bluuebunny/crossref_metadata_2025 huggingface dataset:
Insulation Design of High Voltage and Large Capacity Power Supply Transformer
Authors: Zhao Yingfeng , Chen Yu , Lü Wei , Shi Wei , Yang Bing , Fang Taixun
Published: July 2024

At present, the highest voltage level of DC circuit breakers in the world is 535kV. With the construction of 800kV multi-terminal flexible DC project, the demand for DC circuit breaker with higher voltage level is put forward. The voltage level of valve base power supply transformer as the power supply component of the DC circuit breaker is increased to 800kV. Single-section pendulum structure, single-section 100kV and 50kV schemes used at 535kV cannot meet the demand. An 800kV valve base power supply transformer scheme of four 200kV gas-insulated transformers in series is proposed. Its insulation design is also carried out. Firstly, the topology of hybrid DC circuit breaker power supply system and the structure of power supply transformer were described. Secondly, the design of power supply transformer insulation was carried out. Finally, the power supply transformer insulation was tested and verified. The results show that: SF6 power supply transformer internal insulation withstand voltage needs to be multiplied by the multiplication factor. The electric field strength limit of SF6 obtained by experiments is more than 1.5 times of the empirical design value. The internal field strength design of the 200kV power supply transformer takes into account the operating and seismic conditions, and the maximum electric field strength is 15kV/mm and 16.2kV/mm respectively. The curvature radius of the top shielding ring needs to be larger than that of other layers, after optimization, the maximum field strength is 2.68kV /mm when the curvature radius is 300mm. The internal insulation design of 200kV power supply transformer according to lightning impulse. The simulated and measured values of non-uniform voltage coefficient of 800kV power supply transformer under lightning impulse are 1.048 and 1.0488 respectively, in which the voltage equalizing capacitance is 3000pF. The insulation tests of 200kV and 800kV power supply transformer were all passed, and it can be operated safely. Effectively support the development of UHV DC circuit breaker.
Steady-State Thermal Circuit Modeling of a 10 kV Three-core Cable Based on Distributed Structure
Authors: Li Bing , Huang Baoming , Hu Ran , Ma Nan , Huang Zhanhua , Li Jiangtao
Published: July 2024

With the development of China’s urbanization construction, the proportion of urban power distribution cables is increasing. The existing models for the temperature calculation of urban medium and low voltage three-core cables regard the filler layer and inner sheath as isothermal body structure for research and analysis, and do not take into account the temperature inhomogeneity characteristics of the three-core cable structure itself. In the paper, the uneven distribution characteristics of the buffer layer of the three-core cable are considered, and then the temperature distribution of the inner sheath is analyzed, and the distributed modeling of the inner sheath is carried out by drawing on the idea of analogous distributed model of the electric circuit, and from the heat flow theory, the heat flux assigned to each segment of the structure such as each inner sheath is derived, and the steady-state thermal circuit model of the three-core cable is established based on the principle of equivalency, and the finite element computation method is adopted to recognize the thermal circuit parameters, and finally, after the simulation results are compared with the simulation results, the temperature of the three-core cable structure itself is considered as an isothermal structure. Finally, after comparing with the simulation results, the accuracy of the thermal circuit model reaches 95%, the change of ambient temperature has less influence on the thermal circuit model, and the model has high robustness, which provides support for the on-line detection technology of the state of three-core cables.
Virtual Power Plant Scheduling Model Considering the Power Consumption Satisfaction of Users with Different Flexible Loads
Authors: Du Yang , Li Jianglong , Yang Zhongguang , Sun Pei
Published: July 2024

Aiming at the problem that customer satisfaction with electricity consumption will affect the implementation effect of demand response. This paper proposes a virtual power plant scheduling model considering the satisfaction of users with different flexible loads. Firstly, the flexible load is divided into three categories: reducible load, transferable load and substitutable load. By analyzing the factors that affect the satisfaction of electricity consumption, the satisfaction models of customers with different flexible loads are constructed respectively. Secondly, a virtual power plant scheduling model considering different flexible load demand response models is established. Finally, the scheduling model is simulated and solved based on MATLAB, and the validity of the proposed virtual power plant scheduling model considering the satisfaction of users with different flexible loads is verified.
Research on Winding Dynamic Force and Displacement of Winding in Interturn Short Circuit of Stereo Roll Iron Core Transformer
Authors: Chang Xianghui , Chen Dezhi , Zhao Peng , Gao Youhua
Published: July 2024

The short circuit fault between the turns of the transformer winding accounts for 60% ∼ 70% of the whole winding fault, which seriously adversely impacts the regular functioning of the transformer. This study focuses on analysing the dynamic force and displacement characteristics of the winding in a stereo roll iron core transformer when an inter-turn short circuit occurs. First, a stereo roll iron core transformer finite element model in three dimensions is created. The electromagnetic-solid mechanics coupling method is used to figure out and study the transformer winding’s inter-turn short-circuiting current, leaking electromagnetic field, dynamic force, and displacement distributions. Furthermore, an experimental platform is built to simulate the inter-turn short-circuiting of a stereo roll iron core transformer. The displacement in the time domain and the acceleration in the frequency domain of the winding during the short circuit that occurs between turns will be recorded and analyzed. Finally, it is concluded that under normal working conditions, the winding vibration frequency is between 100 ∼ and 500 Hz. After 19 turns of the short circuit, the winding displacement increases by 32% ∼ 60%, and the high-order harmonic content of the winding vibration frequency increases significantly.
Hydration characteristics and kinetic analysis of polyacrylamide (PAM) anti-dispersion cement-based materials
Authors: He Yang , Wei Hua , Li Chunhe , Lu Hao , Xu Fei , Zhang Jiaming
Published: July 2024

