Effect of pyrolysis conditions on bone char characterization and its ability for arsenic and fluoride removal
- Authors: Alkurdi, Susan , Al-Juboori, Raed , Bundschuh, Jochen , Bowtell, Les , McKnight, Stafford
- Date: 2020
- Type: Text , Journal article
- Relation: Environmental Pollution Vol. 262, no. (2020), p.
- Full Text: false
- Reviewed:
- Description: This study examined arsenite [As(III)], arsenate [As(V)] and fluoride (F−) removal potential of bone char produced from sheep (Ovis aries) bone waste. Pyrolysis conditions tested were in the 500 °C–900 °C range, for a holding time of 1 or 2 h, with or without N2 gas purging. Previous bone char studies mainly focused on either low or high temperature range with limited information provided on As(III) removal. This study aims to address these gaps and provide insights into the effect of pyrolysis conditions on bone char sorption capacity. A range of advanced chemical analyses were employed to track the change in bone char properties. As pyrolysis temperature and holding time increased, the resulting pH, surface charge, surface roughness, crystallinity, pore size and CEC all increased, accompanied by a decrease in the acidic functional groups and surface area. Pyrolysis temperature was a key parameter, showing improvement in the removal of both As(III) and As(V) as pyrolysis temperature was increased, while As(V) removal was higher than As(III) removal overall. F− removal displayed an inverse relationship with increasing pyrolysis temperature. Bone char prepared at 500 °C released significantly more dissolved organic carbon (DOC) then those prepared at a higher temperature. The bone protein is believed to be a major factor. The predominant removal mechanisms for As were surface complexation, precipitation and interaction with nitrogenous functional groups. Whereas F− removal was mainly influenced by interaction with oxygen functional groups and electrostatic interaction. This study recommends that the bone char pyrolysis temperature used for As and F− removal are 900 °C and 650 °C, respectively. © 2020 Elsevier Ltd
- Description: This research was performed as a part of PhD research which was supported in part by the Iraqi Government and the Australian Research Training Program.
Screening, referral and treatment of depression by Australian cardiologists
- Authors: Hare, David , Stewart, Andrew , Driscoll, Andrea , Mathews, Stephanie , Toukhsati, Samia
- Date: 2020
- Type: Text , Journal article
- Relation: Heart Lung and Circulation Vol. 29, no. 3 (2020), p. 401-404
- Full Text: false
- Reviewed:
- Description: Background: Depression is common in cardiovascular disease (CVD). Clinical practice guidelines recommend routine depression screening by cardiologists. The aim of the study was to undertake a national survey of Australian cardiologists’ clinical practice behaviours in relation to depression screening, referral, and treatment. Methods: The Cardiovascular Disease and Depression Questionnaire was sent to 827 eligible cardiologist members of Cardiac Society of Australia and New Zealand, of which a total of 524 were returned (63%). Results: Most Australian cardiologists do not routinely ask their patients about depression and only 3% routinely use depression screening instruments. Most cardiologists (>70%) think that General Practitioners (Primary Care Physicians) are primarily responsible for identifying and treating depression in CVD. Cardiologists, who understand the prognostic risks of depression in CVD and feel confident to identify and treat depression, were more likely to screen, refer and/or treat patients for depression. Conclusions: Australian cardiologists rarely use validated depression screening measures. Several brief instruments are available for use and can be easily integrated into routine patient care without taking additional consultation time. © 2019
- Description: This work was supported by the Beyond Blue Victorian Centre of Excellence in Depression and Anxiety. Prof Andrea Driscoll was supported by a Heart Foundation Future Leader fellowship 100472 from the National Heart Foundation of Australia.
User-avatar bond profiles : how do they associate with disordered gaming?
- Authors: Stavropoulos, Vasileios , Gomez, Rapson , Mueller, Astrid , Yucel, Murat , Griffiths, Mark
- Date: 2020
- Type: Text , Journal article
- Relation: Addictive Behaviors Vol. 103, no. (2020), p.
