Energy Transport Research Articles

Mechano-Responsive Polymers and Nanocomposites: Recent Advances for Self-Adaptive Structural Applications.

Polymer nanocomposites exhibiting remarkable mechanical properties are a focus of research for decades in structural applications. However, their practical application faces challenges due to poor interfacial load transfer, nanofiller dispersion, and processing limitations. These issues are critical in achieving stiff, strong, lightweight, and structurally integrated materials. Additionally, they often suffer from predetermined properties, which may not be effective under specific loading conditions. Addressing these challenges, the development of design strategies for mechano-responsive materials has advanced, enabling self-adaptive properties that respond to various mechanical stimuli. Drawing inspiration from natural systems, these approaches have been implemented in synthetic material systems, leveraging the design flexibility of nanocomposites as needed. Key focus areas include exploring mechanoradical reactions for dynamic mechano-responsiveness, as well as utilizing biomimetic mineralization and mechanical training for self-strengthening. This work also examines multistability, enabling on-demand deformation of materials and structures. Recent advancements in viscoelastic damping and nonreciprocal materials are discussed, highlighting their potential for directional energy absorption, transmission, and vibration control. Despite the need for significant improvements for real-world applications, mechano-responsive polymers and nanocomposites are expected to offer enormous opportunities not only in structural applications but also in other fields such as biomedical engineering, energy harvesting, and soft robotics.

Study on precipitation in (CoCrFeMnNi)90Al6Ti4 high entropy alloy

(CoCrFeMnNi)90Al6Ti4 high entropy alloy (HEA) was prepared by adding Al and Ti elements into CoCrFeMnNi HEA. The alloy underwent processes including copper mold suction casting, 1473 K homogenization, 30 % cold rolling + 1273 K annealing + 1073 K aging, and water quenching and heating treatment. Microstructure and phase composition of both as-cast and heat-treated (CoCrFeMnNi)90Al6Ti4 HEA were studied using metallographic microscope, scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffractometer (XRD), and transmission electron microscope (TEM). The effect of heat treatment processes on the precipitation of second phases in (CoCrFeMnNi)90Al6Ti4 HEA was investigated, and mechanical properties of as-cast and heat-treated (CoCrFeMnNi)90Al6Ti4 HEA were studied via hardness tests. The results show that in as-cast (CoCrFeMnNi)90Al6Ti4 HEA, the second phase precipitated is primarily L21 structured AlTiNi2 phase. After homogenization, cold rolling, annealing, and aging processes, both the quantity and size of the second phase increase, with a small amount of nanoscale L12 phase appearing after aging treatment. With the progression of heat treatment, the hardness of (CoCrFeMnNi)90Al6Ti4 HEA increases, and mechanical properties are improved.

Ionization by radiative energy transport vs. impact ionization in energetic atomiccollisions

Abstract We explore a mechanism for ionization in high-velocity (but not yet relativistic) collisions of
light atomic particles, one of which being initially in an excited internal state. This mechanism is
driven by the generalized Breit interaction and proceeeds via radiative energy transport between the colliding
particles which has an extremely long range. The comparison of this mechanism with those, which
are ”standard” for high-velocity collisions, shows that it can play a noticeable role in collisions with
excited target atoms.

Sustainable Maintenance of Conductors in Transmission/Distribution Networks Using Complex Magnetic Field Analysis

This study presents issues related to electromagnetic pollution and the level of magnetic field radiation occurring around conductors used for electricity transmission and distribution. The fact that modeling and simulation are the most efficient methods of optimization, considering the cost–benefit ratio, was the premise of this work. This paper proposes the performance of a complex analysis, carried out in a comparative manner, which includes physical tests and simulations in the existing field around transmission and distribution cables used in transformer substations. In the first stage, the level of the magnetic field existing near the conductor carried by an electric current was tested (measured), and a virtual model was then designed to simulate the field in conditions similar to those of the test. The results obtained from the simulation were analyzed in comparison with those obtained by testing. The maximum permissible limits of exposure to an electromagnetic field, which are regulated by Government Decision HG 520/2016 of 20 July 2016 and Directive 2013/35/EU of the European Parliament and of the Council of 26 June 2013, were used as the reference to formulate conclusions for both situations considered. These comparisons were intended to determine the level of exposure to electromagnetic fields existing in places where electricity transmission/distribution conductors are located. Energy sustainability exists due to the versatile properties of the conductors, with the energy transmission and distribution network being functional regardless of the source of energy production.

