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Energy Used (energy + used)
Selected AbstractsVariability and minimum detectable change for walking energy efficiency variables in children with cerebral palsyDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 8 2009SUSAN SIENKO THOMAS MA For individuals with neuromuscular disorders, the assessment of walking energy efficiency is useful as a clinical outcome measure. Issues surrounding data collection methodology, normalization of the data, and variability and clinical utility of energy efficiency data preclude universal application. This study examined the variability and the clinical utility of velocity, energy efficiency index (EEI), gross cost, and net nondimensional cost (NNcost) in children and adolescents with spastic diplegic cerebral palsy (CP) in Gross Motor Function Classification System (GMFCS) levels I to III. The energy efficiency of walking was evaluated in 23 children and adolescents (12 males, 11 females, mean age 11y 3mo [SD 3y 5mo]; range 7,17y). Day-to-day variability was similar for all energy efficiency variables, with no significant differences in magnitude of variability between GMFCS levels. Correlations between EEI and gross cost and EEI and NNcost were fairly good (r=0.65, p<0.001, and r=0.74, p<0.001 respectively). However, only gross cost and NNcost discriminated between GMFCS levels in children with CP. Gross cost required the greatest amount of change to be considered clinically significant, whereas NNcost and EEI required a similar amount of change. For cohorts of children with CP who are evaluated over time, NNcost is the best normalization method as it reduces the variability between participants of different ages, height, and weight while evaluating only the amount of energy used to ambulate. [source] Energy requirements of spasticityDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 4 2001Cheryl Hemingway MBCh B Direct measurement of energy expended by spasticity in children with severe spastic quadriparesis is difficult. Insertion of an intrathecal baclofen pump in a 13-year-old boy with severe spasticity and profound mental retardation* resulted in an estimated 30 to 40% decrease in his spasticity. As he had been on a carefully calculated ketogenic diet and fed by gastrostomy, his precise caloric intake was known. Decrease in spasticity, on the same caloric intake, led to marked weight gain. Reduction of 100 calories intake resulted in new weight stability. It was possible therefore, to estimate indirectly energy used by his spasticity. This 100 calories, representing 34% of calories above his resting energy requirement, corresponded to an independently estimated 30 to 40% of caloric expenditure of his spasticity. It was concluded that when calculation of calories is critical, energy utilization by spasticity must be taken into consideration. [source] The effects of multiple passes on the epidermal thermal damage pattern in nonablative fractional resurfacing,LASERS IN SURGERY AND MEDICINE, Issue 2 2009Dieter Manstein MD Background and Objective Nonablative fractional resurfacing is a concept of cutaneous re-modeling whereby laser-induced microscopic treatment zones (MTZs) are surrounded by normal viable tissue. Such thermal damage pattern with a small diameter of individual lesions allows fast re-epithelialization with minimal side effects. The purpose of this in vitro study was to determine the fraction of thermal injury per unit surface area (fill factor) and lesion size in relation to pulse energy and number of passes. Methods Full thickness abdominal skin samples were exposed ex vivo to the Fraxel SR 750 laser (Reliant Technologies, Mountain View, CA). One set of exposures was performed for pulse energies in the range of 8 to 40 mJ for a single pass at 250 MTZ/cm2. A second set of exposures was performed at 10 mJ with number of passes from 1 to 30. The thermal damage pattern was assessed by incubation of epidermal sheets with NitroBlueTetrazoliumChloride (NBTC) stain. Size of individual MTZ and fill factor were determined by image analysis (ImageJ, NIH, Bethesda, MD) of digital micrographs. Results Width of the thermal injury zone was directly related to the pulse energy used. The fill factor did not have a uniform relationship with the number of passes. Due to the stochastic placement of individual MTZs, even for greater number of passes, some residual undamaged tissue was found. Due to formation of thermal damage clusters, defined as overlapping individual