bluuebunny/crossref_metadata_2025 huggingface dataset:
Update on the Applications of Radiomics in Diagnosis, Staging, and Recurrence of Intrahepatic Cholangiocarcinoma
Authors: Brunese Maria Chiara , Fantozzi Maria Rita , Fusco Roberta , De Muzio Federica , Gabelloni Michela , Danti Ginevra , Borgheresi Alessandra , Palumbo Pierpaolo , Bruno Federico , Gandolfo Nicoletta , Giovagnoni Andrea , Miele Vittorio , Barile Antonio , Granata Vincenza
Published: April 2023

Background: This paper offers an assessment of radiomics tools in the evaluation of intrahepatic cholangiocarcinoma. Methods: The PubMed database was searched for papers published in the English language no earlier than October 2022. Results: We found 236 studies, and 37 satisfied our research criteria. Several studies addressed multidisciplinary topics, especially diagnosis, prognosis, response to therapy, and prediction of staging (TNM) or pathomorphological patterns. In this review, we have covered diagnostic tools developed through machine learning, deep learning, and neural network for the recurrence and prediction of biological characteristics. The majority of the studies were retrospective. Conclusions: It is possible to conclude that many performing models have been developed to make differential diagnosis easier for radiologists to predict recurrence and genomic patterns. However, all the studies were retrospective, lacking further external validation in prospective and multicentric cohorts. Furthermore, the radiomics models and the expression of results should be standardized and automatized to be applicable in clinical practice.
A 3D Approach Using a Control Algorithm to Minimize the Effects on the Healthy Tissue in the Hyperthermia for Cancer Treatment
Authors: Fatigate Gustavo Resende , Lobosco Marcelo , Reis Ruy Freitas
Published: April 2023

According to the World Health Organization, cancer is a worldwide health problem. Its high mortality rate motivates scientists to study new treatments. One of these new treatments is hyperthermia using magnetic nanoparticles. This treatment consists in submitting the target region with a low-frequency magnetic field to increase its temperature over 43 °C, as the threshold for tissue damage and leading the cells to necrosis. This paper uses an in silico three-dimensional Pennes’ model described by a set of partial differential equations (PDEs) to estimate the percentage of tissue damage due to hyperthermia. Differential evolution, an optimization method, suggests the best locations to inject the nanoparticles to maximize tumor cell death and minimize damage to healthy tissue. Three different scenarios were performed to evaluate the suggestions obtained by the optimization method. The results indicate the positive impact of the proposed technique: a reduction in the percentage of healthy tissue damage and the complete damage of the tumors were observed. In the best scenario, the optimization method was responsible for decreasing the healthy tissue damage by 59% when the nanoparticles injection sites were located in the non-intuitive points indicated by the optimization method. The numerical solution of the PDEs is computationally expensive. This work also describes the implemented parallel strategy based on CUDA to reduce the computational costs involved in the PDEs resolution. Compared to the sequential version executed on the CPU, the proposed parallel implementation was able to speed the execution time up to 84.4 times.
Outlier-Robust Surrogate Modeling of Ion–Solid Interaction Simulations
Authors: Preuss Roland , von Toussaint Udo
Published: April 2023

Data for complex plasma–wall interactions require long-running and expensive computer simulations. Furthermore, the number of input parameters is large, which results in low coverage of the (physical) parameter space. Unpredictable occasions of outliers create a need to conduct the exploration of this multi-dimensional space using robust analysis tools. We restate the Gaussian process (GP) method as a Bayesian adaptive exploration method for establishing surrogate surfaces in the variables of interest. On this basis, we expand the analysis by the Student-t process (TP) method in order to improve the robustness of the result with respect to outliers. The most obvious difference between both methods shows up in the marginal likelihood for the hyperparameters of the covariance function, where the TP method features a broader marginal probability distribution in the presence of outliers. Eventually, we provide first investigations, with a mixture likelihood of two Gaussians within a Gaussian process ansatz for describing either outlier or non-outlier behavior. The parameters of the two Gaussians are set such that the mixture likelihood resembles the shape of a Student-t likelihood.
Restricted Phase Space Thermodynamics of Einstein-Power-Yang–Mills AdS Black Hole
Authors: Du Yun-Zhi , Li Huai-Fan , Zhang Yang , Zhou Xiang-Nan , Zhao Jun-Xin
Published: April 2023

We consider the thermodynamics of the Einstein-power-Yang–Mills AdS black holes in the context of the gauge-gravity duality. Under this framework, Newton’s gravitational constant and the cosmological constant are varied in the system. We rewrite the thermodynamic first law in a more extended form containing both the pressure and the central charge of the dual conformal field theory, i.e., the restricted phase transition formula. A novel phenomena arises: the dual quantity of pressure is the effective volume, not the geometric one. That leads to a new behavior of the Van de Waals-like phase transition for this system with the fixed central charge: the supercritical phase transition. From the Ehrenfest’s scheme perspective, we check out the second-order phase transition of the EPYM AdS black hole. Furthermore the effect of the non-linear Yang–Mills parameter on these thermodynamic properties is also investigated.
Application of Multiscale Sample Entropy in Assessing Effects of Exercise Training on Skin Blood Flow Oscillations in People with Spinal Cord Injury
Authors: Liao Fuyuan , Zhao Hengyang , Lin Cheng-Feng , Chen Panpan , Chen Philbert , Onyemere Kingsley , Jan Yih-Kuen
Published: April 2023

