154 resultados para Battery chargers


Relevância:

20.00% 20.00%

Publicador:

Resumo:

 A non-aqueous secondary battery has been constructed by using Zn metal as the anode and chemically synthesised PEDOT as the cathode, with a 1-ethyl-3-methylimidazolium dicyanamide ionic liquid as the electrolyte, which avoids dendritic growth processes on the Zn surface upon charge/discharge cycling. The novel Zn/PEDOT rechargeable cell shows high efficiency and cycling ability, performing over 320 cycles with no indication of short circuit. Both the Zn and PEDOT surfaces showed minimal signs of degradation, suggesting that a Zn/PEDOT electrochemical device would be capable of extended cycle life under numerous charge/discharge cycles.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Interconnected microspheres of V2O5 composed of ultra-long nanobelts are synthesized in an environmental friendly way by adopting a conventional anodization process combined with annealing. The synthesis process is simple and low-cost because it does not require any additional chemicals or reagents. Commercial fish-water is used as an electrolyte medium to anodize vanadium foil for the first time. Electron microscopy investigation reveals that each belt consists of numerous nanofibers with free space between them. Therefore, this novel nanostructure demonstrates many outstanding features during electrochemical operation. This structure prevents self-aggregation of active materials and fully utilizes the advantage of active materials by maintaining a large effective contact area between active materials, conductive additives, and electrolyte, which is a key challenge for most nanomaterials. The electrodes exhibit promising electrochemical performance with a stable discharge capacity of 227 mAh·g–1 at 1C after 200 cycles. The rate capability of the electrode is outstanding, and the obtained capacity is as high as 278 at 0.5C, 259 at 1C, 240 at 2C, 206 at 5C, and 166 mAh·g–1 at 10C. Overall, this novel structure could be one of the most favorable nanostructures of vanadium oxide-based cathodes for Li-ion batteries. [Figure not available: see fulltext.]

