Calculation Of Energy Loss Research Articles

Hard jet substructure in a multistage approach

We present predictions and postdictions for a wide variety of hard jet-substructure observables using a multistage model within the framework. The details of the multistage model and the various parameter choices are described in []. A novel feature of this model is the presence of two stages of jet modification: a high-virtuality phase [modeled using the modular all twist transverse-scattering elastic-drag and radiation model ()], where modified coherence effects diminish medium-induced radiation, and a lower virtuality phase [modeled using the linear Boltzmann transport model ()], where parton splits are fully resolved by the medium as they endure multiple scattering induced energy loss. Energy-loss calculations are carried out on event-by-event viscous fluid dynamic backgrounds constrained by experimental data. The uniform and consistent descriptions of multiple experimental observables demonstrate the essential role of modified coherence effects and the multistage modeling of jet evolution. Using the best choice of parameters from [], and with no further tuning, we present calculations for the medium modified jet fragmentation function, the groomed jet momentum fraction zg and angular separation rg distributions, as well as the nuclear modification factor of groomed jets. These calculations provide accurate descriptions of published data from experiments at the Large Hadron Collider. Furthermore, we provide predictions from the multistage model for future measurements at the BNL Relativistic Heavy Ion Collider. Published by the American Physical Society 2024

Theoretical and experimental study of plasmon oscillation dispersion in Si and Ge crystals

Plasma fluctuation dispersion has been theoretically and experimentally studied in monocrystal samples of Si (111) and Ge (111). It has been shown that the dispersion depends on crystallographic orientations of materials under study. In this work, the dispersion effects in the CLEE spectra, which manifest themselves in bulk samples of Si and Ge, have been studied. The loss energy electron was studied by the CLEE method upon their reflection from Si(111) and Ge(111) at different angles of incidence of the electron beam on the surface. Calculation of the total electron energy loss with formula (5) shows that the form of the CLEE spectrum of primary electrons depends on the nature and magnitude of the electron density in a given direction and is in satisfactory agreement with the experimental data. Thus, the theoretical and experimental results show that in the case of single-crystalline Si and Ge, with increasing k, the values of the bulk plasma oscillation increase by 2–3 eV.

Experimental and theoretical evaluation of the effect of fluid resistance on the performance of a tubular indirect evaporative cooler

To evaluate the impact of fluid resistance on the performance of tubular indirect evaporative coolers (TIECs), a mathematical model of secondary air channel resistance was developed. An experimental setup was created to study the effects of factors such as secondary air flow rate and water spray flow rate on R2 under actual conditions. The model used the same conditions to analyze how factors like air flow, water flow, and droplet size influenced R2. The relationship between R2 and wet-bulb effectiveness (εwb) was also examined experimentally. The data from the experiments were compared to the model's predictions, showing a maximum relative error of 10 %, confirming the model's accuracy. It was found that R2 and secondary air flow rate (V2) are positively correlated, and εwb increases with R2. The experiments yielded secondary air resistances ranging from a minimum of 548.2 Pa to a maximum of 554.26 Pa. These results are valuable for selecting appropriate fans for the secondary air channel. Additionally, simulations were conducted to predict and calculate energy losses in the secondary air channel under real working conditions, providing a useful basis for future fan selection.

Calculation of electrical energy losses in distribution networks for power supply using oil and vacuum circuit breakers

A method for approximate estimation of load losses in distribution networks from 6 to 10 kV, as well as for lower voltage networks, has been proposed. The main advantage of this method is that the root mean square current is calculated only once for a series of calculations. This approach significantly reduces the time required for calculations and improves their accuracy, as it eliminates the need for multiple determinations of the root mean square current for each individual calculation. The proposed approach contributes to a better understanding of the influence of various factors on load losses, which allows for more effective planning and management of distribution networks. This is particularly important in the context of increasing loads on electrical networks and higher demands for their reliability and efficiency. In the calculation of electrical energy losses in distribution networks from 6 to 10 kV, methods that use generalized coefficients of electrical circuits and operating modes in the form of regression equations are widely applied. The most significant and independent factors, such as the input of active energy, total line length, number of line sections, total number of transformers, and their total installed capacity, must be taken into account and are included in the calculation equation. Additionally, the components used and their regular maintenance play an important role in electrical energy losses in electrical networks. The main direction of research is the optimization of distribution network parameters, taking into account the latest technologies and materials, as well as the implementation of automated monitoring and control systems that will allow timely detection and elimination of problems associated with electrical energy losses. The proposed method for estimating load losses in distribution networks is a promising direction for the development of the energy sector, which will contribute to improving the efficiency and reliability of electrical networks, as well as reducing the costs of their operation and maintenance.