Coherent destruction of tunneling of quantum energy transport in a driven nonequilibrium spin-boson model

Coherent destruction of tunneling of quantum energy transport in a driven nonequilibrium spin-boson model

Causes of accidents in electrical distribution networks (using the example of the branch of PJSC Rossetti Volga – Saratov Distribution Networks)

The article is a continuation of a series of studies dedicated to the analysis of power transmission through distribution electric networks of PJSC ROSSETI. The presented material analyzes the functioning of the electrical networks of the branch of PJSC Rosseti Volga – Saratov Distribution Networks. An analytical assessment of the electric energy transport through distribution electric networks was carried out for the period 2018–2022. The structure of the company is considered, the structural characteristics of the main elements of the studied electrical networks are given, and the number of emergencies that occurred during the study period is estimated. A quantitative assessment of the magnitude of the electric energy undersupply caused by power supply interruptions is given. The classification of failures according to the degree of the intensity of undersupply was carried out and a quantitative assessment of each group of failures according to their intensity was made. The influence of the seasonal component on the number of emergencies during the study period is considered. Based on the data from 2022–2023, the analysis of the main causes of damage to the elements of electrical networks was carried out. The classification of failures by groups of failure causes is made, their main characteristics for this period are considered. The percentage ratio of the number of failures number for the most characteristic reasons to the total number of outages during the study period has been established. The information published in the open press was used as the source data. General scientific methods as well as numerical methods of analysis were used in the research. MATLAB graphics editor technologies were used to visualize the obtained analysis results. The results obtained may be of interest to the managers of power grid companies, as well as researchers and engineers engaged in research in the field of reliability of power supply.

A Diagnostic Analysis of the Mechanisms for Arctic Cyclone Intensity Evolution

Abstract The intensity evolution of Arctic cyclones (ACs) is examined via cyclone parameter space and composite analyses based on approximately 18 000 AC tracks during 1979–2021. Cyclone parameter spaces are defined by various parameters representing the cyclone structure and physical processes relevant to cyclone development. It is shown that intensifying ACs are associated with diabatic heating and characterized by a cold core in both the lower and upper troposphere, as well as a thermally asymmetric and vertically tilted structure. In contrast, the decay phase is associated with diabatic cooling and characterized by a vertically aligned cyclone with reduced horizontal asymmetry. The cyclone parameter space analysis also indicates a warm core in the lower troposphere for a subset of ACs, which may reflect a frontal occlusion. The transition from AC intensification to decay, on average, is marked by a sharp decrease in both upward motion and diabatic heating, along with the vertical alignment of the cyclone structure. Following this transition, an upright cyclone may persist for a long time due to the weak background vertical wind shear, diabatic cooling, and weak Rossby wave energy dispersion. The evolution of ACs can thus be regarded as a two-stage process: a baroclinic development stage aided by diabatic heating, during which the AC evolution may conform with the Norwegian model for midlatitude cyclones, and a slow decay stage of an equivalent barotropic cyclone, which may leave a remnant tropopause polar vortex after the erosion of the surface circulation. Significance Statement Arctic cyclones are the primary weather system in the Arctic and are also an important component in the Arctic climate system owing to their role in modulating Arctic sea ice variability and poleward moisture and energy transport. We examined the cyclone structural characteristics and physical processes associated with the Arctic cyclone intensity evolution and proposed a two-stage conceptual model. A better understanding of the Arctic cyclone intensity change mechanisms will help us better anticipate the changes in Arctic cyclone activity in a warmer climate.

Exploring distance-based wireless transceiver placements for wireless network-on-chip architecture with deterministic routing algorithms

Network-on-chip (NoC) technology is crucial for integrating multiple embed-ded computing cores onto a single chip. Consequently, this has led to the de-velopment of the wireless network-on-chip (WiNoC) concept, seen as a promis-ing strategy to overcome scalability issues in communication systems withinchips for future many-core architectures. This research analyses the impactof wireless transceiver subnet clustering on the hundred-core mesh-structuredWiNoC architecture. The study aims to examine the effects of distance-basedwireless transceiver placements on the transmission delay, network throughput,and energy consumption within a mesh wireless NoC architecture featuring ahundred cores, under specific routing strategies: X-Y, west-first, negative-first,and north-last. This research investigates the impact of positioning radio sub-nets at the farthest, farther, nearest, and closest positions within an architectureequipped with four wireless transceivers. The Noxim simulator was utilised tosimulate the analysed wireless transceiver placements within the hundred-coremesh-structured WiNoC designs, with the objective of validating the results.The architecture with the wireless transceivers positioned at midway proxim-ity (nearer and further) demonstrated the best performance, as evidenced by thelowest latencies for all evaluated deterministic routing algorithms, according tothe simulation outcomes.

