scholarly journals ANOMALOUS MODULATION OF THE WAVE FIELD IN A PLASMA WAVEGUIDE

2019 ◽  
pp. 111-114
Author(s):  
V.M. Kuklin ◽  
E.V. Poklonskiy
Keyword(s):  
Energy Density ◽  
Wave Field ◽  
Modulation Instability ◽  
Average Energy ◽  
Plasma Waveguide ◽  
Frequency Of Occurrence ◽  
Average Amplitude ◽  
Weak Absorption ◽  
Average Energy Density

The consequences of the development of the modulation instability of an intense wave field in a waveguide filled with plasma are considered. It is shown that in the mode of developed instability, the amplitude of the main wave under conditions of its weak absorption decreases by three to four times. The average energy density of the instability spectrum is almost twice the energy density of the main wave. The amplitude of the modulation envelope is three times the average amplitude of the main wave. The frequency of occurrence of anomalous modulation bursts is estimated.

Macroscale bending large-deformation and microbuckling behavior of a unidirectional fiber-reinforced soft composite

2019 ◽  
Vol 54 (2) ◽  
pp. 243-257
Author(s):  
Xin Lan ◽  
Sida Hao ◽  
Liwu Liu ◽  
Yanju Liu ◽  
Jinsong Leng
Keyword(s):  
Partial Differential Equations ◽  
Energy Density ◽  
Numerical Method ◽  
Large Deformation ◽  
Deformation Behavior ◽  
Average Energy ◽  
Theoretical Method ◽  
Fiber Reinforced ◽  
Average Energy Density ◽  
Soft Composite

Due to microscale fiber microbuckling, a fiber-reinforced soft composite demonstrates large macroscale bending deformation (e.g. 10% reversible macroscale compressive strain), which is larger than that of a convenient fiber-reinforced plastics (e.g. 1.5–2% elongation/compression at break). To investigate the deformation behavior, a normalized average energy density of a fiber-reinforced soft composite laminate was derived. By using a self-consistent approach according to the minimum energy principle, a series of analytical expressions were derived by a simplified theoretical method through solving simplified partial differential equations of average energy density. Furthermore, an improved numerical calculation method was developed using the full four terms of partial differential equations of average energy density by employing the results of simplified theoretical method as initial calculating values. The dimensionless results demonstrated that the trend correlated well between those two methods, and the improved numerical method obtained more accurate results than those of the simplified theoretical method. Analytical and numerical results in normalized expressions systematically descripted the bending large-deformation behavior including position of neutral surface and critical buckling, wavelength, amplitude, shearing strain, macroscale compressive/tensile strain, buckled fiber strain, and actuation moment. To design a fiber-reinforced soft composite for use in engineering, the simplified theoretical method is used to predict trend and obtain approximate results for preliminary design, and the improved numerical method is further used to check and obtain more accurate results on detailed design stage.

Duration of lactation and postweaning changes in mass and body composition of harbour seal, Phoca vitulina, pups

1993 ◽  
Vol 71 (7) ◽  
pp. 1405-1414 ◽  
Author(s):  
M. M. C. Muelbert ◽  
W. D. Bowen
Keyword(s):  
Body Composition ◽  
Energy Density ◽  
Mass Loss ◽  
Body Mass ◽  
Deuterium Oxide ◽  
Average Energy ◽  
Phoca Vitulina ◽  
Low Energy ◽  
Harbour Seal ◽  
Average Energy Density

We studied changes in body mass and body composition of harbour seal pups from weaning to 5 – 6 weeks postweaning in June – August 1988 and 1989 on Sable Island, Canada. Known-age pups (n = 52) were captured at 3-day intervals from late lactation through about 40 days postweaning. Pups were weaned, on average, at 24.1 ± 0.44 days (mean ± SE) postpartum at a body mass of 24.9 ± 0.45 kg. There were no significant differences between years or sexes in the age and mass at weaning or in the rate of mass loss during the postweaning period. The duration of the postweaning fast averaged from 15 – 17 days as assessed by stomach lavage. The rate of mass loss was independent of weaning mass. At weaning, pups contained an average of 47.7% water and 32.8% fat, based on deuterium oxide dilution. During the first 14 days postweaning, the estimated body composition of pups did not change, despite the loss of body mass. Over the next 26 days, the estimated percent body water increased to about 63% and body fat declined to about 12%. The average energy density of harbour seal pups at weaning was low (16.3 kJ/g) compared with that of other phocids (17.7 – 22.2 kJ/g). This low energy density at weaning may reflect the highly aquatic and precocial development of harbour seal pups.

scholarly journals Energy Density and Satiety of Meals Based on the Healthy Food Plate Model for Filipino Adults

2018 ◽  
Vol 52 (6) ◽  
Author(s):  
Maria Julia Golloso-Gubat ◽  
Edward Vincent J. Magtibay ◽  
Jacus S. Nacis ◽  
Robby Carlo A. Tan ◽  
Merlyn G. Tajan ◽  
...  
Keyword(s):  
Energy Density ◽  
Healthy Adult ◽  
Average Energy ◽  
Healthy Food ◽  
Low Energy ◽  
Plate Model ◽  
Short Term ◽  
Average Energy Density ◽  
Adult Volunteers ◽  
Analogue Scales

