bluuebunny/crossref_metadata_2025 huggingface dataset:
A Prototype Assay Multiplexing SARS-CoV-2 3CL-Protease and Angiotensin-Converting Enzyme 2 for Saliva-Based Diagnostics in COVID-19
Authors: Suresh Vallabh , Sheik Daniel A. , Detomasi Tyler C. , Zhao Tianqi , Zepeda Theresa , Saladi Shyam , Rajesh Ummadisetti Chinna , Byers Kaleb , Craik Charles S. , Davisson Vincent Jo
Published: June 2023

With the current state of COVID-19 changing from a pandemic to being more endemic, the priorities of diagnostics will likely vary from rapid detection to stratification for the treatment of the most vulnerable patients. Such patient stratification can be facilitated using multiple markers, including SARS-CoV-2-specific viral enzymes, like the 3CL protease, and viral-life-cycle-associated host proteins, such as ACE2. To enable future explorations, we have developed a fluorescent and Raman spectroscopic SARS-CoV-2 3CL protease assay that can be run sequentially with a fluorescent ACE2 activity measurement within the same sample. Our prototype assay functions well in saliva, enabling non-invasive sampling. ACE2 and 3CL protease activity can be run with minimal sample volumes in 30 min. To test the prototype, a small initial cohort of eight clinical samples was used to check if the assay could differentiate COVID-19-positive and -negative samples. Though these small clinical cohort samples did not reach statistical significance, results trended as expected. The high sensitivity of the assay also allowed the detection of a low-activity 3CL protease mutant.
Neurocognitive and Psychological Outcomes Among Children and Adolescents with Brain Tumors: Development of an Observational and Longitudinal Prospective Study Protocol
Authors: Zucchetti Giulia , Gamberini Giorgia , Ciappina Sabrina , Cagnazzo Celeste , Ricci Federica , Vallero Stefano , Quarello Paola , Peretta Paola , Fagioli Franca
Published: June 2023

Children and adolescents affected by brain tumors are at risk for neuropsychological sequelae that need to be evaluated in order to plan adequate rehabilitation programs, and to support their development and recovery. This work aims to describe an innovative prospective observational study protocol for the early evaluation and monitoring over time of neuropsychological outcomes in this pediatric population. Pediatric patients aged 3–17 with a brain tumor diagnosis will be assessed through the use of a battery of Italian standardized neuropsychological tests, with good psychometric properties and age-appropiate, at three different time points of their clinical course: at diagnosis and before surgery (T0), after surgical removal and before the start of potential adjuvant therapies (T1), and at the one-year follow-up after potential adjuvant therapies (T2). This study will allow clinicians to support the neuropsychological development of these children by promoting appropriate and timely rehabilitation and educational programs from the early phases of their clinical course.
The Influence of Residential Block Form on Summer Thermal Comfort of Street Canyons in the Warm Temperate Zone of China
Authors: Song Xiaoyi , Wang Guangbin , Deng Qingtan , Wang Siyu , Jiao Chenxia
Published: June 2023

The residential block is the cognitive unit for residents to constitute urban imagery. As one of the most frequently used urban outdoor public spaces by residents, the thermal comfort of street canyons is an essential indicator for assessing sustainable and livable cities. The problem of the uncomfortable summer climate in the warm temperate zone of China has not been adequately studied. The study aims to analyze the influence of the building layout form of residential block units and block configuration on the outdoor summer thermal comfort of street canyons. Outdoor air temperature (Ta), mean radiant temperature (Tmrt), wind speed (Va), and physiological equivalent temperature (PET) were simulated using ENVI-met. A new index, PETws, was introduced based on a statistical analysis of the PET index to assess the overall street canyon thermal comfort of the block. The results indicate that the number of rows of buildings in the building row layout has a more significant effect on the summer thermal comfort PET of street canyons than the number of columns in the warm temperate zone, especially on N–S-oriented streets. Reducing the number of rows can increase the overall thermal comfort PETws of street canyons by a maximum of 2.2%. The best choice for the number of building columns is two columns. Adopting different block configurations can increase the thermal comfort PETws of street canyons by up to 2.5%. An optimal block form has been created to improve the overall street canyon summer thermal comfort of the block.
Ground Surface Deformation Caused by Pipe Jacking Construction in a Soft Soil Area: An Experiment-Based Study
Authors: Tang Junfeng , Xu Junkai , Zhou Dezhou , Huang Dong , Zeng Ke , Li Yuhang , Chen Zhuo
Published: June 2023