- Full Text: false
- Reviewed:
- Description: Aims: The avatar constitutes the in-game representation of the gamer. Although aspects of the user-avatar bond (UAB) have been associated with disordered gaming, there is a need for clearer understanding concerning the impact of potential UAB profiles. Methods: To address this need, the present study recruited a normative sample of 1022 World of Warcraft (WoW) players (Mage = 28.55 years, SD = 9.90). Participants completed the User-Avatar Questionnaire (to assess UAB aspects such as identification, immersion, and compensation), the Proteus-Effect Scale (to assess transference of the avatar's behaviour in real life), and the Internet Gaming Disorder Scale–Short-Form (to assess disordered gaming). Results: Latent class analysis indicated the existence of three UAB profiles, ‘differentiated gamers’ (DGs), ‘identified gamers’ (IGs) and ‘fused gamers’ (FGs). The DGs were characterized by low scores across all UAB aspects. The IGs did not report significant Proteus Effect (PE) or immersion behaviours, and despite being more identified with their avatar, did not significantly compensate through it. The FGs presented with higher PE, immersion, and compensation, although they did not significantly identify with their avatars, possibly due to having idealized them. Disordered gaming behaviours were significantly lower for the DGs and sequentially higher for the IGs and the FGs. Preoccupation and mood modification behaviours related to gaming disorder were distinctively associated with FGs. Conclusion: Disordered gaming assessment and treatment implications of the UAB profiles are discussed. © 2019 Elsevier Ltd
- Description: Murat Yucel has received funding from Monash University , and Australian Government funding bodies such as the National Health and Medical Research Council (NHMRC; including Fellowship #APP1117188 ), the Australian Research Council (ARC), and the Department of Industry, Innovation and Science. He has also received philanthropic donations from the David Winston Turner Endowment Fund, Wilson Foundation, as well as payment from law firms in relation to court and/or expert witness reports. The funding sources had no role in the design, management, data analysis, presentation, or interpretation and write-up of the data.
Model predictive control of microgrids – An overview
- Authors: Hu, Jiefeng , Shan, Yinghao , Guerrero, Josep , Ioinovici, Adrian , Chan, Ka , Rodriguez, Jose
- Date: 2021
- Type: Text , Journal article , Review
- Relation: Renewable and Sustainable Energy Reviews Vol. 136, no. (2021), p.
- Full Text: false
- Reviewed:
- Description: The development of microgrids is an advantageous option for integrating rapidly growing renewable energies. However, the stochastic nature of renewable energies and variable power demand have created many challenges like unstable voltage/frequency and complicated power management and interaction with the utility grid. Recently, predictive control with its fast transient response and flexibility to accommodate different constraints has presented huge potentials in microgrid applications. This paper provides a comprehensive review of model predictive control (MPC) in individual and interconnected microgrids, including both converter-level and grid-level control strategies applied to three layers of the hierarchical control architecture. This survey shows that MPC is at the beginning of the application in microgrids and that it emerges as a competitive alternative to conventional methods in voltage regulation, frequency control, power flow management and economic operation optimization. Also, some of the most important trends in MPC development have been highlighted and discussed as future perspectives. © 2020 Elsevier Ltd
- Description: This work was supported by School of Engineering, IT and Physical Sciences, Federation University Australia , under Project RGS20-5 .
Sustainable development of eco-industrial parks in China: Effects of managers' environmental awareness on the relationships between practice and performance
- Authors: Qu, Ying , Liu, Yakun , Nayak, Ravi , Li, Mengru
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Cleaner Production Vol. 87, no. 1 (2015), p. 328-338
- Full Text: false
- Reviewed:
- Description: As an important means of achieving sustainable development, eco-industrial parks have been given great significance at every level of Chinese governments, and as a result, they have made great strides in China. The increasing pressures of resource constraints and the need for environmental protection have made the achievement of optimal sustainable development performance crucial. Managers of eco-industrial park administrative committees, as decision makers and executors, have a pivotal role in the design, plan, and organization for the sustainable development of eco-industrial parks. Furthermore managers' environmental awareness is important when organizing environmental practices in their eco-industrial parks. This paper seeks to establish the value of the effects of managers' environmental awareness on the relationships between environmental practices and sustainable development performance by presenting an analysis of Chinese eco-industrial park projects. Using an empirical study, this paper first identifies the key environmental practices, directed by managers, which impact the sustainable development performance of Chinese eco-industrial parks. The moderating effect of managers' environmental awareness on the relationships between environmental practices and sustainable development performance is then developed. Our results show that instituting environmental norms for eco-industrial park enterprises, building industrial symbiosis, and providing guidance to key enterprises play significant roles in producing sustainable development performance for eco-industrial parks. Managers' environmental awareness is helpful in driving and transforming environmental practices into sustainable development performance. Our results also provide assistance for designing and implementing environmental practices for sustainable development, recruiting managers with higher environmental awareness, and training managers to improve their environmental awareness so that eco-industrial parks can achieve sustainable development performance.
