bluuebunny/crossref_metadata_2025 huggingface dataset:
Effectiveness of Stereotactic Ablative Radiotherapy for Systemic Therapy Respondents with Inoperable Pulmonary Oligometastases and Oligoprogression
Authors: Ho Chin-Beng , Tsai Jo-Ting , Chen Chun-You , Shiah Her-Shyong , Chen Hsuan-Yu , Ting Lai-Lei , Kuo Chia-Chun , Lai I-Chun , Lai Hsin-Yi , Chung Chi-Li , Lee Kai-Ling , Tzeng Huey-En , Lee Kuen-Haur , Lee Hsin-Lun , Chen Shang-Wen , Chiou Jeng-Fong
Published: May 2023

Stereotactic ablative radiotherapy (SABR) may improve survival in patients with inoperable pulmonary oligometastases. However, the impact of pulmonary oligometastatic status after systemic therapy on SABR outcomes remains unclear. Hence, we investigated the outcomes of SABR in 45 patients with 77 lung tumors and the prognostic value of pulmonary oligoprogression. Eligibility criteria were pulmonary oligometastases (defined as ≤5 metastatic lung tumors), controlled extrapulmonary disease (EPD) after front-line systemic therapy, SABR as primary local treatment for inoperable pulmonary metastases, and consecutive imaging follow-up. Oligometastatic lung tumor was classified into controlled or oligoprogressive status. Overall survival (OS), in-field progression-free survival (IFPFS), out-field progression-free survival (OFPFS), and prognostic variables were evaluated. With 21.8 months median follow-up, the median OS, IFPFS, and OFPFS were 28.3, not reached, and 6.5 months, respectively. Two-year OS, IFPFS, and OFPFS rates were 56.0%, 74.2%, and 17.3%, respectively. Oligoprogressive status (p = 0.003), disease-free interval < 24 months (p = 0.041), and biologically effective dose (BED10) < 100 Gy (p = 0.006) were independently associated with inferior OS. BED10 ≥ 100 Gy (p = 0.029) was independently correlated with longer IFPFS. Oligoprogressive status (p = 0.017) and EPD (p = 0.019) were significantly associated with inferior OFPFS. Grade ≥ 2 radiation pneumonitis occurred in four (8.9%) patients. Conclusively, SABR with BED10 ≥ 100 Gy could provide substantial in-field tumor control and longer OS for systemic therapy respondents with inoperable pulmonary oligometastases. Oligoprogressive lung tumors exhibited a higher risk of out-field treatment failure and shorter OS. Hence, systemic therapy should be tailored for patients with oligoprogression to reduce the risk of out-field treatment failure. However, in the absence of effective systemic therapy, SABR is a reasonable alternative to reduce resistant tumor burden.
Single Ventricle Reconstruction III: Brain Connectome and Neurodevelopmental Outcomes: Design, Recruitment, and Technical Challenges of a Multicenter, Observational Neuroimaging Study
Authors: Schmithorst Vanessa , Ceschin Rafael , Lee Vincent , Wallace Julia , Sahel Aurelia , Chenevert Thomas L. , Parmar Hemant , Berman Jeffrey I. , Vossough Arastoo , Qiu Deqiang , Kadom Nadja , Grant Patricia Ellen , Gagoski Borjan , LaViolette Peter S. , Maheshwari Mohit , Sleeper Lynn A. , Bellinger David C. , Ilardi Dawn , O’Neil Sharon , Miller Thomas A. , Detterich Jon , Hill Kevin D. , Atz Andrew M. , Richmond Marc E. , Cnota James , Mahle William T. , Ghanayem Nancy S. , Gaynor J. William , Goldberg Caren S. , Newburger Jane W. , Panigrahy Ashok
Published: May 2023

Patients with hypoplastic left heart syndrome who have been palliated with the Fontan procedure are at risk for adverse neurodevelopmental outcomes, lower quality of life, and reduced employability. We describe the methods (including quality assurance and quality control protocols) and challenges of a multi-center observational ancillary study, SVRIII (Single Ventricle Reconstruction Trial) Brain Connectome. Our original goal was to obtain advanced neuroimaging (Diffusion Tensor Imaging and Resting-BOLD) in 140 SVR III participants and 100 healthy controls for brain connectome analyses. Linear regression and mediation statistical methods will be used to analyze associations of brain connectome measures with neurocognitive measures and clinical risk factors. Initial recruitment challenges occurred that were related to difficulties with: (1) coordinating brain MRI for participants already undergoing extensive testing in the parent study, and (2) recruiting healthy control subjects. The COVID-19 pandemic negatively affected enrollment late in the study. Enrollment challenges were addressed by: (1) adding additional study sites, (2) increasing the frequency of meetings with site coordinators, and (3) developing additional healthy control recruitment strategies, including using research registries and advertising the study to community-based groups. Technical challenges that emerged early in the study were related to the acquisition, harmonization, and transfer of neuroimages. These hurdles were successfully overcome with protocol modifications and frequent site visits that involved human and synthetic phantoms.
Continuous Glucose Monitoring in Patients Following Simultaneous Pancreas–Kidney Transplantation: Time in Range and Glucose Variability
Authors: Dmitriev Ilya V. , Severina Anastasia S. , Zhuravel Nikita S. , Yevloyeva Madina I. , Salimkhanov Rustam K. , Shchelykalina Svetlana P. , Bezunov Evgeniy A. , Shamkhalova Minara S. , Semenova Julia F. , Klimontov Vadim V. , Shestakova Marina V.
Published: May 2023

