67 resultados para Collectors and collecting


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With the expected theoretical capacity of 2596 mA h g-1, phosphorus is considered to be the highest capacity anode material for sodium-ion batteries and one of the most attractive anode materials for lithium-ion systems. This work presents a comprehensive study of phosphorus-carbon nanocomposite anodes for both lithium-ion and sodium-ion batteries. The composite electrodes are able to display high initial capacities of approximately 1700 and 1300 mA h g-1 in lithium and sodium half-cells, respectively, when the cells are tested within a larger potential windows of 2.0-0.01 V vs. Li/Li+ and Na/Na+. The level of demonstrated capacity is underpinned by the storage mechanism, based on the transformation of phosphorus to Li3P phase for lithium cells and an incomplete transformation to Na3P phase for sodium cells. The capacity deteriorates upon cycling, which is shown to originate from disintegration of electrodes and their delamination from current collectors by post-cycling ex situ electron microscopy. Stable cyclic performance at the level of ∼700 and ∼350-400 mA h g-1 can be achieved if the potential windows are restricted to 2.0-0.67 V vs. Li/Li+ for lithium and 2-0.33 vs. Na/Na+ for sodium half-cells. The results are critically discussed in light of existing literature reports

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Many services and applications in vehicular ad-hoc networks (VANETs) require preserving and secure data communications. To improve driving safety and comfort, the traffic-related status information will be broadcasted regularly and shared among drivers. Without the security and privacy guarantees, attackers could track their interested vehicles by collecting and analyzing their traffic messages. Hence, anonymous message authentication is an essential requirement of VANETs. On the other hand, when a vehicle is involved in a dispute event of warning message, the certificate authority should be able to recover the real identity of this vehicle. To deal with this issue, we propose a new privacy-preserving authentication protocol with authority traceability using elliptic curve based chameleon hashing. Compared with existing schemes, our approach possesses the following features: 1) mutual and anonymous authentication for both vehicle-to-vehicle and vehicle-to-roadside communications, 2) vehicle unlinkability, 3) authority tracking capability, and 4) high computational efficiency. We also demonstrate the merits of our proposed scheme through security analysis and extensive performance evaluation.

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BACKGROUND: Participation in electronic media use among 2-3 year olds is high and associated with adverse health and developmental outcomes. This study sought to test the feasibility and potential efficacy of a family-based program to decrease electronic media (EM) use in 2-3-year-old children. METHODS: Family@play was a six-session pilot randomised controlled trial delivered to parents of 2-3 year-old children from August to September 2012 in a community environment in the Illawarra region of New South Wales, Australia. Development of program content was guided by Social Cognitive and Family Systems Theories. The primary outcome was children's electronic media use. Secondary outcomes included children's time in sitting, standing and stepping. Data collectors were blinded to group allocation. Parents completed comprehensive process evaluation measures and participated in focus group discussions following completion of the program. Regression analyses were undertaken and effect sizes calculated using principles of intention to treat. RESULTS: Twenty-two participants (n = 12 intervention; n = 10 control) provided complete baseline data; complete data from 16 participants (n = 6 intervention; n = 10 control) were available post-intervention. Process evaluation results were high, showing the acceptability of the program. Compared with children in the control group, there were greater decreases in total EM use among children in the intervention group (adjusted difference [95 % CI] = -31.2 mins/day [-71.0-8.6] Cohen's d = 0.70). Differences for other outcomes were in the hypothesised direction and ranged from small for postural (sitting, standing, stepping) outcomes to moderate to large for individual electronic media (e.g. TV viewing, DVD/video viewing). CONCLUSIONS: This is the first family-based study to engage families of 2-3 year old children outside the United States and target multiple EM behaviours. Family@play was shown to be a feasible and acceptable intervention to deliver to families of 2-3 year old children. Potential efficacy is evident from moderate to large effect sizes. A larger trial is warranted to test the efficacy of the program. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ( ACTRN12612000470897 ).

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 This study provides insight into how organizational climate can change and influence employee engagement using a structural, longitudinal, case study design. Quantitative and qualitative data were collected in two companies in the Philippines undergoing substantial change. An existing validated model of work practices and outcomes was used as a framework in collecting and analyzing the data. Results showed that both companies significantly changed aspects of their organizations associated with the quality of technology and facilities. However, only Company B showed significant changes in aspects associated with the involvement, development, and recognition of staff. With regard to the outcome of employee engagement, results showed that Company A did not report a significant change in employee engagement while Company B did report a significant change. Coding of qualitative comments supported the quantitative results. The findings support the argument that if organizations wish to improve employee engagement, a core requirement for organizational development is to improve the extent to which employees are involved, developed, and recognized within their organization.

