Energy Partitioning Research Articles

22 Feeding the early gestating gilt during heat stress: Implications towards fetal viability, growth, and development

Abstract Gestational heat stress (GHS) directly impacts litter development and viability and has long term negative postnatal effects on offspring. However, current data on the interactions between GHS, maternal feed energy partitioning, and fetal development measures in pigs are limited. Therefore, the study objective was to gain a greater understanding of how early GHS influences fetal development and viability and whether maternal feed energy partitioning has a role. Gestating gilts (n = 23) were exposed to thermoneutral (TN; n = 11; 18.5 ± 1.2°C) or heat stress (HS; n = 12; cyclic 26 to 38°C) conditions beginning on d 6.0 ± 0.9 of gestation to 33.0 ± 1.7. The HS treatments resulted in greater (P < 0.05) respiration rates and body temperature and HS gilts grew faster (P < 0.05; 0.5 ± 0.1 kg/d) than TN gilts (0.3 ± 0.1 kg/d) as previously reported. Pregnant gilts were individually housed and limit-fed a standard gestating gilt diet (1.82 kg/d; 4.39 Mcal NE intake/d). On gestation d 33 ± 1.7, gilts were harvested and reproductive tract weight, corpus luteum (CL) counts, and fetal weights and counts were recorded. Additionally, fetal images were taken with a digital camera to assess fetal length, width, crown rump length (CRL), and viability using Image J. Fetuses were considered nonviable if CRL was more than 2 standard deviations less than the mean litter CRL or had irregular anatomical traits. All data were analyzed using PROC GLIMMIX with either pregnant gilt as the experimental unit for litter-based measures or individual fetus as the experimental unit for fetal based measures. Gilt NE intake efficiency [average daily gain (ADG); NE intake) was greater for HS (P = 0.04; 0.11 ± 0.01) when compared with TN gilts (0.07 ± 0.01). No fetal ADG (P = 0.26; 0.12 ± 0.04 g/d) or fetal ADG; gilt NE intake differences (P = 0.26; 0.03 ± 0.01) were detected between treatments. Total fetuses per CL were decreased for HS gilts (P = 0.01; 0.72 ± 0.03 fetuses) when compared with TN gilts (0.85 ± 0.04 fetuses). Viable fetuses per CL were reduced for HS gilts (P = 0.05; 0.69 ± 0.01 fetuses) when compared with TN gilts (0.80 ± 0.04 fetuses). The difference between total CL count and total fetuses per gilt tended to be increased for HS (P = 0.08; 6 ± 1 fetus) versus TN gilts (4 ± 1 fetus). No other fetal differences were observed (P > 0.10). In conclusion, early GHS improved gilt growth performance and NE efficiency, but resulted in decreased fertilization rates and reduced fetal viability and had no impact on fetal growth and development.

Energy partitioning among compressional and shear waves in three-dimensional attenuating elastic media.

In strongly scattering elastic media without attenuation and dispersion, the wavefield is dominated by shear waves, and in three dimensions, the ratio of the S to P energy is given by ES/EP=2(vP/vS)3. This study investigates how this ratio is influenced by attenuation. Both the case of the ringdown mode, where the energy evolves from initial values, and the case of energy equilibrium, where the attenuation is balanced by energy injection sources, are treated. It is shown that in ringdown mode, the energy ratio ES/EP satisfies a Ricatti equation in time: hence, the energy ratio is not an exponential function of time. It is also shown that the long-time energy ratio differs from the value in non-attenuating media when the attenuation coefficients for P and S waves are different. In the case of energy equilibrium, the energy ratio only is equal to the value in non-attenuating media when (1) the time scale of P- and S-wave equilibration is much smaller than the attenuation time or (2) the energy injection rate for each wave type is balanced by the dissipation for that wave type. The latter situation happens when the wavefield is excited by thermal fluctuations in thermal equilibrium.