Application of molecular epidemiology in revealing HIV-1 transmission network and recombination patterns in Tianjin, China.

Using a comprehensive molecular epidemiological approach, we characterized the transmission dynamics of HIV-1 among the MSM population in Tianjin, China. Our findings revealed that 38.56% (386/1001) of individuals clustered across 109 molecular transmission clusters (TCs), with MSM aged 50 and below being the group most commonly transmitting HIV-1. Among the identified TCs, CRF01_AE predominated, followed by CRF07_BC. Notably, CRF07_BC demonstrated a higher propensity for forming large clusters compared to CRF01_AE. Birth-death skyline analyses of the two largest clusters indicated that the HIV/AIDS transmission may be at a critical point, nearly all had Re approximately 1 by now. A retrospective analysis revealed that the rapid expansion of these large clusters was primarily driven by the introduction of viruses in 2021, highlighting the crucial importance of continuous molecular surveillance in identifying newly emerging high-risk transmission chains and adapting measures to address evolving epidemic dynamics. Furthermore, we detected the transmission of drug-resistant mutations (DRMs) within the TCs, particularly in the CRF07_BC clusters (K103N, Y181C, and K101E) and CRF01_AE clusters (P225H and K219R), emphasizing the importance of monitoring to support the continued efficacy of first-line therapies and pre-exposure prophylaxis (PrEP). Recombination analyses indicated that complex recombinant patterns, associated with increased amino acid variability, could confer adaptive traits to the viruses, potentially providing a competitive advantage in certain host populations or regions. Our study highlights the potential of integrating molecular epidemiological and phylodynamic approaches to inform targeted interventions.

Averaged flow in a rotating flat layer at librations

Abstract One of the important areas in fluid mechanics is thermal convection; its study is an urgent task from the point of view of effective control of heat and mass transfer. With increasing energy consumption worldwide, improved energy transfer methods are required. Various complicating factors can either strengthen or weaken energy transport mechanisms. In the current work, attention is paid to the libration effect as one of the effective ways to control heat transfer in a rotating cavity. The experiments are aimed at a study of convective flows generated in a flat layer unevenly rotating around a horizontal axis. The flat boundaries are kept at different temperatures. It is found that the cavity librations noticeably intensify the heat transfer in a layer. The flow structure obtained using the PIV method for the cases of uniform and non-uniform rotation of the cavity is presented for the first time. The effectiveness of librations for the intensifying heat and mass transfer in a rotating hydrodynamic system is shown.

Vertical Cavity Surface Emitting Laser technology: A comprehensive review

Vertical Cavity Surface Emitting Laser (VCSEL) technology has become an indispensable element in optical communication systems and optoelectronics due to its many advantages, and the unique characteristics of VCSELs, including vertical emission, high-speed operation, and low power consumption, have attracted much interest from researchers and industry professionals. This paper provides a comprehensive overview of VCSELs, explaining their basic principles and two commonly used structures. It also delves into the field of optical communications, highlighting the challenges faced in the current development, from which it introduces the significant progress made by VCSELs over the past decade in various applications such as high-speed data transmission, multi-mode communications, and long-distance networks. In addition, this study provides valuable insights into the future trajectory and potential evolution of VCSEL technology to facilitate further research and innovation in the field of communications. By providing a holistic analysis, this study is a valuable resource for scientists and researchers to help them realize the full potential of VCSELs in advancing optical communication technologies to meet the ever-changing needs of modern communication networks.

Phylogenetic Network Analyses Reveal the Influence of Transmission Clustering on the Spread of HIV Drug Resistance in Quebec from 2002 to 2022

