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Power estimation is the most important task in the performance assessment of wave energy converters (WEC). Depending on the type of WEC, power take-off (PTO) system, and available instrumentation, different approaches are usually applied to assess power from experimental tests. Since neither for tests execution nor for the analyses exist standard methodologies, the estimated power can significantly differ among the approaches, thus, introducing inaccuracies in the assessment of the WEC’s performance. This study analyzed an extensive set of experimental results of a WEC and applied different power estimation approaches to compare and validate the obtained results. The strengths and weaknesses of those methodologies were analyzed and discussed. The major outcomes were: (a) PTO damping characterization based on bench tests can lead to unrealistic values of the WEC’s absorbed power; (b) the hybrid (experimental plus numerical) approach provide more reliable results than the traditional ones; (c) the kinetic energy harvester approach underestimates power but can be useful for preliminary qualitative performance assessments; (d) the new proposed gross efficiency index allows the definition of upper boundaries for wave power conversion as well as the identification of the wave conditions for which WEC performance can be improved.

A strategy to industrialize microwave synthesis from the perspectives of process optimization, scale up and reactor design was devised for the synthesis of glycerol carbonate (GC). The strategy is based on the application of absorbed energy density (AED) and absorbed power density (APD) parameters. Here, the microwave synthesis was conducted using a constant-power heating mode. The mapping of microwave heating characteristics based on heating power, reaction temperature and AED was first performed for the microwave system. Then, the optimization of APD and AED was conducted and the intensive optimum conditions at 175 J/g AED and 1.9 W/g APD was used to scale up the microwave synthesis from 0.3 mol (27 g) to 3 mol (267 g). The resulting syntheses were highly reproducible and consistent. Based on APD and AED, the thermal and non-thermal microwave effects can be characterized and they are useful in the design of continuous-flow microwave reactor.

This paper presents an in-depth analysis of various aspects of small-scale Linear Fresnel Concentrators (LFCs). As we shall see, the influence of the lateral study of the actual absorbed power is very important in this type of LFC. In order to consider the end-effect of the absorber tube, two types of losses need to be taken into account: the end loss and the reflected light loss. Focussing on the optimization of the length and position of the absorber tube, a new mathematical method is presented. The method based on a geometric algorithm allows the straightforward deduction of the optimal design of a small-scale LFC. Numerous numerical simulations are presented for different configurations. This study constitutes the basis of the prototype that is being constructed at a vocational training centre (CIFP-Mantenimiento y Servicios a la Produccion) in La Felguera, Asturias, Spain. Asturias, Spain.

The application of “shiftable” or “modulable” load (i.e. washing machine, dishwasher, etc.) in a Smart Grid, can provide energy saving or modify the power flows in the grid, allowing a reduction of the electrical power peak. This paper explores the possibility to modulate the indoor artificial lighting to support this reduction. The study examines the impact of two different measures of power shaving. On the one hand, the change of Correlated Colour Temperature of the light source, and, on the other hand, the dimming of its luminous flux. The possibility to merge the above-mentioned technical solutions is also analyzed. Based on these strategies, several daily schedules of lighting management are defined, and the corresponding energy saving during some critical time slots are assessed. Results show that in all cases, it is possible to achieve a significant reduction of the absorbed power and a consequent increment of energy savings (up to 59%) also in specific time ranges. Furthermore, considering the application of a Daylight-linked control system, it was observed that power regulation associated with the exploitation of the daylight represents itself a way to dynamically reduce the electric loads on the grid.

The stable nano-seconds pulsed Er:Lu2O3 laser were realized by employing a molybdenum ditelluride (MoTe2) saturable absorber (SA), which was fabricated with the liquid phase exfoliation (LPEx) method. Under the absorbed power of 7.24 W, the maximum average output power of 0.52 W was achieved in a repetition rate of 105 kHz and a pulse duration of 317 ns at 2.85 μm, corresponding to a pulse energy of 4.94 μJ and a peak power of 15.6 W.

The intrinsic microwave power and energy required for optimizing MAE was investigated for the extraction of active compounds from cocoa (Theobroma cacao L.) leaves at various extraction scales. To carry out this investigation, an optimization method based on absorbed power density (APD) and absorbed energy density (AED) was developed based on the extraction mechanism of MAE using sequential single factor experiments. The optimized results are consistent with those obtained by the conventional optimization method using response surface methodology (RSM) and also comparable with that of the optimized Soxhlet extraction. The main advantage of the method is that the intensive optimum conditions obtained at solvent to feed (S/F) ratio of 50 ml/g, APD of 0.3 W/ml and AED of 300 J/ml are capable of determining the specific optimum operating conditions (S/F ratio, power, time) of the MAE at various scales of 100 to 300 ml with great accuracy.

