Energy Concentration Research Articles

Theoretical investigation of potential energetic material CL-20/TNBP co-crystal explosive based on molecular dynamics method.

The exploration of CL-20 eutectic has been a subject of fervent interest within the realm of high-energy material modification. Through the utilization of density functional and molecular dynamics methods, an investigation into the characteristics of hexanitrohexaazaisowurtzitane (CL-20)/4,4',5,5'-tetranitro-2H,2'H-3,3'-bipyrazole (TNBP)within the molar ratio range of 4:1-1:4 was conducted. This inquiry encompassed the scrutiny of molecular interaction pathways, attachment force, initiating molecular distance, unified energy concentration, and physical characteristics. Furthermore, the EXPLO-5 was harnessed to prognosticate the explosion features and byproducts of unadulterated CL-20, TNBP, and CL-20/TNBP frameworks. The findings delineate a substantial differentiation in the electrostatic charge distribution on the surface between CL-20 and TNBP particles, signifying the preeminence of intermolecular interactions between disparate entities over those within similar entities, thus intimating the plausibility of the eutectic constitution. Remarkably, the identification of maximal attachment force at a molar ratio of 1:1 suggests the heightened likelihood of eutectic formation, propelled primarily by electrostatic and van der Waals forces. The resultant eutectic explosive evinces intermediate reactivity and exemplary mechanical attributes. Moreover, the detonation achievement of the eutectic with a molar proportion of 1:1 straddles that of CL-20 and TNBP, representing a new type of insensitive high-energy material. The testing method employs the Materials Studio software and utilizes the molecular dynamics (MD) method to predict the properties of CL-20/TNBP cocrystals with different ratios and crystal faces. The MD simulation time step is set to 1fs, and the total MD simulation time is 2ns. An isothermal-isobaric (NPT) ensemble is used for the 2ns MD simulation. The COMPASS force field is employed, with the temperature set to 295K. The prediction of detonation characteristics and products is conducted using the EXPLO-5 software.

Iterative local maximum synchrosqueezing-extracting transform

Recently, there has been significant interest in time-varying signal analysis. Multisynchrosqueezing transform (MSST) and improved multisynchrosqueezing transform (IMSST) have shown promise in overcoming the limitations of conventional methods. Although progress has been made, challenges still exist, such as the presence of non-reassigned time–frequency (TF) points and the presence of noise in the TF plane when processing noisy time-varying signals. In this paper, we introduce an innovative TF analysis method known as the iterative local maximum synchrosqueezing-extracting transform (ILMSSTSEO). First, the proposed method extracts the local maximum value of the instantaneous frequency (IF) during each iteration to eliminate non-reassigned TF points. Additionally, a synchroextracting operator is introduced unconventionally to enhance the concentration of TF energy and reduce noise in the TF representation. By doing so, the method effectively solves many challenges faced by existing methods and provides a new extraction framework for synchrosqueezing transform-based TF analysis methods.

Radon Equilibrium Factor and the Assessment of the Annual Effective Dose at Underground Workplaces

The equilibrium factor F is one of the parameters that should be considered when assessing the effective dose based on radon activity concentration. Since the equilibrium factor in various environments ranges theoretically from a value close to 0 to 1, it is expected that dose assessment based on one recommended coefficient value may lead to an underestimation or overestimation of the dose. That is why it is essential to measure this quantity if the basis for dose assessment is the radon concentration and not the concentration of radon decay products. The equilibrium factors were determined based on measurements of radon activity concentration and potential alpha energy concentration and varied from 0.15 to 0.94, with an arithmetic mean of 0.55. The average effective dose calculated for the employee taking into account these values was 31 mSv, assuming an annual working time of 1800 h. In turn, the average effective dose calculated for the equilibrium factor of 0.2 as recommended by the International Commission on Radiological Protection (ICRP) was equal to 13 mSv.