Inversion of shear wave slowness and attenuation from dipole acoustic logging data based on an equivalent tool theory

The presence of a sonic logging tool affects the propagation characteristics of dipole-flexural wave in a fluid-filled borehole. As a result, the tool effect should be considered during the processing and inversion of the dipole-flexural wave for acoustic properties of shear wave. We show that the presence of the tool not only changes the slowness dispersion of the flexural wave but also results in a shift of its frequency-dependent attenuation toward lower frequencies. Equivalent tool theory (ETT) can realistically model the effect of an acoustic tool on guided wave propagation. With the ETT framework, we develop a unified workflow for estimating both the shear wave slowness and attenuation from dipole array acoustic waveforms. The workflow is an extension of the model-based dispersive processing of dipole logging data. The proposed workflow involves two inversion procedures. By matching the actual dispersion data with the theoretical dispersion predicted by the ETT, we can invert the shear wave slowness and tool parameters. With the estimated shear wave slowness and other borehole parameters, we further calculate the partition coefficients of flexural waves using the ETT. Based on the concept of energy partitioning, we formulate a linear optimization problem and invert for the shear wave attenuation from the frequency-dependent dipole attenuation. We use synthetic and field data to demonstrate the effectiveness and applicability of the developed method. The results show that it is important to incorporate the tool effect when processing dipole acoustic logging data for shear wave slowness and attenuation, especially in a fast formation.

Estimating growth using an ecophysiological and scope for growth model for the mussel Perna perna grown under suspended culture in Santa Catarina, Brazil

We present a dynamic simulation ecophysiological model for an important aquaculture mussel, Perna perna, grown under suspended culture in Santa Catarina, Brazil. The ecophysiological model was divided in four sectors; driving variables, feeding, energy reserve, and growth. This generated descriptions and explanations of the functions controlling feeding and metabolic responses to changing food availability and seawater temperature. The driving variables sector included time-series of seston variables likely to influence food and energy acquisition in mussels. It included relationships among seston variables to estimate the energy content of phytoplankton, the main component of mussel diet. The feeding sector described mussel suspension-feeding behavior measured using natural seston. Rates of filtration, rejection, ingestion, and absorption were directly related to the quantity and quality of available food. In the energy reserve sector, absorbed matter was transformed to absorbed energy using estimates of energy content of food provided in the driving variables sector. After accounting for the maintenance requirements of the mussels (heat loss and excretion), surplus energy, or the scope for growth, was directed to the growth sector. The growth sector included byssus, organic shell, and soft tissue production based on energy partitioning estimated from monthly measurements of somatic and reproductive tissue and shell growth. The model successfully predicted mussel growth during the study and provided estimates of the response to food acquisition, energy expenditure and allocation to growth. This was the first attempt to model the ecophysiology of this fast growing sub-tropical mussel. Given the capacity of this ecophysiological model to estimate growth of mussels, it has significant economic and environmental value in estimating carrying capacity to support sustainable management of shellfish farming in Brazil.

Energy partitioning in global marine sedimentation: tidal, geothermal, and solar radiation contributions

Energy partitioning in global marine sedimentation: tidal, geothermal, and solar radiation contributions

Ion Heating by a Fast Magnetosonic Turbulence in the Solar Corona

Observational data at heliocentric distances of tens of solar radii suggest that fast magnetosonic modes make up a considerable fraction of the solar wind fluctuations. Furthermore, this fraction appears to increase closer to the Sun. We carry out three-dimensional kinetic simulations with particle ions and fluid electrons to evaluate the proton and alpha-particle heating produced by the damping of the fast waves in the solar corona. Realistic parameters at 5 solar radii, including the fluctuation amplitude, are used. We show that, due to the cyclotron resonance, the alphas are heated preferentially perpendicularly to the magnetic field and much more strongly than the protons. The presence of the alpha particles alters the energy partition by reducing the heating of the protons. Nevertheless, the proton heating is sufficient to account for the solar wind acceleration.

Revealing the Critical Role of Global Electron Density Transfer in the Reaction Rate of Polar Organic Reactions within Molecular Electron Density Theory.

The critical role of global electron density transfer (GEDT) in increasing the reaction rate of polar organic reactions has been studied within the framework of Molecular Electron Density Theory (MEDT). To this end, the series of the polar Diels-Alder (P-DA) reactions of cyclopentadiene with cyanoethylene derivatives, for which experimental kinetic data are available, have been chosen. A complete linear correlation between the computed activation Gibbs free energies and the GEDT taking place at the polar transition state structures (TSs) is found; the higher the GEDT at the TS, the lower the activation Gibbs free energy. An interacting quantum atoms energy partitioning analysis allows for establishing a complete linear correlation between the electronic stabilization of the electrophilic ethylene frameworks and the GEDT taking place at the polar TSs. This finding supports Parr's proposal for the definition of the electrophilicity ω index. The present MEDT study establishes the critical role of the GEDT in the acceleration of polar reactions, since the electronic stabilization of the electrophilic framework with the electron density gain is greater than the destabilization of the nucleophilic one, making a net favorable electronic contribution to the decrease in the activation energy.