Revisiting primordial black hole capture by neutron stars

A sub-solar mass primordial black hole (PBH) passing through a neutron star, can lose enough energy through interactions with the dense stellar medium to become gravitationally bound to the star. Once captured, the PBH would sink to the core of the neutron star, and completely consume it from the inside. In this paper, we improve previous energy-loss calculations by considering a realistic solution for the neutron star interior, and refine the treatment of the interaction dynamics and collapse likelihood. We then consider the effect of a sub-solar PBH population on neutron stars near the Galactic center. We find that it is not possible to explain the lack of observed pulsars near the galactic center through dynamical capture of PBHs, as the velocity dispersion is too high. We then show that future observations of old neutron stars close to Sgr A* could set stringent constraints on the PBHs abundance. These cannot however be extended in the currently unconstrained asteroid-mass range, since PBHs of smaller mass would lose less energy in their interaction with the neutron star and end up in orbits that are too loosely bound and likely to be disrupted by other stars in the Galactic center.

Turbine-Level Possible Power Prediction using Farm-Wide Spatial Information through Similarity-Based Multivariate Gaussians

Wind farms usually comprise several turbines of the same type in proximity to one another. Therefore, similarities exist between the power production of specific turbines within the wind farm over time. Considering this, it is possible to find a way to express the similarity between turbines and exploit their properties to find a formulation of the expected behavior of a turbine. With this estimation of possible power output, one can analyze the losses generated by curtailments or transients with a higher precision. Based on this, a probabilistic model is proposed that can be used to calculate energy losses due to maintenance or environmental reasons. On top of that, heavy deviations in the behavior of specific wind turbines can be detected on high-frequency (1-second) data. Overall, the goal of this work is to predict possible power on high-frequency SCADA data using a statistical white-box modeling approach. The presented method is based on a probabilistic framework, constructing a system of linear combinations that permits analytically tracking the expected behavior of a turbine, even if it is non-operational for a specific amount of time. The methodology includes two parts, the first one is the use of data-driven power curves, and the second one consists of an inferential framework based on the environmental conditions of the farm. Results show that the method presented performs better than the manufacturer’s power curves under specific wind speeds and wind directions.

Increasing the efficiency of the automotive generator due to active rectification

Problem. Increasing fuel economy requirements for modern vehicles lead to an increase in their electrification. The rise in the number of electrical systems leads to a higher load on the electrical power supply system, with the vehicle's power load reaching 2-3 kW. Leading automobile companies have begun serial production of vehicles with the new 12/48 V power supply voltage standard. The traditional alternator used today is a synchronous alternator, and rectifier diodes are used to convert the generated AC to DC to charge the battery, which is inefficient. A study of losses in an automobile alternator shows that the diode rectifier creates a significant portion of the machine's losses at low speeds, resulting in increased fuel consumption. The solution to this problem is to use a synchronous rectifier to replace traditional rectifier diodes, thus improving the efficiency of the AC/DC rectifier. Goal: To improve the economic and environmental characteristics of a mild hybrid vehicle through the use of a synchronous two-semi-periodic rectifier with a midpoint in the car generator. Methodology: Analytical methods are used to calculate energy losses on diodes and in the phase windings of the generator when employing a two-semiperiod rectifier with a midpoint, compared to a bridge rectifier. Results: The structure, functions, and operation modes of the synchronous rectification system are considered. The effect of synchronous rectification on the generator efficiency of a mild hybrid vehicle is analyzed. It was determined which configurations of synchronous rectification are more effective from the standpoint of energy saving and under which operating conditions. It was determined that in a two-semiperiod rectifier with a midpoint, compared to a bridge rectifier, there will be the same heating of the phase windings and 2 times fewer losses on the diodes. Practical value: A version of the bridge synchronous rectification system of the 48 V generator for a mild hybrid vehicle using MOSFET transistors and specialized control IC is proposed. A synchronous rectification system and its circuit implementation for a 12 V generator based on a two-semi-periodic rectifier scheme with a midpoint is proposed, which allows increasing the energy efficiency and economy of the automobile generator.