Effects of different freezing methods on the quality and microstructure of lotus (Nelumbo nucifera) root
- Authors: Tu, Jing , Zhang, Min , Xu, Baoguo , Liu, Huihua
- Date: 2015
- Type: Text , Journal article
- Relation: International Journal of Refrigeration Vol. 52, no. (2015), p. 59-65
- Full Text: false
- Reviewed:
- Description: The effects of three freezing methods, air blast freezing (ABF), immersion freezing (IF) and ultrasound-assisted immersion freezing (UIF), on quality and microstructure of lotus roots were investigated. The parameters used to evaluate the freezing methods effect were the freezing time, color, firmness, drip loss, vitamin C and microstructure of the final frozen products. The results showed that the UIF products had several advantages in terms of the freezing time, color, firmness and drip loss over ABF and IF. No significant difference (p > 0.05) of vitamin C content was observed between the ABF and IF products, while significant difference (p < 0.05) of vitamin C was observed between UIF and ABF/IF products. ABF caused the largest destruction to the tissue, while the microstructure of the UIF products was the best preserved. It is concluded that UIF processing was a better freezing method for lotus root with improved quality and less damaged microstructure than the two other methods. © 2014 Elsevier Ltd and IIR.
Microstructure changes of on the extruded high-amylose bionanocomposites as affected by moisture content via synchrotron radiation studies
- Authors: Liu, Huihua , Chaudhary, Deeptangshu
- Date: 2014
- Type: Text , Journal article
- Relation: Solid State Communications Vol. 192, no. (August 2014 2014), p. 10-14
- Full Text: false
- Reviewed:
- Description: The crystalline domain changes and lamellar structure observations of sorbitol-plasticized starch nanocomposite had been investigated via synchrotron. Strong interactions were found between amylose-sorbitol, resulting in reduced inter-helix spacing of the starch polymer. Achievable dspacing of nanoclay was confirmed to be correlated to the moisture content (mc) within the nanocomposites. SAXS diffraction patterns changed from circular (high mc samples) to elliptical (low mc samples), indicating the formation of long periodic structure and increased heterogeneities of the electron density within the samples. Two different domains sized at around 90 Ã… and 350 Ã… were found for the low mc samples. However, only the ~90 Ã… domain was observed in high mc samples. Formation of the 380 Ã… domain is attributed to the retrogradation behaviour in the absence of water molecules. Meanwhile, the nucleation effect of nanoclay is another factor leading to the emergence of the larger crystalline domain.
Effective and efficient contour-based corner detectors
- Authors: Teng, Shyh , Najmus Sadat, Rafi , Lu, Guojun
- Date: 2015
- Type: Text , Journal article
- Relation: Pattern Recognition Vol. 48, no. 7 (2015), p. 2185-2197
- Full Text: false
- Reviewed:
- Description: Corner detection is an essential operation in many computer vision applications. Among the contour-based corner detectors in the literature, the Chord-to-Point Distance Accumulation (CPDA) detector is reported to have one of the highest repeatability in detecting robust corners and the lowest localization error. However, based on our analysis, we found that the CPDA detector often fails to accurately detect the true corners when a curve has multiple corners but the sharpness of one or a few of them is much more prominent than the rest. This detector also might not perform well when the corners are closely located. Furthermore, the CPDA detector is also computationally very expensive. To overcome these weaknesses, we propose two effective and efficient corner detectors using simple triangular theory and distance calculation. Our experimental results show that our proposed detectors outperform CPDA and nine other existing corner detectors in terms of repeatability. Our proposed detectors also have a relatively low or comparable localization error and are computationally more efficient. © 2015 Elsevier Ltd.