Energy partition in underwater nanosecond laser ablation

Energy partition in underwater nanosecond laser ablation

Decoupling of nitrogen allocation and energy partitioning in rice after flowering.

Estimation of energy partitioning at leaf scale, such as fluorescence yield (ΦF) and photochemical yield (ΦP), is crucial to tracking vegetation gross primary productivity (GPP) at global scale. Nitrogen is an important participant in the process of light capture, electron transfer, and carboxylation in vegetation photosynthesis. However, the quantitative relationship between leaf nitrogen allocation and leaf energy partitioning remains unexplored. Here, a field experiment was established to explore growth stage variations in energy partitioning and nitrogen allocation at leaf scale using active fluorescence detection and photosynthetic gas exchange method in rice in the subtropical region of China. We observed a strongly positive correlation between the investment proportion of leaf nitrogen in photosynthetic system and ΦF during the vegetative growth stage. There were significant differences in leaf energy partitioning, leaf nitrogen allocation, and the relationship between ΦF and ΦP before and after flowering. Furthermore, flowering weakened the correlation between the investment proportion of leaf nitrogen in photosynthetic system and ΦF. These findings highlight the crucial role of phenological factors in exploring seasonal photosynthetic dynamics and carbon fixation of ecosystems.

Simulations of radiatively cooled magnetic reconnection driven by pulsed power

Magnetic reconnection is an important process in astrophysical environments, as it reconfigures magnetic field topology and converts magnetic energy into thermal and kinetic energy. In extreme astrophysical systems, such as black hole coronae and pulsar magnetospheres, radiative cooling modifies the energy partition by radiating away internal energy, which can lead to the radiative collapse of the reconnection layer. In this paper, we perform two- and three-dimensional simulations to model the MARZ (Magnetic Reconnection on Z) experiments, which are designed to access cooling rates in the laboratory necessary to investigate reconnection in a previously unexplored radiatively cooled regime. These simulations are performed in GORGON, an Eulerian two-temperature resistive magnetohydrodynamic code, which models the experimental geometry comprising two exploding wire arrays driven by 20 MA of current on the Z machine (Sandia National Laboratories). Radiative losses are implemented using non-local thermodynamic equilibrium tables computed using the atomic code Spk, and we probe the effects of radiation transport by implementing both a local radiation loss model and $P_{1/3}$ multi-group radiation transport. The load produces highly collisional, super-Alfvénic (Alfvén Mach number $M_A \approx 1.5$ ), supersonic (Sonic Mach number $M_S \approx 4-5$ ) strongly driven plasma flows which generate an elongated reconnection layer (Aspect Ratio $L/\delta \approx 100$ , Lundquist number $S_L \approx 400$ ). The reconnection layer undergoes radiative collapse when the radiative losses exceed the rates of ohmic and compressional heating (cooling rate/hydrodynamic transit rate = $\tau _{\text {cool}}^{-1}/\tau _{H}^{-1}\approx 100$ ); this generates a cold strongly compressed current sheet, leading to an accelerated reconnection rate, consistent with theoretical predictions. Finally, the current sheet is also unstable to the plasmoid instability, but the magnetic islands are extinguished by strong radiative cooling before ejection from the layer.

Quantified Plasma Heating and Energy Dissipation in the Earth’s Quasi-perpendicular Bow Shock

The high-speed solar wind decelerates as it travels through the Earth’s bow shock, during which a portion of the incident flow energy is converted into the plasma thermal energy. However, the energy partition of plasma heating among different species, as well as the energy dissipation mechanism, remains elusive. In this paper, we quantify the plasma heating and the energy dissipation by calculating the pressure–strain interactions in 33 quasi-perpendicular bow shocks observed by the Magnetospheric Multiscale spacecraft. Our results show that the Joule dissipation measured by J·E′ and the quasi-viscous dissipation quantified by PiD are distinct in the examined shocks. We also reveal that ions gain more energy than electrons, and the compressive effect is more important than the incompressible channel in plasma heating. PiD contributed by the gyrotropic pressure tensor is consistently positive for electrons; however, there is no discernible distinction between the gyrotropic and nongyrotropic contribution to PiD for ions.

