Energy Transport Research Articles

Cost-effective, open-source light shutters with Arduino control

In optical experiments, shutters are devices that open or close a path of light. They are often used to limit the duration of light exposure onto a target or onto a detector to reduce possible light-induced damage. Many commercial shutters are available for different applications – some provide very fast opening and closing times, some can handle large optical powers, and others allow for fail-safe operation. Many of these devices are costly and offer limited control options. Here we provide an open-source design for a low-cost, general purpose shutter system based on ubiquitous actuators (servo motors or solenoids) that are connected to an Arduino-based controller. Several shutters can be controlled by one controller, further reducing system cost. The state of the shutters can be controlled via a display built into the controller, by serial commands via USB, or by electrical control lines. The use of a microcontroller makes the shutter controller adaptable – only control options that are used need to be included, and the design accommodates a selection of display and actuator options. We provide designs for all required components, including 3D print files for the actuator holders and cases, the Arduino code, libraries for serial communication (C and python), and example graphical user interfaces for testing.

Predictive accuracy of wideband absorbance in children with large vestibular aqueduct syndrome: A single-center retrospective study

ObjectivesThis study aimed to assess the clinical significance of Wideband Absorbance (WBA) in children with Large Vestibular Aqueduct Syndrome (LVAS), which could potentially serve as diagnostic and predictive markers for LVAS in children. DesignThis was a single-center retrospective case-control study. Audiological measurements and Wideband Acoustic Immittance (WAI) were performed. Propensity score matching (PSM) was considered to treat group imbalance. The Receiver Operating Characteristic (ROC) curves and area under the ROC curve (AUC) were used to evaluate the sensitivity and specificity of WBA. Study sampleParticipants included 42 children with LVAS and 163 normal children aged 6 months −11 years recruited from clinical audiology settings between 2019 and 2021. ResultsThe WBA at Tympanometric Peak Pressure (WBATPP) and Ambient Pressure (WBAA) in the LVAS group were significantly lower than those of the control group at 1259–2000 Hz but higher at 4000–6349 Hz (p < 0.05, power >0.8). The WBAA (1587 Hz) AUC value was 0.805, identifying a score ≤0.565 as indicative of a LVAS risk. ConclusionsWBA holds promise in distinguishing LVAS from the normal condition and warrants further exploration as a tool to examine the influence of inner ear pressure on acoustic energy transmission in the middle ear.

Comparison of different optimization techniques applied to optimal operation of energy storage systems in standalone and grid-connected direct current microgrids

This study addresses the problem of optimal operation and functioning of lithium-ion batteries in direct current (DC) microgrids with photovoltaic generators, in both urban and rural settings, under an approach that considers three mathematical models as objective functions: reduction of operational costs, reduction of power losses associated with energy transport, and reduction of CO2 emissions produced by conventional generators. After defining the objective functions, six optimization algorithms are integrated as solution methodologies: Equilibrium Optimizer (EO), Salp Swarm Algorithm (SSA), Particle Swarm Optimization (PSO), Sine and Cosine Algorithm (SCA), Black Hole Optimizer (BHO), and the Generalized Normal Distribution Optimizer (GNDO) algorithm. These methodologies are used to determine the hourly power flow through successive approximations, thus evaluating each of the objective functions with the system’s constraints in order to achieve reductions of each objective function and thereby confirm the quality of the solutions applied to the problem under analysis. Where, for the urban case of Medellín, the optimization achieved minimum reductions of 0.163% in fixed costs, 1.436% in variable costs, 7.160% in power losses, and 0.165% in CO2 emissions. In the rural case of Capurganá, the results showed minimum reductions of 0.095% in energy costs and 10.938% in power losses. These numerical results confirm the effectiveness of the applied optimization algorithms in reducing operational costs, power losses, and emissions, thereby validating the quality of the solutions for the analyzed problem.

Temporal assessment of operational resilience of transmission network and adaptation measures for a high-impact long duration cyclonic windstorm

The exposure to High-Impact Low-Probability (HILP) events can have significant impact on the performance of transmission networks. Under such conditions, the power system components must be resilient and robust to meet the uninterrupted load demand. This paper proposes a quantitative framework for temporal assessment of operational resilience of transmission network and suggests suitable adaptation measures when the system is subjected to high impact cyclonic windstorm lasting for a long duration. The fragility curves of transmission lines are correlated with wind profiles during cyclone and failure probability each transmission line is determined using the Monte Carlo Simulation (MCS) The operational resilience of transmission networks is quantified by computing Total Transfer Capability (TTC), Available Transfer Capability (ATC), Existing Transmission Uses (ETU), Total Reliability Margin (TRM) and unserved load. To improve the operational resilience, adaptation measures with modifications in the robustness of the structural strength is proposed and investigated on standard IEEE 57 bus system and IEEE 118 bus system. Sensitivity analysis is performed to understand how changes in the percentage increase of robustness affect the overall system performance. The findings give valuable insights for evaluating the operational resilience of transmission line infrastructure during such extreme weather events.