Spinal cord injury (SCI) causes a disruption of autonomic nervous regulation to the cardiovascular system, leading to various cardiovascular and microvascular diseases. Exercise training is an effective intervention for reducing risk for microvascular diseases in healthy people. However, the effectiveness of exercise training on improving microvascular function in people with SCI is largely unknown. The purpose of this study was to compare blood flow oscillations in people with spinal cord injury and different physical activity levels to determine if such a lifestyle might influence skin blood flow. A total of 37 participants were recruited for this study, including 12 athletes with SCI (ASCI), 9 participants with SCI and a sedentary lifestyle (SSCI), and 16 healthy able-bodied controls (AB). Sacral skin blood flow (SBF) in response to local heating at 42 °C for 50 min was measured using laser Doppler flowmetry. The degree of the regularity of blood flow oscillations (BFOs) was quantified using a multiscale entropy approach. The results showed that BFO was significantly more irregular in ASCI and AB compared to SSCI during the maximal vasodilation period. Our results also demonstrate that the difference in the regularity of BFOs between original SBF signal and phase-randomized surrogate time series was larger in ASCI and AB compared to SSCI. Our findings indicate that SCI causes a loss of complexity of BFOs and exercise training may improve complexity in people with SCI. This study demonstrates that multiscale entropy is a sensitive method for detecting differences between different categories of people with SCI and might be able to detect effects of exercise training related to skin blood flow.
Non-Stationary Non-Hermitian “Wrong-Sign” Quantum Oscillators and Their Meaningful Physical Interpretation
Authors: Znojil Miloslav
Published: April 2023

In the framework of quantum mechanics using quasi-Hermitian operators the standard unitary evolution of a non-stationary but still closed quantum system is only properly described in the non-Hermitian interaction picture (NIP). In this formulation of the theory both the states and the observables vary with time. A few aspects of implementation of this picture are illustrated via the “wrong-sign” quartic oscillators. It is shown that in contrast to the widespread belief, both of the related Schrödinger-equation generators G(t) and the Heisenberg-equation generators Σ(t) are just auxiliary concepts. Their spectra are phenomenologically irrelevant and, in general, complex. It is argued that only the sum H(t)=G(t)+Σ(t) of the latter operators retains the standard physical meaning of the instantaneous energy of the unitary quantum system in question.
An Optimized Schwarz Method for the Optical Response Model Discretized by HDG Method
Authors: Chen Jia-Fen , Gu Xian-Ming , Li Liang , Zhou Ping
Published: April 2023

An optimized Schwarz domain decomposition method (DDM) for solving the local optical response model (LORM) is proposed in this paper. We introduce a hybridizable discontinuous Galerkin (HDG) scheme for the discretization of such a model problem based on a triangular mesh of the computational domain. The discretized linear system of the HDG method on each subdomain is solved by a sparse direct solver. The solution of the interface linear system in the domain decomposition framework is accelerated by a Krylov subspace method. We study the spectral radius of the iteration matrix of the Schwarz method for the LORM problems, and thus propose an optimized parameter for the transmission condition, which is different from that for the classical electromagnetic problems. The numerical results show that the proposed method is effective.
Programming Quantum Neural Networks on NISQ Systems: An Overview of Technologies and Methodologies
Authors: Markidis Stefano
Published: April 2023

Noisy Intermediate-Scale Quantum (NISQ) systems and associated programming interfaces make it possible to explore and investigate the design and development of quantum computing techniques for Machine Learning (ML) applications. Among the most recent quantum ML approaches, Quantum Neural Networks (QNN) emerged as an important tool for data analysis. With the QNN advent, higher-level programming interfaces for QNN have been developed. In this paper, we survey the current state-of-the-art high-level programming approaches for QNN development. We discuss target architectures, critical QNN algorithmic components, such as the hybrid workflow of Quantum Annealers and Parametrized Quantum Circuits, QNN architectures, optimizers, gradient calculations, and applications. Finally, we overview the existing programming QNN frameworks, their software architecture, and associated quantum simulators.
Effect of the Jigsaw Method on Self-Reported Practices by Physical Education Teachers: A Textual Analysis
Authors: Cochon Drouet Océane , Fargier Patrick , Margas Nicolas , Lentillon-Kaestner Vanessa
Published: April 2023