Simultaneous pancreas–kidney transplantation (SPKT) can improve long-term patient survival and restore endogenous insulin secretion in recipients with type 1 diabetes (T1D). There are currently few data on glucose fluctuations assessed by continuous glucose monitoring (CGM) after SPKT. Aim: to evaluate CGM-derived time in range (TIR) and glucose variability (GV) in patients with T1D and functioning pancreatic grafts after SPKT. Fifty-four CGM recordings from 43 patients, 15 men and 28 women, aged 34 (31; 39) years were analyzed. Time since SKPT was up to 1 year (group 1, n = 13), from 1 to 5 years (group 2, n = 15), and from 5 to 12 years (group 3, n = 26). TIR (3.9–10 mmol/L), Time Above Range (TAR), Time Below Range (TBR), and GV parameters were estimated. There were no differences in mean glucose (5.5 [5.1; 6.2], 5.9 [5.4; 6.2], and 5.9 [5.6; 6.7] mmol/L), TIR (97.6 [92.8–99.1], 97.2 [93.2; 99.1], and 97.5 [93.4; 99]%); TAR (0, 1.8 [1.3; 3.7], and 2.5 [2; 5]%), TBR (5 [3.3; 12.7], 4.1 [2.2; 10.1], and 3.5 [1.3; 6.5]%) and GV parameters between three groups (all p > 0.05). Thus, recipients with functioning pancreatic grafts demonstrate remarkably high TIR and low GV after SPKT.
High Intensity Focused Ultrasound Ablation for Juvenile Cystic Adenomyosis: Two Case Reports and Literature Review
Authors: Liu Xin , Wang Jingxi , Liu Yanglu , Luo Shuang , Yan Gaowu , Yang Huaqi , Wan Lili , Huang Guohua
Published: May 2023

Cystic adenomyosis is a rare type of uterine adenomyosis, mainly seen in young women, which is often characterized by severe dysmenorrhea. The quality of life and reproductive function of young women could be affected by misdiagnosis and delayed treatment. At present, there are no universal guidelines and consensus. We report two cases of patients with cystic adenomyosis in juveniles treated with high-intensity focused ultrasound (HIFU) ablation. In the first case, magnetic resonance imaging (MRI) indicated a cystic mass of 2.0 cm × 3.1 cm × 2.4 cm in the uterus. After she underwent HIFU treatment, her pelvic MRI showed a mass of 1.1 × 2.4 cm in size, and her dysmenorrhea symptoms gradually disappeared. In the second case, a pelvic MRI indicated a 5.1 cm × 3.3 cm × 4.7 cm cystic mass in the uterus. After she underwent HIFU and combined four consecutive cycles of GnRH-a treatment, the lesion shrunk 1.2 cm ×1.4 cm × 1.6 cm, without dysmenorrhea. Simultaneously, the report reviewed 14 cases of juvenile cystic adenomyosis over the last ten years. HIFU or HIFU-combined drugs were safe and effective in treating juvenile cystic adenomyosis, but multicenter and prospective studies may be necessary to validate this in the future.
On Two Non-Ergodic Reversible Cellular Automata, One Classical, the Other Quantum
Authors: Prosen Tomaž
Published: May 2023

We propose and discuss two variants of kinetic particle models—cellular automata in 1 + 1 dimensions—that have some appeal due to their simplicity and intriguing properties, which could warrant further research and applications. The first model is a deterministic and reversible automaton describing two species of quasiparticles: stable massless matter particles moving with velocity ±1 and unstable standing (zero velocity) field particles. We discuss two distinct continuity equations for three conserved charges of the model. While the first two charges and the corresponding currents have support of three lattice sites and represent a lattice analogue of the conserved energy–momentum tensor, we find an additional conserved charge and current with support of nine sites, implying non-ergodic behaviour and potentially signalling integrability of the model with a highly nested R-matrix structure. The second model represents a quantum (or stochastic) deformation of a recently introduced and studied charged hardpoint lattice gas, where particles of different binary charge (±1) and binary velocity (±1) can nontrivially mix upon elastic collisional scattering. We show that while the unitary evolution rule of this model does not satisfy the full Yang–Baxter equation, it still satisfies an intriguing related identity which gives birth to an infinite set of local conserved operators, the so-called glider operators.
Amplitude Constrained Vector Gaussian Wiretap Channel: Properties of the Secrecy-Capacity-Achieving Input Distribution
Authors: Favano Antonino , Barletta Luca , Dytso Alex
Published: May 2023

This paper studies the secrecy capacity of an n-dimensional Gaussian wiretap channel under a peak power constraint. This work determines the largest peak power constraint R¯n, such that an input distribution uniformly distributed on a single sphere is optimal; this regime is termed the low-amplitude regime. The asymptotic value of R¯n as n goes to infinity is completely characterized as a function of noise variance at both receivers. Moreover, the secrecy capacity is also characterized in a form amenable to computation. Several numerical examples are provided, such as the example of the secrecy-capacity-achieving distribution beyond the low-amplitude regime. Furthermore, for the scalar case (n=1), we show that the secrecy-capacity-achieving input distribution is discrete with finitely many points at most at the order of R2σ12, where σ12 is the variance of the Gaussian noise over the legitimate channel.
A Semi-Quantum Secret-Sharing Protocol with a High Channel Capacity
Authors: Tian Yuan , Bian Genqing , Chang Jinyong , Tang Ying , Li Jian , Ye Chongqiang
Published: May 2023