Through phase analysis and quantitative calculations of the hydration process, the inclusion of polyacrylamide (PAM) in Anti-dispersion Water Paste affects its hydration characteristics is discovered. Specifically, the presence of PAM reduces early reactivity while accelerating progress in the middle to late stages of hydration. By employing K-D hydration kinetic analysis, it is confirmed that the use of PAM results in the formation of a multi-nucleation homogeneous point system within the cement slurry. This system prolongs the NG (nucleation and growth) process time, increases the hydration degree during the transition from NG to I (induction) process, and inhibits the heterogeneous precipitation of hydration products. Consequently, the early hydration of cement is hindered. As the hydration reaction advances, the microstructure of the product under multi-nucleation points increases the specific surface area. This gradual breakthrough of the hydration threshold barrier shortens the duration of the phase boundary reaction process and reduces the hydration degree during the I and D (diffusion) processes. Consequently, the late-stage hydration rate is accelerated.
Research on discharge characteristics of synthetic ester-paper insulation under power frequency and low frequency
Authors: Li Jiansheng , Wu Peng , Wang Shengquan , Liang Jiabi
Published: July 2024

Synthetic ester insulating oil transformer has broad application prospects in offshore wind power low-frequency power transmission. This paper carried out discharge tests on synthetic ester-paper insulated used sharp plate electrodes at a power frequency of 50 Hz and a low frequency of 17 Hz based on the pulse current method. The research results show that some basic characteristics do not change under 50 Hz and 17 Hz, that is, the discharge is distributed near the voltage peak in a peak shape. The main differences are that the positive peak characteristics at 17 Hz tend to be blurred; the positive maximum discharge amount, and discharge times show an overall downward trend; the phase-resolved partial discharge pattern (PRPD) and the statistical map (n-φ, n-q) have the same overall shape, but different distribution ranges. The test results can be used as a reference for partial discharge pattern identification and insulation design in synthetic ester low-frequency transformers.
Research on the application of balanced windings in wind farm booster stations
Authors: Yao Changqing
Published: July 2024

The 35 kV booster station system is an undisputed main grid in wind farms, and its main transformer wiring and grounding methods directly affect the stable operation of the entire wind farm station. After explaining the important role of balanced windings in transformers, this article uses Matlab/Simulink to build a mathematical model of wind farm stations from the aspects of wind turbines, transmission lines, step-up transformers, grounding transformers, main power grids, loads, etc. From the perspectives of harmonic suppression ability and wind farm operation stability, the applicability of a three-winding transformer with balanced windings as the main transformer of wind farm step-up stations is analyzed in depth. The results show that using a three-winding transformer as the main transformer for the wind farm boosting station has a significant effect on harmonic suppression and can ensure stable operation of the wind farm.
Insulation life prediction of stacking multi-model fusion motors based on Conv1d-LSTM
Authors: Duan Chengxin , Xu Yaosong
Published: July 2024

The insulation system of the mine motor is key to ensuring its stable operation, which affects the efficiency of mine production and transportation and the benefit of enterprises. The prediction of motor insulation life can effectively prevent the deterioration of motor performance. Due to the complex underground environment, many factors affect the insulation of coal mine motors, which are not conducive to the selection of feature parameters. The insulation life prediction efficiency and accuracy of motors need to be improved. To solve this problem, this paper proposes a prediction method based on Conv1d (one-dimensional convolve) and LSTM (long short-term memory neural network), which integrates multiple models and the Stacking integrated algorithms. The operating data and environmental parameters of a coal mine motor under different conditions are analyzed. Three Conv1d-LSTM hybrid models with batch normalization, residual network, and dense number are used as the base learner, and the results are weighted by K-fold to verify the accuracy of the three models. The linear regression model is used as a meta-learner to prevent overfitting of the model and effectively improve the speed and accuracy of single network optimization. Compared with the traditional method, the results show that the optimization of the LSTM neural network by the multi-feature model has a higher accuracy in predicting the remaining life of motor insulation, which provides a new way for the prediction of motor insulation life.
Research on the gas generation characteristics of power cables when heated
Authors: Zheng Jiankang , Zhu Kai , Zhang Hui , Yang Pengtao , Su Xiaoting , Ma Yuan , Ma Liang
Published: July 2024