Fourier coded aperture transform rapid spectral imaging

The Fourier coded aperture transform hyperspectral imaging system (FCTS), which we proposed in our previous work, has excellent physical interpretability compared to other encoding methods. Due to the excellent energy concentration characteristic of Fourier encoding, it can achieve high-quality spectral imaging even under undersampling conditions. However, since the grayscale encoding method limits the system's sampling speed, we propose a binary sampling Fourier-encoded spectral imaging method. Besides, to address the significant errors of reconstructed spectral image at low sampling rates, we construct a spectral image enhancement network, which introduces spatial and channel attention modules to successively enhance the spatial and spectral information of the reconstructed spectral images. During the spectral image refinement and enhancement stage, band grouping is performed to alleviate the difficulty in feature extraction and make the training process more stable. The effectiveness of our proposed method has been validated on both public datasets and our own datasets. When the sampling times are reduced by an order of magnitude, on the three public datasets, the PSNR improved by 10.79 dB, the SSIM increased by 0.35, and the SAM decreased by 12.1° on average. On our own datasets, the PSNR improved by 12 dB, the SSIM increased by 0.24, and the SAM decreased by 6.5°.

52 Differences in body composition measurements for developing Angus heifers

Abstract The profitability of beef cow-calf operations relies on the reproductive ability of females to calve at 2 yr of age and provide a calf each subsequent year for her lifetime. The management of replacement heifers could affect her ability to conceive early, calve, and rebreed. Common management practices use heifer body weight (BW) (and body condition score (BCS) as indicators of puberty onset but do not indicate body composition and fat deposition. The objective of this study was to use ultrasound measurements of carcass traits to compare the effect of different diet management practices on muscle development and fat deposition of post-weaning heifers. The heifers placed on a higher energy diet are expected to have greater mean carcass trait measurements than the lower energy diet heifers. A total of 124 purebred Angus heifers from the Iowa State University McNay Memorial Research and Demonstration Farm were used for this study. Two diets were administered in this study. One group of heifers (G1; n = 61) was developed on a low-energy roughage diet to reach a target BW of 55% of mature BW at the time of breeding. The second group (G2; n = 63) was developed on a grain diet to reach the target BW of 65% mature BW at breeding. Body weight and ultrasound measurements for backfat (BFAT), ribeye area (REA), and intramuscular fat (IMF) were collected over three time points (0-d, 55-d, and 123-d) during the study to quantify the development of body composition characteristics. The initial measurements were collected 1 wk post-weaning. Significant mean differences between the two groups were observed for BW, BFAT, and REA at 55-d (P = 0.027, P = 0.008, and P < 0.0001, respectively), and 123-d (P < 0.001). The mean differences for BW, BFAT, and REA at 123-d between G1 and G2 were 30.98 kg, 0.10 cm, and 7.81 cm2, respectively No significant difference was found between the groups for IMF measurements at 55-d (P = 0.927) or 123-d (P = 0.169). This suggests IMF is not significantly influenced by diet during the early, post-weaning heifer developmental stage. Although further research is needed, the results from this study suggest the development of weight, BFAT, and REA in early post-weaning beef heifers is influenced by the energy concentration of the diet.

Effect of the anti-Alzheimer drug GSK-3β antagonist on numerical modeling of the energy dissipation through the resin-dentin interface

ObjectivesThe aim of this study was to determine the viscoelastic performance and energy dissipation of conditioned dentin infiltrated with polymeric nanoparticles (NPs) doped with tideglusib (TDg) (TDg-NPs). MethodsDentin conditioned surfaces were infiltrated with NPs and TDg-NPs. Bonded interfaces were created, stored for 24 h and submitted to mechanical and thermal challenging. Resin-dentin interfaces were evaluated through nano-DMA/complex-loss-storage moduli-tan delta assessment and atomic force microscopy (AFM) analysis. ResultsDentin infiltrated with NPs and load cycled attained the highest complex modulus at hybrid layer and bottom of hybrid layer. Intertubular dentin treated with undoped NPs showed higher complex modulus than peritubular dentin, after load cycling, provoking energy concentration and breakdown at the interface. After infiltrating with TDg-NPs, complex modulus was similar between peri-intertubular dentin and energy dissipated homogeneously. Tan delta at intertubular dentin was higher than at peritubular dentin, after using TDg-NPs and load cycling. This generated the widest bandwidth of the collagen fibrils and bridge-like mineral structures that, as sight of energy dissipation, fastened active dentin remodeling. TDg-NPs inducted scarce mineralization after thermo-cycling, but these bridging processes limited breakdown zones at the interface. SignificanceTDg-based NPs are then proposed for effective dentin remineralization and tubular seal, from a viscoelastic approach.