Climate variability in south-eastern Australia over the last 1500 years inferred from the high-resolution diatom records of two crater lakes
- Authors: Barr, Cameron , Tibby, John , Gell, Peter , Tyler, Jonathan , Zawadzki, Atun , Jacobsen, Geraldine
- Date: 2014
- Type: Text , Journal article
- Relation: Quaternary Science Reviews Vol. 95, no. (July 2014 2014), p. 115-131
- Full Text: false
- Reviewed:
- Description: Climates of the last two millennia have been the focus of numerous studies due to the availability of high-resolution palaeoclimate records and the occurrence of divergent periods of climate, commonly referred to as the 'Medieval Climatic Anomaly' and 'The Little Ice Age'. The majority of these studies are centred in the Northern Hemisphere and, in comparison, the Southern Hemisphere is relatively under-studied. In Australia, there are few high-resolution, palaeoclimate studies spanning a millennium or more and, consequently, knowledge of long-term natural climate variability is limited for much of the continent. South-eastern Australia, which recently experienced a severe, decade-long drought, is one such region.Results are presented of investigations from two crater lakes in the south-east of mainland Australia. Fluctuations in lake-water conductivity, a proxy for effective moisture, are reconstructed at sub-decadal resolution over the past 1500 years using a statistically robust, diatom-conductivity transfer function. These data are interpreted in conjunction with diatom autecology. The records display coherent patterns of change at centennial scale, signifying that both lakes responded to regional-scale climate forcing, though the nature of that response varied between sites due to differing lake morphometry. Both sites provide evidence for a multi-decadal drought, commencing ca 650 AD, and a period of variable climate between ca 850 and 1400 AD. From ca 1400-1880 AD, coincident with the timing of the 'Little Ice Age', climates of the region are characterised by high effective moisture and a marked reduction in inter-decadal variability. The records provide context for climates of the historical period and reveal the potential for more extreme droughts and more variable climate than that experienced since European settlement of the region ca 170 years ago.
Different methods of training load quantification and their relationship to injury and illness in elite Australian football
- Authors: Veugelers, Kristopher , Young, Warren , Fahrner, Brendan , Harvey, Jack
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. , no. (2015), p.
- Full Text: false
- Reviewed:
- Description: Objectives: To compare different methods of training load (TL) quantification and their relationship to injury and illness in elite Australian footballers. Design: Prospective cohort study. Methods: Forty-five elite Australian footballers (mean ± standard deviation: age = 23.4 ± 3.8 years) from one elite club participated in this 15 week pre-season study. TL was quantified every session for each individual using four different methods involving rating of perceived exertion (RPE). Two of these methods enabled the quantification of TL for all exercise modalities whilsttwo were applicable only to outdoor field activities. One- and two-weekly cumulative TL was investigated against injury and illness data using a logistic regression model where the low TL group was considered as the reference group. Results: A general trend existed across all TL methods which suggested lower odds of injury and illness in high TL groups. The one-week RPE (all) and one-week RPE x Duration (all) methods detected reduced odds ofinjury inhighTL groups comparedto low TL groups (p < 0.05, OR = 0.199–0.202). Similarly,the one-week RPE (field) method identified lower illness odds in the high TL groups (p < 0.05, OR = 0.083–0.182). Conclusions: Higher TL appeared to provide a protective effect against both injury and illness. The inclusion of duration in the quantification of TL via RPE did not improve the ability of RPE to predict change in odds of injury or illness. © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved
Agreement of adolescent ratings with mother ratings and teacher ratings of ADHD symptom groups: A correlated trait-correlated method minus one analysis
- Authors: Gomez, Rapson , Gomez, Andre
- Date: 2015
- Type: Text , Journal article
- Relation: Personality and Individual Differences Vol. 82, no. (2015), p. 131-135
- Full Text: false
- Reviewed:
- Description: This study examined the level of agreement of adolescent ratings with mother ratings, and adolescent ratings with teacher ratings of the inattention (IA) and hyperactivity/impulsivity (HI) symptom groups of ADHD. A total of 214 adolescents provided self-ratings of IA and HI, and their IA and HI were also rated by their mothers and teachers. The correlated trait-correlated method minus one model was applied, with adolescent ratings as the reference method, and the other two ratings as the non-reference methods. The findings indicated no additional variance in adolescent ratings for IA and HI that could not be accounted by mother ratings of IA and HI, respectively. In contrast, there was additional variance in adolescent ratings for IA and HI that could was not accounted by teacher ratings of IA and HI, respectively. The findings suggest that when diagnosing ADHD in adolescents, their reports of their own ADHD behaviors are not needed when mother reports of such behaviors are used. © 2015.
