Safety enhancement of operator protection systems on self-propelled mining equipment

In the long term, with development of skill, knowledge, exposure and confidence within the engineering profession, rigorous analysis techniques have the potential to become a reliable and far more comprehensive method for design and verification of the structural adequacy of OPS, write Nimal J Perera, David P Thambiratnam and Brian Clark. This paper explores the potential to enhance operator safety of self-propelled mechanical plant subjected to roll over and impact of falling objects using the non-linear and dynamic response simulation capabilities of analytical processes to supplement quasi-static testing methods prescribed in International and Australian Codes of Practice for bolt on Operator Protection Systems (OPS) that are post fitted. The paper is based on research work carried out by the authors at the Queensland University of Technology (QUT) over a period of three years by instrumentation of prototype tests, scale model tests in the laboratory and rigorous analysis using validated Finite Element (FE) Models. The FE codes used were ABAQUS for implicit analysis and LSDYNA for explicit analysis. The rigorous analysis and dynamic simulation technique described in the paper can be used to investigate the structural response due to accident scenarios such as multiple roll over, impact of multiple objects and combinations of such events and thereby enhance the safety and performance of Roll Over and Falling Object Protection Systems (ROPS and FOPS). The analytical techniques are based on sound engineering principles and well established practice for investigation of dynamic impact on all self propelled vehicles. They are used for many other similar applications where experimental techniques are not feasible.

Shear-induced enhancement of self-diffusion in interacting colloidal suspensions

We set up the generalized Langevin equations describing coupled single-particle and collective motion in a suspension of interacting colloidal particles in a shear how and use these to show that the measured self-diffusion coefficients in these systems should be strongly dependent on shear rate epsilon. Three regimes are found: (i) an initial const+epsilon(.2), followed by (ii) a large regime of epsilon(.1/2) behavior, crossing over to an asymptotic power-law approach (iii) D-o - const x epsilon(.-1/2) to the Stokes-Einstein value D-o. The shear dependence is isotropic up to very large shear rates and increases with the interparticle interaction strength. Our results provide a straightforward explanation of recent experiments and simulations on sheared colloids.

Self-regulating casing treatment for axial compressor stability enhancement

The operating range of an axial compressor is often restricted by a safety imposed stall margin. One possible way of regaining operating range is with the application of casing treatment. Of particular interest here is the type of casing treatment which extracts air from a high pressure location in the compressor and re-injects it through discrete loops into the rotor tip region. Existing re-circulation systems have the disadvantage of reducing compressor efficiency at design conditions because worked flow is unnecessarily re-circulated at these operating conditions. Re-circulation is really only needed near stall. This paper proposes a self-regulating casing treatment in which the re-circulated flow is minimized at compressor design conditions and maximized near stall. The self-regulating capability is achieved by taking advantage of changes which occur in the tip clearance velocity and pressure fields as the compressor is throttled toward stall. In the proof-of-concept work reported here, flow is extracted from the high pressure region over the rotor tips and re-injected just upstream of the same blade row. Parametric studies are reported in which the flow extraction and re-injection ports are optimized for location, shape and orientation. The optimized design is shown to compare favorably with a circumferential groove tested in the same compressor. The relationship between stall inception type and casing treatment effectiveness is also investigated. The self-regulating aspect of the new design works well: stall margin improvements from 2.2 to 6.0% are achieved for just 0.25% total air re-circulated near stall and half that near design conditions. The self-regulating capability is achieved by the selective location and orientation of the extraction hole; a simple model is discussed which predicts the optimum axial location. Copyright © 2011 by ASME.