The Role of Doping in Modifying Semiconductor Properties

Doping is a fundamental process employed to modify the intrinsic properties of semiconductor materials, making them adaptable for a diverse array of technological applications. By introducing specific impurities into the semiconductor crystal lattice, parameters such as electrical conductivity, bandgap energy, and carrier concentration can be precisely engineered. This paper investigates the effects of various doping methods and elements on semiconductor performance, with a particular focus on their influence in devices like transistors, diodes, and solar cells. The analysis emphasizes how doping alters the optical and electrical properties of semiconductor materials, thereby enhancing their functionality in optoelectronic and advanced electronic applications. Through this study, the critical role of doping in driving the progress of semiconductor technology is underscored, highlighting its importance for the future advancement of electronic devices.

A mathematical model of Casson nanofluid flow over a vertically stretched porous surface along with bioconvection, Joule heating and thermal Robin conditions

The current analysis aims is to investigate the steady-state visco-plastic Casson nanofluid flow over an electrically conducting stretching porous surface. Thermophoresis and Brownian motion parameters are utilized for modeling and analysis. Also, Joule heating, thermal radiation, thermal robin condition, thermo-solutal stratifications, and viscous dissipation are considered for energy and nanoparticle concentration. Using appropriate similarity transformation, the partial differential equations (PDEs) system is altered into ordinary differential equatons (ODEs). The Homotopy analysis method (HAM) is used for solving governing equations. The effect of distinct physical parameters on the velocity, concentration, temperature, and microorganism’s density is revealed graphically and discussed tabularly. Additionally, numerical analysis is conducted on designed Nusselt number, Sherwood number, skin friction, and motile microorganism’s density. The major finding of the study is that the fluid velocity decreases as both the magnetic parameter and Casson fluid parameter increases. Instead, increasing the values of the Deborah number and activation energy results in an increase in fluid temperature. The current study is useful for coating deposition of magnetic nanomaterials at comparatively higher temperatures.

Investigation of machining performance of waspaloy using copper-graphite composite electrodes in electric discharge machining

Abstract This study endeavoured to investigate the machining of Waspaloy using Electric Discharge Machining (EDM), utilizing copper-graphite composites as the tool material. Given the limited existing research on machining Waspaloy with composite tools, this study aims to address this gap by employing a copper-graphite composite tool. In this work, pure copper electrode and three composite electrodes with varying graphite percentages in copper, viz. copper containing 5%, 10%, and 15% graphite (CuGr-5, CuGr-10, and CuGr-15), are utilized for experimentation. Composite electrodes are fabricated by the stir-casting process. The scanning electron microscope reveals that the graphite specks are homogeneously disseminated over the matrix material. The Taguchi mixed orthogonal array was used for developing experimental runs. By varying the current, polarity, pulse on and off times, tool materials, and gap, machining performance was measured in terms of Material Removal Rate (MRR), Tool Wear Rate (TWR), and Surface Roughness (Ra). It was observed that CuGr-5 provides an enhancement in MRR due to the improved electric conductivity, bridging effect, and increased energy concentration at the spark gap. Diverse characteristics witnessed on the surface morphology include black dots, globules, remelted layers, micro-cracks, and scratches. When machined with a CuGr5 electrode, the surface quality improved owing to the completed flushing and uniform distribution of generated heat as confirmed through worn surface morphology. The parameters were optimized utilizing the PROMETHEE optimization technique; it was found that the CuGr-5 electrode with the assessment value 0.02458 was optimal for machining of Waspaloy.

Some aspects of reliability prediction of chemical industry and hydrogen energy facilities (vessels, machinery and equipment) operated in emergency situations and extreme conditions