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundamental movement skills (FMS) competence is low in adolescent girls. An assessment tool for teachers is needed to monitor FMS in this demographic. The present study explored whether the Canadian Agility and Movement Skill Assessment (CAMSA) is feasible for use by physical education (PE) teachers of Australian Year 7 girls in a school setting. Surveys, focus group interviews, and direct observation of 18 specialist PE teachers investigated teachers’ perceptions of this tool. Results indicated that the CAMSA was usable in a real-world school setting and was considered a promising means to assess FMS in Year 7 girls. However, future iterations may require minor logistical alterations and further training for teachers on how to utilize the assessment data to enhance teaching practice. These considerations could be used to improve future design, application, and training of the CAMSA in school-based PE.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The effect of processing history and morphology is of particular importance for lithium-ion electrolytes for achieving higher ionic conductivities. In this study, single ion conducting poly (4-lithium styrene sulfonic acid) was synthesized by neutralization reaction from polystyrene sulfonic acid, and the effect of morphology and processing method was studied by comparing pelletized, electrospun and gel samples. The PSSLi gels displayed best ionic conductivity, while the pelletized samples showed the worst ionic conductivity. Although electrospinning led to a free standing electrolyte, the lower amount of solvent phase led to lower ionic conductivity when compared to the PSSLi gel. The ionic conductivity at room temperature improved from 6.6 × 10−5 S/cm to 1.4 × 10−3 S/cm by optimizing the processing methodology and the lithium ion concentration. The results show that PSSLi based single ion conducting lithium (SICL) gels are a promising candidate for lithium ion battery application.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In order for sodium batteries to become a safe, lower cost option for large scale energy storage, minimising the price of all components is important. We report here on the application of a pyrrolidinium room temperature ionic liquid comprising the dicyanamide anion as a successful electrolyte system for sodium metal batteries that does not contain expensive fluorinated species. The effects of plating/stripping of sodium from Na metal electrodes has been investigated in a symmetrical Na | electrolyte | Na configuration at a current density of 10 μA cm− 2. Comparisons are drawn to reference organic electrolytes comprising propylene carbonate-fluoroethylene carbonate. Residual water molecules in the ionic liquid electrolyte are observed to have a significant effect upon the surface film and subsequent favourable plating/stripping behaviour of symmetrical cells and this is explored in detail. An increase of the moisture content from 90 ppm to 400 ppm impedes both electrodeposition and electrodissolution of the Na+/Na. This is investigated at Ni electrodes using cyclic voltammetry at different Na+-salt concentrations to further understand the mechanism.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Riboflavin-responsive, multiple acylcoenzyme A dehydrogenase deficiency (RR-MAD), a lipid storage myopathy, is characterized by, among others, a decrease in fatty acid (FA) ß-oxidation capacity. Muscle uncoupling protein 3 (UCP3) is up-regulated under conditions that either increase the levels of circulating free FA and/or decrease FA ß-oxidation. Using a relatively large cohort of seven RR-MAD patients, we aimed to better characterize the metabolic disturbances of this disease and to explore the possibility that it might increase UCP3 expression. A battery of biochemical and molecular tests were performed, which demonstrated decreases in FA ß-oxidation and in the activities of respiratory chain complexes I and II. These metabolic alterations were associated with increases of 3.1- and 1.7-fold in UCP3 mRNA and protein expression, respectively. All parameters were restored to control values after riboflavin treatment. We postulate that the up-regulation of UCP3 in RR-MAD is due to the accumulation of muscle FA/acylCoA. RR-MAD is an optimal model to support the hypothesis that UCP3 is involved in the outward translocation of an excess of FA from the mitochondria and to show that, in humans, the effects of FA on UCP3 expression are direct and independent of fatty acid ß-oxidation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Laboratory and practical classes are an important part of the education of students in electronics and electrical engineering. "Hands-on" experience is critical for any engineer working in these fields in particular. For many years, delivering engineering practicals to distance-education students has been a tremendous challenge for universities. For a number of years now, students enrolled in the common first-year electronics course by distance mode at Deakin University have received a home experimentation kit. Using the kit and a laboratory manual, students are required to complete a number of experiments based on components included in the kit. The kit supports a full range of practical activities for digital electronics, and a more limited range of activities for analog electronics. With the kit, off campus students are supplied software for simulating AC electronic circuits, such as amplifiers and rectifiers. In this report we examine the past use of this kit and software,
review anecdotal student experiences with the package, and propose changes to it and to other curriculum resources, aiming to enhance the use of the kit by distance students. Key curriculum resources planned are a web-based 'companion' for the components in and the use of the kit, and two additions to the kit itself: a battery powered function generator, and a PC-based oscilloscope.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conserving of battery power is a critical requirement in WSNs. Past studies have shown that the transceiving process consumes more energy than the internal processing. This work focuses on eliminating overhead messages used for address allocation by employing multiple base-stations. In this context we explore address allocation without Duplicate Address Detection (DAD). We present an alternative approach to Duplicate address detection using the sink as an address pool to maintain and systematize available addresses. Experimental results show that this approach eliminates overhead messages generated by DAD; resulting in energy savings when used in conjunction with an on-demand address allocation mechanism.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A novel geographic routing protocol for multi-hop wireless sensor networks is presented. It exploits the broadcast nature of the wireless channel to enable on-demand cooperative relaying and leapfrogging for circumventing weak radio links. In order to achieve energy efficiency, a metric is introduced for next-hop selection that takes into account information on the residual battery energy, the geographical position of the sensor nodes, and the channel quality of the involved radio links when available. Performance results show that the completely decentralized protocol offers significant benefits by reducing the number of (re)transmissions required to reach the destination. This translates into network-wide energy savings that extend the network lifetime.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The purpose of this study was to evaluate the suitability of the Movement Assessment Battery for Children (M-ABC) for use in Greater China. Chinese children numbering 255 between the ages of 4 and 6 from Hong Kong and 544 from Taiwan were tested individually on the standardized test contained within the M-ABC. Data from these 799 children were compared to that presented in the test manual for the 493 children of the same age comprising the United States standardization sample. Both within-culture and cross-cultural differences were statistically significant when all items of the M-ABC were examined simultaneously, but effect sizes were too low to be considered meaningful. However, descriptive analysis of the cut-off scores used for impairment detection on the test suggested that adjustments to some items would be desirable for these particular Chinese populations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Within the discipline of community psychology there remains considerable debate as to the latent structure of psychological sense of community (PSOC). One of the few theoretical discussions is that of McMillan and Chavis (1986), who hypothesized four dimensions: Belonging; Fulfillment of Needs; Influence; and Shared Connections. Discussion has also emerged in the literature regarding the role of identification within PSOC. However few studies have empirically investigated the role of identification in PSOC. The current study explored PSOC in a sample of residents of rural, regional and urban geographical communities (N = 669). In an endeavor to clarify the underlying dimensions of PSOC, a test battery included several measures of PSOC as well as measures of identification with the community. The study also examined the role of demographic factors in predicting PSOC. Results provided support for McMillan and Chavis' (1986) four dimensions of PSOC. Further, a fifth dimension emerged, that of Conscious Identification, suggesting that identification is separate to existing dimensions of PSOC. The demographic factors significantly associated with PSOC were type of region, with rural participants displaying higher PSOC than their urban counterparts; participation in local organizations; having children; and a vision of one’s neighborhood as broader than just a street or block. These results, and the implications for PSOC research, are discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Third edition of a text for university students providing a basic coverage of the principles of torts law, first published 1997. Covers all aspects of torts law including battery, assault, false imprisonment, trespass, negligence and statutory duty. Designed to be used with 'Torts: Cases and Commentary' or with any other torts law casebook. Includes charts, diagrams, references and index. New edition contains recent High Courts decisions that have changed the law of Torts in Australia. Editor is a senior lecturer at the School of Law, Deakin University.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Purpose: To determine whether childhood fundamental motor skill proficiency predicts subsequent adolescent cardiorespiratory fitness.

