Australian Conditions Research Articles

Evaluation of Barley Cultivars for Competitive Traits in Southern New South Wales.

The potential of multi-purpose barley (Hordeum vulgare L.) cultivars to suppress weeds while maintaining optimal yield and grain quality has been reported but not recently evaluated in replicated field trials performed under southern Australian field conditions. Therefore, to investigate this potential, aboveground competitive traits were assessed in nine genetically diverse commercial barley cultivars in 2015, 2016 and 2017, in two locations in the Riverina region of NSW in replicated field trials performed in the absence of pre-emergent herbicide treatment. Crop and weed establishment, early vigour, leaf area index, photosynthetically active radiation (PAR) and biomass were assessed at various crop growth stages, including early growth, vegetative, flowering, grain fill and harvest. Cultivar differences in crop and weed biomass accumulation at ~50, 100 and 150 days after planting were noted at both locations. Early barley biomass accumulation was inversely related to weed biomass in both locations and most years, suggesting strong (over 90%) potential for heritable competitive barley interference against weeds. The current study also observed a positive relationship between PAR light interception and crop biomass in all three years at both locations, suggesting that PAR light interception contributed positively to crop biomass accumulation by directly increasing photosynthesis (50–70%) and growth or indirectly influencing weed biomass accumulation (10–15%) and weed interference (50–75). Partial least squares modelling was performed with 2015 and 2016 datasets to assess the interactions between crop developmental traits and weed suppression. Cultivars exhibiting enhanced early vigour and PAR light interception were generally more weed suppressive under optimal higher soil moisture conditions. Our results indicate that the choice of barley cultivar has a significant impact on weed establishment, fecundity and seedbank dynamics. The use of competitive barley genotypes is, thus, a cost-effective strategy to reduce weed seedbank numbers over time and may reduce potential herbicide use.

Lifetime cost models for large, long-lived, street trees in Australia

ABSTRACT The costs of maintaining an urban street tree over its lifecycle have been considered in cost models. One used in Australia is a typical relationship between the cost and functional and aesthetic benefits of the urban shrub mass. But are these curves typical of larger, long-lived urban street trees growing under Australian conditions? The costs of maintaining an urban street tree under Australian management regimes, including purchase and planting costs of a common street tree species, herbicide and mulching costs, the cost of irrigation over the first summer after spring planting and of formatively pruning the young tree were calculated based on data obtained from Australian local government agencies. The research-modelled management of an urban tree under five scenarios based upon planting a 2–3 m tall tree with a safe useful life expectancy of 50 years. Scenarios included annual maintenance, regular pruning on a 5-year cycle after 15 years and a major arboricultural intervention in the final decade. The impact of longer lifespans of 100 or 150 years was also modelled. The curves demonstrated that costs associated with a street tree are high in the first 2–3 years of its life but much higher in the final year of life leading to removal but differed in shape from other models. The lifetime costs of maintaining a street tree depending on the management scenario are between AUD$2800 and AUD$6220 or AUD$56 and AUD$124.40 per annum. Doubling the lifespan of a street tree reduces the annual management cost by 30%.

Management options for large plants of glyphosate-resistant feather fingergrass (Chloris virgata) in Australian fallow conditions.

Chloris virgata has become one of the most difficult glyphosate-resistant (GR) grass weeds in summer fallows in the eastern region of Australia. It germinates in several cohorts following rainfall events; therefore, growers are often tempted to wait for most of the weeds to emerge before herbicide application. However, by that time, some seedlings have reached an advanced stage and there is limited information on the efficacy and reliability of alternate herbicides when targeting large plants of GR C. virgata. A series of experiments were conducted to determine the efficacy of alternate herbicides for the control of GR C. virgata. Haloxyfop (80 g a.i. ha-1) on its own, in mixtures, or sequential applications of haloxyfop and paraquat or glufosinate provided 97 to 100% mortality of the 8–10 leaf stage plants. Glufosinate (1500 g a.i. ha-1) also provided complete control of plants at this growth stage. For larger plants at the 24–28 leaf stage, glufosinate, with or without additional tank-mixed adjuvants, generally did not provide full control, however did show very high levels of biomass reduction and panicle suppression at application rates of 750 or 1500 g a.i. ha-1. Haloxyfop (40 to 160 g a.i. ha-1) and clethodim (180 g a.i. ha-1) on their own achieved 96 to 100% mortality at this growth stage. When applied to large plants (40–50 leaf stage), a tank-mix of isoxaflutole plus paraquat demonstrated significantly higher levels of plant mortality and biomass reduction than either herbicide used alone, and this mixture appears to be synergistic when tested via the Colby equation for synergy or antagonism. Plant mortality was greater (83%) when isoxaflutole (75 g a.i. ha-1) plus paraquat (300 g a.i. ha-1) was taken up through the foliage and soil, compared with the foliage alone. This study identified alternative herbicide options for large plants of GR C. virgata.