This work is aimed at a comprehensive solution to the problem of reliable and safe operation of a transport energy system with a high energy concentration based on a universal energy carrier - cryogenic liquid hydrogen.The article discusses the possibility of using various methods and techniques to assess the reliability of machines and equipment operated in emergency situations and extreme conditions. The obtained results are analyzed.Currently, the oil and gas complex pays great attention to the development of hydrogen technologies, as well as hydrogen energy in connection with the relevance of the Climate Agenda. In this regard, hydrogen energy facilities are of the greatest interest: cryogenic hydrogen reservoirs, cryogenic hydrogen pipelines, cryogenic oxygen reservoirs and cryogenic oxygen pipelines, as well as cryogenic reservoirs and pipelines for storing process nitrogen gas. An important role for global energy exchange is played by LH2 tankers for transporting cryogenic hydrogen. For example, Australia and Japan built the first LH2 tanker to transport hydrogen from Australia to Japan. In addition, another 85 LH2 tankers are expected to be built.After transportation, cryogenic hydrogen is stored in cryogenic hydrogen storages, usually also representing cryogenic hydrogen tanks with piping in the form of cryogenic pipelines, as well as cryogenic nitrogen tanks for storing process nitrogen gas. Further, hydrogen is used in road transport, aviation, ship fleet, industry, and energy. The main elements of mobile, stationary and airborne hydrogen storage systems are under critical loads and are in the area of increased study and attention.In this regard, we considered the functions of changing the main operational characteristics, made proposals on the possibility of predicting the development of accumulated faults and proposals for ensuring safety and extending the life of objects, taking into account the determination of local and integral damage to cryogenic tanks and pipelines.

A combination of improved spline-kernelled chirplet transform and multi-synchrosqueezing technique for analyzing nonstationary signals and structural instantaneous frequency identification

To improve the accuracy of structural instantaneous frequency (IF) identified by the spline-kernelled chirplet transform, a combination of an improved spline-kernelled chirplet transform and a multi-synchrosqueezing technique is proposed for analyzing nonstationary signals and structural IF identification in this paper. Firstly, an improved spline-kernelled chirplet transform (ISCT) is put forward by introducing a three parameter Gaussian window function for an existing spline-kernelled chirplet transform. These three parameters are successfully obtained through an optimization algorithm and the energy concentration measure (CM). Then, combined with a multi-synchrosqueezing technique, a so-called improved multi-synchrosqueezing spline-kernelled chirplet transform (IMSSSCT) approach is further presented to improve the time–frequency energy concentration. Finally, the accuracy and practicability of the proposed IMSSSCT method are validated by analytical signals, a single-degree-of-freedom Duffing system, a three-layer shear frame, as well as a cantilever beam experiment. The research results indicate that the IMSSSCT technique can effectively and accurately identify the IFs of nonlinear and time-varying structures.

Apparent metabolizable energy concentration and ileal amino acid digestibility in cereal grains fed to broiler chickens.

This study aimed to determine apparent metabolizable energy concentrations and ileal amino acid (AA) digestibility in cereal grains and to compare those metabolizable energy values between the total collection and index methods for 21-day-old broilers. On day 17 post-hatch, a total of 336 Ross 308 male broilers were assigned to 6 dietary treatments with 8 replicate cages (7 birds/cage). Five experimental diets were formulated to incorporate non-extruded corn, extruded corn, wheat, wheat flour, and barley as the sole source of AA and energy. Retention of dry matter and nitrogen, and energy concentrations in cereal grains determined by the total collection method were greater (p<0.05) than those determined by the index method. Energy concentrations of non-extruded and extruded corn were greater (p<0.05) than those of wheat, wheat flour, and barley. Wheat flour exhibited greater (p<0.05) ileal AA digestibility than non-extruded and extruded corn. Extruded corn and wheat showed comparable ileal AA digestibility values, whereas barley had the lowest among cereal grains. Energy concentrations of cereal grains determined by the total collection method were greater than those determined by the index method. Energy concentrations of non-extruded and extruded corn were greater compared to wheat, wheat flour, and barley, irrespective of the method used. The ileal AA digestibility in wheat flour was the greatest, followed by non-extruded corn, extruded corn, wheat, and barley in broilers.

Design of a High-Frame-Rate and Large-Grayscale Simulation Projection System Based on Digital Micromirror Devices

With the increasing acquisition speed of image sensors, it has become necessary to provide image sources with higher frame rates and grayscale in order to meet testing requirements. In the field of semi-physical simulation projection, digital micromirror devices are often chosen for their high resolution, uniformity, response speed, and energy concentration. In this study, we utilized digital micromirror devices to construct a high-frame-rate and large-grayscale simulation projection system. To achieve our experiment goals, we employed two digital micromirror devices. One DMD was used to modulate the light intensity of the light source, while the other generated images with different bit planes. By projecting the target images onto the image sensor, we were able to achieve a frame rate of 1611 hz for the projected 12-bit image. This system meets the requirements for our experiment design and ensures the accurate testing of image sensors.