For the purposes of new product development, the cycling industry requires an objective means of ranking bicycle comfort with regard to vibration response. Acceleration is currently the standard metric used in the industry. Absorbed power and transmitted force have recently been proposed as metrics to quantify bicycle comfort. The objective of this paper is to compare the relative merits of these 3 metrics. Measurements were done while comparing 2 bikes tested on a cobblestone road and on a laboratory simulator. Acceleration and absorbed power give the same anticipated results but the absorbed power has several advantages over the other metrics.

Next to weight reduction and stiffness increase, increasing the cyclist's comfort has become an additional aspect in the design process of racing bicycles. Several attempts have been made to increase the shock absorption and damping capacity of a racing bicycle, but for the designer it is difficult to estimate the effect on the riding quality of the bicycle and whether the comfort perception of the cyclist increases. This work proposes an experimental test setup for quantifying comfort during outdoor field testing including real time data acquisition and storage from 16 sensors. This data is analysed by means of the whole-body and hand-arm vibration method and the absorbed power method. The initial test results show that the absorbed power method seems to correlate best with the cyclist's comfort. This method does not take acceleration data into account (as in the whole-body and hand-arm vibration method), but the combination of contact force and contact velocity is used for analysis.

This study investigated the significance of blood vessels in the absorbed power and temperature distributions when optimization was employed during hyperthermia. The treated tumor region was simulated using a three-dimensional (3D) tissue model embedded with a countercurrent blood vessel network (Huang et al., 1996). 3D temperature distributions are obtained by solving the conduction equation in the tissues and the convective energy equation with specified Nusselt number in the vessels. 3D absorbed power depositions are obtained by using optimization to reach a uniform temperature of 43 °C for the desired treated region. Results show that the absorbed power deposition for optimization with fine spatial resolution produces a uniform temperature distribution maintained at 43 °C in the desired treated tumor region except for some cold spots and/or small cold strips caused by thermally significant large vessels. The amount of total absorbed power suggests that a region with thermally significant vasculature requires much more power deposited than one without vasculature. In addition, optimization with coarse spatial resolution results in a highly inhomogeneous temperature distribution in the treated region due to the strong cooling effect of blood vessels. Therefore, prior to hyperthermia treatments, thermally significant blood vessels should be identified and handled carefully to effectively reduce their strong cooling effect, particularly those vessels flowing into the treated region.

The effect of three factors on the ozone production was studied in this paper: air pressure, air flow and power. It was shown that for a given air flow, the concentration of produced ozone can be increased or decreased by increasing or decreasing the absorbed power; for a given power level, the concentration varies approximately inversely to air flow and for a given air flow and power level, the concentration of ozone varies inversely to air pressure.

The influence of hand–arm posture on the biodynamic responses under zh-axis vibration is investigated in terms of driving point mechanical impedance and absorbed power under various combinations of hand grip and push forces, handle sizes and excitation levels. Laboratory measurements of the biodynamic responses were performed on seven healthy male subjects exposed to two levels of broadband random vibration in the 8–1000 Hz frequency range using three instrumented cylindrical handles of different diameter (30, 40 and 50 mm), and different grip (10, 30 and 50 N) and push (25, 50 and 75 N) forces. The experiments involved grasping the handle with two different postures, consisting in flexed forearm with elbow angle of 90° and extended forearm with elbow angle of 180°, with wrist being in the neutral position for both postures. The results revealed remarkable effects of the hand–arm posture on both the mechanical impedance and the absorbed power characteristics. The low-frequency apparent mass magnitude of the hand–arm with the extended forearm posture was observed to be approximately three times than that with the flexed forearm posture. Furthermore, the effects of handle size, and push and grip forces on the biodynamic responses of the human hand–arm exposed to vibration were observed to be more significant for the extended forearm posture. This posture revealed considerably higher coupling with the vibrating handle and a damper-like behavior of the hand–arm system in the very low-frequency range. This posture also resulted in considerably higher power absorption than the flexed forearm posture for the majority of the combinations of hand forces considered. Depending on the handle size, excitation level, and hand forces, the total power absorbed by the hand–arm with an extended hand–arm could be up to 96% higher than that with the flexed elbow. From the results, it is evident that the hand–arm posture strongly affects the biodynamic response, when exposed to zh-axis vibration. Relevance to industry Operators assume considerable variations in the hand–arm posture while operating hand-held power tools. Such variations coupled with variations in the hand forces imparted on the tool handle could cause considerably different biodynamic responses of the hand–arm system. The current International Standard describes the range of idealized biodynamic response in terms of the driving-point mechanical impedance under a fixed posture involving 90° elbow angle (ISO-10068, 1998). The standard on the assessment of anti-vibration gloves also requires the same posture (ISO-10819, 1996). This study presents the effect of hand–arm posture on the biodynamic responses in terms of both driving-point mechanical impedance and power absorption by the hand–arm system. The influences of hand forces and handle sizes on both measures are also presented. The results of the study clearly suggest high significance of the hand–arm posture in view of the biodynamic responses. The results of the study attained on the driving-point mechanical impedance are expected to provide the vital knowledge and data for enhancing the current standard and its applications. The results attained on the influence of posture on the absorbed power characteristics of the hand–arm system are further expected to enhance our knowledge on the assessment of vibration exposure.