Background: HIV drug resistance (HIV-DR) may jeopardize the benefit of antiretroviral therapy (ART) in treatment and prevention. This study utilized viral phylogenetics to resolve the influence of transmission networks on sustaining the spread of HIV-DR in Quebec spanning 2002 to 2022. Methods: Time trends in acquired (ADR) and transmitted drug resistance (TDR) were delineated in treatment-experienced (n = 3500) and ART-naïve persons (n = 6011) with subtype B infections. Similarly, non-B-subtype HIV-DR networks were assessed pre- (n = 1577) and post-ART experience (n = 488). Risks of acquisition of resistance-associated mutations (RAMs) were related to clustering using 1, 2–5, vs. 6+ members per cluster as categorical variables. Results: Despite steady declines in treatment failure and ADR since 2007, rates of TDR among newly infected, ART-naive persons remained at 14% spanning the 2007–2011, 2012–2016, and 2017–2022 periods. Notably, half of new infections among men having sex with men and heterosexual groups were linked in large, clustered networks having a median of 35 (14–73 IQR) and 16 (9–26 IQR) members per cluster, respectively. Cluster membership and size were implicated in forward transmission of non-nucleoside reverse transcriptase inhibitor NNRTI RAMs (9%) and thymidine analogue mutations (TAMs) (5%). In contrast, transmission of M184V, K65R, and integrase inhibitors (1–2%) remained rare. Levels of TDR reflected viral replicative fitness. The median baseline viremia in ART-naïve groups having no RAMs, NNRTI RAMs, TAMs, and M184VI were 46.088, 38,447, 20,330, and 6811 copies/mL, respectively (p < 0.0001). Conclusion: Phylogenetics emphasize the need to prioritize ART and pre-exposure prophylaxis strategies to avert the expansion of transmission cascades of HIV-DR.

Implantable Zinc Ion Battery and Osteogenesis-Immunoregulation Bifunction of Its Catabolite.

Biocompatible batteries can power implantable electronic devices and have broad applications in medicine. However, the controlled degradation of implantable batteries, the impact of battery catabolites on surrounding tissues, and wireless charging designs are often overlooked. Here, we designed an implantable zinc ion battery (ZIB) using a gelatin/polycaprolactone-based composite gel electrolyte. The prepared ZIBs deliver a high specific capacity of 244.0 mA h g-1 (0.5C) and long cycling stability of 300 cycles (4C). ZIBs were completely degraded within 8 weeks in rats and 30 days in a phosphate-buffered saline lipase solution, demonstrating good biocompatibility and degradability. ZIBs catabolites induced macrophage M2 polarization and exhibited anti-inflammatory properties, with mRNA levels of the M2 markers Arg-1 and CD206 up-regulated 15.8-fold and 13.4-fold, respectively, compared to the blank control group. Meanwhile, the expressions of two typical osteogenic markers, osteopontin and osteocalcin, were up-regulated by 3.6-fold and 5.6-fold, respectively, demonstrating that designed ZIBs promoted osteogenic differentiation of bone marrow mesenchymal stem cells. Additionally, a wireless energy transmission module was designed using 3D printing technology to realize real-time charging of the ZIB in rats. The designed ZIB is a promising power source for implantable medical electronic devices and also serves as a functional material to accelerate bone repair.

The Nature of X-Rays from Young Stellar Objects in the Orion Nebula Cluster—A Chandra HETGS Legacy Project

The Orion Nebula Cluster (ONC) is the closest site of very young (∼1 Myr) massive star formation The ONC hosts more than 1600 young and X-ray bright stars with masses ranging from ∼0.1–35 M ⊙. The Chandra HETGS Orion Legacy Project observed the ONC with the Chandra High Energy Transmission Grating Spectrometer (HETGS) for 2.1 Ms. We describe the spectral extraction and cleaning processes necessary to separate overlapping spectra. We obtained 36 high-resolution spectra, which include a high-brilliance X-ray spectrum of θ 1 Ori C with over 100 highly significant X-ray lines. The lines show Doppler broadening between 300 and 400 km s−1. Higher spectral diffraction orders allow us to resolve line components of high Z He-like triplets in θ 1 Ori C with unprecedented spectral resolution. Long-term light curves spanning ∼20 yr show all stars to be highly variable, including the massive stars. Spectral fitting with thermal coronal emission line models reveals that most sources show column densities of up to a few times 1022 cm−2 and high coronal temperatures of 10–90 MK. We observe a bifurcation of the high-temperature component where some stars show a high component of 40 MK, while others show above 60 MK, indicating heavy flaring activity. Some lines are resolved with Doppler broadening above our threshold of ∼200 km s−1, up to 500 km s−1. This data set represents the largest collection of HETGS high-resolution X-ray spectra from young pre-main-sequence stars in a single star-forming region to date.

Design and construction of a IoT based automated circuit breaker system

Electrocution is a major fatal issue faced by electricians worldwide. A Circuit breaker is a device for automatic switching of electrical devices against overload and short circuits. However, advancements in technology allow for a more sophisticated approach: the cloud-based circuit breaker with a microcontroller and sensors for monitoring the line current and voltage levels. This system switches OFF the affected line when an electrical wire becomes defective, and the lineman may safely repair it. This design integrates real-time monitoring, remote control, and internet connectivity, enhancing electrical safety and offering valuable features for modern applications. At the heart of this design lies a microcontroller (Atmega328) and Esp8266_01(Wi-Fi Module). This tiny computer chip continuously monitors the circuit using current and voltage sensors. By regulating the power supply on the electrical lines, this system protects the safety of the lineman and reduces the risk of electrocution injuries.

