Specific Energy Loss Research Articles

System for monitoring building heat consumption

Relevance. Energy consumption and efficient use of district heating networks affect the environment, society and the economy. Solutions are needed that can significantly reduce specific thermal energy losses. Using a technically and economically feasible way to assess energy efficiency allows these decisions to be made. Currently, assessing the energy efficiency of buildings raises significant questions among specialists. There is not much modern specialized literature in this area. The problem of energy efficiency requires more rigorous attention to urban planning issues. Thus, refined methods for assessing the energy efficiency of buildings make it possible to simultaneously save capital investments and ensure efficient consumption of thermal energy. Aim. To develop a system for assessing the real heat consumption of buildings to ensure optimization of dispatching of centralized heat supply systems in real time. Methods. Computer modeling of the state of heat consumption of buildings with various characteristics and schemes for their connection to centralized heat supply networks; methods of geographic information analysis. Results. The authors have proposed the system for monitoring the heat consumption of buildings. This system allows assessing the energy efficiency of buildings through the maximum use of computer and software technologies. It is shown that the calculated heat flows of buildings used to predict savings when modernizing buildings do not always correspond to the actual heat loads, which can lead to an incorrect assessment of investment projects. The authors obtained graphical dependences of the quantities influencing specific heat losses on various primary independent factors. Conclusions. The constructed system for monitoring the heat consumption of buildings allows, together with the use of geoinformation analysis methods, obtaining a fairly complete picture of the state of heat consumption for city areas and an assessment of the energy characteristics of buildings.

A new approach of preheating and powder sintering in electron beam powder bed fusion

Preheating is an essential process step in electron beam powder bed fusion. It has the purpose of establishing a sintered powder bed and maintaining an elevated temperature. The sintered powder bed reduces the risk of smoke and in combination with the elevated temperature improves the processability. Today, the line-ordering preheating scheme is widely used. This scheme does not take the previously built layers into account and results in an inhomogeneous elevated temperature and consequently in a variety of sinter degrees, which is disadvantageous for the process. The main challenge is now to modify this scheme to establish a homogeneous temperature distribution. This study addresses this challenge and analyses as well as optimises this scheme. A GPU-parallelised thermal model reveals a heterogeneous temperature distribution during preheating because of varying thermal conditions within a build job. In addition, a work-of-sintering model predicts that the sinter degree of the current powder layer on top of previously consolidated material is smaller than on top of the surrounding powder bed. This work aims to invert this trend to improve powder re-usage and material consolidation. Consequently, this work proposes an extension of the current scheme, compensating for the specific energy loss with local adjustments to the energy input. This adaption results in a uniform temperature distribution and advantageous sintering. Applying the proposed numerical model proves to be an effective method to analyse the evolving process conditions and tailor the local energy input, thereby improving the efficiency of the preheating step.

Riptide: a proton-recoil track imaging detector for fast neutrons

Riptide is a detector concept aiming to track fast neutrons. It is based on neutron-proton elastic collisions inside a plastic scintillator, where the neutron momentum can be measured by imaging the scintillation light. More specifically, by stereoscopically imaging the recoil proton tracks, the proposed apparatus provides neutron spectrometry capability and enable the online analysis of the specific energy loss along the track. In principle, the spatial and topological event reconstruction enables particle discrimination, which is a crucial property for neutron detectors. In this contribution, we report the advances on the Riptide detector concept. In particular, we have developed a Geant4 optical simulation to demonstrate the possibility of reconstructing with sufficient precision the tracks and the vertices of neutron interactions inside a plastic scintillator. To realistically model the optics of the scintillation detector, mono-energetic protons were generated inside a 6 × 6 × 6 cm3 cubic BC-408 scintillator, and the produced optical photons were propagated and then recorded on a scoring plane corresponding to the surfaces of the cube. The photons were then transported through an optical system to a 2 × 2 cm2 photo sensitive area with 1 Megapixel. Moreover, we have developed two different analysis procedures to reconstruct 3D tracks: one based on data fitting and one on Principal Component Analysis. The main results of this study will be presented with a particular focus on the role of the optical system and the attainable spatial and energy resolution.