Methods: In 2000, children's proficiency in a battery of skills was assessed as part of an elementary school-based intervention. Participants were followed up during 2006/2007 as part of the Physical Activity and Skills Study, and cardiorespiratory fitness was measured using the Multistage Fitness Test. Linear regression was used to examine the relationship between childhood fundamental motor skill proficiency and adolescent cardiorespiratory fitness controlling for gender. Composite object control (kick, catch, throw) and locomotor skill (hop, side gallop, vertical jump) were constructed for analysis. A separate linear regression examined the ability of the sprint run to predict cardiorespiratory fitness.

Results: Of the 928 original intervention participants, 481 were in 28 schools, 276 (57%) of whom were assessed. Two hundred and forty-four students (88.4%) completed the fitness test. One hundred and twenty-seven were females (52.1%), 60.1% of whom were in grade 10 and 39.0% were in grade 11. As children, almost all 244 completed each motor assessments, except for the sprint run (n = 154, 55.8%). The mean composite skill score in 2000 was 17.7 (SD 5.1). In 2006/2007, the mean number of laps on the Multistage Fitness Test was 50.5 (SD 24.4). Object control proficiency in childhood, adjusting for gender (P = 0.000), was associated with adolescent cardiorespiratory fitness (P = 0.012), accounting for 26% of fitness variation.

Conclusion: Children with good object control skills are more likely to become fit adolescents. Fundamental motor skill development in childhood may be an important component of interventions aiming to promote long-term fitness.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

An important part of educating students in electronics and electrical engineering is laboratory practicals. Providing effective practical experience to students by distance education has always been a significant challenge to the engineering educator. Deakin University has for many years taught practicals in basic digital electronics to off-campus students by means of a kit. The same students have performed related exercises in analogue electronics, which require generating and measuring AC signals, by means of either software simulations or on-campus attendance at lab classes. This year, for the first time, off-campus students are being provided with a new kit, which contains a low-cost, battery-powered AC signal generator, and an interface that allows a PC to be used as an oscilloscope. This kit allows the off-campus student further flexibility in learning basic electronics.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Abstract As part of an international,multicentered project, the burden of care, health, and subjective well-being experienced by select Australian family carers supporting a relative with disability at home were investigated. Some 448 family carers residing in New South Wales and Tasmania completed a battery of instruments, including a self-report demographic survey, the Family Caregiver Burden Inventory, the General Health Questionnaire, and the Personal Wellbeing Index. Respondents were predominantly females (mean
age = 48 years), married, and supporting a son or daughter with an intellectual disability (mean age = 18 years). Although caring for their family member was not perceived to be a burden, respondents reported notable limitations on their social networks and social activities. They reported higher levels of unemployment than would be expected for the general population and were over represented in lower income groups. They reported seriously low levels of mental health and personal well-being when compared with the general population. The findings revealed that this group of family carers were at high risk of social and economic disadvantage and at high risk of mental health challenges. Social policy makers and service providers should take these factors into account, both in the interests of promoting the health and well-being of the carers and considering the long-term needs of family members with disability who rely on family carers for daily support when designing services.