Uniformity enhancement of the self-organized InAs quantum dots

Growth interruption was introduced after the deposition of GaAs cap layer, which is thinner than the height of quantum dots. Uniformity of quantum dots has been enhanced because the full-width of half-maximum of photoluminescence decrease from 80 to 27 meV in these samples as the interruption time is increased. Meanwhile, we have observed that the peak position of photoluminescence is a function of interruption time, which can be used to modulate energy level of quantum dots. All of the phenomenon mentioned above can be attributed to the diffusion of In atoms from the tops of InAs islands to the top of GaAs cap layer caused by the difference between the surface energies of InAs and GaAs. (C) 1999 Elsevier Science B.V. All rights reserved.

Synchronization enhancement via an oscillatory bath in a network of self-excited cells

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mobile phone technologies and advanced data analysis towards the enhancement of diabetes self-management

Advances in the area of mobile and wireless communication for healthcare (m-Health) along with the improvements in information science allow the design and development of new patient-centric models for the provision of personalised healthcare services, increase of patient independence and improvement of patient's self-control and self-management capabilities. This paper comprises a brief overview of the m-Health applications towards the self-management of individuals with diabetes mellitus and the enhancement of their quality of life. Furthermore, the design and development of a mobile phone application for Type 1 Diabetes Mellitus (T1DM) self-management is presented. The technical evaluation of the application, which permits the management of blood glucose measurements, blood pressure measurements, insulin dosage, food/drink intake and physical activity, has shown that the use of the mobile phone technologies along with data analysis methods might improve the self-management of T1DM.

Self-validating technique for the measurement of the linewidth enhancement factor in semiconductor lasers

A new method for measuring the linewidth enhancement factor (α-parameter) of semiconductor lasers is proposed and discussed. The method itself provides an estimation of the measurement error, thus self-validating the entire procedure. The α-parameter is obtained from the temporal profile and the instantaneous frequency (chirp) of the pulses generated by gain switching. The time resolved chirp is measured with a polarization based optical differentiator. The accuracy of the obtained values of the α-parameter is estimated from the comparison between the directly measured pulse spectrum and the spectrum reconstructed from the chirp and the temporal profile of the pulse. The method is applied to a VCSEL and to a DFB laser emitting around 1550 nm at different temperatures, obtaining a measurement error lower than ± 8%.

Direct observation of the enhancement of noncooperative protein self-assembly by macromolecular crowding: Indefinite linear self-association of bacterial cell division protein FtsZ

Recent measurements of sedimentation equilibrium and sedimentation velocity have shown that the bacterial cell division protein FtsZ self-associates to form indefinitely long rod-like linear aggregates in the presence of GDP and Mg2+. In the present study, the newly developed technique of non-ideal tracer sedimentation equilibrium was used to measure the effect of high concentrations—up to 150 g/liter—of each of two inert “crowder” proteins, cyanmethemoglobin or BSA, on the thermodynamic activity and state of association of dilute FtsZ under conditions inhibiting (−Mg2+) and promoting (+Mg2+) FtsZ self-association. Analysis of equilibrium gradients of both FtsZ and crowder proteins indicates that, under the conditions of the present experiment, FtsZ interacts with each of the two crowder proteins essentially entirely via steric repulsion, which may be accounted for quantitatively by a simple model in which hemoglobin, albumin, and monomeric FtsZ are modeled as effective spherical hard particles, and each oligomeric species of FtsZ is modeled as an effective hard spherocylinder. The functional dependence of the sedimentation of FtsZ on the concentrations of FtsZ and either crowder indicates that, in the presence of high concentrations of crowder, both the weight-average degree of FtsZ self-association and the range of FtsZ oligomer sizes present in significant abundance are increased substantially.

Enhancement of ‘dry’ proton conductivity by self-assembled nanochannels in all-solid polyelectrolytes

Proton transport has been recognized as an essential process in many biological systems, as well as electrochemical devices including fuel cells and redox flow batteries. In the present study, we address the pressing need for solvent-free proton conducting polymer electrolytes for high-temperature PEM fuel cell applications by developing a novel all-solid polyelectrolyte membrane with a self-assembled proton-channel structure. We show that this self-assembled nanostructure endows the material with exciting ‘dry’ proton conductivity at elevated temperatures, as high as 0.3 mS cm−1 at 120 °C, making it an attractive candidate for high-temperature PEM fuel cell applications. Based on the combined investigation of solid-state NMR, FTIR and conductivity measurements, we propose that both molecular design and nano-scale structures are essential for obtaining highly conductive anhydrous proton conductors.