Soft soil has the characteristics of high compressibility, large void ratio, and strong structure. Therefore, it is more likely to cause surface subsidence or even surface cracking and collapse when laying oil and gas pipelines in soft soil areas through the pipe jacking method. In this study, test soil was pressurized using a flexible loading bladder, and variable formation losses brought on by pipe jacking were mimicked by varying the loading bladder’s water injection level. The surface deformation brought on by pipe jacking construction is related to the four parameters of stratum loss rate, overburden load, soil disturbance, soil tension fissures, and horizontal deformation. The findings demonstrate that the surface deformation brought on by the excavation gradually reduces and starts to stabilize after the thickness of the overlying soil layer on the pipe jacking surpasses 1.5 times the diameter of the pipe jacking. The constructed settling tank is broader the deeper the jacking pipe is submerged. Further ground surface settling will be exacerbated by the weight above the jacking pipe. The maximum ground surface deformation value will decrease with an increase in the overlying load when the overlying load is high (0.018 MPa).
Effect of Nanographite Conductive Concrete Mixed with Magnetite Sand Excited by Different Alkali Activators and Their Combinations on the Properties of Conductive Concrete
Authors: Ren Zhenhua , Zeng Hao , Zeng Xiantao , Chen Xi , Wang Xiangyu
Published: June 2023

In order to obtain conductive concrete with good electrical conductivity and good mechanical properties, nanographite and magnetite sand excited by different activators and their combinations are added to ordinary concrete to obtain high quality and efficient conductive concrete. The optimal mixture ratio of alkali-excited conductive concrete and the effects of different activators and their combinations on the mechanics and electrical conductivity of concrete were studied. The microstructure of alkali-excited conductive concrete was analyzed by scanning electron microscope (SEM) to study its conductive mechanism. Results show that the conductive concrete obtained by compounding sodium hydroxide, sodium sulfate and calcium hydroxide has optimal mechanical and electrical properties when the graphite is 6% cement, and magnetite sand is 40% fine aggregate. The conductive concrete sample prepared by this method has a flexural strength of 6.84 MPa, a compressive strength of 47.79 MPa and a resistivity of 4805 Ω·cm (28 days). Compared with ordinary concrete (no nanographite and no magnetite sand), the compressive strength of conductive concrete is increased by 122.3%, the bending strength is increased by 116.5%, and the resistivity is reduced by 99.1%. SEM shows that the distribution of conductive materials in concrete is more uniform due to alkali excitation and calcium silicate hydrate (CSH) gel can be formed, which leads to better performance. The research in this paper is only a preliminary exploration of the characteristics of green conductive concrete, and the conductive heating characteristics and electromagnetic wave absorption properties of concrete, along with strength characteristics after adding conductive fillers, need to be further studied. It is suggested that further research should be carried out on the deicing characteristics of conductive concrete and the electromagnetic wave absorption properties used in stealth military engineering.
Urban Building Energy Modelling for the Renovation Wave: A Bespoke Approach Based on EPC Databases
Authors: Rodríguez-Álvarez Jorge
Published: June 2023

In 2020, domestic buildings represented 27% of the energy consumption in the European Union. The EC Renovation Wave concluded that the annual renovation rate should be doubled, from 1% to 2%, over the next decade in order to meet the 2030 energy efficiency targets. Funding programs are being implemented at national and European levels to accelerate this process. These aim to prioritize large-scale interventions and the most efficient energy conservation measures by including strict performance targets as eligibility conditions. However, these programs are coordinated by local authorities, and they struggle to generate reliable energy estimates for large areas, not least predict potential savings at both aggregated and individual levels. This paper presents a bespoke energy retrofit analysis methodology based on urban building energy modelling, which is defined and calibrated with the Energy Performance Certificate Database. We apply this method to the case study Barrio das Flores. The model adopts a hybrid approach, defining and simulating representative typologies to extrapolate the results to the whole district according to each dwelling’s specific parameters. This methodology will be used to predict the potential energy savings in the study area and support the grant application for the funding renovation program.
DNA-Programmed Biomolecular Spatial Pattern Recognition
Authors: Wang Yue , Ren Lei , Peng Hongzhen , Guo Linjie , Wang Lihua
Published: June 2023

Molecular recognition based on non-covalent interactions between two or more molecules plays a crucial role in biological systems. Specific biological molecule recognition has been widely applied in biotechnology, clinical diagnosis, and treatment. The efficiency and affinity of molecular recognition are greatly determined by the spatial conformation of biomolecules. The designability of DNA nanotechnology makes possible the precise programming of the spatial conformation of biomolecules including valency and spacing, further achieving spatial pattern recognition regulation between biomolecules. This review summarizes recent achievements with DNA-based molecular spatial pattern recognition systems, the important factors affecting spatial pattern recognition, and their applications in biosensing, bioimaging, and targeted therapy. The future challenges in and development of this field are discussed and prospected. This review will provide valuable guidance for the creation of new DNA tools to enhance the efficiency and specificity of biomolecular recognition.
Ovarian Masses in Children and Adolescents: A Review of the Literature with Emphasis on the Diagnostic Approach
Authors: Birbas Effrosyni , Kanavos Theofilos , Gkrozou Fani , Skentou Chara , Daniilidis Angelos , Vatopoulou Anastasia
Published: June 2023