The Center for Epidemiological Studies Depression Scale: Measurement and structural invariance across ratings of older adult men and women
- Authors: Gomez, Rapson , McLaren, Suzanne
- Date: 2015
- Type: Text , Journal article
- Relation: Personality and Individual Differences Vol. 75, no. (2015), p. 130-134
- Full Text: false
- Reviewed:
- Description: The current study examined the measurement and structural invariance of the Center for Epidemiological Studies Depression Scale (CES-D; Radloff, 1977) across ratings provided by older adult men (. n=. 573) and women (. n=. 605). Ratings were modeled in terms of the original four-factor oblique model: a simple structure with correlated factors for Depressed Affect, Positive Affect, Somatic Symptoms, and Interpersonal Difficulties. Multiple-group confirmatory factor analysis supported full measurement and structural invariance, and no sex difference for the four latent factors. These findings indicate good support for measurement and structural invariance of CES-D ratings across older adult men and women. The psychometric and practical implications of the findings are discussed.
Rotational traction testing : How can we improve the current test device?
- Authors: Twomey, Dara , Connell, Monique , Petrass, Lauren
- Date: 2014
- Type: Text , Conference paper
- Relation: 2014 10th Conference of the International Sports Engineering Association, ISEA 2014; Sheffield, United Kingdom; 14th-17th July 2014; published in Procedia Engineering, Vol. 72, p. 919-924
- Full Text:
- Reviewed:
- Description: Rotational resistance is an important sports surface property in optimising both performance and safety for participants. Despite various attempts to create valid devices to measure the rotational traction, the Studded Boot Apparatus (SBA) originally developed in 1975 is still used in the synthetic turf standards of many governing bodies of sport. In addition to validity limitations, poor operator reliability of the SBA has been reported and it was postulated that the manual nature of the device contributed significantly to this result. Therefore, the aim of this paper is to present data on the automation of the SBA and to discuss the reliability and validity issues of the device. An automated version of the SBA was developed called the UB Turf Tester (UBTT) and data was collected by ten inexperienced operators using the original SBA and the UBTT. Testing was undertaken on a synthetic turf and each operator completed ten trials with each device. Despite a slightly greater peak traction value for the UBTT, there was no significant difference between the peak traction for the two devices, F 1,2 = 0.341, p = 0.57. Greater reliability was found between operators for the UB Turf Tester. Given that the SBA is still commonly used to comply with standards, achieving the highest level of intra- and inter-operator reliability is both desirable and invaluable. However, the research on the validity of the device also needs to continue. Interestingly, limitations of the device were identified when it was first developed but very few adaptations have been implemented since then. Undoubtedly, the interaction between the human and the surface is a complex phenomenon but the weight force, the level of penetration, the pattern, shape and position of the cleats and the possibility of measuring rotational stiffness rather than peak traction all require further discussion and investigation.
Drying and denaturation characteristics of whey protein isolate in the presence of lactose and trehalose
- Authors: Haque, M. Amdadul , Chen, Jie , Aldred, Peter , Adhikari, Benu
- Date: 2015
- Type: Text , Journal article
- Relation: Food Chemistry Vol. 177, no. (2015), p. 8-16
- Full Text: false
- Reviewed:
- Description: The denaturation kinetics of whey protein isolate (WPI), in the presence and absence of lactose and trehalose, was quantified in a convective air-drying environment. Single droplets of WPI, WPI-lactose and WPI-trehalose were dried in conditioned air (2.5% RH, 0.5 m/s air velocity) at two temperatures (65°C and 80°C) for 500 s. The initial solid concentration of these solutions was 10% (w/v) in all the samples. Approximately 68% of WPI was denatured when it was dried in the absence of sugars. Addition of 20% trehalose prevented the irreversible denaturation of WPI at both temperatures. Thirty percent lactose was required to prevent denaturation of WPI at 65°C and the same amount of lactose protected only 70% of WPI from denaturation at 80°C. The secondary structures of WPI were found to be altered by the drying-induced stresses, even in the presence of 20% trehalose and 30% lactose.