Jigsaw is a cooperative teaching method that is easy to implement and may engage teachers who use it. Previous studies have mainly focused on the effects of the Jigsaw method on students and rarely on teachers. The present study aimed to determine whether Jigsaw implementation influenced the discourses of physical education (PE) teachers related to their teaching practices. Six volunteer teachers used the Jigsaw method during three PE teaching sequences with various physical activities practiced, and semi-directive interviews were conducted before and after the Jigsaw implementation. Each interview was recorded and transcribed with the aim of performing textual analysis using Alceste2018®. The qualitative content analysis performed from the outputs of the automatic textual analysis led to determine the emergent themes in the interviewees’ discourses and the focuses used to address these themes, before and after the Jigsaw implementation. The themes in the discourses were found to be teacher-centered before the Jigsaw implementation (e.g., the guidelines and principles for teaching) and student-centered after the implementation (e.g., the student activity during learning). The focuses were found to vary accordingly (e.g., teachers’ intentions, before the implementation, and students’ characteristics, after the implementation). Such changes in the teachers’ discourse thus suggest that the Jigsaw method might be a useful tool for the development of teaching practices.
Where Is It Best to Sit in Class? Description of an Experience Based on STEM Problem Solving in a School Context
Authors: Ferrando Irene , Albarracín Lluís , Diago Pascual D.
Published: April 2023

This study aims to describe the design and development of a STEM problem-solving activity involving mathematics and physics content. It is an activity whose starting point is a question based on a real problem: to identify the areas of the classroom where the intensity of sound is higher. In this way, the problem involves the physics of sound. However, in addition, by trying to give an answer to the initial question, students have the opportunity to develop progressively more complex mathematical models from already known mathematical concepts and procedures. The analysis of the results of the implementation based on the identification of the learning opportunities and the catalyst elements that generate them, allows us to state that the activity encourages students to enrich their mathematical models by incorporating new mathematical concepts such as the function of two variables. We conclude that the design of the activity and the choice of data acquisition technology are key, but also the interaction between the students and the teacher.
Heart Rate Variability during Virtual Reality Activity in Individuals after Hospitalization for COVID-19: A Cross-Sectional Control Study
Authors: Ribeiro Cinthia Mucci , Gomes Renata de Andrade , Monteiro Carlos Bandeira de Mello , Dias Rodrigo Martins , Simcsik Amanda Orasmo , Araújo Luciano Vieira de , Maia Laura Cristina Pereira , Oliveira Adriana Paulino de , Freitas Bruna Leal de , Dawes Helen , Ferreira Celso , Moraes Íbis Ariana Peña de , Silva Talita Dias da
Published: April 2023

(1) Background: COVID-19 can lead to many complications, including cardiorespiratory complications and dysautonomia. This can be assessed by heart rate variability (HRV), which reflects the autonomic nervous system. There are different possibilities for physical rehabilitation after COVID, one of which that has been growing fast is the use of Virtual reality (VR) for rehabilitation. VR may represent an innovative and effective tool to minimize deficits that could lead to permanent disabilities in patients of outpatient rehabilitation services. The aim of this protocol is to establish whether practicing a task using a VR game with body movements influences physiological variables, such as heart rate, HRV, oxygen saturation, blood pressure, and perceptual variables during exercise in individuals post-hospitalization for COVID. (2) Methods: This cross-sectional study evaluated individuals divided into two groups, a post-hospitalization for COVID-19 group and a healthy control group. Subjects underwent one session of a VR task, and physiological variables, including HRV, were measured during rest, VR activity, and recovery. In addition, considering the influence of age in HRV and the impact of COVID-19, we divided participants by age. (3) Results: In all HRV indices and in both groups, an increase in sympathetic and a decrease in parasympathetic activity were found during VR. Additionally, the older post-COVID-19 group performed worse in non-linear indices, peripheral oxygen saturation, and rating of perceived exertion (RPE). (4) Conclusions: The VR game positively affects physiological variables and can therefore be utilized as a secure physical activity in both healthy individuals and individuals after hospitalization for COVID-19. COVID-19 affects the autonomic nervous system of older patients’ post-hospitalization, which may be partly due to a higher BMI and the reduced exercise capacity in this population, affecting their ability to perform exercise activities. Other important observations were the higher RPE in COVID-19 patients during and after exercise, which may reflect altered physiological and autonomic responses. Taken together with the high reporting of fatigue after COVID-19, this is an important finding, and considering that RPE is usually lower during VR exercise compared to non-VR strengthens the potential for the use of VR in COVID-19 patients.
Research and Implementation of Low-Power Anomaly Recognition Method for Intelligent Manhole Covers
Authors: Guo Jiahu , Wang Kai , Sun Jianquan , Jia Youcheng
Published: April 2023

This paper addresses the difficulty of balancing a real-time response and low power consumption in intelligent manhole cover application scenarios. It proposes a method to distinguish normal and abnormal events by segmenting the boundary at which the acceleration of the intelligent manhole cover deviates from a set threshold and lasts for a certain period, based on the difference in the intelligent manhole cover’s vibration patterns when a normal event and an abnormal event occur. This paper uses the autonomous data fusion of digital output motion sensor data to implement a pattern recognition algorithm for the above-mentioned pattern, which reduces the MCU computing and working time and the overall power consumption of the system while meeting real-time response requirements. The test results demonstrate that the method has a high rate of anomaly recognition accuracy. The method ensures the system’s real-time response capability, and the actual low power consumption test demonstrates that the device can operate continuously for 9.5 years. The low power consumption index exceeds the requirements of the existing national standard, thereby resolving the issue that it is challenging to balance intelligent manhole cover abnormality recognition and low power consumption.
Inaudible Attack on AI Speakers
Authors: Alchekov Seyitmammet Saparmammedovich , Al-Absi Mohammed Abdulhakim , Al-Absi Ahmed Abdulhakim , Lee Hoon Jae
Published: April 2023