Brief opportunistic intervention : the role of psychologists in initiating self-change amongst problem drinkers

Excessive consumption of alcohol is a serious public health problem. While intensive treatments are suitable for those who are physically dependent on alcohol, they are not cost-effective options for the vast majority of problem drinkers who are not dependent. There is good evidence that brief interventions are effective in reducing overall alcohol consumption, alcohol-related problems, and health-care utilisation among nondependent problem drinkers. Psychologists are in an ideal position to opportunistically detect people who drink excessively and to offer them brief advice to reduce their drinking. In this paper we outline the process involved in providing brief opportunistic screening and intervention for problem drinkers. We also discuss methods that psychologists can employ if a client is not ready to reduce drinking, or is ambivalent about change. Depending on the client's level of motivation to change, psychologists can engage in either an education-clarification approach, a commitment-enhancement approach, or a skills-training approach. Routine engagement in opportunistic intervention is an important public-health approach to reducing alcohol-related harm in the community.

The role of extreme sports in lifestyle enhancement and wellness

Alternative sports are fast becoming the physical activity of choice. Participation rates are even outstripping more traditional activities such as golf. At their most extreme there is no second chance, the most likely outcome of a mismanaged error or accident is death. At this level participants enjoy activities such as B.A.S.E. (Buildings, Antennae, Space, Earth) jumping, big wave surfing, waterfall kayaking, extreme skiing, rope-free climbing and extreme mountaineering. Probably the most common explanation for participation in extreme sports is the notion that participation is just a matter of some people‟s need to take unnecessary risks. This study reports on findings that indicate a more positive experience. A phenomenological method was used via unstructured interviews with 15 extreme sports participants (ages 30 – 72 years) and other firsthand accounts. Extreme sport participants directly related their experience to personal transformations that spill over to life in general. Athletes report feelings of deep psychological wellbeing and meaningfulness. The extreme sport experience enables a participant to break through personal barriers and develop an understanding of their own resourcefulness and emotional, cognitive, physical and spiritual capabilities. Furthermore such a breakthrough also seems to trigger a change in personal philosophy or view on life. The extreme sport experience transforms a participant though not in terms of working towards an external (social or cultural) perception of identity or towards some constructed perception of an ideal self, but by touching something within.

Self-management of cancer treatment-related fatigue, nausea, vomiting and oral mucositis in Chinese cancer patients