Multiphysics modeling femtosecond laser ablation of Ti6Al4V with material transient properties

Femtosecond laser ablation associates with a series of multiphysics phenomena (electron thermalization, electron thermal conduction, electron-phonon coupled energy transport, melting, vaporization and phase explosion) and the instant variation of material transient properties, which impacts the laser energy absorption and the subsequent material removal. In this work, a multiphysics model with material transient properties is developed to study the femtosecond laser ablation of Ti6Al4V. A two-dimensional axisymmetric simulation is performed. The predicted ablation depth and ablation diameter with material transient properties show good agreements with the experimental data. The necessity of material transient properties for femtosecond laser ablation is demonstrated. Besides analyzing the roles of material transient properties on femtosecond laser ablation, the ablation thresholds of Ti6Al4V are probed for different pulse durations. In addition, the impact of pulse duration on femtosecond laser heat affected zone is studied. This work contributes to understand roles of material transient properties in femtosecond laser ablation.

МЕРОПРИЯТИЯ ПО ПОВЫШЕНИЮ НАДЁЖНОСТИ СИСТЕМЫ ЭЛЕКТРОСНАБЖЕНИЯ ИРКУТСКОЙ ОБЛАСТИ ПРИ МОДЕРНИЗАЦИИ И СТРОИТЕЛЬСТВЕ НОВЫХ ВЫСОКОВОЛЬТНЫХ ВОЗДУШНЫХ ЛИНИЙ

The issue of modernization and construction of new high-voltage lines in the Irkutsk region was con-sidered in the light of the requirements of the order of the Ministry of Energy of the Russian Federa-tion No. 108 dated 02/28/2023

Merchant investment in electricity transmission networks

Many electricity economists have long hoped that it might be possible to establish competition, not just in providing generation and load assets, but also in the provision of the transmission network itself. Attempts in the 1990s to achieve so-called merchant transmission investment using conventional Financial Transmission Rights (FTRs) proved disappointing. We develop an extension of screening-curve models to include the optimal choice of both generation and transmission. Such models, although stylised, provide valuable insight into the long-run co-optimisation of generation and transmission. We propose new regulatory and merchant transmission investment mechanisms that achieve the socially optimal investment.

Waveform Design for the Integrated Sensing, Communication, and Simultaneous Wireless Information and Power Transfer System.

Next-generation communication systems demand the integration of sensing, communication, and power transfer (PT) capabilities, requiring high spectral efficiency, energy efficiency, and low cost while also necessitating robustness in high-speed scenarios. Integrated sensing and communication systems (ISACSs) exhibit the ability to simultaneously perform communication and sensing tasks using a single RF signal, while simultaneous wireless information and power transfer (SWIPT) systems can handle simultaneous information and energy transmission, and orthogonal time frequency space (OTFS) signals are adept at handling high Doppler scenarios. Combining the advantages of these three technologies, a novel cyclic prefix (CP) OTFS-based integrated simultaneous wireless sensing, communication, and power transfer system (ISWSCPTS) framework is proposed in this work. Within the ISWSCPTS, the CP-OTFS matched filter (MF)-based target detection and parameter estimation (MF-TDaPE) algorithm is proposed to endow the system with sensing capabilities. To enhance the system's sensing capability, a waveform design algorithm based on CP-OTFS ambiguity function shaping (AFS) is proposed, which is solved by an iterative method. Furthermore, to maximize the system's sensing performance under communication and PT quality of service (QoS) constraints, a semidefinite relaxation (SDR) beamforming design (SDR-BD) algorithm is proposed, which is solved using through the SDR technique. The simulation results demonstrate that the ISWSCPTS exhibits stronger parameter estimation performance in high-speed scenarios compared to orthogonal frequency division multiplexing (OFDM), the waveform designed by CP-OTFS AFS demonstrates superior interference resilience, and the beamforming designed by SDR-BD strikes a balance in the overall performance of the ISWSCPTS.