MTZs, the size of the resulting clustering lesions which we defined as microscopic treatment cluster (MTC) increased linearly as a function of the number of passes. Conclusion We have described the fill factor as it relates to the number of passes and have demonstrated that the average size of individual lesions depends on the number of passes. Clustering of MTZs lead to the development of MTC, the average size of which increased with the number of passes. The clinical implications of these findings are contingent on further studies. Lasers Surg. Med. 41:149,153, 2009. © 2009 Wiley-Liss, Inc. [source] Mate selection in Litoria chloris and Litoria xanthomera: Females prefer smaller malesAUSTRAL ECOLOGY, Issue 3 2001Clare Morrison Abstract It is generally accepted that high quality males are those that succeed in male,male competition: in either aggression or rivalry to attract and be selected by females. Previous studies of amphibians have suggested that the main characters influencing male mating success include variation in call characteristics (e.g. call rate, call intensity), calling behaviour, body condition, age and chorus tenure. In the present paper, several of the characters influencing female mate choice (male body size, body condition, call rate, call frequency and chorus tenure) are investigated in two closely related, explosive breeding frog species Litoria chloris and Litoria xanthomera. Smaller males of both species are shown to be more successful than larger males and this success is attributed to the increased chorus tenure of smaller males in L. xanthomera. This increased chorus tenure was attributed to the lower total energy used per call by a small male calling at a higher frequency. Whether increased chorus tenure explains female mate choice in L. chloris is uncertain but is highly probable given the strong similarity between the two species in both ecology and call characteristics. [source] Die Ermittlung des Jahresnutzkühlenergiebedarfs in Bürogebäuden mit dem Berechnungsverfahren nach Energieeinsparverordnung 2007 bzw.BAUPHYSIK, Issue 2 2009DIN V 1859 Energieinsparung; Technische Regelwerke Abstract Die seit 2007 gültige Energieeinsparverordnung (EnEV) schreibt für Bürogebäude eine gesamtheitliche Bilanzierung des Energiebedarfs vor, so dass neben dem Heizwärmeverbrauch und dem Energieverbrauch für Lüftungsanlagen erstmals auch der Kühlenergieverbrauch und der Stromverbrauch für Beleuchtung zu berücksichtigen ist. Die vorliegende Studie fokussiert auf den Jahreskühlenergieverbrauch von Büroräumen, welcher neben den Rechenregeln nach EnEV 2007 bzw. DIN V 18599 auch mit Hilfe der Algorithmen in der VDI 2067 oder mittels dynamischer, thermischer Simulationen ermittelt werden kann. Hierzu wird der Jahreskühlenergiebedarf für einen typischen Büroraum mit unterschiedlichen Fassadentypen nach den verschiedenen Verfahren berechnet, um Unterschiede aufzuzeigen. Abschließend wird exemplarisch der Einfluss des dem jeweiligen Verfahren zugrundeliegenden Außenklimas aufgezeigt. Determining the annual cooling energy demand for office buildings using the calculation procedure according to the 2007 Building Energy Conservation Ordinance or the DIN V 18599 standard. The German Building Energy Conservation Ordinance (EnEV), which has been in force since 2007, requires a holistic balance of the energy demand for office buildings, so that for the first time energy used for cooling and electricity used for lighting must be taken into account besides energy used for thermal heat and ventilation systems. This study focuses on the annual energy consumption for cooling offices which can be determined not only according to the calculation rules laid down in the EnEV 2007 or DIN V 18599 standards but also with the aid of algorithms specified in VDI 2067 or by means of dynamic thermal simulations. Here the annual energy demand for cooling a typical office with different types of facade is calculated by means of various calculation procedures in order to highlight the differences and deduce which types of facade react particularly sensitively. An example is used to illustrate the influence of the prevailing outdoor weather conditions for each procedure. [source] Energy scavenging for energy efficiency in networks and applicationsBELL LABS TECHNICAL JOURNAL, Issue 2 2010Kyoung Joon Kim Telecommunication networks will play a huge part in enabling eco-sustainability of human activity; one of the first steps towards this is to dramatically increase network energy efficiency. In