Power cable fires evolve through several stages. Initially, the fire’s early phase is characterized by an anomalous temperature in the outer sheath without considerable smoke generation. It progresses to a smoldering stage with significant smoke production, leading eventually to open flames, which persist until extinguished. Fault-induced high temperatures initiate the breakdown of chemical bonds in the polymer materials composing the cable’s outer sheath, resulting in specific pyrolysis gases that bear the cable’s temperature information. Investigating the heating and gas production properties of the cable can enhance our understanding of the gas phase characteristics at the onset of fires. This paper presents an experimental platform comprising a power cable overheating fault simulation device and chemical analysis instruments. It examines the gas production traits and sources in power cables under fault-induced, high-temperature conditions based on gas chromatography and infrared spectrum data.
Design of main parameter of modular multilevel converter applied in power grid simulator
Authors: Wang Jia , Zhang Yongming , Chen Guochu
Published: July 2024

In the context of application in a power grid simulator, we investigated the parameter design issues of several crucial components of the Modular Multilevel Converter (MMC) topology applied to the power grid simulator system. These components include the bridge arm inductance and submodule capacitance. Based on the fundamental circuit of the MMC applied to the power grid simulator system, we introduced an equal discharge time constant H. We analyzed the capacitor voltage fluctuation rate and the equivalent capacitance discharge time constant “H”, discovering that they still exhibit an inversely proportional relationship across different engineering scenarios. Consequently, a general method for determining submodule capacitance parameters was proposed, and in conjunction with previous engineering parameters, recommended values for an equal discharge time constant of 40 ms were provided. Furthermore, we introduced the concepts of double-frequency circulating resonant angular frequency and phase resonant angular frequency, outlining the principles for determining the bridge arm reactance values. Through the analysis of corresponding parameters in previous engineering studies, universally applicable recommended values for the bridge arm reactance parameters were proposed, considering the unit resonant angular frequency as the power grid frequency angular frequency 1.0ω.
Performance evaluation and stability analysis of super-junction IGBTs in high-temperature environments
Authors: Lou Huifang , Xiao Fei
Published: July 2024

This paper aims to evaluate and analyze the performance and stability of super-junction IGBTs (Insulated Gate Bipolar Transistors) in high-temperature environments. The study begins with an overview of the significance of IGBTs in the field of power electronics. It provides a comprehensive discussion of the advantages of super-junction technology and the challenges posed by high temperatures on the performance of IGBTs. Through a series of experiments on various commercial super-junction IGBT models, this research thoroughly assesses the devices’ saturated current, threshold voltage, leakage current, switching time, and switching losses at different temperature points (25°C, 75°C, 125°C, and 175°C). The experimental results demonstrate a significant impact of high temperatures on the performance of IGBTs, particularly in terms of changes in saturated current and threshold voltage. Additionally, the study predicts the lifespan of super-junction IGBTs through High-Temperature Operating Life (HTOL) testing and analyzes the failure modes in high-temperature environments. The results indicate that the expected lifespan of the devices significantly decreases with increasing temperature, with primary failure modes including degradation of the gate oxide layer, an increase in interface traps, and disruption in conductive pathways. The paper also compares experimental results with existing literature, emphasizing the potential and importance of optimized design for super-junction IGBTs in high-temperature environments. The study suggests that improvements in materials, structural design, manufacturing processes, and innovative cooling technologies can further enhance the performance and stability of IGBTs in high-temperature applications. Finally, this research provides new insights into the development of super-junction IGBTs in high-temperature power applications and offers valuable references for professionals in related fields.
Design of voltage and frequency stabilization system for fishing vessel shaft generator based on UPS backup power supply
Authors: Xue Huafeng , Zhang Cunxi , Wang Rui , Hao Dongyu
Published: July 2024

A fishing boat shaft generator is a kind of power supply device driven by the main diesel engine, which has the advantage of saving energy compared with a diesel generator and eliminating the need to be equipped with an additional diesel engine, witnessing wide applications in the use of power supply equipment for fishing boats. However, because the shaft generator is mounted on the main diesel engine, the fishing boat encounters bad sea conditions at sea, and the speed of the diesel engine fluctuates, resulting in the instability of the power frequency and voltage sent by the shaft generator, which will endanger the electrical equipment of the fishing vessel in serious cases. In this paper, a design of a voltage and frequency stabilization system for a fishing vessel shaft generator based on a UPS backup power supply was proposed. The system consists of a three-phase shaft generator, inverter, battery, and electrical equipment. The inverter control strategy is introduced, and the battery charge/discharge and DC boost are designed.
Wireless charging system design based on ICPT topology
Authors: Wei Chuankang , Zhao Zhikang , Zhao Rentao , Jiang Hongwei
Published: July 2024

Aiming at the situation that the wired charger for inspection equipment has electrodes that are prone to rust and corrosion, poor contact, and inspection equipment cannot enter and exit the charging dock normally, this paper designs a set of non-contact charging systems. The system consists of two parts, the transmitter board, and the receiver board, mainly including power factor correction, high-frequency inverter, resonant circuit, charging control, circuit protection, and other modules. The transmitter board first converts the utility power into 60 kHz AC power and then transmits it to the receiver board through the resonant network. The receiving board charges the battery through the charging control circuit. The test results show that the wireless charger works stably and reliably, has perfect protection functions, and has a maximum output power of 150 W, which can meet the charging needs of most inspection equipment.
Electric theft detection based on multi-source heterogeneous time series GRU network
Authors: Min Wenhao , Liu Tianyu
Published: July 2024