Semi-quantum cryptography communication stipulates that the quantum user has complete quantum capabilities, and the classical user has limited quantum capabilities, only being able to perform the following operations: (1) measuring and preparing qubits with a Z basis and (2) returning qubits without any processing. Secret sharing requires participants to work together to obtain complete secret information, which ensures the security of the secret information. In the semi-quantum secret sharing (SQSS) protocol, the quantum user Alice divides the secret information into two parts and gives them to two classical participants. Only when they cooperate can they obtain Alice’s original secret information. The quantum states with multiple degrees of freedom (DoFs) are defined as hyper-entangled states. Based on the hyper-entangled single-photon states, an efficient SQSS protocol is proposed. The security analysis proves that the protocol can effectively resist well-known attacks. Compared with the existing protocols, this protocol uses hyper-entangled states to expand the channel capacity. The transmission efficiency is 100% higher than that of single-degree-of-freedom (DoF) single-photon states, providing an innovative scheme for the design of the SQSS protocol in quantum communication networks. This research also provides a theoretical basis for the practical application of semi-quantum cryptography communication.
Dynamic Information-Hiding Method with High Capacity Based on Image Interpolating and Bit Flipping
Authors: Huang Cheng-Ta , Lin Cheng-Yi , Weng Chi-Yao
Published: May 2023

In this era of rapid information exchange in public networks, there is a risk to information security. Data hiding is an important technique for privacy protection. Image interpolation is an important data-hiding technique in image processing. This study proposed a method called neighbor mean interpolation by neighboring pixels (NMINP) that calculates a cover image pixel by neighbor mean interpolation and neighboring pixels. To reduce image distortion, NMINP limits the number of bits when embedding secret data, making NMINP have a higher hiding capacity and peak signal-to-noise ratio (PSNR) than other methods. Furthermore, in some cases, the secret data are flipped, and the flipped data are treated in ones’ complement format. A location map is not needed in the proposed method. Experimental results comparing NMINP with other state-of-the-art methods show that NMINP improves the hiding capacity by more than 20% and PSNR by 8%.
Bilingual Science Lexicon of Pre-Serviced Primary School Teachers
Authors: López-Pérez Magdalena , de la Montaña Conchiña Juan Luis , Bravo Galán José Luis , de la Maya Retamar Guadalupe
Published: May 2023

Bilingual teaching has experienced rapid growth in the Spanish educational panorama and numerous university programmes have emerged with the aim of training future CLIL (Content and Language Integrated Learning) teachers. However, there is little research assessing the level of linguistic competence in Spanish and foreign languages of future teachers, especially those who are studying for a bilingual degree. Although this work is part of a broader project that analyses bilingual lexical competence in subjects related to the Social Sciences and Experimental Sciences, we focus on the analysis of lexical availability of content related to the teaching of science. The sample consisted of 46 students of the Degree in Primary Education at the University of Extremadura. Using a lexical availability test, lexical production in Spanish and English is analysed and compared to determine whether the fact of studying in English affects the acquisition and consolidation of lexical knowledge in Spanish. The results show that there are no significant differences in lexical production between Spanish and English. In addition to the quantitative data, results from the qualitative analysis are presented, analysing the most available words and the organisation of the lexicon in both languages.
Learning Peer Recommendation Based on Weighted Heterogeneous Information Networks on Online Learning Platforms
Authors: Shou Zhaoyu , Shi Zhixuan , Wen Hui , Liu Jinghua , Zhang Huibing
Published: May 2023

With the development of online education, there is an urgent need to solve the problem of the low completion rate of online learning courses. Although learning peer recommendation can effectively address this problem, prior studies of learning peer-recommendation methods extract only a portion of the interaction information and fail to take into account the heterogeneity of the various types of objects (e.g., students, teachers, videos, exercises, and knowledge points). To better motivate students to complete online learning courses, we propose a novel method to recommend learning peers based on a weighted heterogeneous information network. First, we integrate the above different objects, various relationships between objects, and the attribute values to links in a weighted heterogeneous information network. Second, we propose a method for automatically generating all meaningful weighted meta-paths to extract and identify meaningful meta-paths. Finally, we use the Bayesian Personalized Ranking (BPR) optimization framework to discover the personalized weights of target students on different meaningful weighted meta-paths. We conducted experiments using three real datasets, and the experimental results demonstrate the effectiveness and interpretability of the proposed method.
Safety-Critical Control for Control Affine Systems under Spatio-Temporal and Input Constraints
Authors: Wang Shang , Liu Fangzhou , Li Cong , Liu Qingchen
Published: May 2023