The method of Pb-212 measurements in air with the application of the LSC technique

This paper describes a method enabling the measurement of the potential alpha energy concentration (PAEC) of thoron decay products based on the determined concentration of lead 212Pb (T1/2 = 10.64 h) in the air [Lever et al., 2003]. A liquid scintillation spectrometer was used to determine the concentration of the 212Pb isotope, and the sample was taken by pumping air through a filter where thoron decay products were stored. This method can be classified as integrating because the sample takes several hours, and the measurement results in one value for the entire sampling period. Measurements were carried out in laboratory conditions, in a climatic chamber where a constant supply of thoron was maintained, and in environmental conditions, in the basement of the family house and outdoors. Sampling took from 12 to 48 h. This article presents the preliminary results of the study. The obtained results were in the range of 170–195 Bq/m3 in the case of laboratory measurements and from 0.04 to 0.79 Bq/m3 in the case of environmental measurements. Based on the obtained results, the potential alpha energy concentration (PAEC) was calculated. The application of the low-level LS spectrometer allows for the achievement of a lower limit of detection (LLD) at level 0.04–0.05 Bq/m3, while the use of the portable LS spectrometer allows for the measurement of deficient 212Pb concentrations in the range of 0.4–0.5 Bq/m3. The obtained results confirm that the method is suitable for determining the concentration of 212Pb and, consequently, assessing exposure to thoron progeny.

CFRP surface ply-centric electrified spatiotemporal self-heating for anti-icing/de-icing

With the widespread application of carbon fiber reinforced polymer (CFRP) in engineering, the characteristics of uniformly carbon fiber (CF) orientation within a single-ply and laminated structure have inspired us to develop high-efficiency, low-consumption, manufacture-friendly, and non-destructive anti-icing/de-icing methods. Here, we propose a CFRP surface ply-centric electrified spatiotemporal self-heating (STSH) approach, which utilizes CFs in the surface ply as natural heating elements to achieve in-situ adaptable electrothermal anti-icing/de-icing. By adjusting the current waveform, the temporal heating profile can flexibly switch between a consistently stable temperature and periodically high peak temperatures, meeting the different heating characteristics required for anti-icing and de-icing, respectively. Simultaneously, the entangled CFs branch current, generating a spatial temperature gradient that enhances the design flexibility of temperature distribution. This enables energy concentration in icing-prone areas while maintaining a baseline temperature in less susceptible areas, thus reducing energy waste by up to 20%. Overall, this STSH approach is simple, efficient, and holds significant application potential, offering an innovative and feasible solution to long-standing challenges associated with anti-icing/de-icing.

Energy concentration pipe based on passive jet control for enhancing flow induced vibration energy harvesting

Passive control is a classic method for enhancing the energy harvesting from flow-induced vibrations. This study introduces the Energy Concentration Pipe (ECP), a hollow pipe featuring a passive windward suction inlet and jet outlets, mounted on a circular cylinder to improve the performance of flow-induced vibration energy harvester. The effects of ECP configurations—single outlet, symmetrical dual outlet, and asymmetrical dual outlet—are investigated both experimentally and numerically. Experimental results demonstrate that the ECP significantly broadens the lock-in region and generates higher output voltage compared to conventional cylinders. Specifically, the lock-in region of the symmetrical dual outlet configuration increases by 108.33%, meanwhile the maximum output voltage improves by 12.69% over the baseline case. Numerical simulations further elucidate the mechanisms of the ECP, identifying the energy concentration phenomenon. An additional portion of incoming airflow, along with its energy, is channeled through the ECP and jetted into the wake vortex behind the cylinder, altering the wake vortex shedding process. The wake structure is characterized by large primary vortex pairs and smaller secondary vortices. The energy concentration also results in larger and stronger wake vortices, enhancing unsteadiness and broadening the lock-in region. Moreover, a transverse oscillation of vortices induces additional excitation on the cylinder due to pressure oscillation, leading to larger vibration amplitude and higher output voltage.