Relative Yield of Thermal and Nonthermal Emission during Weak Flares Observed by STIX during 2021 September 20–25

The disparate nature of the thermal–nonthermal energy partition during flares, particularly during weak flares, is still an open issue. Following the Neupert effect, quantifying the relative yield of X-ray emission in different energy bands can enable the inferring of the underlying energy release mechanism. During 2021 September 20–25, the Solar Orbiter mission—being closer to the Sun (∼0.6 au) and having a moderate separation angle (<40°) from the Sun–Earth line—offered a unique opportunity to analyze multiwavelength emission from ∼200 (mostly weak) flares, commonly observed by the Spectrometer Telescope for Imaging X-rays (STIX), STEREO-A, GOES, and the Solar Dynamics Observatory. Associating the quotient (q f ) of hard X-ray fluence (12–20 keV) and soft X-ray flux (4–10 keV) with the peak soft X-ray flux enabled us to identify strongly nonthermal flares. A multiwavelength investigation of spectral and imaging-mode observations of the 20 strongly nonthermal weak flares reveals an inverse relationship of q f with the emission measure (and density), and a positive relationship with the flare plasma temperature. This indicates that the plasma in tenuous loops attains higher temperatures compared to that in the denser loops, in response to nonthermal energy deposition. This is in agreement with the plasma parameters of the coronal loops, as derived by applying the one-dimensional Palermo–Harvard hydrodynamical code to coronal loop plasma with different initial coronal loop base pressures when subjected to similar heating inputs. Our investigation, therefore, indicates that the plasma parameters of the flaring loop in the initial phase have a decisive role in the thermal–nonthermal energy partitioning.

Energy partitioning over an irrigated vineyard in arid northwest China: Variation characteristics, influence degree, and path of influencing factors

In this study, a two-year experiment in an irrigated vineyard was conducted to investigate the variations in energy fluxes (net radiation, Rn; latent heat flux, LE; sensible heat flux, H; and soil heat flux, G) and quantify the influence of arid advection and environmental factors (vapor pressure deficit (VPD), Rn, air temperature, wind speed, precipitation, and volumetric soil water content) on energy partitioning in arid Northwest China. For the diurnal variation, the peak values of the energy fluxes appeared at approximately 14:00, except for G (which appeared at approximately 16:00). LE was the main consumer of daytime (Rn>0) energy during the growing season (average LE/(Rn–G) was 87% and 89% in the two years), even during the shooting and leaf-fall stages. Arid advection, which affects energy partitioning mainly by increasing atmospheric evaporative demand and providing heat energy, contributed 6–60% and 1–56% of the average daytime LE during the two growing seasons, especially at the fruiting stage. Moreover, advection accounted for more than half of average daytime energy imbalances. We found that the arid advection induced by irrigation could be attenuated by selecting a reasonable irrigation time. According to the structural equation modeling (SEM) analysis, Rn had the strongest direct and positive regulation effect on LE at the half-hourly and daily scales, indicating that LE was limited by energy rather than water in the study area. The influence of Rn on LE gradually weakened with an increase in the time scale, whereas the effect of VPD increased, which may have been due to the smaller time-lag effect between VPD and LE. The diurnal variations in LE at approximately 08:00–19:30 and 19:30–08:00 were mainly controlled by the direct positive effects of Rn and VPD, respectively. The results obtained in this study will provide a better understanding of surface processes and help improve water resource management in arid agricultural areas.