We report an all-solid-state laser giving 67 mW of 309 nm output when pumped with a frequency-quadrupled, all-solid-state Raman-shifted Nd:YAG laser. This efficient laser source has an optical-to-optical conversion efficiency of 41%, with respect to 289 nm conversion to 309 nm, and slope efficiencies of up to 62% (based on absorbed power).

Objective . To experimentally measure the seated vertical direction whole-body absorbed power characteristics of small children less than 18 kg in mass. Background . Several studies have reported whole-body absorbed power for adult humans, but no data has been published previously for small children. Methods . Eight children were tested in a laboratory test rig which incorporated safety features which satisfy existing international standards for human testing. Force and acceleration were measured at the point of input to a rigid seat at a sampling rate of 200 Hz, and analysis was performed over the interval from 1.0 to 45.0 Hz. A double normalised (both input acceleration and test subject mass) measure of absorbed power was used. Results . The vertical whole-body power absorption characteristics of the small children were found to present differences with respect to those of adults. The mean frequency of peak absorption was found to be 7.4 Hz as opposed to approximately 4.0–5.0 for adults. The interval of absorption was found to be from approximately 3 to 16 Hz and the total double normalised absorbed power was found to be 86% that of adults. Conclusions . The differences in dynamic response between small children and adults raise questions regarding the applicability of whole-body vibration guidelines such as ISO-2631 in the case of small children since these guidelines were developed from mechanical and subjective response data of adults. Relevance Knowledge of the differences in whole-body vibration response between small children and adults is useful towards the design of systems intended for children such as child seats. The child data may also prove useful should absorbed power find application as a screening tool in clinical settings.

The correlation between objective methods for determining ride comfort and subjective comments from crew driving in vehicles were investigated. For objective measurements, the ISO 2631, BS 6841, Average Absorbed Power and VDI 2057 methods were used. The emphasis was on the ride comfort of military vehicles operated under off-road conditions over typical terrains. An experiment was devised and executed in order to obtain both objective and subjective ride comfort values. The correlation between the different methods, measuring positions, measurement directions and calculation methods was determined. It is concluded that all the methods can be used to specify and evaluate ride comfort, but that acceptable ride comfort limits vary. The vertical measurement direction was dominant. Due to the frequency content of the measured acceleration, the specific weighing curve is not very important for the type of vehicle considered.

We have discovered a 107 min periodic modulation in the light curve of source XMMU J004308.6+411247 from the XMM–Newton observation carried out on 2002 January 6. The source count rate was consistent with zero at the dip minimum. The same modulation is also detected in archival XMM–Newton observations carried out on 2000 June 25, 2001 June 29 and in Chandra observation carried out on 2001 October 5. The dips show no energy dependence. The average X–ray flux of XMMU J004308.6+411247 was nearly constant across different observations (∼ 1037 erg s−1 for an assumed M31 distance of 780 kpc in the 0.3–10 keV band); the spectrum was well fit by an absorbed power law with a photon index ∼0.8 or an absorbed Comptonization model. Observed flux and spectral parameters of the XMMU J004308.6+411247 are consistent with a dipping low mass X–ray binary (LMXRB) located in M31.