Safety-critical control is a type of modern control task where potentially conflicting stability, safety, and input constraints coexist. In this paper, the Prescribed-Time Zeroing Control Barrier Function (PT-ZCBF) is introduced, which can be applied as a prescribed-time stability constraint in safety-critical control tasks. Furthermore, we formulate a PT-ZCBF-based Quadratic Program (QP), which is able to mediate the potentially conflicting constraints of safety-critical control. The solution of the newly designed QP, acting as the control input of a safety-critical system, can drive the closed-loop trajectories to converge in a user-defined prescribed time period while observing the safety and input constraints. Finally, we use the Adaptive Cruise Control (ACC) problem as an example of numerical simulation to evaluate the performance of the QP-based method.
Knowledge-Based Features for Speech Analysis and Classification: Pronunciation Diagnoses
Authors: Liu Lichuan , Li Wei , Morris Sherrill , Zhuang Mutian
Published: May 2023

Accurate pronunciation of speech sounds is essential in communication. As children learn their native language, they refine the movements necessary for intelligible speech. While there is variability in the order of acquisition of speech sounds, there are some sounds that are more complex and are later developing. The rhotic /r/ is a later-developing sound in English, and some children require intervention to achieve accurate production. Additionally, individuals learning English as a second language may have difficulty learning accurate /r/ production, especially if their native language does not have an /r/, or the /r/ they produce is at a different place of articulation. The goal of this research is to provide a novel approach on how a knowledge-based intelligence program can provide immediate feedback on the accuracy of productions. In the proposed approach, the audio signals will first be detected, after which features of audio signals will be extracted, and finally, knowledge-based intelligent classification will be performed. Based on the obtained knowledge and application scenarios, novel features are proposed and used to classify various speaker scenarios.
Deep Learning and Cloud-Based Computation for Cervical Spine Fracture Detection System
Authors: Chłąd Paweł , Ogiela Marek R.
Published: May 2023

Modern machine learning models, such as vision transformers (ViT), have been shown to outperform convolutional neural networks (CNNs) while using fewer computational resources. Although computed tomography (CT) is now the standard for imaging diagnosis of adult spine fractures, analyzing CT scans by hand is both time consuming and error prone. Deep learning (DL) techniques can offer more effective methods for detecting fractures, and with the increasing availability of ubiquitous cloud resources, implementing such systems worldwide is becoming more feasible. This study aims to evaluate the effectiveness of ViT for detecting cervical spine fractures. Data gathered during the research indicates that ViT models are suitable for large-scale automatic detection system implementation. The model achieved 98% accuracy and was easy to train while also being easily explainable.
Map-in-Parallel-Coordinates Plot (MPCP): Field Trial Studies of High-Dimensional Geographical Data Analysis
Authors: Liu Jia , Wan Gang , Jia Yutong , Liu Wei , Xie Zhuli , Su Zhijuan , Li Chu , Peng Siqing
Published: May 2023

As the world has become increasingly digitalized in recent years, high-dimensional data with geographical location coordinate attributes, mainly referring to latitude and longitude, have been accumulated and spread to many disciplines. It is challenging to analyze such data. The map-in-parallel-coordinates plot (MPCP) is an incorporate visual analysis method that can express, filter, and highlight high-dimensional geographical data to facilitate data exploration and comprehension. In this paper, the MPCP underwent a series of field trial studies to verify its applicability, adaptability, and high efficacy in the real-world. The results of the evaluation were positive, which provides reasonable proof and new insights into the benefits of using MPCP to visually analyze high-dimensional geographical datasets.
A Modular Haptic Agent System with Encountered-Type Active Interaction
Authors: Dongye Xiaonuo , Weng Dongdong , Jiang Haiyan , Feng Lulu
Published: May 2023

Virtual agents are artificial intelligence systems that can interact with users in virtual reality (VR), providing users with companionship and entertainment. Virtual pets have become the most popular virtual agents due to their many benefits. However, haptic interaction with virtual pets involves two challenges: the rapid construction of various haptic proxies, and the design of agent-initiated active interaction. In this paper, we propose a modular haptic agent (MHA) prototype system, enabling the tactile simulation and encountered-type haptic interaction of common virtual pet agents through a modular design method and a haptic mapping method. Meanwhile, the MHA system with haptic interaction is actively initiated by the agents according to the user’s intention, which makes the virtual agents appear more autonomous and provides a better experience of human–agent interaction. Finally, we conduct three user studies to demonstrate that the MHA system has more advantages in terms of realism, interactivity, attraction, and raising user emotions. Overall, MHA is a system that can build multiple companion agents, provide active interaction and has the potential to quickly build diverse haptic agents for an intelligent and comfortable virtual world.
Congestion Avoidance in Intelligent Transport Networks Based on WSN-IoT through Controlling Data Rate of Zigbee Protocol by Learning Automata
Authors: He Zhou , Chen Lian , Li Feng , Jin Ge
Published: May 2023

Congestion control is one of the primary challenges in improving the performance of wireless sensor networks (WSNs). With the development of this network based on the Internet of Things (IoT), the importance of congestion control increases, and the need to provide more efficient strategies to deal with this problem is strongly felt. This problem is even more important in applications such as Intelligent Transport Systems (ITSs). This article introduces a new method for congestion control in ITSs based on WSN-IoT infrastructure, namely, the Congestion Avoidance by Reinforcement Learning algorithm (CARLA). The purpose of the research was to improve the performance of the Zigbee protocol in congestion control through more efficient routing and also the intelligent adjustment of the data rate of the nodes. For this purpose, a topology control and routing strategy based on the multiple Bloom filter (MBF) is proposed in this research. Further, learning automata (LA) was used as a reinforcement learning model to adjust the data rate of network nodes in a distributed manner. These strategies distinguish the current research from previous efforts and can be effective in reducing the probability of congestion in the network. The performance evaluation results of the proposed algorithm in a simulated ITS environment were compared with conventional Zigbee and state of the art methods. According to the results, CARLA can improve PDR by 4.64%, and at the same time, reduce energy consumption and end-to-end delay by 11.44% and 25.26%, respectively. The results confirm that by using CARLA, in addition to congestion control in the ITS, energy consumption and the end-to-end delay can also be reduced.
Electromagnetic Interference in Cardiac Implantable Electronic Devices Due to Dynamic Wireless Power Systems for Electric Vehicles
Authors: Campi Tommaso , Cruciani Silvano , Maradei Francesca , Feliziani Mauro
Published: May 2023