Idealisation of soil-structure system to determine inelastic seismic response of mid-rise building frames
- Authors: Tabatabaiefar, Hamid , Fatahi, Behzad
- Date: 2014
- Type: Text , Journal article
- Relation: Soil Dynamics and Earthquake Engineering Vol. 66, no. (November 2014), p. 339-351
- Full Text: false
- Reviewed:
- Description: In this study, a novel and enhanced soil-structure model is developed adopting the direct analysis method using FLAC 2D software to simulate the complex dynamic soil-structure interaction and treat the behaviour of both soil and structure with equal rigour simultaneously. To have a better judgment on the inelastic structural response, three types of mid-rise moment resisting building frames, including 5, 10, and 15 storey buildings are selected in conjunction with three soil types with the shear wave velocities less than 600m/s, representing soil classes Ce, De and Ee, according to Australian Standards. The above mentioned frames have been analysed under two different boundary conditions: (i) fixed-base (no soil-structure interaction) and (ii) flexible-base (considering soil-structure interaction). The results of the analyses in terms of structural displacements and drifts for the above mentioned boundary conditions have been compared and discussed. It is concluded that considering dynamic soil-structure interaction effects in seismic design of moment resisting building frames resting on soil classes De and Ee is essential.
Control of the sheep blowfly in Australia and New Zealand - are we there yet?
- Authors: Sandeman, Mark , Levot, Garry , Heath, Allen , James, Peter , Greeff, Johan , Scott, Max , Batterham, Philip , Bowles, Vern
- Date: 2014
- Type: Text , Journal article
- Relation: International Journal for Parasitology Vol. 44, no. 12 (2014), p. 879-891
- Full Text: false
- Reviewed:
- Description: The last 50. years of research into infections in Australia and New Zealand caused by larvae of the sheep blowfly, Lucilia cuprina, have significantly advanced our understanding of this blowfly and its primary host, the sheep. However, apart from some highly effective drugs it could be argued that no new control methodologies have resulted. This review addresses the major areas of sheep blowfly research over this period describing the significant outcomes and analyses, and what is still required to produce new commercial control technologies. The use of drugs against this fly species has been very successful but resistance has developed to almost all current compounds. Integrated pest management is becoming basic to control, especially in the absence of mulesing, and has clearly benefited from computer-aided technologies. Biological control has more challenges but natural and perhaps transformed biopesticides offer possibilities for the future. Experimental vaccines have been developed but require further analysis of antigens and formulations to boost protection. Genetic technologies may provide potential for long-term control through more rapid indirect selection of sheep less prone to flystrike. Finally in the future, genetic analysis of the fly may allow suppression and perhaps eradication of blowfly populations or identification of new and more viable targets for drug and vaccine intervention. Clearly all these areas of research offer potential new controls but commercial development is perhaps inhibited by the success of current chemical insecticides and certainly requires a significant additional injection of resources.
Thiamin analysis in red wine by fluorescence reverse phase-HPLC
- Authors: Liddicoat, Callum , Hucker, Barry , Liang, Hao , Vriesekoop, Frank
- Date: 2015
- Type: Text , Journal article
- Relation: Food Chemistry Vol. 177, no. (2015), p. 325-329
- Full Text: false
- Reviewed:
- Description: The derivatization of thiamin vitamers to their respective thiochrome by ferricyanide to facilitate fluorescence detection following separation by HPLC provides a powerful analytical tool. However the polyphenolic compounds in red wine readily interact with ferricyanide, reducing the effectiveness of ferricyanide oxidation in the derivatization of thiamin. We describe a method to facilitate the removal of polyphenolic compounds that interfere with the ferricyanide derivatization of thiamin. Polyvinylpolypyrrolidone afforded the total removal of phenolic compounds from red wines and allowed a spike recovery of thiamin vitamers (101% for thiamin; 104% for TMP; and 100% for TDP) in a wide range of red wines. This research found that Merlot styles of red wine contained the highest concentration of total thiamin (29.01 ng/mL) while Pinot Noir wines contained the lowest total concentration (8.27 ng/mL).