We present a new technique to analyze the absorption efficiency of the active medium for a LD side-pumped Nd:YAG laser. A detailed ray trace has been carried out to evaluate the route of the pump LD-rays propagating inside the diffusing chamber. The method, named the infinite convergence approach, is used to determine the total absorbed power of a Nd:YAG rod when random reflection takes place at the inner surface of the reflector wall. By reason of losses caused by slits milled the reflector wall, there is an optimum slit width corresponding to the maximum absorption efficiency. It has been theoretically determined that the absorption efficiency can be summarized by a convergent result for the infinite energy transfer process inside the diffusing chamber. The method is applicable to the cavity design for any LD side-pumped solid-state lasers.

Exposure to mechanical shocks might pose a greater health risk than exposure to continuous vibration. Previous studies have investigated subjective responses, muscle activity or transmission of vibration to the spine or head during shock. If there is a difference between biomechanic responses of the seated body to shocks when compared to continuous vibration, then this may indicate a more, or less, hazardous vibration waveform. This paper presents measurements of apparent mass and absorbed power during exposure to random vibration, repeated shocks and combinations of shocks and random vibration. Eleven male and 13 female subjects were exposed to 15 vibration conditions generated using an electro-dynamic shaker. Subjects were exposed to five 20 s acceleration waveforms with nominally identical power spectra (random vibration, equally spaced shocks, unequally spaced shocks, random combined with equally spaced shocks, random combined with unequally spaced shocks) at each of 0·5, 1·0 and 1·5 m/s2r.m.s. The general shapes of the apparent mass or absorbed power curves were not affected by stimulus type, indicating that the biomechanical response of the body is fundamentally the same when exposed to shocks or random vibration. Two non-linear effects were observed: apparent mass resonance frequencies were slightly higher for exposure to shocks; apparent mass and absorbed power resonance frequencies decreased with increases in vibration magnitude for each stimulus type. It is concluded that the two non-linear mechanisms operate simultaneously: a stiffening effect during exposure to shocks and a softening effect as vibration magnitudes increase. Total absorbed powers were greatest for shock stimuli and least for random vibration.

The divertor geometry of JT-60U was modified in 1998 to add a pumping slot near the outer strike point for improved pumping. In the both-side pumping divertor, the x-point MARFE onset density is ∼10% higher with pumping than without pumping. Radiated power near the x-point is decreased by pumping, and the divertor pumping is effective in suppression of the x-point MARFE. The effect of outer pumping is investigated in L-mode plasmas. The onset densities of the x-point MARFE are the same in both divertors. The fraction of total radiated power over absorbed power at the x-point MARFE onset is ∼20% higher in the both-side pumping divertor than in the inside pumping divertor, but it does not depend on the onset density and on a distance between the private dome and the outer leg. Carbon penetration from the divertor region to the main plasma has a weak dependence on the gap-out in the both-side pumping divertor.

Evaluation of human exposure whole-body vibration (WBV) and shock can be carried out in a variety of ways. The most commonly used standards for predicting discomfort from WBV are BS6841 (1987) and ISO2631-1 (1997) which offer different frequency weightings ( W b and W k ) and three methods of assessment: vibration dose value (VDV), estimated VDV (eVDV) and maximum transient vibration value (MTVV). Previous studies have also used DRI and absorbed power for assessments of shock and WBV. This paper reports a laboratory study in which 24 human subjects were exposed to 15 vertical vibration stimuli comprising of random vibration, repeated shocks and combinations of random vibration and shocks at 0·5, 1·0 and 1·5 m/s 2 r.m.s. Subjects rated the discomfort from the vibration on a numerical scale after each exposure. Acquired acceleration signals were analyzed using VDV, r.m.s. and MTVV for unweighted, W b , W k and DRI weighted signals. Acceleration and force were combined to give a measure of absorbed power. Subjective responses were correlated to vibration magnitude for the 13 analysis types. VDV was the best standard method of assessment; MTVV was the worst. W b and W k frequency weightings showed slightly greater correlations between vibration magnitude and discomfort than DRI weighted or unweighted signals. For VDV, there were no significant differences between the correlations obtained using any frequency weighting. For assessment of all stimuli types together, absorbed power gave higher correlations with subjective discomfort than acceleration-based methods. It is concluded that the methods described in ISO2631-1 should be clarified and simplified. Due to the difficulty in measuring absorbed power in the field, methods proposed in BS6841 are recommended as the most appropriate for assessment of discomfort from continuous vibration or repeated shocks.