Electric vehicles (EV) are now considered the present and future of road transportation to reduce the emission of CO2 into the environment and thus progressively reduce global warming and climate change. However, EVs currently have some weaknesses such as the available range of battery-powered EVs and the recharging time of the batteries. To overcome these problems, some electrification projects have been proposed for road transportation such as the dynamic wireless power transfer (DWPT), where an EV charges as it moves along an electrified lane using magneto-resonant coupling between short tracks mounted on the road pavement and the vehicle’s onboard pickup coils. While the results are encouraging from an electrical point of view, there is concern regarding the magnetic field in the environment produced by the DWPT coils, which can produce adverse health effects in humans and electromagnetic interference (EMI) in electronic devices. The latter also includes implantable medical devices (IMDs) and in particular cardiac implantable electronic devices (CIEDs), which may be present among vehicle passengers and pedestrians in areas surrounding the vehicle. The aim of this study is the numerical analysis of the EMI produced by a DWPT system in CIEDs with leads such as pacemakers, implantable cardioverter defibrillators (ICDs), etc. EMI is mainly produced by the incident magnetic field and the induced voltage at the input port of a CIED; therefore, in this work the magnetic field levels produced by a DWPT system operating at 85 kHz are calculated first, then the voltage at the input port of a pacemaker is evaluated as that produced by the magnetic field incident on the loop surface formed by a lead implanted in the venous system. According to ISO 14117 standard, it is assumed that the lead loop is planar, semicircular in shape and with an area equal to 225 cm2. Since the lead can be placed anywhere where a human can be and with any orientation, an innovative and sophisticated roto-translation algorithm is proposed to find the maximum value of the peak-to-peak induced loop voltage in the most critical regions inside the vehicle cabin and beside the vehicle near the DWPT coils. The preliminary results obtained show that there is no EMI risk inside the vehicle for the passengers with CIEDs, while some concern for pedestrians is due to the induced voltage at the input port of a CIED with unipolar leads which can exceed the ISO 14117 limit in the region next to the vehicle.
Comparing the Performance of a Straight-Channel Heat Sink with Different Channel Heights: An Experimental and Numerical Study
Authors: Hajialibabaei Mahsa , Saghir Mohamad Ziad , Bicer Yusuf
Published: May 2023

Straight-channel heat sinks are widely used as a cooling method for electronic devices and lithium battery thermal management. This study aims to enhance the thermal performance of a straight-channel heat sink while decreasing the pressure drop. In this design, the height of inside channels is reduced to provide open space above the channel while the size of the heat sink remains constant. Both experimental investigation and numerical analysis were conducted to study the thermal efficiency of heat sinks with varying heights, at flow rates ranging from 6.94 to 19.56 m3/s and heat fluxes between 3.8 and 7.43 W/cm2. The comparison is carried out between channels with four different heights in terms of temperature distribution, local Nusselt number, velocity, and flow characteristic. The results indicate that lowering the height of the channel from 12.7 to 7 and 4 mm raises the highest temperature of the heat sink, whereas the change in height to 10 mm reduces the temperature. Furthermore, increasing the flow rate has a higher impact on improving the Nusselt number in channels with a height of 10 mm. When the height is decreased from 12.7 to 10 mm, the performance evaluation criterion is obtained higher than one for all flow rates.
Numerical Modeling and Simulation of the Solid Oxide Cell Stacks and Metal Interconnect Oxidation with OpenFOAM
Authors: Yu Shangzhe , Zhang Shidong , Schäfer Dominik , Peters Roland , Kunz Felix , Eichel Rüdiger-A.
Published: May 2023

Solid oxide cells are capable of efficiently converting various chemical energy carriers to electricity and vice versa. The urgent challenge nowadays is the faster degradation rate compared with other fuel cell/electrolyzer technologies. To understand the degradation mechanisms, simulation of a solid oxide cell is helpful. Since most previous research developed models using commercial software, such as COMSOL and ANSYS Fluent, a gap for knowledge transfer is being gradually formed between academia and industry due to licensing issues. This paper introduces a multiphysics model, developed by a computational code, openFuelCell2. The code is implemented with an open-source library, OpenFOAM. It accounts for momentum transfer, mass transfer, electrochemical reactions and metal interconnect oxidation. The model can precisely predict I–V curves under different temperatures, fuel humidity and operation modes. Comparison between OpenFOAM and COMSOL simulations shows good agreement. The metal interconnect oxidation is modeled, which can predict the thickness of the oxide scale under different protective coatings. Simulations are conducted by assuming an ultra-thin film resistance on the rib surface. It is revealed that coatings fabricated by atmospheric plasma spraying can efficiently prevent metal interconnect oxidation, with a contribution of only 0.53 % to the total degradation rate.
Two- and Three-Stage Natural Gas Combustion System—Experimental Comparative Analysis
Authors: Pielecha Ireneusz , Szwajca Filip
Published: May 2023