Productive, reproductive and bioenergetic characteristics of cows with different body condition score

The aim of this work was to study the influence of fattening of dairy cows body condition score on reproductive traits, productivity and bioenergetic indicators. The research was conducted during May-August 2021 in the conditions of the Terezine of the Vilnotarasivske branch (Kyiv region). The values of average monthly temperatures were within the limits of thermoneutrality for cows of dairy breeds. Three groups of second-lactation cows were formed for the study. The first group (n=14) included animals with a fatness score of 2.0 to 3.0 points, and the second group (n=24) with a score of 3.0 to 3.75 points and to the III-rd group (n=15) – 4 and above points. Assessment of fatness in groups of animals was carried out during the period of deep body. The productivity of cows during the first 120 days of lactation was determined using computer records and the DelPro program. Cows of the II group had a somewhat shorter dry period (by 3 and 1 day) compared to animals of the I and III groups. The shortest service period was observed in the first group of cows – 164 days, which is 7 and 24 days less than in animals of the second and third groups, respectively. Cows of the II group had the highest average daily productivity during each of the first 4 months of lactation (120 days). At the same time, productivity was the lowest in cows of the III group, and intermediate values were observed in the animals of the I group. At the same time, cows of the III-rd group had the lowest productivity during the same period. Analyzing the bioenergetic characteristics of cows of different levels of fatness, it was established that the highest rate of net energy expenditure for the production of 1 kg of 4 % milk was in cows of the IIIrd group – 3.71 MJ, and the lowest in animals of the IInd group – 3.49 MJ. Research results showed that cows of different fattening levels before calving had high energy indices – from 50.25 to 53.99 %, productive – from 0.260 to 0.286 kg for specific net energy loss from 1.852 to 1.988 MJ per 1 MJ of milk energy. Key words: dairy cows, fatness, productivity, reproduction, bioenergetic characteristics.

Identification of deuterons at BESIII* *Supported by the National Natural Science Foundation of China (11975118, 12205141, 12375071)

The identification of deuterons with momenta in the range of 0.52−0.72 GeV/c is studied with specific ionization energy loss information using a data sample collected by the BESIII detector at center-of-mass energies between 4.009 and 4.946 GeV. Clean deuteron samples are selected using time of flight information. For all data samples, the deuteron identification efficiencies are higher than 95%, with a maximum difference of % between data and Monte Carlo simulation. This verifies the effectiveness of the deuteron identification method based on specific ionization energy loss and provides valuable information for future studies on processes involving deuterons in the final state at BESIII.

Modeling and Optimizing the Performance of Green Forage Maize Harvester Header Using a Combined Response Surface Methodology–Artificial Neural Network Approach

Green forage maize harvesters face challenges such as high soil humidity and soft soil in the field, mismatched working parameters, and poor reliability and adaptability. These challenges often result in header blockage, significant harvest loss, and increased energy consumption. Traditional testing and statistical analysis methods used in most existing studies are limited by complex test processes, their time-consuming nature, high costs, and poor prediction accuracy. To address these problems, a test bench was constructed to analyze the effects of forward speed, cutting height, number of rows, and their interactions on specific energy consumption and harvest loss of the green forage maize (GFM) header. A combined response surface method (RSM)–artificial neural network (ANN) approach is proposed for modeling and predicting the performance parameters of the header. The optimal conditions were determined by optimizing the specific energy consumption and loss rate. The optimal combination parameters are a forward speed of 1.6 km/h, a cutting height of 167 mm, and a number of rows of 4. However, RSM–ANN has larger R2 values and lower root mean square errors (RMSE) and mean square errors (MSE) compared to RSM. Specifically, the R2 of the RSM–ANN model for specific energy consumption and loss rate a 0.9925 and 0.9906, MSE are 0.00001775 and 0.004558, and RMSE are 0.004214 and 0.006752, respectively. The results show that the combined RSM–ANN method has higher precision and accuracy and can better predict and optimize the header performance. This study overcomes the limitations of traditional methods and has the potential to provide data and method references for the design, optimization, prediction, and intelligent diagnosis of faults in the operational parameters of agricultural machinery.