275 Access to Shade Mitigate Heat Stress and Improves Growth Performance in Lambs During Summer

Abstract The objective of the present study was to investigate the effects of provision of shade on behavior, physiology, and growth of Merino lambs exposed to natural Australian summer conditions. Sixty Merino lambs were randomly allocated to either pasture with shade (n = 30;paddock with trees) or a pasture without shade (n = 30;paddock without any trees) for one month during southern-Australian summer (February-2021). Sheep were grazing on the pastures as per standard protocols followed on the farm with ad libitum access to water. Lambs were monitored twice daily between 0900-1000h and 1400-1600h to record their behavior, and physiological parameters were recorded on hot days (environmental temperature (T) >30°C). Behavioral patterns were represented as the proportion of animals doing specific activities in each treatment group. Grazing was the most frequent activity observed in animals during morning measurement (> 60% in both groups). However, high temperature (T > 30°C) decreased grazing behavior in sheep to < 5% in both treatments. Standing behavior was significantly greater (65.2 vs 21.6%; P < 0.05) for animals under non-shade treatment, while lying behavior was more frequent (17.3 vs 76.3%; P < 0.01) in animals having access to shade. Significantly more animals were seeking water troughs (P < 0.05) in the non-shade group (33.2%) compared to the shade group (10.3%). On an average hot day (T >28°C), most lambs in the shade group were seeking shade (P < 0.01), and when the temperature exceeded >32°C, 90% of the lambs were seeking tree shade. Sheep with access to shade exhibited lower (P < 0.01) respiration rate (117breaths/min) and rectal temperature (39.7°C) than non-shade group (151breaths/min;40.2°C). Overall, access to shade improved (P < 0.001) average daily gain (+0.047kg/day) in sheep compared to the non-shade group (-0.028kg/day). In conclusion, our research confirms that providing access to shade is an effective ameliorative strategy to mitigate heat-stress in sheep during summer heatwaves.

The Work Assessment Method shows potential to improve performance and social sustainability on Australian dairy farms

Context Social aspects of livestock farming systems, including farm workforce and how work is organised, have received less research attention than the biophysical and technological aspects. This constrains understanding of social challenges to the sustainability of livestock systems, such as farm labour shortages, farmers’ overwork, the undesirability of farming careers, workforce and skills changes linked to new technologies, and the connections of all these to farm performance and profitability. Aims We introduce and test the applicability and utility in the Australian context of a method developed in France for assessing work organisation: The Work Assessment Method (WAM). The WAM goes beyond standard labour productivity metrics, such as total labour cost or livestock units per worker, to examine different types of work (routine, seasonal), who does the work (owner–managers, employees, contractors) and how these change seasonally. A measure of social sustainability (‘calculated time available’) is a key feature. Methods We conducted the first Australian trial of the WAM on two Victorian dairy farms. Through facilitated discussions between participating farmers and the research team, we evaluated the utility of the method, and identified requirements to adapt it for larger, pasture-based dairy systems. Key results The WAM was applied successfully on the pilot farms, despite differences in farm systems between France and Australia. The method characterised in detail the sources of overwork for each farm, enabling discussion of how the social sustainability and overall performance of the farms could be improved. The participating farmers reported that the method provided insights that were not available from current financial and physical analyses. Conclusions The WAM shows potential for supporting farmers, advisors and researchers in work aimed at improving farm social sustainability and profitability, but requires adaptation to suit Australian conditions. A larger exploratory study applying the WAM on additional dairy farms, and on mixed farms, is suggested. Implications This study provides a strong foundation for further research to develop the WAM as a useful research and advisory tool for Australian livestock production systems.