The use of fuels with tendencies to reduce carbon dioxide emissions, particularly gaseous fuels, and improve combustion systems is one of the directions for increasing an internal combustion engine’s attractiveness as a power source. This article presents the effects of combining natural gas combustion with a multi-stage combustion system. A two- and three-stage lean charge combustion system was proposed in order to increase the energy system efficiency. In order to achieve this, a single-cylinder test engine was used, with two interchangeably implemented combustion systems. The tests were carried out with two values of the excess air coefficient (λ = 1.3 and λ = 1.5), as well as two different fuel dose values (qo = 0.35 and 0.55 mg/inj), injected into the prechamber at the same indicated mean effective pressure value (IMEP = 6.5 bar) and the same engine speed (n = 1500 rpm). Based on the obtained research results, it was found that the use of a three-stage system limited the maximum combustion pressure and heat release rate due to the increased resistance of flows between the chambers. At the same time, it was found that the increase in the engine’s indicated efficiency took place in a two-stage system, regardless of the excess air coefficient. Changing the dose of fuel fed into the prechamber significantly affects the engine performance (and efficiency) but only in the two-stage combustion system.
A Review of Econometric Approaches for the Oil Price-Exchange Rate Nexus: Lessons for ASEAN-5 Countries
Authors: Kisswani Khalid M. , Fikru Mahelet G.
Published: May 2023

This paper reviews alternative econometric approaches the literature has used to examine the connectedness between oil prices and exchange rates and illustrates their application using quarterly data from 1970: Q1 to 2022: Q1 for ASEAN-5 countries, which are as follows: Indonesia, Malaysia, the Philippines, Singapore, and Thailand. Although most studies examining the impact of oil prices and exchange rates apply the Ordinary Least Squares (OLS) approach with symmetry, the quantile regression (QR) method is shown to offer a thorough investigation of the connectedness. For ASEAN-5 countries, we present a comparative analysis of both methodologies (OLS and QR) with and without asymmetry. Our findings suggest that asymmetric effects triggered by oil prices are noticeably heterogeneous across quantiles. Hence, future studies should allow for asymmetry in the oil price by decomposing the price into positive and negative changes to further investigate the connectedness between oil prices and exchange rates.
Recent Trends in Additive Manufacturing and Topology Optimization of Reluctance Machines
Authors: Hussain Shahid , Kallaste Ants , Vaimann Toomas
Published: May 2023

Additive manufacturing (AM) or 3D printing has opened up new opportunities for researchers in the field of electrical machines, as it allows for more flexibility in design and faster prototyping, which can lead to more efficient and cost-effective production. An overview of the primary AM techniques utilized for designing electrical machines is presented in this paper. AM enables the creation of complex and intricate designs that are difficult or impossible to achieve using traditional methods. Topology Optimization (TO) can be used to optimize the design of parts for various purposes such as weight, thermal, material usage and structural performance. This paper primarily concentrates on the most recent studies of the AM and TO of the reluctance machines. The integration of AM with TO can enhance the design and fabrication process of magnetic components in electrical machines by overcoming current manufacturing limitations and enabling the exploration of new design possibilities. The technology of AM and TO both have limitations and challenges which are discussed in this paper. Overall, the paper offers a valuable resource for researchers and practitioners working in the field of AM and TO of electrical machines.
CFD Investigation of a Hybrid Wells Turbine with Passive Flow Control
Authors: Uddin Mohammad Nasim , Atkinson Michael , Opoku Frimpong
Published: May 2023

In the past decade, there has been renewed interest in wave energy harvesting utilizing oscillating water columns (OWC), one of the most well-studied wave energy harnessing technologies. In the OWC, pneumatic power from ocean waves is converted to mechanical energy by Wells turbines. It should be noted, however, that such turbines tend to perform poorly, have a limited operating range, and have low efficiency. In the present study, we incorporate a rectangular Gurney flap (GF) at the trailing edge (TE) of a Wells turbine consisting of hybrid airfoil (NACA 0015 and NACA 0025) blades with variable chord distribution along the span. This passive flow control mechanism was adopted to achieve increased power production by the Wells turbine. This study aimed to determine the aerodynamic performance of the variable chord turbine with GF compared to a turbine with a constant chord. By using ANSYS™ CFX, the three-dimensional, steady-state, incompressible Reynolds averaged Navier–Stokes (RANS) equations coupled with the k-ω SST turbulence model are solved. The performance was evaluated through the use of non-dimensional coefficients of torque, pressure drop, and efficiency. In addition, the numerical accuracy was achieved through a grid independence study. There was a good agreement between the computed results and the available experimental and numerical data. The GF increased the torque coefficient by 18.6% and 47.3% but with the expense of peak efficiency of 8.5% and 7.4% for the baseline and the hybrid turbine, respectively. Additionally, the hybrid turbine with GF delayed the onset of the stall by ~3° angle of attack (AOA).
Performance of Mn-Ce-Fe/FA Catalysts on Selective Catalytic Reduction of NOX with CO under Different Atmospheres
Authors: Xia Zheng , Zhang Ruiping , Duan Jixin , Liu Yanxing , Li Zhengyuan , Gou Xiang
Published: May 2023