Leveraging Pumped Storage Power Plants for Innovative Stability Enhancement of Weakly Interconnected Power Systems

The hybrid AC/DC grid, based on a significant share of renewable energy sources, is gradually becoming an essential aspect of the modern energy system. The integration of intermittent renewable generators into contemporary energy systems is accompanied by the decommissioning of power plants containing synchronous generators. Consequently, this leads to a reduction in system inertia and an increase in the risk of stability disruption. The abrupt disconnection of the primary generator or power line can result in an unanticipated mismatch between power generation and consumption. This discrepancy can trigger substantial and swiftly evolving alterations in power distribution, angular speed, load flow, and the frequency of generators. The risks of an energy system collapse can be mitigated through automation, enabling rapid adjustments to generation and load capacities, as well as power flows, in the electrical network. This article justifies the utilisation of a power control method for high-voltage power line interconnections. The technology of hydro storage power plants and measurements of voltage phasors are employed. The potential for easing power flow restrictions and realising substantial economic benefits is supported by the results obtained using simplified dynamic model of the Baltic power system and Nord Pool electricity market model.

A generalized van Genuchten model for unsaturated soil hydraulic conductivity

AbstractThe hydrodynamics of variably saturated soils or porous media in general are described via nonlinear functions of water retention and hydraulic conductivity, which facilitate the simulation of various mass and energy transport processes (e.g., water, heat, contaminants, colloids) within the porous medium. We set out to derive improved functions for more accurate estimations of soil hydraulic functions to advance the simulation of porous medium hydrodynamics. A new model is proposed for estimating the unsaturated hydraulic conductivity (UHC) from a soil water retention (SWR) function that is parameterized via nonlinear regression of measured data. The function can be viewed as a generalized van Genuchten (1980) model (GVG). We tested the new SWR and UHC expressions for numerous data sets from literature that cover a wide range of soil textures. Our comparisons reveal more accurate estimations using the GVG model by comparison with the original van Genuchten model.

Reliability, Availability, and Maintainability Assessment-Based Sustainability-Informed Maintenance Optimization in Power Transmission Networks

Reliability, Availability, and Maintainability Assessment-Based Sustainability-Informed Maintenance Optimization in Power Transmission Networks

Vibrational Energy Landscapes and Energy Flow in GPCRs.

We construct and analyze disconnectivity graphs to provide the first graphical representation of the vibrational energy landscape of a protein, in this study β2AR, a G-protein coupled receptor (GPCR), in active and inactive states. The graphs, which indicate the relative free energy of each residue and the minimum free energy barriers for energy transfer between them, reveal important composition, structural and dynamic properties that mediate the flow of energy. Prolines and glycines, which contribute to GPCR plasticity and function, are identified as bottlenecks to energy transport along the backbone from which alternative pathways for energy transport via nearby noncovalent contacts emerge, seen also in the analysis of first passage time (FPT) distributions presented here. Striking differences between the disconnectivity graphs and FPT distributions for the inactive and active states of β2AR are found where structural and dynamic changes occur upon activation, contributing to allosteric regulation.

Synergistic Effect of Rutile and Brookite TiO2 for Photocatalytic Formic Acid Dehydrogenation.

Solar energy is an ideal clean and inexhaustible energy source. Solar-driven formic acid (FA) dehydrogenation is one of the promising strategies to address safety and cost issues related to the storage, transport, and distribution of hydrogen energy. For FA dehydrogenation, the O-H and C-H cleavages are the key steps, and developing a photocatalyst with the ability to break these two bonds is critical. In this work, both density functional theory (DFT) calculation and experimental results confirmed the positive synergistic effect between brookite and rutile TiO2 for O-H and C-H cleavage in HCOOH. Further, brookite TiO2 is beneficial to the generation of the •OH radical and significantly promotes C-H cleavage in formate. Under optimized conditions, the H2 production efficiency of FA dehydrogenation can reach up to 30.4 μmol·mg-1·h-1, which is the highest value compared with similar reported TiO2-based systems and over 1.7 times the reported highest value of Au0.75Pd0.25/TiO2 photocatalysts. More importantly, after more than 42 days (>500 h) of irradiation, the system still demonstrated high H2 production activity, indicating the potential for practical application. This work provides a valuable strategy to improve both the efficiency and stability of photocatalytic FA dehydrogenation under mild conditions.