The modern world does not stand still. We used to be surprised that technology could speak, but now voice assistants have become real family members. They do not simply turn on the alarm clock or play music. They communicate with children, help solving problems, and sometimes even take offense. Since all voice assistants have artificial intelligence, when communicating with the user, they take into account the change in their location, time of day and days of the week, search query history, previous orders in the online store, etc. However, voice assistants, which are part of modern smartphones or smart speakers, pose a threat to their owner’s personal data since their main function is to capture audio commands from the user. Generally, AI smart speakers such as Siri, Google Assistance, Google Home, and so on are moderately harmless. As voice assistants become versatile, like any other product, they can be used for the most nefarious purposes. There are many common attacks that people with bad intentions can use to hack our voice assistant. We show in our experience that a laser beam can control Google Assistance, smart speakers, and Siri. The attacker does not need to make physical contact with the victim’s equipment or interact with the victim; since the attacker’s laser can hit the smart speaker, it can send commands. In our experiments, we achieve a successful attack that allows us to transmit invisible commands by aiming lasers up to 87 m into the microphone. We have discovered the possibility of attacking Android and Siri devices using the built-in voice assistant module through the charging port.
Comparison between a Cascaded H-Bridge and a Conventional H-Bridge for a 5-kW Grid-Tied Solar Inverter
Authors: Bertin Thibault , Despesse Ghislain , Thomas Remy
Published: April 2023

This paper compares the cost and efficiency of two inverter topologies for a 5-kW grid-connected solar inverter application: the Conventional H-Bridge Inverter (CHB) and the Cascaded H-Bridge Multilevel Inverter (CHBMLI). Emphasis is put on power switches and passive elements with a detailed study of the losses. Both designs respect the same constraints (cost, efficiency, and junction temperature of the transistors) to ensure a fair comparison between both topologies. The work highlights the important parameters when choosing the components (MOSFETs, capacitors, and magnetic cores for the inductors). The DC-link voltage ripple and the output AC current ripple are the key parameters for the design of the passive elements (capacitors and inductors). On top of that, the transistors MOSFETs are chosen, in both topologies, to limit the conduction losses (by selecting the Rdson) and the switching losses (by selecting the Qrr and dv/dt). Real components are picked in order to make the comparison as complete as possible. Numerical simulations are performed using the MATLAB platform. All equations and parameters are provided. A CHBMLI prototype was built with eight independent H-Bridges to validate the proposed design with thermal and efficiency measurements.
Obstacle Avoidance Strategy for Mobile Robot Based on Monocular Camera
Authors: Dang Thai-Viet , Bui Ngoc-Tam
Published: April 2023

This research paper proposes a real-time obstacle avoidance strategy for mobile robots with a monocular camera. The approach uses a binary semantic segmentation FCN-VGG-16 to extract features from images captured by the monocular camera and estimate the position and distance of obstacles in the robot’s environment. Segmented images are used to create the frontal view of a mobile robot. Then, the optimized path planning based on the enhanced A* algorithm with a set of weighted factors, such as collision, path, and smooth cost improves the performance of a mobile robot’s path. In addition, a collision-free and smooth obstacle avoidance strategy will be devised by optimizing the cost functions. Lastly, the results of our evaluation show that the approach successfully detects and avoids static and dynamic obstacles in real time with high accuracy, efficiency, and smooth steering with low angle changes. Our approach offers a potential solution for obstacle avoidance in both global and local path planning, addressing the challenges of complex environments while minimizing the need for expensive and complicated sensor systems.
Recycling in Building Materials: Analysis of the Possibilities and Results of Using Recycled Glass Sand in Autoclaved Materials
Authors: Stepien Anna
Published: April 2023

The construction industry is particularly responsible for the appearance of the earth and the environment and for its partial degradation related to climate warming through the production of cement, brick burning, and the processing of substrates for the production of building materials (lime, gypsum, polystyrene, processed materials, etc.). An important aspect of the 21st century has been the overproduction and excessive use of natural resources, including sand. The purpose of this article is to analyze the possibility of using glass sand as a substitute for quartz sand in the production of materials resulting from hydrothermal treatment (so-called silicate bricks). The article is a review of the research conducted since 2016 on laboratory tests on the modification of silicate mass with glass sand from recycled bottle glass, the properties of the mass modified in this way (hydration temperature, consistency, and humidity of the mixture), its physical and mechanical properties, and its structural and potential durability, which is related to, e.g., the direction and degree of crystallization of the C-S-H phase. Tests of compressive strength, density, water absorption, oxide composition (XRF), structure (XRD), microstructure (SEM), and porosity (CT analysis using computer tomography) were carried out. A special point of the research was the use of geochemical modeling code in the form of the GEMS-PSI program in the process of analyzing the modification of silicate mass by glass sand, which is beneficial in limiting ineffective modifications, thus saving time, money, and energy. Studies have shown that the use of glass cullet has a positive effect on the consistency of the modified raw material mass, on the density (1.6–1.75 kg/dm3), and on the compressive strength (15.729–20.3 MPa), while the crystallization of the C-S-H phase occurs in the direction of natrolite and gyrolite, less frequently towards the M-S-H or brucite phase.
The Interplay between Parameters of Light Pollution and Energy Efficiency for Outdoor Amenity Lighting
Authors: Skarżyński Krzysztof , Rutkowska Anna
Published: April 2023

