque, slope difference, state of charge of battery, and engine and electric motor rotation speeds. Then, it determines the best values for continuous variable transmission ratio, speed, and torque. A slope window scheme is also developed to take into account the look-ahead slope information and determine the best vehicle speed for better fuel economy. The developed model and control strategy are simulated. The simulation results are presented and discussed. It is shown that the use of the proposed fuzzy controller reduces fuel consumption.

Look-ahead intelligent energy management of a parallel hybrid electric vehicle

Improving fuel efficiency in vehicles can reduce the energy consumption concerns associated with operating the vehicles. This paper presents a model for a parallel hybrid electric vehicle. In the model, the flow of energy starts from wheels and spreads toward engine and electric motor. A fuzzy logic based control strategy is implemented for the vehicle. The controller manages the energy flow from the engine and the electric motor, controlling transmission ratio, adjusting speed, and sustaining battery's state of charge. The controller examines the vehicle speed, demand torque, slope difference, state of charge of battery, and engine and electric motor rotation speeds. It then determines the best values for continuous variable transmission ratio, speed, and torque. A slope window method is formed that takes into account the look-ahead slope information, and determines the best vehicle speed. The developed model and control strategy are simulated using real highway data relating to Nowra-Bateman Bay in Australia, and SAE Highway Fuel Economy Driving Schedule. The simulation results are presented and discussed. It is shown that the use of the proposed fuzzy controller reduces the fuel consumption of the vehicle.

Context-dependent correlation between resting metabolic rate and daily energy expenditure in wild chipmunks

Several empirical studies have shown that variation in daily energy expenditure (DEE) and resting metabolic rate (RMR) is influenced by environmental and individual factors, but whether these shared influences are responsible for, or independent of, relationships between DEE and RMR remains unknown. The objectives of this study were to (i) simultaneously evaluate the effects of environmental and individual variables on DEE and RMR in free-ranging eastern chipmunks (Tamias striatus) and (ii) quantify the correlation between DEE and RMR before and after controlling for common sources of variation. We found that the influence of individual factors on DEE and RMR is most often shared, whereas the influence of environmental factors tends to be distinct. Both raw and mass-adjusted DEE and RMR were significantly correlated, but this correlation vanished after accounting for the shared effect of reproduction on both traits. However, within reproductive individuals, DEE and RMR remained positively correlated after accounting for all other significant covariates. The ratio of DEE to RMR was significantly higher during reproduction than at other times of the year and was negatively correlated with ambient temperature. DEE and RMR appear to be inherently correlated during reproduction, but this correlation does not persist during other, less energy-demanding periods of the annual cycle.

The relationship between repeated sprint ability and the aerobic and anaerobic energy systems

A large number of team games require participants to repeatedly produce maximal or near maximal sprints of short duration with brief recovery periods. The purpose of the present study was to determine the relationship between a repeated sprint ability (RSA) test that is specific to the energy demands of Australian Rules football (ARF), and the aerobic and anaerobic energy systems.