A Multi-Environment Trial Analysis of Frost Susceptibility in Wheat and Barley Under Australian Frost-Prone Field Conditions.

Low temperatures during the flowering period of cereals can lead to floret sterility, yield reduction, and economic losses in Australian crops. In order to breed for improved frost susceptibility, selection methods are urgently required to identify novel sources of frost tolerant germplasm. However, the presence of genotype by environment interactions (i.e. variety responses to a change in environment) is a major constraint to select the most appropriate varieties in any given target environment. An advanced method of analysis for multi-environment trials that includes factor analytic selection tools to summarize overall performance and stability to a specific trait across the environments could deliver useful information to guide growers and plant breeding programs in providing the most appropriate decision making-strategy. In this study, the updated selection tools approached in this multi-environment trials (MET) analysis have allowed variety comparisons with similar frost susceptibility but which have a different response to changes in the environment or vice versa. This MET analysis included a wide range of sowing dates grown at multiple locations from 2010 to 2019, respectively. These results, as far as we are aware, show for the first-time genotypic differences to frost damage through a MET analysis by phenotyping a vast number of accurate empirical measurements that reached in excess of 557,000 spikes. This has resulted in a substantial number of experimental units (10,317 and 5,563 in wheat and barley, respectively) across a wide range of sowing times grown at multiple locations from 2010 to 2019. Varieties with low frost overall performance (OP) and low frost stability (root mean square deviation -RMSD) were less frost susceptible, with performance more consistent across all environments, while varieties with low OP and high RMSD were adapted to specific environmental conditions.

Increased livestock weight gain from improved water quality in farm dams: A cost-benefit analysis.

Access to water is a critical aspect of livestock production, although the relationship between livestock weight gain and water quality remains poorly understood. Previous work has shown that water quality of poorly managed farm dams can be improved by fencing and constructing hardened watering points to limit stock access to the dam, and revegetation to filter contaminant inflow. Here we use cattle weight gain data from three North American studies to develop a cost-benefit analysis for the renovation of farm dams to improve water quality and, in turn, promote cattle weight gain on farms in south-eastern Australia. Our analysis indicated a strong likelihood of positive results and suggested there may be substantial net economic benefit from renovating dams in poor condition to improve water quality. The average per-farm Benefit-Cost Ratios based on deterministic assumptions was 1.5 for New South Wales (NSW) and 3.0 for Victoria in areas where rainfall exceeds 600mm annually. Our analyses suggested that cattle on farms in NSW and Victoria would need to experience additional weight gain from switching to clean water of at least 6.5% and 1.8% per annum respectively, to break even in present value terms. Monte Carlo simulation based on conservative assumptions indicated that the probability of per-farm benefits exceeding costs was greater than 70%. We recommend localised experiments to assess the impact of improved water quality on livestock weight gain in Australian conditions to confirm these expectations empirically.

The Unique Australian Flora, A Veritable Pandora’s Pharmacopeia of Compounds with Therapeutic Biomedical Potential: Are the Chalcones the Geni in The Box?

The aim of this review was to highlight the unique biodiversity of the flowering plants and shrubs of Australia and their component chemicals that evolved during the separation of the Australian continent from Gondwanaland. The chemicals produced by these flowering plants provided protection ensuring the survival of the Australian flora which had to contend with often harsh Australian climatic conditions. The diversity of plant phytochemicals produced by these flowering plants reflects the unique diversity of the Australian Flora and these represent a Pharmacological goldmine. It was beyond the scope of this review to cover the full spectrum of these chemical compounds present in Australian plants instead we focused on the chalcones in this review. This compound has a special status in medicinal chemistry as a base intermediate for the synthesis of a large repertoire of polycyclic compounds that display anti-bacterial, antifungal, anti-viral and anti-tumour properties and these are thus of considerable interest in Biomedicine.