This paper is related to light pollution and the energy efficiency of outdoor amenity lighting. It concerns the standard design assessment parameters of light pollution, the Upward Light Ratio (ULR) and Upward Flux Ratio (UFR), and the classic energy efficiency parameter—Normalized Power Density (NPD). The motivation for this research was the observation of certain inaccuracies related to the applicability and interpretation of these parameters in practice and the lack of connection between parameters of light pollution and energy efficiency. The multi-variant computer simulations of the exemplary large-area parking lot lighting system were conducted. Over four hundred cases were carefully analyzed. Individual cases differ in the shape of the task area, luminaire arrangements, mounting height, luminous intensity distribution, aiming, and maintenance factor. The results confirmed that the criteria values of ULR and UFR are often overestimated for modern luminaires, which emit luminous flux emitted only downwards. In this case, the ULR and UFR values do not exceed the criteria values for even zones with lower ambient brightness. Thus, lighting solutions with much lower energy efficiency easily meet the requirements of these parameters. This situation is not rational. So, it is crucial to make the criteria of ULR and UFR much more stringent in all environmental zones. Moreover, the research confirms a strong positive linear correlation between UFR and NPD (0.92, p < 0.001), which means that light pollution can be reduced by ensuring an appropriate level of energy efficiency. It is a great help in designing sustainable outdoor amenity lighting.
Energy Geotechnics and Geostructures
Authors: Pei Peng , Su Faqiang
Published: April 2023

Continuous global economic and population growth has driven the ever-increasing demand for energy [...]
Battery Energy Management System Using Edge-Driven Fuzzy Logic
Authors: Habib Mustapha , Bollin Elmar , Wang Qian
Published: April 2023

Building energy management systems (BEMSs), dedicated to sustainable buildings, may have additional duties, such as hosting efficient energy management systems (EMSs) algorithms. This duty can become crucial when operating renewable energy sources (RES) and eventual electric energy storage systems (ESSs). Sophisticated EMS approaches that aim to manage RES and ESSs in real time may need high computing capabilities that BEMSs typically cannot provide. This article addresses and validates a fuzzy logic-based EMS for the optimal management of photovoltaic (PV) systems with lead-acid ESSs using an edge computing technology. The proposed method is tested on a real smart grid prototype in comparison with a classical rule-based EMS for different weather conditions. The goal is to investigate the efficacy of islanding the building local network as a control command, along with ESS power control. The results show the implementation feasibility and performance of the fuzzy algorithm in the optimal management of ESSs in both operation modes: grid-connected and islanded modes.
Balancing Electricity Supply and Demand in a Carbon-Neutral Northern Europe
Authors: Göransson Lisa
Published: April 2023

This work investigates how to balance the electricity supply and demand in a carbon-neutral northern Europe. Applying a cost-minimizing electricity system model including options to invest in eleven different flexibility measures, and cost-efficient combinations of strategies to manage variations were identified. The results of the model were post-processed using a novel method to map the net load before and after flexibility measures were applied to reveal the contribution of each flexibility measure. The net load was mapped in the space spanned by the amplitude, duration and number of occurrences. The mapping shows that, depending on cost structure, flexibility measures contribute to reduce the net load in three different ways; (1) by reducing variations with a long duration but low amplitude, (2) by reducing variations with a high amplitude but short duration and low occurrence or (3) by reducing variations with a high amplitude, short duration and high occurrence. It was found that cost-efficient variation management was achieved by combining wind and solar power and by combining strategies (1–3) to manage the variations. The cost-efficient combination of strategies depends on electricity system context where electricity trade, flexible hydrogen and heat production (1) manage the majority of the variations in regions with good conditions for wind power while stationary batteries (3) were the main contributors in regions with good conditions for solar power.
Uncertainty Quantification Analysis of Exhaust Gas Plume in a Crosswind
Authors: Cravero Carlo , De Domenico Davide , Marsano Davide
Published: April 2023