Background: Treatment-related symptoms continue to place a significant burden on many cancer patients. Many side effects require patients to engage in a range of self-management actions. While some studies have explored self-management of treatment-related side effects in Western settings, very few studies were identified that described the self-management practices of cancer patients in China. Objective: The purposes of this study are to: (1) Investigate Chinese cancer patients. self-management behaviours in dealing with the fatigue, nausea/vomiting and oral mucositis that result from treatment, as well as the perceived effectiveness of these behaviours and related self-efficacy in performing them. (2) Explore factors influencing symptom self-management behaviours using the Cancer Symptom Self-management Framework based on Grey, Knafl and McCorkle.s (2006) self-management framework as a guide. Methods: This study was divided into two phases. Phase One consisted of the translation and modification of two instruments. The adaptation of these instruments to ensure applicability in the Chinese context was achieved through semi-structured interviews with six cancer patients, and content evaluation with eight experienced oncology nurses. A pilot study was conducted with nine cancer patients to trial the questionnaire set in the Chinese context. Based on the results of Phase One, Phase Two involved a cross-sectional survey of Chinese cancer patients undergoing cancer treatment using these instruments. A total of 277 chemotherapy patients with fatigue and/or nausea and vomiting, and 100 radiotherapy patients with oral mucositis were surveyed. Results: Participants in this study reported a variety of self-management behaviours to cope with fatigue, nausea, vomiting and oral mucositis. There are some consistencies as well disparities between strategies that are frequently used and those rated as effective. For fatigue self-management, participants were more likely to use strategies related to rest and sleep, while activity enhancement strategies were rated as achieving higher relief. For nausea and vomiting self-management, dietary modification and taking medication were most frequently used and rated as moderately effective. Psychological strategies were used by more than a third of participants and were rated as mildly effective. Some other infrequently used strategies, such as distraction by keeping busy and acupressure, were rated as moderately effective. For oral mucositis self-management, having soft, bland food and keeping the mouth moisturised were most frequently reported and they were rated as achieving moderate relief. A prescribed mouthwash was used by most but not all participants and brought moderate relief. In general, patients had low-to-moderate self-efficacy in nausea and vomiting self-management behaviours, moderate self-efficacy in fatigue self-management behaviours, and low-to-moderate self-efficacy in oral mucositis self-management behaviours. In terms of the factors influencing symptom self-management, different predictors were identified affecting engagement in fatigue, nausea/vomiting and oral mucositis self-management behaviours. Self-efficacy scores of different behaviours were consistently found to be a positive predictor of the relief level from corresponding behaviours, after controlling for other variables. Perceived social support from health care professionals was identified as an important factor influencing nausea and vomiting self-management behaviours, while neighbourhood support was important for fatigue self-management. In addition, symptom distress was identified as an important factor influencing nausea and vomiting self-management. Conclusion: Similar to reports from overseas, Chinese cancer patients initiate a wide range of self-management behaviours in response to treatment-related side effects. While some behaviours were reported to provide relief, many did not. Given these results, this study has a number of practical implications for health care professionals, particularly in relation to developing tailored self-management programs for fatigue, nausea, vomiting and oral mucositis. Additionally, this study suggests a number of theoretical implications and directions for future research. It is envisaged that these recommendations may pave the way for further studies understanding and promoting cancer symptom self-management in Chinese people affected by cancer.

Measurement and correlates of caregiver self-efficacy amongst family caregivers of persons with dementia living in Shanghai, China