Optimization of losses by switching to higher voltage in distribution networks

The article considers the basis of scientific research in the field of electric power industry the issues of transition to 20 kV voltage in the distribution power grids of Uzbekistan. The main advantages of this method are analysed, as well as the factors affecting power and energy losses in electrical systems and networks. The paper presents a schematic diagram of an electric network section, on which a comparative calculation and analysis of voltage, energy and power losses in 6/10/20 kV networks is carried out. Special attention is paid to the peculiarities of calculation of these parameters, as well as the basic expressions for their calculation and the resulting graphical relationships. From the analysis it can be concluded that it is reasonable to use 20 kV voltage in distribution networks. It allows to reduce power and energy losses, which is an important factor in the efficient operation of electric power systems, to increase line capacity and service range. However, when selecting the optimal voltage for certain conditions, it is necessary to take into account a number of factors, such as the length of transmission lines, the type of wires and transformers used, and the load level of the network.

Damage Energy Threshold Anisotropy in Non Ionizing Energy Loss Calculation

Damage Energy Threshold Anisotropy in Non Ionizing Energy Loss Calculation

Fragmentation of data packets in wireless sensor network with variable temperature and channel conditions

This study formalizes and solves the problem of minimizing the energy dissipated by a node in order to successfully transmit the initial data amount during one round of communication over a wireless channel affected by Rice fading under varying temperature conditions. In this work, the models for the temperature dependence of the parameters in an incoherent frequency shift key (FSK) demodulator are presented and investigated for the first time, taking into account both the frequency separation and the synchronization type of the clock generator. The studied orthogonality coefficients of FSK signals represent internal parameters in the proposed model of the incoherent Rice wireless channel. This model allows the analytical relationship between the bit error probability (BEP) and node heating temperature, signal fading depth in the channel (Rician K-factor), and signal-to-noise ratio (SNR) to be established.Since it is necessary to retransmit the entire data packet when an erroneous bit is detected in a communication system that uses an automatic repeat request, at high BEP values, it is recommended to fragment packets in order to improve the energy efficiency of the nodes. By using the developed models for calculating energy losses during the communication round, it was determined that optimal fragmentation options (OFO) for data packets can be identified within specific ranges of temperature and Rician K-factor, which includes the overhead costs for packeting and retransmission. As a result, OFO matrices of packets in the "temperature – K-factor" (t0–K) coordinate system were obtained for minimizing the energy loss of nodes at different SNR values. In our example of using TI CC2500 node transceivers for 90-day monitoring of corn vegetation, the t0K-Frag algorithm reduced node energy losses by a factor of K = 3.3 compared to the case of transmitting an unfragmented packet of initial length.

Analysis of vortex characteristics and energy losses in a cryogenic hydrogen turbo-expander for a 5 t/d hydrogen liquefier

The cryogenic hydrogen turbo-expander (CHTB) is the most core component which determines the dependability and efficiency of hydrogen liquefiers. In present study, CFD method are adopted to simulate the internal flow field inside a CHTB for a 5 t/d hydrogen liquefier. The Ω method and entropy generation method are implemented to identify vortex structures and calculate energy losses. The results show tip leakage vortex is the primary vortex and causes energy losses through strong fluid shear but not rotation effect. The turbulent dissipation is the main energy dissipation. The total entropy generation of CHTB impeller is significantly higher than nozzle because of tip clearances. As tip clearances increase from 0% to 1.6%, total entropy generation increases by 83%, and output shaft power and isentropic efficiency reduce by 9% and 6% respectively. Working conditions mainly affect the inlet angle of attack and significantly impact vortex characteristics and energy losses in the CHTB.