The design of naval exhaust funnels has to take into account the interaction between the hot gases and topside structures, which usually includes critical electronic devices. Being able to predict the propagation trajectory, shape and temperature distribution of an exhaust gas plume is highly strategic in different industrial sectors. The propagation of a stack plume can be affected by different uncertainty factors, such as those related to the wind flow and gas flow conditions at the funnel exit. The constant growth of computational resources has allowed simulations to gain a key role in the early design phase. However, it is still difficult to model all the aspects of real physical problems in actual applications and, therefore, to completely rely upon the quantitative results of numerical simulations. One of the most important aspects is related to input variable uncertainty, which can significantly affect the simulation result. With this aim, the discipline of Uncertainty Quantification provides several methods to evaluate uncertainty propagation in numerical simulations. In this paper, UQ procedures are applied to a CFD simulation of a single plume in a crossflow. The authors test the influence of the uncertainty propagation of the chimney exit velocity and the main flow angle on the plume flow development. Two different UQ methods are applied to the analysis: the surrogate-based approach and the polynomial chaos expansion method. A comparison of the two methods is performed in order to find their pros and cons, focusing on the different and detailed quantities of interest.
Experimental Investigation to Assess the Performance Characteristics of a Marine Two-Stroke Dual Fuel Engine under Diesel and Natural Gas Mode
Authors: Hountalas Theofanis D. , Founti Maria , Zannis Theodoros C.
Published: April 2023

With the aim of CO2 emissions reduction in the maritime sector, dual fuel engines operating on natural gas are the most prominent technical and commercially available solution. A promising variant is the two-stroke high-pressure natural gas injection engine, utilizing diesel pilot fuel injection for ignition of the gaseous fuel while being able to operate in diesel-only mode. In this study, a comparative analysis of the performance and the combustion mechanism of dual fuel and diesel mode for this engine type is conducted using experimental data. Studies based on measurements conducted on actual scale are limited in the literature due to the engines’ sheer size not allowing lab testing. The analysis was conducted using measurements acquired during the factory acceptance tests involving conventional operating data and cylinder pressure data acquired using a piezoelectric sensor. In terms of the mean pressure and temperature, only minor differences were found. The specific fuel consumption was improved under low load operation for the dual fuel mode by 1.8%, while a small increase of 1.2% was found near full load. Differences were found in the combustion process from 25 to 75% load with considerably faster premixed and diffusion combustion for the dual fuel mode leading to a 6–8% decrease in combustion duration. Despite the combustion process differences, the performance under dual fuel operation was overall close to that of conventional diesel with an acceptable 1.5% efficiency reduction on average. This confirms that modern dual fuel marine engines can achieve the performance standards of conventional ones while benefiting from low-carbon fuel use to reduce CO2 emissions.
Infrastructure Development for Electric Vehicle Charging Stations in Cluj-Napoca Municipality—A Case Study
Authors: Pop Horatiu , Grama Alin , Fodor Alexandra , Rusu Corneliu
Published: April 2023

This paper presents the status regarding electric vehicles (EVs) and public charging stations managed by Cluj-Napoca City Hall. The types of charging stations and the quantity of the used energy were stated. The behavior of EV owners in charging their vehicles was also studied. The presented work proposes an extension of the EV charging infrastructure to support current and future EV owners. Simulations were carried out in Simulink to create an overview of the existing infrastructure. The simulation results showed the amount of greenhouse gas (CO2 emissions) reduced by using EVs. An estimated number of kilometers traveled with EVs was calculated by tracking the loads in all public charging stations.
Simple Diesel Train Fuel Consumption Model for Real-Time Train Applications
Authors: Ahn Kyoungho , Aredah Ahmed , Rakha Hesham A. , Wei Tongchuan , Frey H. Christopher
Published: April 2023

This paper introduces a simple diesel train energy consumption model that calculates the instantaneous energy consumption using vehicle operational input variables, including the instantaneous speed, acceleration, and roadway grade, which can be easily obtained from global positioning system (GPS) loggers. The model was tested against real-world data and produced an error of −1.33% for all data and errors ranging from −12.4% to +8.0% for energy consumption of four train datasets amounting to a total of 5854 km trips. The study also validated the proposed model with separate data that were collected between Valencia and Cuenca, Spain, which had a total length of 198 km and found that the model was accurate, yielding a relative error of −1.55% for the total energy consumption. These results show that the proposed model can be used by train operators, transportation planners, policy makers, and environmental engineers to evaluate the energy consumption effects of train operational projects and train simulation within intermodal transportation planning tools.
Discharge Characteristics and Numerical Simulation of the Oil–Gas Surface under DC Voltage
Authors: Zhou Yuanxiang , Yang Xiaojing , Li Yuhang , Jiang Guiming , Chen Jianning
Published: April 2023

Low insulation strength at the oil–gas surface due to oil leakage and partial discharge of oil-immersed power equipment is a major threat to the safe and reliable operation of power systems. This paper investigates the initiation and development of the oil–gas surface discharge. The oil–gas surface discharge test platform was established, and discharge tests were carried out at different gap distances (1–2.5 mm). By coupling the electric field and flow field, the multi-layer dielectric discharge streamer model was built, and the characteristics of charge and electric field distribution at different gap distances were studied. The test results show that the liquid surface between the electrodes rises during the discharge process. Furthermore, the surface discharge voltage exceeds the air gap discharge voltage. With the simulation analysis, the oil–gas surface discharge is a typical streamer development process. Under 50 kV applied voltage and 2.5 mm gap distance, the average development speed of the streamer is 12.5 km/s. The larger the gap distance is, the greater the average streamer development speed is. The recording and numerical simulation of the discharge process are of great significance for exploring the mechanism of oil–gas surface discharge, optimizing the discharge process, and diagnosing partial discharges.
Understanding Urban Residents’ Perceptions of Street Trees to Develop Sustainable Maintenance Guidelines in the Seoul Metropolitan Area, Korea
Authors: Jeong Na-Ra , Han Seung-Won , Ko Baul
Published: April 2023