Background: Caring for family members with dementia can be a long-term, burdensome task resulting in physical and emotional distress and impairment. Research has demonstrated significantly lower levels of selfefficacy among family caregivers of people with dementia (CGs) than caregivers of relatives with non-dementia diseases. Intervention studies have also suggested that the mental and physical health of dementia CGs could be improved through the enhancement of their self-efficacy. However, studies are limited in terms of the influences of caregiver self-efficacy on caregiver behaviour, subjective burden and health-related quality of life. Of particular note is that there are no studies on the applicability of caregiver self-efficacy in the social context of China. Objective: The purpose of this thesis was to undertake theoretical exploration using Bandura’s (1997) self-efficacy theory to 1) revise the Revised Caregiving Self-Efficacy Scale (C-RCSES) (Steffen, McKibbin, Zeiss, Gallagher-Thompson, & Bandura, 2002), and 2) explore determinants of caregiver self-efficacy and the role of caregiver self-efficacy and other conceptual constructs (including CGs’ socio-demographic characteristics, CRs’ impairment and CGs’ social support) in explaining and predicting caregiver behaviour, subjective burden and health-related quality of life among CGs in China. Methodology: Two studies were undertaken: a qualitative elicitation study with 10 CGs; and a cross-sectional survey with 196 CGs. In the first study, semi-structured interviews were conducted to explore caregiver behaviours and corresponding challenges for their performance. The findings of the study assisted in the development of the initial items and domains of the Chinese version of the Revised Caregiving Self-Efficacy Scale (C-RCSES). Following changes to items in the scale, the second study, a cross-sectional survey with 196 CGs was conducted to evaluate the psychometric properties of C-RCSES and to test a hypothesised self-efficacy model of family caregiving adapted from Bandura’s theory (1997). Results: 35 items were generated from the qualitative data. The content validity of the C-RCSES was assessed and ensured in Study One before being used for the cross-sectional survey. Eight items were removed and five subscales (caregiver self-efficacy for gathering information about treatment, symptoms and health care; obtaining support; responding to problematic behaviours; management of household, personal and medical care; and controlling upsetting thoughts about caregiving) were identified after principal component factor analysis on the cross-sectional survey data. The reliability of the scale is acceptable: the Cronbach’s alpha coefficients for the whole scale and for each subscale were all over .80; and the fourweek test-retest reliabilities for the whole scale and for each subscale ranged from .64 to .85. The concurrent, convergent and divergent validity were also acceptable. CGs reported moderate levels of caregiver self-efficacy. Furthermore, the level of self-efficacy for management of household, personal and medical care was relatively high in comparison to those of the other four domains of caregiver self-efficacy. Caregiver self-efficacy was also significantly influenced by CGs’ socio-demographic characteristics and the caregiving external factors (CR impairment and social support that CGs obtained). The level of caregiver behaviour that CGs reported was higher than that reported in other Chinese research. CGs’ socio-demographics significantly influenced caregiver behaviour, whereas caregiver self-efficacy did not influence caregiver behaviour. Regarding the two external factors, CGs who cared for highly impaired relatives reported high levels of caregiver behaviour, but social support did not influence caregiver behaviour. Regarding caregiver subjective burden and health-related quality of life, CGs reported moderate levels of subjective burden, and their level of healthrelated quality of life was significantly lower than that of the general population in China. The findings also indicated that CGs’ subjective burden and health-related quality of life were influenced by all major factors in the hypothesised model, including CGs’ socio-demographics, CRs’ impairment, social support that CGs obtained, caregiver self-efficacy and caregiver behaviour. Of these factors, caregiver self-efficacy and social support significantly improved their subjective burden and health-related quality of life; whereas caregiver behaviour and CRs’ impairment were detrimental to CGs, such as increasing subjective burden and worsening health-related quality of life. Conclusion: While requiring further exploration, the qualitative study was the first qualitative research conducted in China to provide an in-depth understanding of CGs’ caregiving experience, including their major caregiver behaviours and the corresponding challenges. Meanwhile, although the C-RCSES needs further psychometric testing, it is a useful tool for assessing caregiver self-efficacy in Chinese populations. Results of the qualitative and quantitative study provide useful information for future studies regarding the explanatory power of caregiver self-efficacy to caregiver behaviour, subjective burden and health-related quality of life. Additionally, integrated with Bandura’s theory, the findings from the quantitative study also suggested a further study exploring the role of outcome expectations in caregiver behaviour, subjective burden and healthrelated quality of life.

The dual orexin/hypocretin receptor antagonist, almorexant, in the ventral tegmental area attenuates ethanol self-administration

Recent studies have implicated the hypocretin/orexinergic system in reward-seeking behavior. Almorexant, a dual orexin/hypocretin R1 and R2 receptor antagonist, has proven effective in preclinical studies in promoting sleep in animal models and was in Phase III clinical trials for sleep disorders. The present study combines behavioral assays with in vitro biochemical and electrophysiological techniques to elucidate the role of almorexant in ethanol and sucrose intake. Using an operant self-administration paradigm, we demonstrate that systemic administration of almorexant decreased operant selfadministration of both 20% ethanol and 5% sucrose. We further demonstrate that intraventral tegmental area (VTA) infusions, but not intra substantia nigra infusions, of almorexant reduced ethanol self-administration. Extracellular recordings performed in VTA neurons revealed that orexin-A increased firing and this enhancement of firing was blocked by almorexant. The results demonstrate that orexin/hypocretin receptors in distinct brain regions regulate ethanol and sucrose mediated behaviors.