154 resultados para Battery chargers


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The objectives of this study were to examine the contribution of anxiety and fundamental emotions to perceived emotion functionality and evaluate the informational value of anxiety measures used in sport versus measures of fundamental emotions in terms of appraisal. A battery of questionnaires comprising the somatic and cognitive subscale of the Competitive State Anxiety Inventory-2 (CSAI-2), the State Anxiety Inventory, the Differential Emotions Scale–IV, a perceived functionality of emotions single item, and two items assessing challenge and threat appraisals was administered to 202 athletes competing in individual sports in the United Kingdom. They were tested on recalled pre-competitive emotions experienced before their best and worst competition ever and momentary emotions experienced one hour before an actual competition. In general, measures of fundamental emotions with clear approach or avoidance action tendencies were better predictors of emotion functionality than anxiety measures. Results also suggested that the CSAI-2 does not convey clear information about an athlete’s appraisal of a competition. Measures of negative and positive fundamental emotions with clear action tendencies were better indicators of athletes’ appraisal patterns. It was concluded that assessment of athletes’ emotional state should not be exclusively based on anxiety measures but should encompass or be replaced with measures of emotions conveying unambiguous information about the athlete-competition relationship.

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Background:  Cognitive models of body dysmorphic disorder (BDD) suggest that beliefs and evaluations related to self-concept are central to the maintenance of the disorder, but such beliefs have received little empirical attention. This study examined the relative importance of contingent self-worth and self-ambivalence to BDD symptoms in comparison to their importance to obsessive–compulsive disorder and social phobia symptoms.

Method: 
The sample comprised 194 non-clinical participants (female, N = 148; males, N = 46) with a mean age of 24.70 years (standard deviation = 9.34). Participants were asked to complete a battery of self-report questionnaires. Results:  While significant relationships were found between the self-beliefs and symptoms of all three disorders, some specificity was found in the relationships.

Conclusions: 
Self-worth based upon appearance was most important in BDD, while contingent self-worth based on the approval of others was important in social phobia. Self-ambivalence was associated with each disorder. Implications and limitations are discussed.

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Recent theories of Obsessive Compulsive Disorder have suggested that meta-cognitive beliefs, particular confidence in memory, may relate to the maintenance of symptoms. For example, individuals who worry that their memory is deficient may check in order to ensure that the doors are locked, regardless of their actual memory ability. While studies have related meta-memory beliefs to OCD symptoms, and have found that memory is affected by checking behaviours; to date, no experimental literature has attempted to ascertain whether lowered confidence in memory directly leads to greater checking behaviours. In the current study 46 non-clinical participants completed a battery of questionnaires measuring these constructs, before undertaking a “memory task” designed to manipulate their level of confidence in their memory. The effect of the manipulation on the level of checking on a visuomemory task was subsequently assessed. The questionnaires indicated that cognitive confidence predicted variation in obsessive-compulsive symptoms over-and-above the influence of depressive symptoms and other OCD-related beliefs. However, while confidence in memory was successfully manipulated, the group with increased memory confidence was not found to have lower checking behaviours. Limitations of the study are discussed and directions for further research are suggested.

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Background

Available data suggest that body dissatisfaction is common during pregnancy and may even be a precursor to post-natal depression. However, in order to accurately identify at-risk women, it is essential to first establish that body image measures function appropriately in pregnant populations. Our study examines the suitability of the Body Attitudes Questionnaire (BAQ) for measuring body dissatisfaction among pregnant women by comparing the psychometric functioning of the BAQ: (1) across key phases of pregnancy, and (2) between pregnant and non-pregnant women. 

Methods:
A total of 176 pregnant women from Melbourne, Victoria filled out a questionnaire battery containing demographic questions and the Body Attitudes Questionnaire at 16, 24, and 32 weeks during pregnancy. A comparison group of 148 non-pregnant women also completed the questionnaire battery at Time 1. Evaluations of the psychometric properties of the BAQ consisted of a series of measurement invariance tests conducted within a structural equation modelling framework.

Results:
Although the internal consistency and factorial validity of the subscales of the BAQ were established across time and also in comparisons between pregnant and non- pregnant women, measurement invariance tests showed non-invariant item intercepts across pregnancy and also in comparison with the non-pregnant subgroup. Inspection of modification indices revealed a complex, non-uniform pattern of differences in item intercepts across groups.

Conclusions:
Collectively, our findings suggest that comparisons of body dissatisfaction between pregnant and non-pregnant women (at least based on the BAQ) are likely to be conflated by differential measurement biases that serve to undermine attempts to accurately assess level of body dissatisfaction. Researchers should be cautious in assessments of body dissatisfaction among pregnant women until a suitable measure has been established for use in this population. Given the fact that body dissatisfaction is often associated with maladaptive behaviours, such as unhealthy eating and extreme weight loss behaviours, and with ante-and post-natal depression, that have serious negative implications for women’s health and well-being, and potentially also for the unborn foetus during pregnancy, developing a suitable body image screening tool, specific to the perinatal period is clearly warranted.