Street trees play a crucial role in improving urban environments, and their management depends on the perceptions and preferences of urban residents. This study surveyed 884 urban residents’ preferences and perceptions towards street trees in a metropolitan area in Korea and proposed guidelines for their sustainable management. Urban residents were aware of the presence of street trees based on visual changes and were generally satisfied with their shape, size, and growth. They preferred trees that provide environmental and ecological services, such as offering shade, purifying the air, and preserving the ecosystem, while viewing the generation of debris from street trees as the most significant problem. Urban residents’ perspectives on street tree preference and issues varied based on age, income, and housing type. Although urban residents acknowledged the need for the maintenance and management of street trees, they believed that this was the responsibility of central and local governments, not local residents. Collectively, the residents had a positive view of urban street trees and believed that maintenance and management are necessary to address problems caused by their presence. Our research findings provide valuable information to help city and landscaping experts select street tree species and establish maintenance and management strategies.
Transcriptomics-Guided Investigation of the SLCG_Lrp Regulon Provides New Insights into Its Role for Lincomycin Biosynthesis
Authors: Xu Yurong , Xu Wanlian , Yi Jing , Li Binglin , Liu Meng , Zhang Maifei , Zheng Yang , Liu Ruihua , Wu Hang , Zhang Buchang
Published: April 2023

Lincomycin industrially produced by Streptomyces lincolnensis can be adopted to treat infections caused by Gram-positive bacteria. SLCG_Lrp, a transcriptional regulator of the Lrp family, was first identified to positively regulate lincomycin biosynthesis. However, the regulatory role of SLCG_Lrp is yet to be elucidated. This study utilized RNA-seq for comparing the transcriptome profile of original-strain LCGL and the ΔSLCGL_Lrp mutant. A total of 244 genes comprising 116 downregulated and 128 upregulated genes were differentially expressed between LCGL and ΔSLCGL_Lrp. An in-depth analysis revealed that SLCG_Lrp promotes nitrate assimilation but inhibits fatty acid metabolism, as well as directly regulates five regulators participating in the modulation of multiple cellular processes. With individual inactivation of those regulatory genes in S. lincolnensis LCGL, we confirmed the FadR transcriptional regulator SLCG_2185 was obviously correlated with lincomycin production and found it to transcriptionally stimulate the lincomycin biosynthetic cluster. Furthermore, SLCG_2185 overexpression in the high-yield S. lincolnensis LA219X promoted lincomycin production by 17.8%, and SLCG_2185 being co-overexpressed with SLCG_Lrp in LA219X increased lincomycin production by 28.1% compared to LA219X. Therefore, this investigation not only provides a direction for further investigations regarding the regulation mechanism of SLCG_Lrp, but also provides a basis for guiding the further improvement of lincomycin levels.
Enhanced Pentostatin Production in Actinomadura sp. by Combining ARTP Mutagenesis, Ribosome Engineering and Subsequent Fermentation Optimization
Authors: Zhang Hongyu , Zhang Deguang , Liu Ran , Lou Tingting , Tan Ruyue , Wang Suying
Published: April 2023

The special structure of pentostatin causes it to possess a wide spectrum of biological and pharmacological properties, and it has been extensively employed to treat malignant tumors and is the first-line treatment for hairy cell leukemia. Pentostatin is mainly distributed in several actinomycetes and fungi species. However, its low titer in microbes is not able to meet medical needs. Here, we report a strain improvement strategy based on combined atmospheric and room-temperature plasma (ARTP) mutagenesis and ribosome engineering screening, as well as fermentation optimization, for enhanced pentostatin production. The original strain, Actinomadura sp. ATCC 39365, was treated with ARTP and screened by ribosome engineering to obtain one stable pentostatin high-yield mutant Actinomadura sp. S-15, which produced 86.35 mg/L pentostatin, representing a 33.79% increase compared to Actinomadura sp. ATCC 39365. qRT-PCR analysis revealed that pentostatin biosynthesis-related gene expression was significantly upregulated in Actinomadura sp. S-15. Then, to further enhance pentostatin production, the fermentation medium was optimized in flask culture and the pentostatin production of Actinomadura sp. S-15 reached 152.06 mg/L, which is the highest pentostatin production reported so far. These results demonstrate the effectiveness of combined ARTP mutation, ribosome engineering screening, and medium optimization for the enhancement of pentostatin production, and provide a methodology enabling the sustainable production of pentostatin on an industrial scale.
Survival, Energy Status, and Cellular Stress Responses of the Juvenile Swimming Crab Portunus trituberculatus under Acute Nitrite Stress
Authors: Liu Xiaochen , Wang Daixia , Shang Yan , Yu Xuee , Gao Baoquan , Lv Jianjian , Li Jitao , Liu Ping , Li Jian , Meng Xianliang
Published: April 2023