Gas turbines produce a large amount of NOx and CO due to high temperatures and insufficient combustion. Through the selective catalytic reduction of NO with CO (CO-SCR) in a gas turbine, the activities of the Mn-Fe-Ce/FA catalyst using fly ash (FA) as a carrier under different atmospheres were studied. The catalysts prepared by calcining different active materials under different atmospheres were used to analyze their denitrification abilities and resistance to water vapor. The denitrification performance of the catalyst prepared under reducing atmosphere is about 30 percent higher than that of the catalyst prepared under air atmosphere, and the decarburization performance is about 40 percent higher. In the presence of oxygen, the denitrification rate and decarburization rate of the 1:1 ratio of the Mn-Ce catalyst reach 67.16% and 59.57%, respectively. In an oxygen-containing atmosphere, the catalyst prepared by replacing Ce with Fe shows better denitrification and decarburization performances, which are 78.56% and 78.39%, respectively. When the flue gas space velocity is 4000 h−1 and the carbon-nitrogen ratio is 1.6, the catalyst shows better performance. After the water vapor is introduced, the denitrification and decarbonization rates of the catalyst decrease by about 10% and 9%, respectively. After ceasing water vapor, it rebounds by about 8%, and the activity could not be fully restored. However, the catalyst still shows strong water resistance in general.
The Material Entropy and the Fourth Law of Thermodynamics in the Evaluation of Energy Technologies of the Future
Authors: Jakimowicz Aleksander
Published: May 2023

The primary purpose of this article is to use the laws of thermodynamics, mainly the second and fourth laws, to evaluate three energy technologies of the future: fusion, solar, and fission. Among the criteria used to evaluate them, the most important are the amount of matter needed to sustain the technology itself and the environmental impact. Much emphasis is placed here on the fourth law of thermodynamics, which introduces the concept of material entropy. Zemansky–Georgescu-Roegen’s Law of Inevitable Dissipation of Useful Concentrated Matter states that, in the economic process, some matter is inevitably degraded and becomes unavailable matter. This has tremendous implications for humanity as a whole since the Earth is thermodynamically a closed system, meaning that it cannot exchange matter with space but is open to the flow of solar energy. This results in the need to conserve matter and natural resources. This law can be used as an important criterion for the selection of energy technology. Moreover, the flow–fund model, which was proposed by Georgescu-Roegen, was used to assess the viability of energy technologies. The final conclusion is that there is no Promethean technology of the third kind yet, but the closest to meeting this condition is solar technology. Technology based on nuclear fission has been rejected due to its adverse ecological effects, while fusion technology has proven to be less useful due to the matter criterion, the negative environmental impact, since radioactive waste only becomes safe for humans after 500 years, and the risks associated with nuclear proliferation. Solar technology can become Prometheus III only after all of humanity is involved with this project, which requires profound social changes, widespread demilitarization, and the development of organic agriculture. This implies the necessity of the emergence of a global solar society based on an economic system called solar communism.
Optimization of Fermentation Conditions for Elevating Limonene Production with Engineered Rhodosporidium toruloides
Authors: Zhao Di , Gao Qidou , Zheng Xiaochun , Liu Sasa , Qi Qingsheng , Wang Xue , Yang Xiaobing
Published: May 2023

Limonene is a valuable monoterpenoid with diverse applications in food, medicine, agriculture, etc. Currently, the commercial production of limonene from citrus pomace cannot meet the evergrowing market demand. With the development of synthetic biology, microbial biosynthesis is offering a sustainable alternative to plant-based extraction. However, the performance of engineered strains can be affected by many factors including the microbial host, the cultivation conditions, etc. Therefore, in the present study, potential factors that influence the limonene production of the engineered strains were investigated through single-factor and orthogonal experiments. The optimized medium was MM, with a working volume of 50 mL, inoculum OD600 = 0.6, 22 °C, pH 6, and a dodecane coverage (v/v) of 20%. The final limonene titer was improved from 52.5 to 358.1 mg/L, a 586% net increase in titer and 34.8-fold improvement in production efficiency (mg/OD600) on 250-mL flasks. The results here demonstrated that R. toruloides could be explored as an efficient limonene producer and could facilitate the study of the biosynthesis of other terpenes using R. toruloides.
Modification of the Fermentation Process and Papain Enzymes in The Manufacture of Virgin Coconut Oil Using Optimization of Response Surface Methodology, Central Composite Design
Authors: Jakfar  , Husin Husni , Pontas Komala , Mamat Rizalman , Salleh Mohd Rosdi , Zulrika Mirna , Ahmadi
Published: May 2023