Electricity theft has long been one of the major problems faced by power supply enterprises. To improve the robustness and accuracy of power theft detection, this article explores the method of multi-source heterogeneous time series feature fusion and designs a gated cyclic unit network model that adapts to its feature fusion. Firstly, through correlation analysis, it is verified that there is a logical correlation between different time series features and classification features, providing a theoretical basis for feature fusion. Then, an encoder decoder model framework is constructed with an attention mechanism to achieve effective fusion and state detection of user multi-source time series features. The experimental results show that compared to a single data source, the fusion of multi-source features can significantly improve detection performance, and the designed model is superior to the control model. This study provides a reference for constructing an efficient power theft detection system and also provides examples of multi-source heterogeneous feature fusion in related fields.
Multi-classification fault diagnosis of AC series arc based on wavelet decomposition and probabilistic neural network
Authors: Guo Jie , Chi Changchun , Yao Diancheng
Published: July 2024

AC series arc is difficult to detect because of its complex characteristics, and it can easily cause electrical fire or explosion and other accidents. In order to solve the problem that multi-class loads can not be easily recognized when an arc fault occurs, this paper presents a method for AC series arc multi-classification fault diagnosis based on wavelet decomposition and probabilistic neural network (PNN). According to the standard, the experiment platform of fault arc is designed in this paper, and the current waveform data of fault arc and normal operation under different load types are collected. The multi-dimensional characteristics of the high-frequency current waveform are extracted by processing the detail coefficients obtained by wavelet decomposition. According to the load type and working state, multi-classification data sets are built and input into PNN to train and test the fault diagnosis model. The proposed method can not only accurately detect the fault arc, but also effectively identify the fault load line, which has important reference significance for AC series arc fault diagnosis.
Comparison of transfer function measurement methods for AIMD MRI safety evaluation
Authors: Wang Zhichao , Li Yonghua , Li Chengling , Wu Dajing , Hu Shen
Published: July 2024

The transfer function is an important method in ISO/TS 10974 used to evaluate the safety of active implantable medical devices (AIMD). To measure the transfer function, there are two methods used during research and testing, which are the piecewise excitation method and the reciprocity method. In theory, they are equivalent. And for measurement, they have their own advantages and disadvantages. Simulations and experiments using both methods were performed and it is proved that they have good agreement in simulations and experiments.
On the possibility of accelerating charged particles in the low-pressure acoustoplasma and plasma bunches in the air
Authors: Abrahamyan A.S. , Chilingaryan R.Yu. , Mkhitaryan S.A. , Kocharyan V.R. , Margaryan A.A. , Mkrtchyan A.H.
Published: July 2024

In this paper obtained results of two experimental investigations are presented: on the acceleration of electrons in low-pressure acoustoplasma discharge and acceleration of plasma bunch-plasmoids in the air. The first experimental results on the acceleration of electrons in the low-pressure discharge were obtained in 2008. In the current paper an attempt to explain the obtained results by means of wake accelerations of particles in electromagnetic fields without utilization of usual drivers is made. Formerly calculated theoretical data for accelerated particles even in the energy range of 10–100 eV are experimentally confirmed. Experimental investigations on origination and initiating acceleration of plasma bunches in crossed fields in the air were conducted in 2023. In the current paper the obtained first results on acceleration of the originated long-life plasmoids in the air are presented as an announcement of our planned subsequent corresponding investigations. To carry out corresponding experiments a unique experimental setup, as well as appropriate devices and equipment were developed. A new conceptual model of a plasmoid is offered. The realization of this concept opens the possibility of carrying out the experimental investigations of the phenomena of origination of long-life plasmoids in air. During the experimental investigations, any ionizing additives into the discharge were not injected.
Land-use change as a major driver for mid-20th-century flood intensity reduction in the Southeastern US
Authors: Shen Zhixiong , Conway Nicholas , Bao Shaowu , Muñoz Samuel , Lang Andreas
Published: July 2024

Land-use changes affect hydrologic processes, but their impact on flooding remains obscure amid increasingly heavy precipitation. Instrumental records are short relative to land-use change history and inadequate for flood attribution studies. Here we integrate a high-resolution paleodischarge record spanning the past ∼200 years from the largest basin in the Southeastern United States with instrumental data and hydrological modeling. We find that the 100 yr flood magnitude for large regional rivers exhibits 50%–75% reductions in the mid-20th century. We attribute at least 50% of the reductions to a regional shift from widespread agricultural land to conservation and reforestation and the rest to streamflow regulations. A sensitivity test of the largest post-1950s flood in our study area using the WRF-Hydro model shows that the peak early-1900s agriculture activity in the region could have doubled the flood’s magnitude. Our findings suggest that land-use change can profoundly impact flood severity at catchment to regional scales. Therefore, reforestation and soil conservation contribute to alleviating flood hazard in some regions, while aggressive agriculture expansion in other areas will amplify the hazard.
Geometrically frustrated systems which are as singles hotter than in company
Authors: Bauer Wolfgang Rudolf
Published: July 2024