It is shown that the reasons for the poor replicability of the nonthermal bioeffects of radiofrequency have the fundamental bases. The efficiency of the living system process is determined by the conversion of electromagnetic energy into Helmholtz free energy. The efficiency dependence on the absorbed power of electromagnetic radiation is quite different in the Wien region (visible light) and in the Rayleigh-Jeans region (radiofrequency). In the Wien region the endergonic and exergonic processes could never be confused. In the Rayleigh-Jeans region the endergonic and exergonic processes could be confused. It gives the poor replicability.

The power absorbed by 12 male subjects during exposure to vertical whole-body vibration at six magnitudes of random vibration (0·25, 0·5, 1·0, 1·5, 2·0 and 2·5 ms−2r.m.s.) has been measured in the laboratory. All subjects showed greatest absorbed power at about 5 Hz, but the frequency of this peak in the absorbed power reduced with increasing vibration magnitude. The total absorbed power increased approximately in proportion to the square of the acceleration magnitude: normalizing the absorbed power to the square of the r.m.s. vibration magnitude removed most of the differences, although the changes in resonance frequency were still evident. The frequency dependence of absorbed power at a constant magnitude of acceleration was approximated by a simple weighting having slopes of ±6 dB/octave either side of 5 Hz. Comparing the characteristics of this absorbed power weighting to standard frequency weightings showed substantial differences, especially at high frequencies. It is concluded that the differences from currently accepted frequency weightings are so great that the absorbed power is unlikely to yield good general predictions of the discomfort or risks of injury from whole-body vertical vibration.

Road surface roughness is the excitation source for the dynamic response of a moving vehicle system. Driving comfort is indicated by either the driver absorbed power level or the vehicle vertical acceleration level. An autocorrelation function model for road roughness is proposed to specify the road surface random characteristics. Subsequently, the power spectral densities (PSDs) for both road roughness and vehicle response, the driver-absorbed power level, are formulated. A road quality index (RQI) in accordance with such energy considerations is defined to catalog the road grade. The laboratory test results show the applicability of the RQI method for road classification using the ISO criteria as a comparison check.

The dependence of carrier-phonon interaction on dimensionality and on quantum well thickness is studied in bulk Ga 0.47 In 0.53 As and in 3.4, 8.0, and 13.8 nm thick Ga 0.47 In 0.53 As/Al 0.48 In 0.52 As quantum well structures. The variation of carrier temperature with absorbed power in a steady-state photoluminescence experiment yields effective longitudinal optical phonon energies and carrier-polar optical scattering times, which are within experimental error independent of sample structure and agree with the theoretical value.

Statistical samples of quad 2-input NAND gates (CMOS) were submitted to electrostatic discharge (ESD) according to MIL specifications. The tests were performed at five levels of ESD. Failure thresholds for the devices were measured, and using reliability models such as the Normal, the Two-Parameter Exponential and the lognormal, reliability and hazard rate plots have been generated as functions of absorbed power. An ESD adjacent circuit sensitivity analysis was also performed.

The charged topological solitons in trans-polyacetylene induce the absorption of the IR-signal by the collective mode of the order parameter. The frequency dependence of the absorbed power is obtained.

The low-frequency automodulation of r.f. power, absorbed at antiferromagnetic resonance, is discovered at temperatures below 1K. The effect is shown to be caused by non-linear oscillations of occupation numbers of magnons, excited by r.f. pumping.

The Japan Atomic Energy Research Institute has been constructing a large tokamak JT-60, which constitutes a focus of the second phase (1975-□) of the Japanese fusion development program. Its objective is to investigate plasma confinement and heating in reactor-grade hydrogen plasmas and to conduct an integrated test of associated fusion technologies. It has a long-pulse capability of 5–10 s in pulse length and, among other features, has a magnetic limiter (divertor), various methods of supplementary heating, and radiofrequency current drive. Construction of the JT-60 device, which started in April 1978, will be completed in April 1985. Development of heating devices has been successful, and full installation and test of the heating devices of 30 MW in absorbed power in plasmas will be completed by July 1986. The present paper describes the JT-60 project for its objective, device features, status of construction and development, and its experimental program.

A h.f. plasma is created in a cavity; the density is such that the plasma is in a resonance state: main or secondary. The shift in the resonance frequency (mode E 010 ) and the luminosity give the measurement if the density versus absorbed power.