An Efficient Method for the Euthanasia of Cane Toads (Rhinella marina) under Northern Australian Field Conditions.

Simple SummaryCane toads are a highly invasive species that present a serious threat to most vertebrates that eat them. In Australia, their spread from the point of introduction in 1935 has seen them occupy any suitable habitat across the north of the country, with the potential to be transported to locations in southern Australia. Control and safe removal of unwanted toads presents ethical and occupational health risks to those engaged in such activities. This study describes an efficient method of control suitable for application under field conditions anywhere in Australia.The euthanasia of cane toads under field conditions presents a number of logistical and animal welfare challenges. One recommended method of control involves the use of carbon dioxide in plastic bags. This paper describes the minimum amount of time (4 h) required to efficiently euthanase toads with a carbon dioxide concentration of 4.96% under field conditions experienced in northern Australia. Discussion is also provided on the issues of safe disposal of biological and plastic waste associated with the application of this method.

Cyclic loading response and associated yield criteria for soft railway subgrade – Theoretical and experimental perspectives

Heavy haul rail transport certainly demands a more robust and stable railway foundation as the subgrade soils are prone to instability at higher axle loads. The current paper presents a series of cyclic triaxial tests to investigate the response of different subgrade soils with varying cyclic stress ratio (CSR). Theoretical models based on the Modified Cam Clay (MCC) model are extended to predict the experimental results. Two different hypotheses are proposed and discussed in this paper, namely, Model A: yield surface changes its size, and Model B: yield surface changes its shape, during cyclic loading. The results indicate that when CSR exceeds a critical threshold (CSRc), the excess pore water pressure (EPWP) and axial strain (εac) increase rapidly as the number of cycles (N) reaches a certain critical level (Nc,i). This causes soil instability and leads to specimen failure. At the same level of CSR, the faster the cyclic load is applied (i.e., at higher frequencies), the greater is the number of cycles required to trigger soil instability. The proposed models predict the inception of soil instability under cyclic rail loading with reasonable accuracy for Australian heavy haul track conditions.

Bazı Ekmeklik Buğdayların Tuz Uygulamasına Tepkileri ve Besin Elementi İçeriklerinin Belirlenmesi

The aim of this research is to evaluate and analyze the influence of different degrees of salt stress on the tolerance of Australian wheat lines having characteristics derived from wild types in comparison with a local cultivar well–adapted to Anatolian conditions under controlled conditions. In the research, the two lines, namely AU5924 and AU5907, adapted to Australian conditions harbor HKT1;4 and HKT1;5 loci and Bayraktar 2000 cultivar used as genetic material. In our study, a trial plan with four replicates and two salt treatment doses (0 mM control group and 200 mM stress group) was designed. The samples were collected for elemental analysis, measuring physiological parameters as well as determining proline content after the appearance of stress symptoms. In this respect, (K), known to play an important role in enhancing stress tolerance, was found to be higher in HKT–containing lines in comparison to Bayraktar 2000. HKT genes could improve the production of Anatolian varieties. While the dry weight of the genotype Bayraktar 2000 was higher than the lines checked, the proline content of line 5907 was lower and the potassium and (K/Na) ratio decreased. These parameters effectively increased the dry weight under salt stress. However, the line 5907 demonstrated the best tolerance among all analyzed genotypes.

The composition of Australian Plantago seeds highlights their potential as nutritionally-rich functional food ingredients

When wetted, Plantago seeds become covered with a polysaccharide-rich gel called mucilage that has value as a food additive and bulking dietary fibre. Industrially, the dry husk layer that becomes mucilage, called psyllium, is milled off Plantago ovata seeds, the only commercial-relevant Plantago species, while the residual inner seed tissues are either used for low value animal feed or discarded. We suggest that this practice is potentially wasting a highly nutritious resource and here describe the use of histological, physicochemical, and chromatographic analyses to compare whole seed composition/characteristics of P. ovata with 11 relatives already adapted to harsh Australian conditions that may represent novel commercial crop options. We show that substantial interspecific differences in mucilage yield and macromolecular properties are mainly a consequence of differences in heteroxylan and pectin composition and probably represent wide differences in hydrocolloid functionality that can be exploited in industry. We also show that non-mucilage producing inner seed tissues contain a substantial mannan-rich endosperm, high in fermentable sugars, protein, and fats. Whole seed Plantago flour, particularly from some species obtained from harsh Australian environments, may provide improved economic and health benefits compared to purified P. ovata psyllium husk, by retaining the functionality of the seed mucilage and providing additional essential nutrients.