This research focuses on optimizing fermentation modification and papain enzymes. In manufacturing virgin coconut oil using the response surface methodology (RSM), the experiment was carried out based on the Central Composite Design (CCD). Coconut oil yield, as a function of crude papain enzyme (CPE) mass (0–1 g) and fermentation time (12–60 h), was observed for 13 runs. The yield of virgin coconut oil with natural fermentation without the addition of crude enzyme papain is 19%, and with the addition of 1 g of the enzyme, it can reach a maximum of 27.7%. Optimal conditions were obtained at a mass of crude papain enzyme 993.5 mg, fermentation time 60 h respectively, yields: Banda Aceh virgin coconut oil (BAVCO) 28.4%, Pidie Jaya virgin coconut oil (PJVCO) 25.6%, and Bireuen virgin coconut oil (BVCO) 24.7%, quality of virgin coconut oil (VCO): water content (WC) 0.047%, free fatty acid (FFA) 0.01%, and peroxide (PN) 0.024% from each of the total mass of 300 g grated coconut, VCO modified by fermentation with the addition of CPE increased the yield. The quality of VCO in terms of WC, FFA, and PN meets the VCO quality standard. The optimization for desirability was 0.998, and the product had a transparent color, a distinct aroma, and did not have a putrid aroma.
Mobile Application for Real-Time Food Plan Management for Alzheimer Patients through Design-Based Research
Authors: Duarte Rui P. , Cunha Carlos A. S. , Alves Valter N. N.
Published: May 2023

Alzheimer’s disease is a type of dementia that affects many individuals, mainly in an older age group. Over time, it leads to other diseases that affect their autonomy and independence. The quality of food ingestion is a way to mitigate the disease and preserve the patient’s well-being, which substantially impacts their health. Many existing applications for food plan management focus on the prescription of food plans but do not provide feedback to the nutritionist on the real amount of ingested calories. It makes these applications inadequate for these diseases, where monitoring and control are most important. This paper proposed the design and development of a mobile application to monitor and control the food plans of Alzheimer’s patients, focused on informal caregivers and respective patients. It allows both the realistic visualization of the food plans and users to adjust their consumption and register extra meals and water consumption. The interface design process comprises a two-level approach: the user centered design methodology that accounts for users’ needs and requirements and the user experience questionnaire to measure user satisfaction. The results show that the interface is intuitive, visually appealing, and easy to use, adjusted for users that require a particular level of understanding regarding specific subjects.
Mechanical Properties and Morphological Alterations in Fiber-Based Scaffolds Affecting Tissue Engineering Outcomes
Authors: Dolgin James , Hanumantharao Samerender Nagam , Farias Stephen , Simon Carl G. , Rao Smitha
Published: May 2023

Electrospinning is a versatile tool used to produce highly customizable nonwoven nanofiber mats of various fiber diameters, pore sizes, and alignment. It is possible to create electrospun mats from synthetic polymers, biobased polymers, and combinations thereof. The post-processing of the end products can occur in many ways, such as cross-linking, enzyme linking, and thermal curing, to achieve enhanced chemical and physical properties. Such multi-factor tunability is very promising in applications such as tissue engineering, 3D organs/organoids, and cell differentiation. While the established methods involve the use of soluble small molecules, growth factors, stereolithography, and micro-patterning, electrospinning involves an inexpensive, labor un-intensive, and highly scalable approach to using environmental cues, to promote and guide cell proliferation, migration, and differentiation. By influencing cell morphology, mechanosensing, and intracellular communication, nanofibers can affect the fate of cells in a multitude of ways. Ultimately, nanofibers may have the potential to precisely form whole organs for tissue engineering, regenerative medicine, and cellular agriculture, as well as to create in vitro microenvironments. In this review, the focus will be on the mechanical and physical characteristics such as porosity, fiber diameter, crystallinity, mechanical strength, alignment, and topography of the nanofiber scaffolds, and the impact on cell proliferation, migration, and differentiation.
Factors Associated with Concurrent Tobacco Smoking and Heavy Drinking within a Women Firefighters’ Sample
Authors: Jitnarin Nattinee , Haddock Christopher K. , Kaipust Christopher M. , Poston Walker S. C. , Jahnke Sara A.
Published: May 2023

Studies showed that tobacco use and excessive alcohol consumption frequently occur, and both are significant causes of preventable morbidity and mortality. Data were collected as part of a national online study of the health of women in the fire service. Multinomial logistic regression was employed to determine factors associated with smoking and drinking characteristics. A total of 2330 women firefighters completed questions regarding tobacco and alcohol use; 3.2% (n = 75) were concurrent users, 0.9% (n = 22) were smokers only, 49.4% (n = 1150) were heavy drinkers only, and 46.5% (n = 1083) were low-risk users. Compared with those who neither smoked nor binge drank, concurrent users were more likely to be younger and live alone or not married. The findings also suggested that smokers, heavy drinkers, or those who were both were more likely to report symptoms of depression and PTSD and a history of physician diagnosis of anxiety disorder compared to low-risk users. Smoking rates are relatively low among women firefighters; however, mental health risks are prevalent, particularly for those who both smoked and drank heavily. Results can be potentially used to inform prevention and treatment research to better address the unique condition of this occupational group.
Modeling and Experimental Characterization of a Clutch Control Strategy Using a Magnetorheological Fluid
Authors: Lo Sciuto Grazia , Kowol Paweł , Capizzi Giacomo
Published: May 2023

In this paper, the characterization of a new clutch control strategy by means of a magnetorheological fluid (MR) has been investigated. The clutch system was designed and manufactured in the laboratory in order to determine its static and dynamic characteristics. As a result of experimental measurements, the torque control of the developed MR clutch was determined in the frequency and time domains, as were the analytical relationships describing the connection between the control and controlled variables. The obtained results demonstrate that the analytical models are in good agreement with the experimental data, with an overall error of about 7%.