We show that a set of thermally weakly coupled geometrically frustrated systems (GFSs), each of which is constraint to reside at negative Boltzmann temperatures, is in equilibrium cooler than its constituents. It may even exhibit positive temperatures at low energies. The challenge for the second law of thermodynamics arising from potential heat flow related to the gradient of temperatures between a GFS and its environment is resolved by considering the energy fluctuations above the ground state. They are comprised in the canonical temperature, derived from information theory. Whereas the gradient of Boltzmann temperatures gives the direction of the stochastic drift of the most probable state of a GFS within its environment, the canonical temperature gradient defines that of heat flow.
Fabrication of heterocellular spheroids with controllable core-shell structure using inertial focusing effect for scaffold-free 3D cell culture models
Authors: Tang Tan , Zhang Pengfei , Zhang Qiuting , Man Xingkun , Xu Ye
Published: July 2024

Three-dimensional (3D) cell culture models capable of emulating the biological functions of natural tissues are pivotal in tissue engineering and regenerative medicine. Despite progress, the fabrication of in vitro heterocellular models that mimic the intricate structures of natural tissues remains a significant challenge. In this study, we introduce a novel, scaffold-free approach leveraging the inertial focusing effect in rotating hanging droplets for the reliable production of heterocellular spheroids with controllable core-shell structures. Our method offers precise control over the core-shell spheroid’s size and geometry by adjusting the cell suspension density and droplet morphology. We successfully applied this technique to create hair follicle organoids, integrating dermal papilla cells within the core and epidermal cells in the shell, thereby achieving markedly enhanced hair inducibility compared to mixed-structure models. Furthermore, we have developed melanoma tumor spheroids that accurately mimic the dynamic interactions between tumor and stromal cells, showing increased invasion capabilities and altered expressions of cellular adhesion molecules and proteolytic enzymes. These findings underscore the critical role of cellular spatial organization in replicating tissue functionality in vitro. Our method represents a significant advancement towards generating heterocellular spheroids with well-defined architectures, offering broad implications for biological research and applications in tissue engineering.
Can pulsed laser treatment reduce microbial adhesion on the surface of resin denture base materials?
Authors: Saran Runki , K Keerthi , V K Unnikrishnan , George Sajan Daniel , H Raghu Chandrashekhar , Upadhya P Nagaraja , Ginjupalli Kishore
Published: July 2024

Objectives. The present work investigates the influence of pulsed nanosecond laser patterning of two commercial heat cure poly (methyl methacrylate) denture base materials, Trevalon and DPI heat cure, on their surface characteristics such as roughness, hydrophobicity, and microbial adhesion. Methods. A Q-switched Nd:YAG solid state nanosecond pulsed laser at a wavelength of 532 nm with a fluence of 2.55 × 1010 W cm−2 having a pulse frequency of 10 Hz was used at varying translation stage speed and vertical spacing for the surface patterning of denture base materials. The surface properties of control and patterned materials were characterized by measuring the compositional changes, wettability, and roughness. Microbial adhesion was assessed by incubating the specimens in Candida albicans suspension at 37 °C for 2 h followed by estimating the number of adherent Candida cells. Results. The micro-Raman spectroscopic studies indicated no chemical changes in the materials due to laser patterning. However, laser patterning increased the average surface roughness from 0.02 ± 0.005 and 0.04 ± 0.003 μm to 3.85 ± 0.20 μm and 3.70 ± 0.12 μm respectively for Trevalon and DPI heat cure materials. In addition, a reduction in the surface wettability was evident as manifested by an increase in water contact angle from 76 ± 2° to 105 ± 1° for Trevalon and from 72 ± 1° to 97 ± 1° for DPI heat cure. Finally, the microbial adhesion studies clearly indicated that the surfaces with higher hydrophobicity and roughness following laser patterning exhibited reduced microbial adhesion. Significance. Laser patterning can be utilized to tune the surface features of denture base materials and thus offer a promising method to create microbial adhesion resistant surfaces. Clinically, such surfaces help in reducing the incidence of denture stomatitis, especially in immunocompromised patients, without altering the composition and bulk properties of denture base materials.
Modeling chlorine residuals in urban water distribution networks (Al-Ashrafieh – Homs)
Authors: Alsaeed Ruba D , Alaji Bassam , Khouri Lina
Published: July 2024

Maintaining water quality in the water distribution networks has become a prominent issue. Chlorine Residual is an indicator to ensure water quality in the network A hydraulic analysis of the water distribution network in the Al-Ashrafieh city in Homs governorate was used to determine the chlorine residual concentration in the network. Samples were collected from the network to determine the percentage of free residual chlorine at three points and to compare with the program results. The results of the program represent a good simulation of field values, with an error less than 5%, RMSE = 0.02, 0.1, 0.02 for nodes 14, 11, and 3 respectively. The simulation showed that chlorine values in the network were within the permissible values in more than 95% of the network pipes, where Chlorine values decrease at peak times and at high-pressure values. Available data indicate a decrease in the percentage of free residual chlorine at some points. Three support point scenarios were studied, where the UCC (Uniform Chlorine Coefficients) increases when the support is used by using number of points of support near the pipes that has the low levels of chlorine from a value of 0.84 to 0.9.
Net evaporation-induced mangrove area loss across low-lying Caribbean islands
Authors: Cortés Isamar M , Lorenzo-Trueba Jorge , Rovai Andre S , Twilley Robert R , Chopping Mark , Fatoyinbo Temilola
Published: July 2024