Favourable inland wetland conditions increase apparent survival of migratory shorebirds in Australia

ABSTRACT Many migratory shorebird species using the East Asian–Australasian Flyway are declining rapidly. While the loss of staging habitats in East Asia is considered the primary cause, stressors to fitness often occur throughout the geographic range of declining species, and threats in the non-breeding grounds have been comparatively poorly studied. Three species of migratory shorebird, Curlew Sandpiper (Calidris ferruginea), Sharp-tailed Sandpiper (C. acuminata) and Red-necked Stint (C. ruficollis), use Australia’s dynamic temporary wetland systems opportunistically, yet these large wetland systems have become increasingly degraded, with reduced frequency and extent of flooding. Here, we test whether variables related to wetland availability in Australia’s interior can explain annual variation in apparent survival, abundance or immature to adult ratios at three well-monitored coastal shorebird areas in southern Australia (total area > 1315 km2). We show that coastal annual bird abundance and ratios of immatures at the coast were higher when inland Australia was relatively hot and dry. Also, a small but significant amount of variation in annual apparent survival can be explained by annual variation in inland conditions, with higher survival rates in years when inland conditions were relatively wet and cool. For the endangered Curlew Sandpiper, the impacts of Australian environmental conditions may be exacerbating the impacts of conditions experienced in other parts of its range on fitness and survival. While the effects we document here are relatively weak, they do suggest that management of inland wetlands for these shorebirds may positively affect survival rates of these sharply declining species.

Potamopyrgus antipodarum has the potential to detect effects from various land use activities on a freshwater ecosystem

Identifying risks to ecosystems from contaminants needs a diversity of bioindicators, to understand the effects of these contaminants on a range of taxa. Molluscs are an ideal bioindicator because they are one of the largest phyla with extremely high ecological and economic importance. The aim of this study was to evaluate if laboratory bred Potamopyrgus antipodarum has the potential to show the impact of contaminants from various land use activities and degree of pollution on a freshwater ecosystem. We assessed the impact of contaminants arising from runoff and direct discharges in Merri Creek by measuring organism level responses (survival, growth, and reproduction), and sub-organism level responses (glutathione S-transferase (GST) activity, lipid peroxidation (LPO) activity and catalase (CAT) activity) in snails after 28-d of deployment at nine sites in Merri Creek and one site in Cardinia Creek. In Merri Creek, the top two sites were reference sites (with low impact from human activities), while the rest were impact sites (impacted by various anthropogenic land uses). Cardinia Creek (an additional reference site) had lower human activity. High concentrations of heavy metals, nutrients, and/or synthetic pyrethroids (bifenthrin) dominated these sites, which are likely to have contributed towards the negative responses observed in the snails. There was little influence from environmental conditions and site location on the endpoints because we found a similar response at an additional reference site compared to the reference sites in Merri Creek. At the organism level, reproduction increased and/or reduced, while CAT was affected at the sub-organism level. Potamopyrgus antipodarum has the potential to be a sensitive bioindicator for Australian conditions because the snails responded to varying concentrations of contaminants across different land use activities and showed similar sensitivity to P. antipodarum found in other regions of the globe and other bioindicators.

Compound natural disasters in Australia: a historical analysis

ABSTRACT Compound disasters, defined here as two or more disasters occurring within a three-month window and within a given jurisdiction, pose complex disaster coordination and recovery challenges. Planning for the management of such disasters would benefit from a better understanding of their frequency and their underlying climate influences. Here we utilise an Australian natural disaster database of normalised insurance losses to show compound disasters are responsible for the highest seasonal financial losses. Though their component events occur most frequently in the eastern seaboard, they may also comprise disasters on both sides of the continent. There has been no temporal trend in their frequency since 1966. A new compound disaster scale is proposed for Australian conditions. A bootstrapping analysis reveals the pairing of Bushfire and Tropical Cyclone to occur far less often than would be expected by chance. This is because these perils occur most frequently under contrasting climate states. Climate variability influences the frequency, intensity and type of perils contributing to compound disasters with the clearest relationship being with the El Niño Southern Oscillation. Given that ENSO is the most predictable climate driver at seasonal timescales, this may assist better forecasting of their occurrence and higher degrees of readiness.