Electron and Proton Energization in 3D Reconnecting Current Sheets in Semirelativistic Plasma with Guide Magnetic Field

Using 3D particle-in-cell simulation, we characterize energy conversion, as a function of guide magnetic field, in a thin current sheet in semirelativistic plasma, with relativistic electrons and subrelativistic protons. There, magnetic reconnection, the drift-kink instability (DKI), and the flux-rope kink instability all compete and interact in their nonlinear stages to convert magnetic energy to plasma energy. We compare fully 3D simulations with 2D in two different planes to isolate reconnection and DKI effects. In zero guide field, these processes yield distinct energy conversion signatures: ions gain more energy than electrons in 2Dxy (reconnection), while the opposite is true in 2Dyz (DKI), and the 3D result falls in between. The flux-rope instability, which occurs only in 3D, allows more magnetic energy to be released than in 2D, but the rate of energy conversion in 3D tends to be lower. Increasing the guide magnetic field strongly suppresses DKI, and in all cases slows and reduces the overall amount of energy conversion; it also favors electron energization through a process by which energy is first stored in the motional electric field of flux ropes before energizing particles. Understanding the evolution of the energy partition thus provides insight into the role of various plasma processes, and is important for modeling radiation from astrophysical sources such as accreting black holes and their jets.

Reflection of plane waves in a rotating micropolar double porous thermoelastic medium with temperature dependent properties

AbstractThe objective of this empirical investigation is to explore the behavior of different waves reflected in a homogenous isotropic double porous structured micropolar thermoelastic medium with rotation and temperature‐dependent characteristics. Three‐phase‐lag theory of thermoelasticity is adopted to acquire the governing equations of the model. Six coupled plane waves have been found to propagate across the medium at distinct velocities. Derivation for energy and amplitude ratios of reflected waves were carried out by employing appropriate boundary conditions. For different angles of incidence, the outcomes for energy partition were determined numerically and displayed graphically. It is found that amplitude ratios associated with various reflected waves are affected by angular velocity, temperature‐dependent properties, micropolar parameter, and double porosity. Also, it has been discovered that throughout the reflection phenomena there is no dissipation of energy. Furthermore, this study concludes with a summary of the findings and subsequent observations. The current investigation has yielded inferences regarding specific cases that are of particular interest.

Platonic solids bouncing on a vibrating plate.

The energy transfer between bouncing particles and rigid boundaries during impacts is crucially influenced not only by restitution coefficients of the material but also by particle shapes. This is particularly important when such particles are mechanically agitated with vibrating plates. Inertial measurement units are able to measure all acceleration and rotational velocity components of an object and store these data for subsequent analysis. We employ them to measure the dynamics of cubes and icosahedra on vibrating plates to study the efficiency of energy transfer into the individual degrees of freedom (DOFs) of the excited object. The rotational DOFs turn out to be much less excited than the vertical translational motion. Most remarkably, there is only little difference between the two Platonic solids in both the absolute energies and the energy partition ratios.

Photosystem II Tolerance to Excess Zinc Exposure and High Light Stress in Salvia sclarea L.

High light (HL) intensity has a substantial impact on light energy flow and partitioning within photosynthetic apparatus. To realize the impact of HL intensity on zinc (Zn) tolerance mechanisms in clary sage (Salvia sclarea L., Lamiaceae) plants, we examined the effect of the altered chlorophyll and nutrient uptake under excess Zn supply on the response mechanism of photosystem II (PSII) photochemistry. Eight-week-old clary sage plants were treated with 5 μM Zn (control) or 900 μM Zn in Hoagland nutrient solution. Leaf elemental analysis for Zn, Mn, Mg, and Fe was performed by inductively coupled plasma mass spectrometry (ICP-MS), whereas PSII functioning under HL was evaluated by chlorophyll fluorescence imaging analysis. Exposure of S. sclarea plants to 900 μM Zn increased leaf Zn accumulation and decreased leaf Mg and chlorophyll. The decreased non-photochemical quenching (NPQ) provided evidence of the photoprotection offered by the smaller light-harvesting antennae due to the reduced chlorophyll. The increased Mn after Zn exposure corresponded with higher efficiency of the oxygen-evolving complex (OEC) that was significantly correlated with the maximum efficiency of photosystem II (PSII) photochemistry (Fv/Fm). An increased electron transport rate (ETR) coincided with increased leaf Fe, which is known to play a vital role in the enzymes engaged in ETR. The decreased (32%) NPQ after an 8-day exposure to Zn caused an increased (10%) quantum yield of non-regulated energy loss in PSII (ΦNO), indicative of an increased singlet oxygen (1O2) production. It is suggested that the decreased NPQ induced acclimation responses of clary sage plants to HL and excess Zn by increasing 1O2 production. The reduced (18%) excess excitation energy (EXC) at PSII and the increased (24%) quantum yield of PSII photochemistry (ΦPSII) and ETR indicated improved photosynthetic efficiency under excess Zn and HL intensity. Therefore, the exposure of medicinal plants to excess Zn not only boosts their photosynthetic efficiency, enhancing crop yields, but can also improve Fe and Zn content, ameliorating the human health deficiency of these two essential micronutrients.