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Determining the foraging behaviour of free-ranging marine animals is fundamental for assessing their habitat use and how they may respond to changes in the environment. However, despite recent advances in bio-logging technology, collecting information on both at-sea movement patterns and activity budgets still remains difficult in small pelagic seabird species due to the constraints of instrument size. The short-tailed shearwater, the most abundant seabird species in Australia (ca 23 million individuals), is a highly pelagic procellariiform. Despite its ecological importance to the region, almost nothing is known about its at-sea behaviour, in particular, its foraging activity. Using a combination of GPS and tri-axial accelerometer data-loggers, the fine scale three-dimensional foraging behaviour of 10 breeding individuals from two colonies was investigated. Five at-sea behaviours were identified: (1) resting on water, (2) flapping flight, (3) gliding flight, (4) foraging (i.e., surface foraging and diving events), and (5) taking-off. There were substantial intra- and inter- individual variations in activity patterns, with individuals spending on average 45.8% (range: 17.1-70.0%) of time at sea resting on water and 18.2% (range: 2.3-49.6%) foraging. Individuals made 76.4 ± 65.3 dives (range: 8-237) per foraging trip (mean duration 9.0 ± 1.9 s), with dives also recorded during night-time. With the continued miniaturisation of recording devices, the use of combined data-loggers could provide us with further insights into the foraging behaviour of small procellariiforms, helping to better understand interactions with their prey.

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In marine cartilaginous fish, reabsorption of filtered urea by the kidney is essential for retaining a large amount of urea in their body. However, the mechanism for urea reabsorption is poorly understood due to the complexity of the kidney. To address this problem, we focused on elephant fish (Callorhinchus milii) for which a genome database is available, and conducted molecular mapping of membrane transporters along the different segments of the nephron. Basically, the nephron architecture of elephant fish was similar to that described for elasmobranch nephrons, but some unique features were observed. The late distal tubule (LDT), which corresponded to the fourth loop of the nephron, ran straight near the renal corpuscle, while it was convoluted around the tip of the loop. The ascending and descending limbs of the straight portion were closely apposed to each other and were arranged in a countercurrent fashion. The convoluted portion of LDT was tightly packed and enveloped by the larger convolution of the second loop that originated from the same renal corpuscle. In situ hybridization analysis demonstrated that co-localization of Na(+),K(+),2Cl(-) cotransporter 2 and Na(+)/K(+)-ATPase α1 subunit was observed in the early distal tubule and the posterior part of LDT, indicating the existence of two separate diluting segments. The diluting segments most likely facilitate NaCl absorption and thereby water reabsorption to elevate urea concentration in the filtrate, and subsequently contribute to efficient urea reabsorption in the final segment of the nephron, the collecting tubule, where urea transporter-1 was intensely localized.

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OBJECTIVE: Point of service feedback (POSF) enables patients to give health services feedback about their experiences during or immediately after care. Despite the increasing use of POSF, little is known regarding patients' and staffs' opinions of this practice and whether they consider it acceptable or useful. The study aimed to determine patient and staff opinions regarding POSF. DESIGN: A cross-sectional survey. SETTING: Acute and subacute healthcare facilities. PARTICIPANTS: Two hundred and forty-seven patients and 221 staff. RESULTS: Participants indicated that patients should be invited to evaluate health services when they are in hospital or subacute care and improving services was the most important reason for doing so. Staff indicated that:• collecting patients' feedback during their stay was an important part of providing care and not an interruption to it (n = 187 of 221, 85%).• collecting patients' feedback was best done with a variety of methods; talking directly with patients during their stay was the preferred option (n = 161 of 219, 74%).More patients preferred to:• give feedback during their stay (51%) than after discharge from care (15%).• give feedback by talking with someone (45%) than completing a questionnaire (31%).Some patients (14%) were concerned about reprisal from staff if they gave negative feedback. CONCLUSIONS: POSF can be acceptable and useful for evaluating health services and should be incorporated into a person-centred approach that allows patients to choose from a variety of feedback options both during and after their stay. To be most useful, feedback should be incorporated into a quality improvement system.