Impact of Roadside Drying on Delivered Costs for Eucalyptus globulus Logging Residue and Whole Trees Supplying a Hypothetical Energy Plant in Western Australia Using a Linear-Programming Model

Australia’s large potential forest bioenergy resource is considerably underutilised, due largely to its high delivered costs. Drying forest biomass at the roadside can potentially reduce its delivered cost through weight reduction and increased net calorific value. There has been little research on the impact of roadside drying for Australian conditions and plantation species. This study compared delivered costs for three forest biomass types—Eucalyptus globulus plantation whole trees and logging residue (LR)-disaggregated (LR conventional) or aggregated (LR fuel-adapted)—and three roadside storage scenarios—no storage, ≤two-month storage and optimal storage—to supply a hypothetical thermal power plant in south-west Western Australia. The study was performed using a tactical linear programming tool (MCPlan). Roadside storage reduced delivered costs, with optimal storage (storage for up to 14 months) producing the lowest costs. Delivered costs were inversely related to forest biomass spatial density due to transport cost reductions. Whole trees, which had the highest spatial density, stored under the optimal storage scenario had the lowest delivered costs (AUD 7.89/MWh) while LR conventional, with the lowest spatial density, had the highest delivered costs when delivered without storage (AUD 15.51/MWh). For both LR types, two-month storage achieved ~60% of the savings from the optimal storage scenario but only 23% of the savings for whole trees. The findings suggested that roadside drying and high forest biomass spatial density are critical to reducing forest biomass delivered costs.

Bioeconomic modelling of hatchery, grow‐out and combined business of Australian black tiger shrimp Penaeus monodon farming

AbstractPenaeus monodon is the primary shrimp species farmed in Australia. Based on an extensive survey of the literature and industry information, we identified and compiled 318 different parameters related to shrimp aquaculture enterprises and production. Using these as input parameters, we performed detailed bioeconomic modelling for evaluating the economic viability of intensive culture scenarios and identified the major drivers of business profitability under Australian conditions. Three business types (hatchery, grow‐out and combined hatchery + grow‐out) were evaluated by simulating varying numbers of female broodstock and ponds in operation based on annual, six‐monthly, quarterly and monthly stocking events per year over a 10‐year period. Net present value was the main economic variable for comparison. The hatchery business was most profitable in scenario with 250 females being spawned monthly or 500 females at least quarterly, that is, >2000 females spawned per year. Feed, acquisition of broodstock and fixed labour were major costs for hatchery scenarios. For a grow‐out business, all scenarios were profitable even at the smallest scale modelled (50 ponds stocked annually). Feed, power and purchase of post‐larvae were major costs for grow‐out business. The combined business was the most profitable for a large enterprise and required at least 100 ponds stocked over the year. The three major costs in the combined business were feed, power and labour. Sensitivity analyses showed feed cost and survival parameters were critical for profitability.

Re-analysis of Abutment Angle Method for Moderate and Deep Cover Retreat Room and Pillar Mines and Investigation of Loading Mechanics Using Finite Volume Modeling