Four-dimensional electron energy-loss spectroscopy

Recent advances in scanning transmission electron microscopy have enabled atomic-scale focused, coherent, and monochromatic electron probes, achieving nanoscale spatial resolution, meV energy resolution, sufficient momentum resolution, and a wide energy detection range in electron energy-loss spectroscopy (EELS). A four-dimensional EELS (4D-EELS) dataset can be recorded with a slot aperture selecting the specific momentum direction in the diffraction plane and the beam scanning in two spatial dimensions. In this paper, the basic principle of the 4D-EELS technique and a few examples of its application are presented. In addition to parallelly acquired dispersion with energy down to a lattice vibration scale, it can map the real space variation of any EELS spectrum features with a specific momentum transfer and energy loss to study various locally inhomogeneous scattering processes. Furthermore, simple mathematical combinations associating the spectra at different momenta are feasible from the 4D dataset, e.g., the efficient acquisition of a reliable electron magnetic circular dichroism (EMCD) signal is demonstrated. This 4D-EELS technique provides new opportunities to probe the local dispersion and related physical properties at the nanoscale.

Evaluating the energy properties of the short-flow process based on the industrial metabolism: A case study on the metal 3D printing of hybrid deposition and micro rolling (HDMR)

The hybrid deposition and micro rolling (HDMR) is a new ultra-short process additive manufacturing (AM) technology, which combines in-situ rolling with additive manufacturing to greatly shorten and integrate the processing flow. In order to well understand the energy properties of the new technology, an industrial metabolic (IM) model is proposed with the complex processing parameters and equipment properties. The experimental test verifies that the deviation of specific energy consumption (SEC) computed by the IM model is 4.43% in the short-flow process of HDMR. Further study compares the energy properties of HDMR process with the conventional manufacturing (CM) processes by taking a cross-shaping part made of Ti-6Al-4V as an example. The results using the IM model show that the energy consumption of HDMR is reduced by 46.83% comparing with CM, by shortening the processing flow greatly. The short flow process of HDMR extremely reduces the melting heat and deformation energy in the deposition and rolling processes, compared with the significant energy consumption in the conventional processes of casting and forging. Meanwhile, the specific energy loss (SEL, energy loss per kilogram of materials) in HDMR is approximately 2 times lower than that of CM, which implies that HDMR has obvious advantages in the energy utilization with a shorter processing cycle. The study implies that industrial metabolism of the short-flow process like HDMR is more effective and appropriate to processing the titanium alloy with higher efficiency.

Organic heterostructured scintillators with a high pulse shape discrimination capability

Recently, we have developed a new type of the scintillation material, namely organic composite scintillators. It is a non-scintillating transparent gel composition (a polysiloxane elastomer) containing grains of organic single crystals. The grains are obtained after directional crystallization of the material by crushing a crystalline ingot under a layer of liquid nitrogen. This approach removes technological restrictions on the area of the entrance window of a scintillator, does not require the growth of structurally perfect single crystals and their subsequent mechanical treatment. In contrast to organic single crystals and liquids, these materials are not continuous media but heterostructured ones.The ability of single crystals and liquids to separate signals from radiations with different specific energy losses dE/dx is well known. Due to the peculiarities of the creation and recombination of triplet-excited (T) states in these objects is also well studied. Such information on heterostructured scintillation materials, for which the grain size can limit migration of T-states, is practically absent.We discuss the results of the investigation of the luminescence spectra upon excitation by light into the T-states absorption region and the relative light yield of composite scintillators containing p-terphenyl grains (both activated and non-activated) and trans-stilbene grains. We used the grain fractions from 0.04 to 1.0 mm. We obtained and studied both single-layer samples (the thickness of a sample practically corresponded to the grain size of the scintillation material) and samples of 5 mm thick. The research results showed that samples with grain fractions of less than 0.04, 0.06 and between 0.06 and 0.1 mm have low intensity of the delayed fluorescence and relative light output values. We obtained that to separate radiations with different dE/dx by the shape of the radioluminescence pulse it is advisable to use grain fractions larger than 0.1 mm. We also discuss the physical processes that can lead to such results.