Although mangroves provide many beneficial ecosystem services, such as blue carbon storage and coastal protection, they are currently under threat due to changes in climate conditions, such as prolonged drought exposure. Under drought conditions, evaporation exceeds precipitation and high soil salinities can lead to stunted growth and die-back. To quantify this interplay, we developed a database for low-lying and uninhabited mangrove islands in the Caribbean under various evaporation and precipitation regimes. We extracted physical and biological information from each island using remote sensing techniques and coupled it with a process-based model. We used this database to develop a model that explains both the spatial variability in vegetated area across the Caribbean—as a function of rates of evaporation and precipitation—and porewater salinity concentration and dispersion from island edge towards the interior of mangrove islands. We then used this validated model to predict mangrove area loss associated with increases in evaporation to precipitation rates by 2100 for different Shared Socioeconomic Pathways (SSP). Less wealthy Caribbean regions such as Belize, Puerto Rico, and Venezuela are disproportionally affected, with mangrove area losses ranging from 3%–7% for SSP 2.6 and 13%–21% for SSP 7.0. Furthermore, foregone carbon sequestration in lost biomass under SSP 4.5 and 7.0 scenarios could compromise the ability of low-lying Caribbean mangrove islands to vertically adjust to sea level rise.
Why Delight in Screamed Vocals? Emotional Hardcore and the Case Against Beautifying Pain
Authors: Murphy Sean T
Published: July 2024

Emotional hardcore and other music genres featuring screamed vocals are puzzling for the appreciator. The typical fan attaches appreciative value to musical screams of emotional pain, all the while acknowledging it would be inappropriate to hold similar attitudes towards their sonically similar everyday counterpart: actual human screaming. Call this the screamed vocals problem. To solve the problem, I argue we must attend to the anti-sublimating aims that get expressed in the emotional hardcore vocalist’s choice to scream the lyrics. Screamed vocals help us see the value in rejecting (a) restrictive social norms of emotional expressiveness and (b) restrictive artistic norms about how one ought to express or represent pain in art—namely that if one is going to do so, one must ensure the pain has been ‘beautified’. In developing this second point, I argue that emotional hardcore is well-suited (although not individually so) for putting pressure on longstanding views in the history of aesthetics about the formal relationship between art and human pain.
Confidentiality and privacy of arbitration in the digital era: pies in the sky?
Authors: Teramura Nobumichi , Trakman Leon
Published: July 2024

Confidentiality and privacy are essential components of arbitration, preceding the digital data era. This article discusses how arbitration stakeholders—arbitration institutions and associations, arbitrators, attorneys, and commercial users—have increasingly lost control over confidentiality and privacy in international commercial arbitration by adopting digital technologies provided by Internet giants, such as Microsoft, Google, Dropbox, and Zoom. Arbitration institutions and users have, often unconsciously, defined confidentiality and privacy expansively to promote the wider use of email, cloud storage, and video conferencing platforms in conducting arbitration proceedings. However, they have overlooked the extent to which the use of digital technologies exposes private and confidential information to third parties, including but not limited to Big Data. They have also placed undue faith in the capacity of Internet giants that dominate the Internet to protect highly sensitive arbitration proceedings which those giants commercialize to garner public attention including in arbitration disputes. In responding to this troubling reality, the article examines how to better protect confidentiality and privacy in arbitration, by refining existing protections embodied in international rules and guidelines and choosing domestic forums that favour such protections. It also encourages arbitration stakeholders to update the rules and their application to arbitral proceedings to respond to both intended and unintended violations of commercial and personal data. That strategy includes redressing the downstream disclosure of injurious data, including by choosing legal forums that protect against the use of intelligence to violate private and confidential data.
Safety and efficacy of very low calorie diet in patients receiving haemodialysis therapy
Authors: Woods Julie E , Snelson Anne , Kok Joanne , Leger Melinda A , Wei Jenny , Hung Jessica , Rio Ruth , Medara Sujatha , Prasad Seema , Ganesh Kalaiselvi , Kerr Peter G , Polkinghorne Kevan R
Published: July 2024

Background

Very low calorie diets (VLCDs) are an obesity treatment option in the general population, but their efficacy and safety in patients on haemodialysis (HD) is unknown.

Methods

Prospective single arm study of VLCD in haemodialysis patients. All participants received 2.5–3.3 MJ/day for 12 weeks. Weekly assessment of VLCD, pre- and post-dialysis weight, inter-dialytic weight gain, and blood electrolytes occurred for the first 4 weeks, then fortnightly for another 8 weeks. Linear mixed models compared the change in weight over time as well as biochemical outcomes including potassium.