Mining-induced stresses in underground coal mines play a significant role in pillar and ground support design, hence in the safety of mining operations. In the US, Analysis of Longwall Pillar Stability (ALPS) and in Australia, Analysis of Longwall Tailgate Serviceability (ALTS) software are used for designing Longwall coal mine layouts; and in the US, Analysis of Retreat Mining Pillar Stability (ARMPS) software is used to design retreat room-and-pillar mine layouts. All these software determine the adequacy of the design by comparing the estimated loads to the load-bearing capacity of the pillars and they use the “abutment angle” concept and a square decay stress distribution function to calculate the magnitude and distribution of the mining-induced loads. The abutment angle concept has been successfully applied to US longwall coal mines with the use of ALPS and ALTS in Australia. ARMPS uses the same concept for retreat room and pillar coal mine design in the US. The suggested abutment angle for coal mines in the US was derived as 21° by the back analysis of underground stress measurements from the 1990s and implemented in ALPS and ARMPS. The ALPS methodology was re-examined and calibrated for Australian conditions with additional Australian stress measurements and resulted in the original ALTS methodology which has been continually improved and expanded with additional cases. In this paper, some recent stress measurements are back-analyzed, and the abutment angles are investigated to verify the applicability of using 21° in retreat room and pillar mines with different depths and mining dimensions. For shallow mines, the derivation of the 21° abutment angle is supported by the new case histories. However, at depths greater than 200 m, the abutment angle was found to be decreasing with increasing depth. In this study, a new equation for the calculation of abutment angle for moderate and deep cover cases was constructed and tested for its applicability in retreat room and pillar mines. The differences in the mechanism of complete side abutment loads in shallow and deep cover mines are further analyzed by applying the finite volume modeling (FVM) approach to two case study mines, one shallow, and one deep cover. A 2D model of each mine is created and one-side and two-side abutment loads of consecutive panels are analyzed. Analysis of the deep cover mine indicated that the prior panel gobs provide a considerable amount of support to the overburden strata. These higher gob loads prevent a higher percentage of overburden loads from being transferred to the active panel workings, and this is in agreement with the lower abutment angles observed for deep cover mines. The findings of this study should only be used for retreat room-and-pillar mines’ production pillar loads since these are calculated geometrically using the abutment angle concept.

Environmental assessment of small scale solar thermal electricity generation

Solar thermal electricity probably has the greatest potential of any single renewable energy process and it can be economically competitive with other technologies, if environmental costs are accounted for. In spite of the many investigations conducted so far there is no one dominant technology and no single life cycle assessment study conducted to compare different STE technologies. This life cycle study has been undertaken to identify potential materials flow, energy consumption and emissions for small scale STE options. The processes are described by the typical process inputs and outputs including energy, materials, solid wastes and other emissions. The results show sufficient efficiency for Australian conditions of small scale.

Phenolic profiles and nutritional quality of four new mungbean lines grown in northern Australia

AbstractFour new lines of mungbean cultivated under northern Australian cropping conditions (19.8462°S, 147.2448°E) were characterised for yield, seed characteristics, nutritional contents, phytochemical profiles and phenolic acid contents. Their performance was compared to a commercially grown mungbean line (Jade‐AU). The seed yield for three of the new lines (AVTMB 1, 3 and 4) was 14% higher compared to Jade‐AU. However, the seed size of AVTMB 1 was also significantly smaller compared to the other lines and Jade‐AU. in vitro sprouting acceptability scores ranged between 80% and 100%, with no significant difference between lines. Ash content was highest (4.26% w/w) for lines with smallest seed (e.g., AVTMB 1), while higher protein content was recorded for AVTMB 1 followed by AVTMB 4, AVTMB 3 and Jade‐AU, and lowest in AVTMB 2. The seed coat colour of AVTMB 1 and 4 was significantly different (lighter green) than other lines and Jade‐AU, whereas the flour colour did not vary significantly. Total polyphenolic content, antioxidant capacity and total monomeric anthocyanin content did not vary significantly between lines. Phenolic acid and flavonoid profiling by HPLC showed the predominant constituents to be vitexin (which averaged between 115 and 149 μg/g for different lines), isovitexin (132–174 μg/g) and catechin (94–105 μg/g). There were statistically significant differences between the mungbean lines for several individual phenolic acids, including p‐hydroxybenzoic, vanillic, caffeic, sinapic, ferulic and cinnamic acids, as well as for the flavonoid glycoside vitexin. In most cases, with the highest concentrations of these compounds were found in AVTMB 4 or AVTMB 1. Several of these new mungbean lines show potential for commercial cropping in the drier, hotter regions of northern Australia due to their yield and seed quality performance.