The Relevance of Implanted Percutaneous Electrical Nerve Stimulation in Orthopedics Surgery: A Systematic Review.

Background: Percutaneous peripheral nerve stimulation (PNS) is a form of neuromodulation that involves the transmission of electrical energy via metal contacts known as leads or electrodes. PNS has gained popularity in orthopedic surgery as several studies have supported its use as a pain control device for patients suffering from pain due to orthopedic pathologies involving the knee, shoulder, and foot. The purpose of this systematic review is to summarize the literature involving peripheral nerve stimulation in orthopedic surgery. The existing body of literature provides support for further research regarding the use of PNS in the management of knee pain, hip pain, shoulder pain, foot pain, and orthopedic trauma. Notably, the evidence for its efficacy in addressing knee and shoulder pain is present. Methods: This study was conducted following PRISMA guidelines. Seven hundred and forty-five unique entries were identified. Two blinded reviewers assessed each article by title and abstract to determine its relevance and categorized them as "include", "exclude", and "maybe". After a preliminary review was completed, reviewers were unblinded and a third reviewer retrieved articles labeled as "maybe" and those with conflicting labels to determine their relevance. Twenty-eight articles were included, and seven hundred and seventeen articles were excluded. Articles discussing the use of PNS in the field of orthopedic surgery in patients > 18 years of age after 2010 were included. Exclusion criteria included neuropathic pain, phantom limb pain, amputation, non-musculoskeletal related pathology, non-orthopedic surgery related pathology, spinal cord stimulator, no reported outcomes, review articles, abstracts only, non-human subjects. Results: A total of 16 studies analyzing 69 patients were included. All studies were either case series or case reports. Most articles involved the application of PNS in the knee (8) and shoulder (6) joint. Few articles discussed its application in the foot and orthopedic trauma. All studies demonstrated that PNS was effective in reducing pain. Discussion: Peripheral nerve stimulation can be effective in managing postoperative or chronic pain in patients suffering from orthopedic pathology. This systematic review is limited by the scarcity of robust studies with substantial sample sizes and extended follow up periods in the existing literature.

ТЕНДЕНЦИИ РАЗВИТИЯ МИРОВОЙ ЭНЕРГЕТИКИ В СОВРЕМЕННЫХ УСЛОВИЯХ

The trends in the development of global energy in modern conditions are considered with the intro-duction of a wide range of energy-efficient technologies in conjunction with the digitalization of all stages of production, transmission and conversion of electrical energy

An Analysis of Policy Transmission Flow in the Chengdu Plain Urban Agglomeration in Southwest China: Towards Building an Ecological Protection Network

Regional ecological protection is an urgent task in today’s social development, and constructing an ecological protection network is an important way to achieve regional ecological coordination. However, previous studies have lacked a systematic review and analysis of policy document transmission paths, failing to consider the spatial network structure and its complex characteristics of regional ecological protection policies, resulting in deficiencies in regional coordinated governance of the ecological environment. To address this gap, this study constructs an ecological policy transmission network lineage for the Chengdu Plain urban agglomeration (CDPUA) based on 400 ecological environmental protection policy documents issued by cities in the CDPUA from 2015 to 2022, focusing on the transmission perspective of policy documents. Social network analysis methods, a GIS spatial analysis, and other methods were employed to construct the ecological protection network of the CDPUA and analyze the complex spatial structure and characteristics of the network. It was found that the integrated ecological protection network of the CDPUA exhibits a multi-core triangular pattern with spatial characteristics of density in the east and sparsity in the west. The integrated ecological protection network has a density of 60.71%, indicating a strong intercity linkage, with Suining as the central nucleus transmitting policies to surrounding cities, forming the Suining–Chengdu–Mianyang policy transmission triangle. The urban agglomeration has formed an ecological protection network dominated by multiple cities, offering diverse and distinct types of ecosystem services. This study provides insights to enhance regional collaborative ecological governance and protection, promoting sustainable development in the region.

Frequency stability control method for multi-energy system considering storage characteristics and transmission inertia of hot and gas pipeline network

The grid-connected capacity of renewable energy generation in multi-energy microgrid is increasing. This leads to a decrease in the inertia level in the microgrid, which has a great impact on the frequency stabilization control. This article proposes an adaptive control method for frequency control of inertia in multi-energy microgrids. Firstly, the system frequency fluctuation problem is addressed. Analyze the response characteristics of virtual inertia and the influence of physical inertia of rotating equipment on system frequency dynamics in multi-energy microgrid. Secondly, study the energy transfer characteristics of electric, thermal and gas systems in multi-energy microgrids. The energy coupling model between the subsystems in the multi-energy microgrid is established. And according to the difference of energy transmission time inertia of electric, heat and gas subsystems, the microgrid inertia response time model of different energy systems is established. Then, according to the energy balance stability criterion of multi-energy microgrid, combined with the current operating state of the system and the state of the higher-level distribution network, the fast response adaptive over-compensation control of multi-energy microgrid cluster is carried out to realize the inertia allocation in multi-energy microgrids. Finally, the proposed advanced frequency control method of multi-energy microgrid considering inertia demand is verified by simulation.