Results

Twenty-two participants [nine home HD (HHD) and 13 satellite HD (SHD)] enrolled with 19 completing the 12-week intervention. Mean post-dialysis weight declined from 121.1 kg at baseline to 109.9 at week 12 resulting in average decline of 0.88 kg per week (95% C.I. 0.71, 1.05, P < .001) with 12-week mean percentage weight loss9.3% (SD 3.5). Mean post-dialysis body mass index declined from 40.9 kg/m2 at baseline to 37.1 kg/m2 at week 12 (95% C.I. 0.25, 0.35, P < .001). Serum potassium rose from week 1 to 3, stabilized during weeks 4 to 6, and fell from week 8, returning near baseline by week 12. Six of the nine (66.6%) HHD participants and seven of the 13 (70%) SHD participants had at least one episode of hyperkalaemia (K > 6 mmol/l). There were no clinical changes in serum sodium, corrected calcium, or phosphate levels during the study.

Conclusion

VLCD with dietitian supervision was effective in producing significant weight reduction, with an acceptable safety profile in patients treated with haemodialysis.
Takayasu arteritis manifesting as acute kidney injury and congestion due to renal artery stenosis and myocarditis: a case report
Authors: Hara Misato , Mandai Shintaro , Mori Takayasu , Maejima Yasuhiro , Uchida Shinichi
Published: July 2024

Background

Takayasu arteritis is a large-vessel vasculitis that affects the aorta and its primary branches. Myocarditis is a rare life-threatening complication and potential diagnostic pitfall in patients with Takayasu arteritis.

Case summary

A previously healthy 18-year-old woman presenting with fever, back pain, and dyspnoea was admitted to another hospital for acute hypertension (blood pressure, 230/106 mmHg) and congestive heart failure. Intravenous methylprednisolone pulse with antihypertensive and diuretic medications slightly improved her congestion. However, she developed acute kidney injury and was transferred to our hospital. Transthoracic echocardiography indicated a left ventricular ejection fraction of 45% and diffuse left ventricular hypokinesis. Doppler ultrasound test and magnetic resonance angiography revealed severe bilateral renal artery stenosis. Her diagnosis was Takayasu arteritis, and she received high-dose glucocorticoids. She required temporary haemodialysis, but 2 months after admission, her serum creatinine improved to 1.1 mg/dL without surgical or cardiovascular interventions. Although the pre-discharge test with 1.5 T cardiac magnetic resonance initially failed to diagnose myocarditis, 3 T cardiac magnetic resonance imaging revealed increased native T1 values on T1 mapping (1283–1393 ms), moderate pericardial effusion, and systolic left ventricular wall motion abnormality, indicating active myocarditis. During 6-month subcutaneous tocilizumab treatment (162 mg/week), a left ventricular ejection fraction improved to 55–60% without a relapse.

Discussion

This case report highlights the benefits of early multimodal imaging tests including cardiac magnetic resonance imaging for myocarditis and renal artery involvement in Takayasu arteritis. Tocilizumab might be an efficient therapeutic option for severe acute manifestations including myocarditis in young women of reproductive age.
Echocardiographic parameters and Galectin-3 in patients with atrial fibrillation as a marker of left atrial fibrosis
Authors: Barros Melo Da Silveira M M B , Victor Batista Cabral J O Ã O , Remigio Figueiredo T H A I S A , Tavares Xavier A M A N D A , Palmeira Do O K L E Y T O , Furtado De Mendonca Belmont T A C I A N , Maria Del Castillo J O S E , Sibelly Pereira De Lima V , Jesus Barreto De Melo Rego M O A C Y R , Carneiro Da Silva Filho J , Silva T A M A R A , Araujo Medeiros C , Cavalcanti De Oliveira D , Celestino Sobral Filho D A R I O , Richardson Da Silva Vasconcelos L
Published: July 2024

Background

Atrial fibrillation (AF) is the most common type of sustained arrhythmia in clinical practice. Many cardiovascular nursing studies incorporate markers into the design and conduct of the study. Biochemical markers and imaging tests have been used with the aim of stratifying the risk and detecting atrial fibrosis. Speckle-tracking echocardiography (STE) is used for the detection of atrial fibrosis and Gal-3 provides an important prognostic value. The objective of the study was to assess the association between atrial fibrosis markers and serum levels and genic expression of galectin-3.

Methods

Two hundred and six patients with permanent AF and 70 patients with paroxysmal AF were included in the study. Serum levels of Gal-3 were determined by ELISA and STE was performed to assess fibrosis.

Results

Mean age of individuals with permanent AF was 66.56±12 years. With regard to echocardiographic parameters, the alterations that occur mainly in the permanent AF group when compared to the paroxysmal AF group are noteworthy, namely LA diameter (46.49±7.68 vs. 41±5.85, p=0.007), LA volume (106.5±41.64 vs. 79; P25: 54.7, P75: 97, p=0.02), and LA volume indexed to body surface area (51.29; P25: 39.9, P75: 78.1 vs. 41.55; P25: 28; P75: 54.9, p=0.04), in addition to the peak atrial longitudinal strain values (PALS) (10; P25: 7.2, P75: 12.4 vs. 16.3; P25: 8.1, P75: 21.2, p=0.002). When we compared the Gal-3 mRNA expression with the types of AF, there was no association (p=0.95). Serum levels of Gal-3 were assessed and compared to the parameter LA strain (PALS). The Spearman and Pearson correlations were evaluated in both groups and the group with permanent AF was correlated with serum levels of Gal-3 (r=0.24; p=0.01). The lower is the Gal-3 serum levels, the lower is the LA strain. Other comparisons presented no statistically significant correlation.