Nitrite is a common pollutant encountered in aquaculture systems. During intensive hatchery, accumulation of nitrite can cause massive mortality of juvenile crustaceans. However, the nitrite toxicity and cellular stress responses in juvenile crustaceans is not clearly understood. Here, we investigate the survival, energy metabolism, and cellular stress responses in juvenile P. trituberculatus, an important aquaculture species in China, under acute nitrite stress. The results revealed nitrite resulted in a significant decrease in survival rate of juvenile swimming crab. After nitrite exposure, the activity of catabolic enzymes, such as HK, PK, CS, and CPT-1, were initially enhanced, and then they showed significant decrease at the late stage of exposure, accompanied by reduction in ATP and adenylate energy charge (AEC). The impaired energy homeostasis was possibly associated with disturbed AMPK signaling and enhanced anaerobic metabolism, which was indicated by the high levels of LDH activity and HIF-1α expression. Furthermore, we found that nitrite stress can depress antioxidant systems and unfold protein responses, causing oxidative damage and endoplasmic reticulum (ER) stress, and this, in turn, can trigger autophagy and apoptosis through both caspase-dependent and caspase-independent pathways. The results of the present study improve our understanding regarding adverse effects of nitrite on P. trituberculatus and provide valuable information for hatchery management.
Antibiotic Resistance Profiles and ARG Detection from Isolated Bacteria in a Culture-Dependent Study at the Codfish Industry Level
Authors: Ferri Gianluigi , Lauteri Carlotta , Scattolini Mauro , Vergara Alberto
Published: April 2023

The antibiotic resistance phenomenon horizontally involves numerous bacteria cultured from fresh or processed seafood matrix microbiomes. In this study, the identified bacteria from food-producing processes and industrial environments were screened for phenotypic and genotypic resistance determinants. A total of 684 bacterial strains [537 from processed codfish (Gadus morhua and Gadus macrocephalus) products as salted and seasoned and soaked and 147 from environmental samples] were isolated. Antibiotic susceptibility tests showed resistance against tetracycline, oxacillin, and clindamycin in the Staphylococcus genus (both from food and environmental samples) and against beta-lactams (cefotaxime, carbapenems, etc.) and nitrofurans (nitrofurantoin) from E. coli and Salmonella enterica serovar. Enteritidis isolates. One-thousand and ten genetic determinants—tetracycline tetC (25.17%), tetK (21.06%), tetL (11.70%), clindamycin ermC (17.23%), ermB (7.60%), linezolid cfr (8.22%), optrA (3.62%), poxtA (2.05%), and oxacillin mecA (17.37%)—were amplified from Gram-positive resistant and phenotypically susceptible bacteria. Concerning Gram-negative bacteria, the beta-lactam-resistant genes (blaTEM, blaCIT, blaCTX-M, blaIMP, blaKPC, blaOXA-48-like) represented 57.30% of the amplified ARGs. This study found high antibiotic resistance genes in circulation in the fish food industry chain from the macro- to microenvironment. The obtained data confirmed the diffusion of the “antibiotic resistance phenomenon” and its repercussions on the One-health and food-producing systems.
Influence of Fermentation on Functional Properties and Bioactivities of Different Cowpea Leaf Smoothies during In Vitro Digestion
Authors: Moloto Mapula R. , Akinola Stephen A. , Seke Faith , Shoko Tinotenda , Sultanbawa Yasmina , Shai Jerry L. , Remize Fabienne , Sivakumar Dharini
Published: April 2023

This study investigated the effects of Lactiplantibacillus plantarum 75 (LAB 75) fermentation at 37 °C for 48 h on the pH, total soluble solids (TSS), colour, total titratable acidity (TTA), carotenoids, and bioactivities of cowpea leaf smoothies from three cultivars (VOP 1, VOP 3, and VOP 4). Fermentation reduced the pH from 6.57 to 5.05 after 48 h. The TTA increased with the fermentation period, whilst the TSS reduced. Fermentation of the smoothies resulted in the least colour changes (∆E) in VOP 1 after 48 h. Fermentation of cowpea smoothies (VOP 1, VOP 3, and VOP 4) improved the antioxidant capacity (FRAP, DPPH, and ABTS), which was attributed to the increase in total phenolic compounds and carotenoid constituents in all of the fermented cowpea smoothies. VOP 1 was further selected for analysis due to its high phenolic content and antioxidant activity. The VOP 1 smoothie fermented for 24 h showed the lowest reduction in TPC (11%) and had the highest antioxidant (FRAP, DPPH, and ABTS) activity. Ltp. plantarum 75 was viable and survived the harsh conditions of the gastrointestinal tract, and, hence, could be used as a probiotic. VOP 1 intestinal digesta showed significantly higher glucose uptake relative to the undigested and the gastric digesta, while the gastric phase had higher levels of α-amylase and α-glucosidase compared to the undigested samples.