this paper we present two novel approaches for energy scavenging in networks. One involves thermal energy scavenging for improving wireless base station energy efficiency, and the other involves mechanical energy scavenging for powering sensors in sensor networks, for machine-to-machine (M2M) communications, and for smart grid applications. Power amplifier (PA) transistors in base stations waste 30 percent of the total energy used in a wireless access network (WAN) as heat to the environment. We propose a thermoelectric energy recovery module (TERM) to recover electricity from the waste heat of PA transistors. A fully coupled thermoelectric (TE) model, combining thermoelectricity and heat transfer physics, is developed to explore the power generation performance and efficiency as well as the thermal performance of the TERM. The TE model is comprehensively used to determine optimized pellet geometries for power generation and efficiency as a function of PA transistor heat dissipation, heat sink performance, and load resistance. Maximum power generation and efficiency for various parametric conditions are also explored. Untapped kinetic energy is almost everywhere in the form of vibrations. This energy can be converted into electrical energy by means of transducers to power wireless sensors and mobile electronics in the range of microwatts to a few milliwatts. However, many problems limit the efficiency of current harvesting generators: narrow bandwidth, low power density, micro-electro-mechanical system (MEMS) scaling, and inconsistency of vibrating sources. We explore energy scavenger designs based on multiple-mass systems to increase harvesting efficiency. A theoretical and experimental study of two degrees-of-freedom (2-DOF) vibration-powered generators is presented. Both electromagnetic and piezoelectric conversion methods are modeled by using a general approach. Experimental results for the multi-resonant system are in agreement with the analytical predictions and demonstrate significantly better performance in terms of maximum power density per total mass and a wider bandwidth compared to single DOF (1-DOF) generators. © 2010 Alcatel-Lucent. [source] Teenage and adult tonsillectomy: dose,response relationship between diathermy energy used and morbidityCLINICAL OTOLARYNGOLOGY, Issue 5 2007A.A.J. Cardozo Objective:, To determine whether an increase in the use of bipolar diathermy energy to perform a tonsillectomy is associated with an increase in postoperative pain and haemorrhage. Study design:, Prospective study. Setting:, District General Hospital. Methods:, In all, 101 patients above the age of 13 years who underwent a tonsillectomy that involved the use of bipolar diathermy during the study period were included. The cumulative amount of diathermy energy used to perform each tonsillectomy was calculated with the help of a digital stop clock timing device connected to the diathermy foot-pedal. Main outcome measures:, Postoperative pain scores and the incidence of secondary haemorrhage were recorded for each patient at four points in time following surgery, up to the tenth postoperative day. The haemorrhage rates were categorised into three groups (no bleeding, minor bleeding and major bleeding) according to severity. Associations between the diathermy energy used to perform each tonsillectomy and the corresponding postoperative pain scores and secondary bleeding rates were investigated. Results:, There was a statistically significant positive relationship between the total amount of bipolar diathermy energy used per tonsillectomy and the pain scores at all the four recorded points in time (rs = 0.44,0.72, P < 0.001). When the median energy consumption in the three groups (no bleeding, minor bleeding and major bleeding) were compared using the Kruskal,Wallis test, we found that there was limited evidence of a difference between the groups, but this was not statistically significant at the 5% level [H (2) = 5.374, P = 0.065, 99% CI 0.058,0.071]. Conclusions:, Increased use of bipolar diathermy during the performance of a tonsillectomy is associated with a statistically significant increased amount of postoperative pain. The dose,response relationship between diathermy energy and postoperative bleeding is less clear. This suggests that there could be other important factors such as surgical instrument characteristics and degree of tonsillar adherence that have an additional influence and are therefore possible areas for future research. [source] | ||||||||||