Characterization and application of flexible operation region of virtual power plant

The construction of a virtual power plant (VPP) represents a powerful approach for harnessing the adjustable capacity of flexible resources. VPP actively participates in transmission network dispatching by aggregating these flexible resources. However, existing practical implementations and research cannot describe the influence of renewable energy's inherent unpredictability on the dispatching boundaries of VPPs. This shortfall leads to a lack of organic coordination between flexible resources and the power transmission network. Therefore, this paper suggests a way to characterize the dispatching boundaries of VPPs based on the concept of flexible operation region (FOR), aiming to better incorporate the flexible resources of decentralized access and lessen the issue of insufficient computing power caused by unified optimization. Initially, an analytical model for the VPP's FOR is presented, followed by dimensionality reduction of the FOR to the VPP's gateway. Subsequently, participation in transmission network scheduling is facilitated using an equivalent dimensionality reduction model. Based on standard example testing, the proposed method's effectiveness and accuracy have been verified in this paper.

Thunderstorm total lightning activity behavior associated with transmission line trip events of power system

High-voltage transmission lines are susceptible targets for lightning strikes. It is an interesting topic how the trip event of transmission line is related to the area, location, and intensity of thunderstorms occurring at that time and that place. Based on total lightning observation containing intra-cloud and cloud-to-ground lightning, and transmission line trip information from relaying system of power system, 8 thunderstorms associated with the lightning strike trip of local transmission lines were selected in the Pearl River Delta (PRD) region. Analysis was conducted on the total lightning activity of each thunderstorm process, including the characteristics of total lightning counts and density, followed by the variations in total lightning activity before and after lightning strike trips. Further, our investigation encompassed the spatial and temporal evolution, charge structure, and kinematic parameters of thunderstorms. It was revealed that almost all lightning trips in this area emerged in close proximity to bodies of water, accompanied by a discernible reduction in thunderstorm cloud altitude during line trip occurrences. This paper aims to enhance the understanding of total lightning and thunderstorm activity behavior, thereby providing valuable insights for lightning disaster prevention and mitigation in the meteorological bureau and power system.

A Review on Single Phase AC System of Railway Electrification

The widespread adoption of 25 kV, 50 Hz single-phase AC supply in long-distance electrified railway systems poses significant challenges to power quality in transmission networks. This paper presents an in-depth investigation into the influence of electric railway systems on a 110 kV transmission system, with a specific focus on locomotives equipped with diode rectifiers. Harmonic currents generated by these locomotives and unbalanced voltages introduced by single-phase traction loads are known to adversely affect power system components, leading to issues such as overheating, additional losses, and interference with communication systems. The focus of this paper is not only to understand the fundamental principles but to conduct a deep exploration of the functioning of various components such as locomotives, contact lines, and substations. High voltage This voltage is supplied from the substation or directly from the generating station. This high AC voltage (25KV) is first transformed into low AC voltage (415V). Three-phase induction motors are used because they provide high torque, are reliable, and are more efficient. The AC voltage in the second phase is rectified to DC and then converted into a phase AC using VFD. The VFD provides variable frequency and voltage to run the induction motor at different speeds.

On the practical aspects of machine learning based active power loss forecasting in transmission networks

AbstractThe cost for covering active power losses makes a significant item in transmission system operators (TSO) annual budgets, and still it received limited attention in the existing literature. The focus of accurate power loss forecasting and procurement is of high increase during the past 2 years due to spikes in electricity prices, making the cost of covering the active power losses a dominant factor of TSO operational costs. This paper presents practical aspects of the highly accurate models for transmission loss forecast in the day ahead time frame for the Croatian transmission system. The contributions are two‐fold: 1) Practical insights into usable TSO data are provided, filling a critical research gap and a foundational literature review is established on transmission loss forecasting. 2) A novel method utilizing only electricity transit data as input which outperforms existing practices is presented. For this, several algorithms such as gradient boosted decision tree model (XGB), support vector regressors, multiple linear regression and fully connected feedforward artificial neural networks are developed, and implemented and validated on data obtained from the Croatian TSO. The results show that the XGB model outperforms current TSO model by 32% for 4 months of comparison and TSCNET's commercial solution by 25% during a year‐long testing period. The developed XGB model is also implemented as a software tool and put into everyday operation with the Croatian TSO.