Dynamic Analysis of a Downhole Regulator for Drilling in Interbedded Formations

Summary In this paper, we investigate the effect of a downhole passive regulator [anti-stall tool (AST)] on the dynamics of rotary drilling systems in interbedded formations. Drilling in interbedded formations can significantly affect the vibrational signature of these systems and the associated drilling performance. Hence, models to assess the impact of drilling in such formations are needed. Here, we construct a dynamic model of the drillstring system which incorporates the bit/rock interface laws for the transitional phase of bit motion between rock layers with distinct mechanical properties. In the model, the axial and torsional dynamics of the drillstring systems are coupled by these interface laws and cast in the form of discontinuous (state-dependent) delay differential equations. Next, we include the AST in the dynamic model to enable the assessment of the influence of this downhole tool on drilling performance, in particular in terms of rate-of-penetration (ROP) and drilling efficiency. Furthermore, we also investigate the mechanical specific energy (MSE) and steady-state power losses at the bit (due to frictional torque) for different operational conditions and rock layer thicknesses. The analysis reveals that an increased drilling efficiency and lower MSE are obtained by incorporating the downhole tool in the drillstring, resulting in a higher ROP and a lower frictional contact between the bit and rock in interbedded formations.

Measurement of wide energy range neutrons with a CLYC(Ce) scintillator

The CLYC(Ce) (Cs2LiYCl6:Ce3+) scintillator can identify different particles with various specific energy losses and is capable of measuring the fast neutron energy via the 35Cl(n,p)35S reaction. Thus, it is rational to expect using this detector for monitoring the on-site neutron dose rate for astronauts or equipments working at a spacecraft, which may undergo the irradiation of cosmic rays of energetic protons or alpha particles that could induce the production of spallation neutrons. However, as the spallation neutrons, as well as the moderated neutrons, have an energy distribution from the thermal region to several hundred MeV, the direct measurement of the neutron spectrum, which helps calculate the exact value of dose rate in the spacecraft, requires that the energy response matrices should be known in advance. In this study, we calibrated a Φ38 mm × 38 mm CLYC(Ce) scintillator detector with the Back-n beamline at the China Spallation Neutron Source (CSNS), acquiring its energy response matrices (ERM) ranging from 0.1 MeV to 100 MeV. To verify the CLYC(Ce) scintillator detector's capability for measuring neutrons with such a wide region, using the ERM, the energy spectrum of the Back-n beamline was reconstructed and the result conformed to the CSNS-measured result well; a good conformation between the reconstructed spectrum and the standard Watt fission neutron spectrum of 252Cf was also observed. This calibrated detector then was used to measure the cosmic-ray induced neutron spectra at five different sites in China of various altitudes. The measured neutron fluxes at five different sites conformed to results predicted by the EXcel based Program Atmospheric Cosmic-ray Spectrum (EXPACS). The results presented in this study indicate that the CLYC(Ce) scintillator detector is promising to be used in spacecraft as a neutron monitor with a wide energy range.

Computational Method for Specific Energy Loss by Fast Inverse Laplace Transform

This study proposes a novel computational technique for specific energy loss for pulse incidence. Our method is based on a fast inverse Laplace transform (FILT) with an electromagnetic field solver in the complex frequency domain. Using the FILT algorithm, the specific energy loss in the complex frequency domain can be computed and transformed into the time domain. In our method, the specific energy loss can be computed until the desired observation time without solving the electromagnetic field at the previous observation time. The finite-difference complex-frequency domain (FDCFD) was used for the complex frequency domain solver. The results demonstrated that our proposed method could compute the dissipated energy of inhomogeneous, non-dispersive lossy dielectrics.