Objective. This study aimed to determine the energy density and satiety of meals based on the healthy food plate model for Filipino adults. Methods. Thirteen healthy adult volunteers consumed breakfast test meals consisting of 1 cup go food, ½ cup grow food and 1 ½ cups glow food, following the recommended proportions in the plate model. Energy density (kcal/g) of the test meals was calculated. Feelings of hunger and fullness were assessed with 100-mm visual analogue scales (VAS) at pre-prandial (0 minute) and at 30, 60, 90, 120, 150, 180, and 240 minutes postprandial. Ghrelin levels at 0, 30, 60, 120, 180, and 240 minutes were determined by radioimmunoassay (RIA). Results. The test meals had an average energy density of 0.83 kcal/g. Hunger and fullness scores gradually changed with time but hunger remained significantly lower and fullness significantly higher than the pre-prandial levels at 180 minutes postprandial. Ghrelin declined after intake of the test meals and stayed significantly lower than the pre-prandial level at 240 minutes postprandial (30.21 ± 4.58 pmol/L). Conclusion. Meals following the recommendations in the healthy food plate model for Filipino adults have low energy density and its consumption sustained short-term satiety.

scholarly journals Rechargeable Concrete Battery

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 103
Author(s):  
Emma Qingnan Zhang ◽  
Luping Tang
Keyword(s):  
Energy Density ◽  
Carbon Fibers ◽  
Average Energy ◽  
Metal Coating ◽  
Rechargeable Battery ◽  
Powder Mixing ◽  
Coating Method ◽  
Average Energy Density ◽  
Short Carbon ◽  
Charge Discharge

A rechargeable cement-based battery was developed, with an average energy density of 7 Wh/m2 (or 0.8 Wh/L) during six charge/discharge cycles. Iron (Fe) and zinc (Zn) were selected as anodes, and nickel-based (Ni) oxides as cathodes. The conductivity of cement-based electrolytes was modified by adding short carbon fibers (CF). The cement-based electrodes were produced by two methods: powder-mixing and metal-coating. Different combinations of cells were tested. The results showed that the best performance of the rechargeable battery was the Ni–Fe battery, produced by the metal-coating method.

scholarly journals THE GRAVITATIONAL ENERGY PROBLEM FOR COSMOLOGICAL MODELS IN TELEPARALLEL GRAVITY

2010 ◽  
Vol 19 (12) ◽  
pp. 1925-1935 ◽  
Author(s):  
S. C. ULHOA ◽  
J. F. DA ROCHA NETO ◽  
J. W. MALUF
Keyword(s):  
Average Energy ◽  
Teleparallel Gravity ◽  
Space Time ◽  
Gravitational Energy ◽  
Cosmological Models ◽  
De Sitter ◽  
Energy Problem ◽  
First Case ◽  
Einstein's Equation ◽  
Average Energy Density

We present a method to calculate the gravitational energy when asymptotic boundary conditions for the space–time are not given. This is the situation for most of the cosmological models. The expression for the gravitational energy is obtained in the context of the teleparallel equivalent of general relativity. We apply our method first to the Schwarzschild–de Sitter solution of Einstein's equation, and then to the Robertson–Walker universe. We show that in the first case our method leads to an average energy density of the vacuum space–time, and in the latter case the energy vanishes in the case of null curvature.

scholarly journals A Global Model for the Diapycnal Diffusivity Induced by Internal Gravity Waves

2013 ◽  
Vol 43 (8) ◽  
pp. 1759-1779 ◽  
Author(s):  
Dirk Olbers ◽  
Carsten Eden
Keyword(s):  
Energy Density ◽  
Internal Wave ◽  
Wave Field ◽  
Ocean Circulation ◽  
Gravity Waves ◽  
Wave Energy ◽  
Internal Gravity Waves ◽  
Radiation Balance ◽  
Dissipation Rates ◽  
Diapycnal Diffusivity

Abstract An energetically consistent model for the diapycnal diffusivity induced by breaking of internal gravity waves is proposed and tested in local and global settings. The model [Internal Wave Dissipation, Energy and Mixing (IDEMIX)] is based on the spectral radiation balance of the wave field, reduced by integration over the wavenumber space, which yields a set of balances for energy density variables in physical space. A further simplification results in a single partial differential equation for the total energy density of the wave field. The flux of energy to high vertical wavenumbers is parameterized by a functional derived from the wave–wave scattering integral of resonant wave triad interactions, which also forms the basis for estimates of dissipation rates and related diffusivities of ADCP and hydrography fine-structure data. In the current version of IDEMIX, the wave energy is forced by wind-driven near-inertial motions and baroclinic tides, radiating waves from the respective boundary layers at the surface and the bottom into the ocean interior. The model predicts plausible magnitudes and three-dimensional structures of internal wave energy, dissipation rates, and diapycnal diffusivities in rough agreement to observational estimates. IDEMIX is ready for use as a mixing module in ocean circulation models and can be extended with more spectral components.

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