The Cost of Dying Exhibition: public, professional and political reactions to a visual exhibition depicting experiences of poverty at the end of life

Public health approaches to palliative care are internationally endorsed for their potential to improve the social determinants of dying such as energy costs, transport and housing. Enhancing public understanding of...

Application of GPR to Detect Lost Valve Chambers in a Utility Network

The exact geographic location of the fresh water transmission network of Dhaka WASA was not known to the agency. With time and development works, access to many such underground valve chambers were lost. Their recovery was usually done through manual digging and trenching. This was expensive, time- and labour-consuming, often led to traffic jams, and the rate of success was low. This study was conducted to use the non-intrusive method of Ground Penetrating Radar to locate those valves as an alternative. A total of 27 out of the 41 lost nodes in the network was successfully recovered and their precise location was recorded using RTK-GNSS. The article presents the detail procedure of locating the valve chambers of underground pipeline network. It also highlights how the lack of collaboration between agencies are causing water supply and maintenance problems to this day, and how infrastructure development of one agency may erode successes of another. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 12(2), 2023, P 139-151

Strain-Dependent Effects on Confinement of Folded Acoustic and Optical Phonons in Short-Period (XC)m/(YC)n with X,Y (≡Si, Ge, Sn) Superlattices.

Carbon-based novel low-dimensional XC/YC (with X, Y ≡ Si, Ge, and Sn) heterostructures have recently gained considerable scientific and technological interest in the design of electronic devices for energy transport use in extreme environments. Despite many efforts made to understand the structural, electronic, and vibrational properties of XC and XxY1-xC alloys, no measurements exist for identifying the phonon characteristics of superlattices (SLs) by employing either an infrared and/or Raman scattering spectroscopy. In this work, we report the results of a systematic study to investigate the lattice dynamics of the ideal (XC)m/(YC)n as well as graded (XC)10-∆/(X0.5Y0.5C)∆/(YC)10-∆/(X0.5Y0.5C)∆ SLs by meticulously including the interfacial layer thickness ∆ (≡1-3 monolayers). While the folded acoustic phonons (FAPs) are calculated using a Rytov model, the confined optical modes (COMs) and FAPs are described by adopting a modified linear-chain model. Although the simulations of low-energy dispersions for the FAPs indicated no significant changes by increasing ∆, the results revealed, however, considerable "downward" shifts of high frequency COMs and "upward" shifts for the low energy optical modes. In the framework of a bond polarizability model, the calculated results of Raman scattering spectra for graded SLs are presented as a function of ∆. Special attention is paid to those modes in the middle of the frequency region, which offer strong contributions for enhancing the Raman intensity profiles. These simulated changes are linked to the localization of atomic displacements constrained either by the XC/YC or YC/XC unabrupt interfaces. We strongly feel that this study will encourage spectroscopists to perform Raman scattering measurements to check our theoretical conjectures.

Optimization and heat transfer analysis for MHD radiative natural convective flow of hybrid nanofluid within a partially heated cavity

The current study consists of optimization and heat transfer analysis for magnetohydrodynamic (MHD) radiative-natural convective flow of hybrid nanofluid (mixture of silver and copper nanoparticles with ethylene glycol (base fluid)) saturated inside the partially heated isosceles triangular cavity. Additionally, the current analysis investigates the distraction of available energy during thermal mixing and flow friction through local entropy generation. The conservation laws of total mass, momentum, and energy balance equations have been utilized to govern the physical flow problem. After eradicating the pressure terms in the governing partial differential equations (PDEs) via the penalty technique, the Galerkin finite element method (FEM) with the Newton-Raphson technique has been utilized to solve it. The outcomes established that the concentration of silver nanoparticles, as compared to copper nanoparticles, gives better energy transport. An increase in the concentration of nano-particles from ( ϕ 1 = ϕ 2 = 0 ) to ( ϕ 1 = ϕ 2 = 0.1 ) increased the intensity of streamlines from ψ max = 1.5 to ψ max = 4 and energy transmit rate increases by 57.4 % . The influence of thermal radiation decreased the fluid flow friction or local entropy via fluid flow.