Mathematical Modelling of the Thermosolutal Effect on Blood Flow through a Micro-Channel in the Presence of a Magnetic Field

Substances such as mass concentrations in the blood cause circulation challenges. Blood is a substance made up of 55% plasma and 45% hemoglobin, which flows through the blood vessels and is aided by the heart in pumping to all organs and other tissues and cells in the human body. Mathematical modelling plays an important role in understanding the blood circulation problem in the human body, and it helps transform the real-life cardiovascular problem into a system of mathematical equations. In this research, we transformed the real-life cardiovascular problem of the heat effect on mass concentration and blood flow through blood vessels into a system of partial differential equations representing blood momentum, energy, and mass concentration equations after modifying the Navier-Stoke equation. The models are scaled from dimensional to dimensionless using specific scaling parameters. The scaled dimensionless equations were further perturbed and reduced to a system of ordinary differential equations, and the system of ODEs was solved using the Laplace method, where mathematical models representing blood velocity profiles, temperature profiles, and mass concentration profiles were obtained. A numerical simulation was performed using Wolfram Mathematica, version 12, where the effect of the pertinent parameters on the flow profiles was investigated and the results were presented graphically. The variation of the pertinent parameters such as the Grashof number, solutal Grashof number, Prandtl number, Soret number, Schmidt number, Darcy number, and magnetic field affect the flow profile such that the increase in Grashof number and solutal Grashof number causes the blood velocity to increase substantially at the centre of the vessel before decreasing to zero as the wall boundary layer increases, while the increase in Prandtl number and Soret number increases the blood temperature and velocity.

Risk and protective factors for the severity of long COVID – A network analytic perspective

Background and objectivesIn light of the late stage of COVID-19 pandemic, the occurrence of persistent symptoms after COVID-19 infection has become more frequent. To date, there are no standardized treatments. Underlying mechanisms, risk and protective factors for severe persisting symptoms should be investigated to develop effective interventions. MethodsAn online questionnaire was used to assess gender, presence of prior mental disorder, severity of COVID-19 infection, and social connectedness (SCS-R) to determine their influence on symptom severity of persisting symptoms. The sample used to examine risk and protective factors consisted of 693 participants. ResultsThe analysis revealed no significant gender differences for severity of persisting symptoms. However, prior mental health condition was associated with severity of persisting symptoms. Moreover, there was a positive association between symptom severity during COVID-19 infection and Post COVID 19. Social connectedness was found to be negatively associated with Post COVID 19 symptoms. Social connectedness was shown to be negatively associated with depressive symptoms and disordered self-organization. The symptoms of energy loss and concentration had the highest centrality. ConclusionThe results of the study indicate that severity of post-covid symptoms is associated with higher levels of psychopathological symptoms and a lower level of social connectedness. In conclusion, social connectedness may be an important factor in the development of post-COVID symptoms and should be considered for future interventions. The results from the network analyses provide a first step for a more granular syndrome profile.

Anisotropic Filtering Based on the WY Distribution and Multiscale Energy Concentration Accumulation Method for Dim and Small Target Enhancement

Anisotropic Filtering Based on the WY Distribution and Multiscale Energy Concentration Accumulation Method for Dim and Small Target Enhancement

A Novel Approach to Wave Energy Conversion Using CFD Technique

Abstract This article details the development and evaluation of a novel wave energy converter (WEC) aimed at efficiently capturing wave energy for electricity production. The study employs Computational Fluid Dynamics (CFD) techniques, specifically the URANS method and the k-ω SST turbulence model, to solve the Navier-Stokes equations and capture the free surface using the Volume of Fluid (VOF) model. The CFD results are validated against experimental data to ensure accuracy. Various design parameters of the proposed device were tested, revealing that the arms and bottom angle significantly affect its performance. Unlike the floating Wave Dragon (WD) device, which utilises potential energy and is set in deep water, the new fixed-seabed device is positioned in the transitional wave region near the shore, where waves retain 80% of their energy. It can be constructed from environmentally friendly cement, making it resistant to hurricanes and suitable for any wave turbine in the open sea. The MP687 turbine was used to capture the wave energy in the proposed device, testing its performance in three positions: in the open sea, in the middle of the device, and at the device’s outlet. The results show that the device significantly enhances wave energy concentration, especially when the turbine is placed at the outlet. The proposed device offers numerous advantages, including its fixed position in a high-energy wave zone, the efficient use of turbulent kinetic energy, and robust construction that can withstand storms.