Results on light (anti)nuclei production in Pb–Pb collisions with ALICE at the LHC

The high collision energies reached at the LHC lead to significant production yields of light (anti)nuclei in proton-proton, p–Pb and Pb–Pb collisions. Light (anti)nuclei are identified using their specific energy loss (dE/dx), measured in the Time Projection Chamber, and their velocity using the Time-Of-Flight detector. The excellent tracking and particle identification capabilities of the ALICE experiment, as well as its low material budget, make this detector unique for measurements of these rarely produced particles. Results on (anti)deuteron, (anti)triton, (anti)3He and (anti) He production in Pb–Pb collisions at p sNN = 5.02 TeV, including their transverse momentum (pT) spectra, production yields and coalescence parameters BA, are presented. These results will be compared to the expectations of coalescence and statistical hadronization models to obtain information on the production mechanism of light (anti)nuclei in heavy-ion collisions. Furthermore, the first measurements of the d and 3He absorption cross section are shown.

Double-hit separation and dE/dx resolution of a time projection chamber with GEM readout

A time projection chamber (TPC) with micropattern gaseous detector (MPGD) readout is investigated as main tracking device of the International Large Detector (ILD) concept at the planned International Linear Collider (ILC). A prototype TPC equipped with a triple gas electron multiplier (GEM) readout has been built and operated in an electron test beam. The TPC was placed in a 1 T solenoidal field at the DESY II Test Beam Facility, which provides an electron beam up to 6 GeV/c. The performance of the readout modules, in particular the spatial point resolution, is determined and compared to earlier tests. New studies are presented with first results on the separation of close-by tracks and the capability of the system to measure the specific energy loss dE/dx. This is complemented by a simulation study on the optimization of the readout granularity to improve particle identification by dE/dx.

Ternary particles of Z =1 to 4 emitted in spontaneous fission of 252Cf

This paper presents the results of ternary light charged particles from 252Cf spontenous fission source. The method DeltaE - E was applied to identify the particle by a position sensitive DeltaE - E telescope.The specific energy loss (DeltaE) was measured using the transmission type DeltaE detector (thicknesses of 150 μm ) ordered from the company Micron Semiconductors, while the residual energy (E) was measured by a Timepix detector with thicknesses of 600 μm . It was possible to measure partial-energy spectra of the various ternary particle types due to the thicknesses of Al foil (31 μm) and DeltaE detector (150 μm) placed before E detector. The energy spectrum of protons was qualitatively different from the spectra of the other particles since protons from Al(n,p) and Si (n,p) reactions could contribute to the spectra.

Experimental and numerical analysis of thermodynamic performance of microwave dryer of onion

AbstractThe present study was designed for the experimental and modeling investigations on thermodynamic analysis of drying onion slices using four microwave power levels (100, 350, 500, and 750 W) and the four samples thicknesses (2.5, 5, 7.5, and 10 mm). A multilayer feedforward artificial neural network was employed in order to predict energy and exergy performance of the dryer and the prediction success were compared using three evaluation criteria. The average values for energy efficiency and specific energy loss ranged from 13.52% to 37.94% and from 1.35 to 7.43 MJ/kgwater, respectively. Findings showed that the exergy efficiency changed from 11.79% to 30.84%. In addition, the statistical analysis revealed that higher microwave power levels and the thinner samples significantly (p < .05) enhanced both the energy and exergy efficiencies. The obtained results for exergy improvement potential (accounted for 37.83%–69.41% from the total exergy inlet) indicated that the drying process has good potential for exergy performance improvement. Based on the modeling outcomes, the energy efficiency was well predicted by an artificial neural network with a topology of 3–18–18–1 and LM training algorithm and threshold function of Tan–Tan–Lin. However, the best topology for the exergy efficiency prediction had 3–20–16–1 structure, LM training algorithm and Log–Log–Lin transfer function (R2 of .94).Practical ApplicationsIn this study, onion slices were dried in a domestic microwave oven and the influence of the power level and thickness of the samples on energy and exergy parameters was investigated. In addition to experimental evaluation, the multi‐layer feed‐forward neural network can be used to model and predict changes in energy efficiency and exergy during the process.