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Integrating rechargeable battery cells with fibre reinforced polymer matrix composites is a promising technology to enable composite structures to concurrently carry load and store electric energy, thus significantly reducing weight at the system level. To develop a design criterion for structural battery composites, rechargeable lithium polymer battery cells were embedded into carbon fibre/epoxy matrix composite laminates, which were then subjected to tensile, flexural and compressive loading. The electric charging/discharging properties were measured at varying levels of applied loads. The results showed that degradation in battery performance, such as voltagea and energy storage capacity, correlated well with the applied strain under three different loading conditions. Under compressive loading, battery cells, due to their multilayer construction, were unable to prevent buckling of composite face sheets due to the low lateral stiffness, leading to lower compressive strength that sandwich panels with foam core.

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Deep brain stimulation has emerged as an effective medical procedure that has therapeutic efficacy in a number of neuropsychiatric disorders. Preclinical research involving laboratory animals is being conducted to study the principles, mechanisms, and therapeutic effects of deep brain stimulation. A bottleneck is, however, the lack of deep brain stimulation devices that enable long term brain stimulation in freely moving laboratory animals. Most of the existing devices employ complex circuitry, and are thus bulky. These devices are usually connected to the electrode that is implanted into the animal brain using long fixed wires. In long term behavioral trials, however, laboratory animals often need to continuously receive brain stimulation for days without interruption, which is difficult with existing technology. This paper presents a low power and lightweight portable microdeep brain stimulation device for laboratory animals. Three different configurations of the device are presented as follows: 1) single piece head mountable; 2) single piece back mountable; and 3) two piece back mountable. The device can be easily carried by the animal during the course of a clinical trial, and that it can produce non-stop stimulation current pulses of desired characteristics for over 12 days on a single battery. It employs passive charge balancing to minimize undesirable effects on the target tissue. The results of bench, in-vitro, and in-vivo tests to evaluate the performance of the device are presented.

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Perovskite oxide offers an attractive alternative to precious metal electrocatalysts given its low cost and high oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity. The results obtained in this work suggest a correlation of crystal structure with ORR and OER activity for LaNiO3-?. LaNiO3-? perovskites with different crystal structure were obtained by heating at different temperatures, e.g., 400, 600, and 800 C followed by quenching into room temperature. Cubic structure (relative to rhombohedral) leads to higher ORR and OER activity as well as enhanced bi-functional electrocatalytic activity, e.g., lower difference in potential between the ORR at -3 mA cm-2 and OER at 5 mA cm -2 (?E). Therefore, this work shows the possibility to adjust bi-functional activity through a simple process. This correlation may also extend to other perovskite oxide systems.

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Purpose
The purpose of this paper is to critically examine the instruments used in the screening process, with particular attention given to supporting research validation. Psychological screening is a well-established process used in the selection of employees across public safety industries, particularly in police settings. Screening in and screening out are both possible, with screening out being the most commonly used method. Little attention, however, has been given to evaluating the comparative validities of the instruments used.

Design/methodology/approach
This review investigates literature supporting the use of the Minnesota Multiphasic Personality Inventory (MMPI), the California Personality Inventory (CPI), the Inwald Personality Inventory (IPI), the Australian Institute of Forensic Psychology's test battery (AIFP), and some other less researched tests. Research supporting the validity of each test is discussed.

Findings
It was found that no test possesses unequivocal research support, although the CPI and AIFP tests show promise. Most formal research into the validity of the instruments lacks appropriate experimental structure and is therefore less powerful as “evidence” of the utility of the instrument(s).

Practical implications
This research raises the notion that many current screening practices are likely to be adding minimal value to the selection process by way of using instruments that are not “cut out” for the job. This has implications for policy and practice at the recruitment stage of police employment.

Originality/value
This research provides a critical overview of the instruments and their validity studies rather than examining the general process of psychological screening. As such, it is useful to those working in selection who are facing the choice of psychological instrument. Possibilities for future research are presented, and development opportunities for a best practice instrument are discussed.

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The charging of an undivided cerium–zinc redox battery by various current waveforms some of which mimic the output of renewable energy (solar, wind, tidal, biofuel burning) to electricity transducers is considered in this work, where the battery operates through diffusion-only conditions, and is discharged galvanostatically. Under reasonable assumption, the mathematical model developed enables the observation that the performance characteristic of the cells charged with a constant power input differentiates between the various current–charge waveforms, with cell geometry and electrode kinetics playing subtle, but significant, roles; in particular, high efficiency is observed for sunlight-charged batteries which are thin and suffer no corrosion of the sacrificial electrode, and which have already experienced a charge–discharge cycle. The performance characteristics of the systems are interpreted in the light of consequences for smart grid realisation, and indicate that, for a constant power input, the most matched renewable is biofuel burning with a current output that linearly increases with time.