An analytical model of ultrasonic transducers considering acoustic losses of contact surfaces

In this paper, a continuum electromechanical model of a Langevin ultrasonic transducer is developed considering acoustic losses of contact surfaces. The calculated energy losses between components of a transducer are considered as loss modulus of backing and matching parts. Considering the losses, the calculated vibrations amplitude of the transducer is matched to measured values. In addition, the calculated frequency response of the electrical admittance of the transducer is in good agreement with experimental results. The errors of calculated resonant frequency, anti-resonance frequency and amplitude of vibrations compared to the experimental results are 0.02%, 0.03%, 4.5% respectively. The values of the electrical admittance in the resonant and anti-resonant frequency have errors of 2.7%, 9.5% compared to empirical results. The developed model, fixes the drawback of previous models to anticipate amplitude of vibrations and the frequency response of the electrical admittance of ultrasonic transducers.

Analisis Jaringan Pipa Distribusi Air Baku WTP1 Waduk Gongseng Kabupaten Bojonegoro Provinsi Jawa Timur Menggunakan Qepanet

The WTP 1 service area is planned to meet raw water needs in the Temayang and Sukosewu Districts with a raw water supply of 150 l/s. The research objective is to plan a pipeline network to help the people of Temayang and Sukosewu Districts meet their clean water needs. The pipeline network is planned using the QEpanet application to make it easier to describe the network and find out the elevation and length of the pipes. Hydraulic simulation using the Epanet application with the calculation of energy loss using the Hazen William method. The projected population is calculated using the arithmetic method. The pipeline network is planned to use pipes with a diameter of 76.2 – 406.4 mm. The pump is placed in WTP1 with a capacity of 150 l/s and a pump head of 130 m. From the results of the Epanet 2.2 hydraulic simulation on the Junc J22 branch, the pressure value is 1.19 m. so a pump is needed on the L22 pipe section.

High frequency magnetic loss characteristic analysis and calculation of magnetostrictive Tb-Dy-Fe alloys under multivariable comprehensive operation conditions

The accurate calculation of magnetic energy losses for electromagnetic materials directly affects the global optimization design and operating efficiency of electromagnetic devices, especially under high frequency excitation. This study gropes for measurement methods of hysteresis, loss, and temperature rise characteristics for magnetostrictive Tb-Dy-Fe alloys materials under comprehensive operation conditions of high-frequency excitation, compressive stresses, temperature, and DC bias. Based on the measured data, a multiple variables loss matrix that can describe the characteristics of multiple energy fields (electromagnetic-, thermal- and mechanical fields) is established. Using loss matrix transformation method, the variation of hysteresis loss coefficients and generalized eddy current loss coefficients with different energy field characteristic variables are obtained. By establishing a dual statistical framework of sensitivity and deviation degree, the main influence variables which have the greatest impact on loss coefficients are extracted from these variables. Then a loss model for magnetostrictive material considering comprehensive operation conditions is presented which can describe the output characteristics of electromagnetic devices with strong non-linearity and multi-coupling effects among different energy fields. Furthermore, this method allows for the expansion of dimensions of linear or nonlinear variables and considers more energy fields, enabling a comprehensive analysis of interplay between multiple fields and facilitating engineering calculations.

Energy loss profile measurements using the ACTAR TPC demonstrator active target

The energy loss profiles of different ion beams (6Li, 27Al and 50Ti) impinging on CF4, isobutane and P10 have been measured with the active target ACTAR TPC demonstrator. The pressure of the gas, monitored during the experiment, has been chosen in order to stop the ions inside the active zone. Starting from the energy loss calculation produced by the SRIM code, the experimental ion tracks have been simulated, taking into account the effect of the thermal diffusion of electrons during their drift towards the pad plane under the effect of a uniform electric field. The uncertainty in the geometry, mainly due to the thickness and deformation of the mylar interface window between the gas volume and the high vacuum line, has been taken into account. A good agreement is obtained between the experimental and simulated energy loss profiles.