149 Using respiratory gas flux and backward dietary energy partitioning to estimate energy intake by beef cattle fed a high concentrate diet

Abstract Twelve Charolais steers (BW = 498 ± 47.4 kg) were used in a 73-d feeding experiment. Our objective was to determine if CH4 and CO2 emissions, and O2 consumption could be used as biomarkers to estimate energy intake in growing beef cattle when integrated with backward dietary energy partitioning calculations when fed a high concentrate diet. Steers were housed in a pen equipped with individual feed bunks with access to an automated head chamber system (AHCS; GreenFeed, C-Lock, Inc., Rapid City, SD). Steers were randomly assigned to 1 of 3 treatments according to DMI as multiple of maintenance, which are 1.1 (1.1 M, n = 4), 1.4 (1.4 M, n = 4), and 1.8 (1.8 M, n = 4). The diet fed was 35% chopped sorghum hay (CP = 6.39% of DM; in vitro OM digestibility = 57.77%) and 65% concentrate (CP = 19.10% of DM; in vitro OM digestibility = 91.84%). The concentrate consisted of 41.75% flaked corn, 8.5% cottonseed meal, 13% distillers’ grain and 1.75% limestone. Steers were supplemented daily with 0.85 kg of alfalfa pellets (Medicago sativa; CP= 16.55%; in vitro OM digestibility = 87.01%) that were fed through the AHCS as bait. Methane tended (P = 0.09) and CO2 emissions and O2 consumption (P &amp;lt; 0.01) increased with the increasing feeding rates. Measured gross energy (GE; 21.9, 24.8, 29.5 Mcal/d, respectively), digestible energy (DE; 19.7, 22.0, 25.8 Mcal/d, respectively), and metabolizable energy (ME; 17.2, 19.2, 22.7 Mcal/d, respectively) intake levels increased with the increases in energy retention and heat production. The predicted values for GE (17.4, 23.6, 28.2 Mcal/d), DE (15.1, 20.8, 24.4 Mcal/d), and ME (12.6, 17.9, 21.3 Mcal/d) intake rates increased with the increase from 1.1 M to 1.8 M. Comparison of measured and predicted GE, DE, and ME intake rates agreed closely (r = 0.95, 0.93, 0.92 Pearson correlation, respectively). This experiment shows that together with multiple short-term breath measurements from an AHCS, BW, and an estimate of average daily gain, GE, DE, and ME intakes by cattle consuming a high concentrate diet can be predicted.

Spring Irrigation Reduces the Frequency and Intensity of Summer Extreme Heat Events in the North China Plain

AbstractIrrigation has distinct impacts on extreme temperatures. Due to the carryover effect of soil moisture into other seasons, temperature impacts of irrigation are not limited to irrigated seasons. Focusing on the North China Plain, where irrigation occurs in both spring (March‐April‐May) and summer (June‐July‐August), with a higher proportion of irrigation water applied during spring, we investigate the impact of spring irrigation on summer extreme heat events. Based on partial correlation analysis of data products, we find positive correlations between spring and summer soil moisture, suggesting that spring irrigation‐induced water surplus persists into the following summer and affects regional climate by impacting surface energy partitioning. Regional climate simulations confirm cross‐seasonal climatic effects and show that spring irrigation reduces the frequency and intensity of summer extreme heat events by approximately −2.5 days and −0.29°C, respectively. Our results highlight the importance of the cross‐seasonal climatic effect of irrigation in mitigating climate extremes.

A Mini-Review of the Kinetic Energy Partition Method in Quantum Mechanics

Based on the idea of adiabatic symmetry, we present a novel basis set expansion method—the kinetic energy partition (KEP) method—for solving quantum eigenvalue problems. Broken symmetry is responsible for quantum entanglement in many-body systems via parametric non-adiabatic corrections. Starting from simple one-particle-in-one-dimension problems, we gradually increase the complexity in the number of particles and the interaction patterns. Our goal in the mini-review is to advocate for the utility of the KEP method in front-line research, in particular for research beginners in quantum many-body problems.