Conclusions

The integration of markers in cardiovascular nursing studies unfolds as a complex journey from the initial study design to the reporting phase, researchers may be intricately involved in all of these steps. The present study assessed the association between echocardiographic parameters that are suggestive of atrial fibrosis and coding for galectin-3, as well as its genic expression and serum levels in patients with atrial fibrillation. In this way, the use biomarkers can be incorporated into care practice as a tool for assessment and care planning.
Gender related incidence of frailty syndrome occurrence in patients with atrial fibrillation
Authors: Mlynarska A , Mikulakova W , Hudakova Z , Mlynarski R
Published: July 2024

Introduction

Atrial fibrillation (AF) is one of the biggest challenges associated with the treatment of cardiovascular diseases in modern countries. On the other hand frailty syndrome is one of the main problems of modern gerontology and is also an indicator of a poor prognosis. The exact relationship between frailty syndrome and AF is still the subject of research. The aim of the study was to evaluate the relationship between the gender of patients with AF and the presence of frailty syndrome.

Methods

132 consecutive patients over 60 years (58 women; 72,71 ± 6,73) of age with diagnosed atrial fibrillation were included. In all patients occurrence of frailty syndrome using the Tilburg Frailty Indicator scale (TFI) was analyzed. Having 5 or more points indicates that a patient has frailty syndrome. AF was also divided into types according to modified ESC guidelines: paroxysmal (first diagnosed AF + paroxysmal AF); persistent AF and permanent AF (long-standing persistent AF + permanent AF).

Results

Frailty syndrome was diagnosed in 59,85% of patients with atrial fibrillation, including 47,95% of men and 81,49% of women, p = 0,0002. The mean point value of the frailty syndrome was 5,31 ± 2,69. Women had a greater severity of frailty syndrome in general and in the physical and social domain – exact results are presented in the table below. Regardless of the type of atrial fibrillation, frailty syndrome was more common syndrome in women: persistent AF: 7,64 ± 2,53 vs 5,28 ± 2,39; p = 0,0226 paroxysmal AF: 6,18 ± 2,63 vs 3,88 ± 2,47; p = 0,0465, permanent AF: 5,52 ± 2,58 vs 3,86 ± 1,77; p = 0,0324.

Conclusions

Frailty syndrome is more common among women what can suggest worst prognosis. Existing of frailty syndrome was independently from the type of AF.
Optimizing diuretic management in acute decompensated heart failure: the impact of diuretic algorithm in real-world setting
Authors: Van Der Laan J , Shakoor A , Scholte N , Van Der Boon R , Emans M E
Published: July 2024

Background/Introduction

Achieving euvolaemia is an important prognostic factor in acutely decompensated heart failure (ADHF). The European Society of Cardiology (ESC) guidelines suggest that a stepwise diuretic treatment algorithm based on regular reassessment of urinary output and natriuresis may be superior compared to current standard of care. We studied the implementation and effectiveness of such a pre-specified algorithm in a real-word cohort for realizing euvolaemia.

Methods

In 2020 we implemented the stepped diuretic strategy from the Heart Failure Association position statement, now stated in the 2021 ESC guidelines, in a peripheral hospital. Afterwards we conducted a retrospective cohort study, including patients with ADHF (with hospitalization duration > 3 days for decongestive treatment). Patients admitted between 10-Jan-2021 and 04-Dec-2021, who were treated according to the diuretic algorithm (protocol cohort), were compared to patients who were treated between 04-Jan-2018 and 19-jan-2019 (before implementation of this algorithm). Our primary outcomes were length of hospital stay (days), complications during hospitalization, such as electrolyte disturbance, kidney function, arrhythmias, infections and mortality during hospitalization.

Results

The study comprised 221 patients, with 107 in the pre-protocol cohort and 114 in the protocol cohort. Baseline characteristics were similar between the cohorts, expect for the kidney function and NT-proBNP levels at admission. Mean eGFR was slightly better in the protocol cohort (53 [36-71] vs 43 [29-63] ml/min/1.73m2, p .016), were as NT-proBNP was higher in the pre-protocol cohort (990 vs 480 pmol/l) (Table 1). The mean length of stay was shorter in the protocol cohort (7.0 [5.1-10.3] vs 7.5 [5.9-10.9] days). The incidence of complications, such as electrolyte disturbances and arrhythmias, were comparable. Notably, the mean eGFR on third day of hospitalization was higher in the protocol cohort (50 ± 21 vs. 42 ± 19 ml/min/1.73m2). There was a difference in the median weight lost during the admission between the two cohorts (Figure 1).

Conclusion

Our data suggest that a pre-specified stepwise diuretic treatment algorithm, based on urinary output is feasible and effective in achieving euvolaemia in a real-world cohort. Furthermore, it reduces length of hospital stay without increasing the risk of complications.