Cavitation characteristics and energy loss in high-pressure differential control valve

PurposeThe purpose of this study is to determine the cavitation flow characteristics of the high-pressure differential control valve. The relationship between cavitation, flow coefficient and spool angle is obtained. By analyzing the relationship between different spool angles and energy loss, the energy loss at different spool angles is predicted.Design/methodology/approachA series of numerical simulations were performed to study the cavitation problem of a high-pressure differential control valve using the RNG k–e turbulence model and the Zwart cavitation model. The flow states and energy distribution at different spool angles were analyzed under specific working conditions.FindingsThe cavitation was the weakest when the spool angle was 120° or the outlet pressure was 8 MPa. The pressure and speed fluctuations of the valve in the throttle section were greater than those at other locations. By calculating the entropy production rate, the reason and location of valve energy loss are analyzed. The energy loss near the throttling section accounts for about 92.7% of the total energy loss. According to the calculated energy loss relationship between different regions of the spool angle, the relationship between any spool angle and energy loss in the [80,120] interval is proposed.Originality/valueThis study analyzes the cavitation flow characteristics of the high-pressure differential control valve and provides the law of energy loss in the valve through the analysis method of entropy. The relationship between spool angle and energy loss under cavitation is finally proposed. The research results are expected to provide a theoretical basis for the optimal design of valves.

Measurement of electrons from open heavy-flavor hadron decays in Au+Au collisions at sqrt{s_{textrm{NN}}} = 200 GeV with the STAR detector

We report a new measurement of the production of electrons from open heavy-flavor hadron decays (HFEs) at mid-rapidity (|y| < 0.7) in Au+Au collisions at sqrt{s_{textrm{NN}}} = 200 GeV. Invariant yields of HFEs are measured for the transverse momentum range of 3.5 < pT< 9 GeV/c in various configurations of the collision geometry. The HFE yields in head-on Au+Au collisions are suppressed by approximately a factor of 2 compared to that in p + p collisions scaled by the average number of binary collisions, indicating strong interactions between heavy quarks and the hot and dense medium created in heavy-ion collisions. Comparison of these results with models provides additional tests of theoretical calculations of heavy quark energy loss in the quark-gluon plasma.

Accounting for plasma constituent mass effects in heavy fermion energy loss calculations in hot QED and QCD

Accounting for plasma constituent mass effects in heavy fermion energy loss calculations in hot QED and QCD

Multi-phase flow simulation of powder streaming in laser-based directed energy deposition

As a promising additive manufacturing technique, laser-based directed energy deposition has been widely applied in part fabrication, surface cladding, and part restoration. During the powder feeding process, the gas, particles, and laser interact and further affect the molten pool flow. To study the powder feeding process, a multi-physics gas-particle multi-phase flow model coupled with a laser ray-tracing heat source model is developed to predict the powder particle temperature, velocity, and concentration distribution as well as laser energy loss, which is then validated against experimental results. The single-nozzle simulation shows that powder particles out of the nozzle follow a radial Weibull distribution instead of a 2D Gaussian distribution from the inlet of the nozzle. In the four-nozzle powder feeding process, the particles converge further after passing the focal plane, and setting the focal plane above the molten pool surface could potentially increase the powder catchment. Moreover, the laser ray-tracing model incorporates laser reflection and laser incident angle into laser energy loss calculation, which would be more accurate than those models based on the Beer-Lambert law. Additionally, by increasing the powder feed rate or decreasing the carrier gas flow rate, the laser energy loss linearly increases. The predicted powder velocity, temperature distribution, and attenuated laser can be further implemented into the molten pool flow model to more comprehensively study the interaction between particles and the molten pool in the future.

A new hysteresis simulation method for interpreting the magnetic properties of non-oriented electrical steels

The magnetic properties of non-oriented electrical steels (NOESs) are characterized using an analytical simulation method accounting for the microstructures in ferromagnetic materials. Complementary experimental data for thin sheet laminations, obtained using a standard single strip tester (SST), are employed with the hysteresis mechanism investigated in terms of the measurement system and Weiss Mean Field effects. It is shown that the magnetic hysteresis loops of NOESs of 3% SiFe can be generated with remarkable accuracy for a broad range of magnetization frequencies and peak flux densities. The simulation method is also suitable for performing an energy loss analysis with calculated energy losses, when compared to corresponding measured data, showing a strikingly accurate match with, in most cases, an error of less than 1%.