2D dynamic analysis of cracks and interface cracks in piezoelectric composites using the SBFEM
- Authors: Li, Chao , Song, Chongmin , Man, Hou , Ooi, Ean Tat , Gao, Wei
- Date: 2014
- Type: Text , Journal article
- Relation: International Journal of Solids and Structures Vol. 51, no. 11-12 (June 2014), p. 2096-2108
- Full Text: false
- Reviewed:
- Description: The dynamic stress and electric displacement intensity factors of impermeable cracks in homogeneous piezoelectric materials and interface cracks in piezoelectric bimaterials are evaluated by extending the scaled boundary finite element method (SBFEM). In this method, a piezoelectric plate is divided into polygons. Each polygon is treated as a scaled boundary finite element subdomain. Only the boundaries of the subdomains need to be discretized with line elements. The dynamic properties of a subdomain are represented by the high order stiffness and mass matrices obtained from a continued fraction solution, which is able to represent the high frequency response with only 3-4 terms per wavelength. The semi-analytical solutions model singular stress and electric displacement fields in the vicinity of crack tips accurately and efficiently. The dynamic stress and electric displacement intensity factors are evaluated directly from the scaled boundary finite element solutions. No asymptotic solution, local mesh refinement or other special treatments around a crack tip are required. Numerical examples are presented to verify the proposed technique with the analytical solutions and the results from the literature. The present results highlight the accuracy, simplicity and efficiency of the proposed technique.
A critical examination of the reliability and validity of the SZTPI-15 in British, American and Australian samples
- Authors: McKay, Michael , Worrell, Frank , Temple, Elizabeth , Perry, John , Cole, Jon
- Date: 2014
- Type: Text , Journal article
- Relation: Personality and Individual Differences Vol. 69, no. (October 2014 2014), p. 168-172
- Full Text: false
- Reviewed:
- Description: As an individual difference variable assessing the extent to which attitudes towards past, present and future influence behavior, time perspective is a potentially useful construct. However, its development and utility has been compromised by measurement issues. Recently, a short form of the Zimbardo Time Perspective Inventory (ZTPI), the SZTPI-15 has been suggested to yield valid and reliable scores. Using three independent samples from America, Australia, and the United Kingdom, the present study tested the psychometric properties of SZPTI-15 scores. Confirmatory factor analyses did not support the 5-factor structure and internal consistency estimates for four of the subscales were low. Fit indices obtained from exploratory structural equation modeling were better, suggesting that permitting items to load on multiple factors improved model fit. Correlations with variables shown to be related to ZTPI factors broadly supported the concurrent validity of the SZTPI-15. Results suggest that further psychometric examination of SZTPI-15 scores is required.
- Description: C1
The need for speed: Timely prevention of the dispersal of noxious weeds in relief fodder using efficient sampling procedures
- Authors: Weller, Sandra , Florentine, Singarayer , Sillitoe, Jim , Grech, Charles , McLaren, David , Chauhan, Bhagirath
- Date: 2015
- Type: Text , Journal article
- Relation: Crop Protection Vol. 70, no. (2015), p. 21-27
- Full Text:
- Reviewed:
- Description: Invasive and noxious weeds are well known as a pervasive problem, imposing significant economic burdens on all areas of agriculture. Whilst there are multiple possible pathways of weed dispersal in this industry, of particular interest to this discussion is the unintended dispersal of weed seeds within fodder. During periods of drought or following natural disasters such as wild fire or flood, there arises the urgent need for 'relief' fodder to ensure survival and recovery of livestock. In emergency situations, relief fodder may be sourced from widely dispersed geographic regions, and some of these regions may be invaded by an extensive variety of weeds that are both exotic and detrimental to the intended destination for the fodder. Pasture hay is a common source of relief fodder and it typically consists of a mixture of grassy and broadleaf species that may include noxious weeds. When required urgently, pasture hay for relief fodder can be cut, baled, and transported over long distances in a short period of time, with little opportunity for prebaling inspection. It appears that, at the present time, there has been little effort towards rapid testing of bales, post-baling, for the presence of noxious weeds, as a measure to prevent dispersal of seeds. Published studies have relied on the analysis of relatively small numbers of bales, tested to destruction, in order to reveal seed species for identification and enumeration. The development of faster, more reliable, and non-destructive sampling methods is essential to increase the fodder industry's capacity to prevent the dispersal of noxious weeds to previously unaffected locales.