An experimental analysis on thermal runaway and its propagation in Cell-to-Pack lithium-ion batteries

• A description of the characteristics of TR in Cell-to-Pack batteries is provided. • There is very low variability between jelly roll temperature at different locations. • The specific heat capacity and energy loss of the multiphase vents were calculated. • The time it takes for TR to propagate within the battery is affected by heating power. • The temperature of the jelly roll is 487℃ higher than the surface temperature. Thermal runaway and its propagation are the technological barriers for the large-scale promotion of new energy vehicles and energy storage. This paper investigates the temperature characteristics between jelly rolls, influence of heating power on internal propagation time and energy flow during thermal runaway propagation through experiments and models. Results indicated that the maximum temperature between jelly rolls has a maximum temperature difference up to 487℃ compared to the surface temperature during thermal runaway. The distribution of energy flow showed that approximately 60% of total energy was used to self-heated and approximately 31% was emitted through venting. Experimental results and model calculation shows that the time it takes for thermal runaway to propagate within the Cell-to-Pack battery is affected by heating power. This study provides a reference for creating safe cell designs, developing mitigation strategies for addressing thermal runaway propagation in system, and investigating battery-related accidents in new energy vehicles and energy storage.

Modelling of a Stilling Basins with Sloping Apron in IBER to Improve Efficiency in High-slope Rivers

This research shows the influence of stilling basin slopes on energy loss in rivers with a high gradient. This study takes as a case San Pedro water intake (Ayacucho, Peru). The main objective is to improve efficiency of stilling basins in rivers with high slope. Five dissipation pools of different slopes were modelled: 0%, 1.52%, 3.04%, 4.56% and 6.08% to propose the optimum pool among these, for the San Pedro intake. Results were validated by means of a Sensitivity Analysis, trough comparison with the results of previous investigation and results of modelling San Pedro river with HEC-RAS and IBER. It was obtained that the steeper the slope of the stilling basin, the higher the specific energy loss, the higher the output rate, the longer the stilling basin. It can be concluded that the 3.04% slope stilling basin is the most appropriate for the 6.08% slope river since the slope variation is not abrupt as in the case of the horizontal one, that is, 30% more energy loss with respect to the horizontal pool and velocity and Froude results similar to the modelling of the San Pedro river.

Comparative Performance Evaluation of Conventional and Superjunction Vertical 4H-SiC High-Voltage Power MOSFETs

We evaluate and compare the static and dynamic performances of four different 4H-SiC power MOSFETs (Conventional DMOS and UMOS, Superjunction (SJ) DMOS and UMOS FETs) from 0.6 to 10kV. The static on-state performance is determined by analytically calculating the specific on-resistance (RON,sp), while the dynamic switching performance is determined by extracting the specific gate charge (QG,sp) and switching energy loss per cycle (Esw,cycle) using 2D device simulations. It has been found that the SJ UMOS FET exhibits at least a 31% (up to 53% at 0.6kV) reduction in the RON,sp · QG,sp Figure-of-Merit (FoM) compared to the SJ DMOS FET within the breakdown voltage rating range studied.

Testing, Evaluating and Simulate the Performance of the Newly Designed Drum for a Sunflower Threshing Machine

The stationary thresher machines are widely used worldwide in threshing and separating many crops; they proved to have a high performance, especially in small spaces. The threshing drum is the essential working device of the thresher and plays a fundamental role in threshing efficiency, consumed specific energy, machine productivity, and seeds loss. In this study, a structure of sunflower thresher (open style drum with 45 incline degree loop teeth) was tested, and evaluated for performance under different drum rotational speeds (150, 200, 250, and 300 rpm) and different concave clearances ( 10, 15 and 20 mm). The thresher structure and operating parameters were assessed and optimized concerning damaged and unthreshed seed percentage, threshing efficiency, consumed specific energy, and machine productivity. The obtained results revealed that increasing cylinder rotating speed positively related to threshing efficiency, power requirements, and machine productivity while increasing concave negatively related to threshing efficiency, power requirements, and machine productivity. The highest efficiency of 97.40 %, the maximum productivity of 434.50 kg/h, and the lowest consumed specific energy of 6.85 kW.h/t were obtained at the operational condition of 300 rpm drum rotational speed 10 mm concave clearance. Buckingham's π theorem was followed to find an equation to predict the threshing efficiency theoretically, resulting in an equation with an R2 value of 0.8892. These developments were an excellent choice to uprising the performance of the original thresher drum.