Most abdominal masses in the pediatric population derive from the ovaries. Ovarian masses can occur in all ages, although their incidence, clinical presentation and histological distribution vary among different age groups. Children and adolescents may develop non-neoplastic ovarian lesions, such as functional cysts, endometrioma, torsion, abscess and lymphangioma as well as neoplasms, which are divided into germ cell, epithelial, sex-cord stromal and miscellaneous tumors. Germ cell tumors account for the majority of ovarian neoplasms in the pediatric population, while adults most frequently present with epithelial tumors. Mature teratoma is the most common ovarian neoplasm in children and adolescents, whereas dysgerminoma constitutes the most frequent ovarian malignancy. Clinical manifestations generally include abdominal pain, palpable mass, nausea/vomiting and endocrine alterations, such as menstrual abnormalities, precocious puberty and virilization. During the investigation of pediatric ovarian masses, the most important objective is to evaluate the likelihood of malignancy since the management of benign and malignant lesions is fundamentally different. The presence of solid components, large size and heterogenous appearance on transabdominal ultrasonography, magnetic resonance imaging and computed tomography indicate an increased risk of malignancy. Useful tumor markers that raise concern for ovarian cancer in children and adolescents include alpha-fetoprotein, lactate dehydrogenase, beta subunit of human chorionic gonadotropin, cancer antigen 125 and inhibin. However, their serum levels can neither confirm nor exclude malignancy. Management of pediatric ovarian masses needs to be curative and, when feasible, function-preserving and minimally invasive. Children and adolescents with an ovarian mass should be treated in specialized centers to avoid unnecessary oophorectomies and ensure the best possible outcome.
Mercury Removal from Mining Wastewater by Phytoaccumulation in Autochthonous Aquatic Plant Species
Authors: Gomez Franco Hernan , Collivignarelli Maria Cristina , Masoud Ahmed Mohammad Nafea , Carnevale Miino Marco , Torres Kelly Cristina , Quintero Jesus Antonio , Sorlini Sabrina , Vaccari Mentore
Published: June 2023

Mining wastewater (MWW) can contain mercury in high concentrations. In this study, four autochthonous aquatic plant species (Eichhornia Crassipes—EC, Marsilea Quadrifolia—MQ, Ludwigia Helminthorrhiza—LH, and Lemna Minor—LM) were identified and tested for phytoaccumulation of total mercury (THg). To better study the accumulation phenomenon and macrophyte responses, this work has been divided into three phases, and pilot-scale reactors have been used to simulate real conditions. The results highlighted that, in case of 15 µgTHg,fed, the bioconcentration factor (BCF) was significantly higher in EC (19.04) and LH (18.41) with respect to MQ and LM (almost six times and two times higher, respectively). EC granted the best results in terms of THg accumulation (50.90%) and lower evapotranspiration of THg phenomenon with respect to LH. A significant decrease of the BCF (from 23.45 to 21.98) and an increase of the TF (from 0.23 up to 0.73) after 42 d highlighted that a breaking-time in terms of THg accumulation was reached due to the deterioration of the roots. In terms of the kinetics of THg removal by bioaccumulation, an HLT of 69.31 d was found, which is more than the breaking-time of the EC system, proving that a periodic replacement of exhausted macrophytes is required to obtain a higher percentage of THg removal.
Market Connectedness and Volatility Spillovers: A Meta-Literature Review
Authors: Anand K Kamesh , Mishra Aswini Kumar
Published: June 2023

Evaluation of market connectedness and asymmetric volatility spillover has recently seen a surge in financial risk analytics and portfolio diversification. We carried out a meta-literature review on connectedness and spillovers, providing solid insight into the research field and robust guidelines for future investigation. The review consists of a quantitative bibliometric analysis of 594 papers and a qualitative content analysis of 77 papers covering 1991 to 2021. The results of the meta-citation analysis show that Diebold’s Spillover index (2007) is the predominant method in most works as far as market connectedness and spillover are concerned. With an extensive review, we achieved the following objectives: (1) Analyze the most influential authors, journals, and publications. (2) Understand the research streams and most studied streams. (3) Understand the theme’s structure, thematic evolution, and keyword trends. (4) Examine the pattern of collaboration and most productive affiliations. (5) Explore future research directions and untapped areas. The content analysis revealed the following important research streams in the current literature: (1) Asymmetries in market connectedness. (2) Influence of macro factors in market connectedness and spillover. (3) The role of oil in market spillovers and hedging portfolios. (4) Dynamic cross-market connectedness and spillovers. Our study is the first to employ a meta-review to assess the domain of market connectedness; thus, our work will significantly contribute to macroeconomic policymakers, researchers and hedging investors.
A Novel Dynamic Software-Defined Networking Approach to Neutralize Traffic Burst
Authors: Sharma Aakanksha , Balasubramanian Venki , Kamruzzaman Joarder
Published: June 2023

Software-defined networks (SDN) has a holistic view of the network. It is highly suitable for handling dynamic loads in the traditional network with a minimal update in the network infrastructure. However, the standard SDN architecture control plane has been designed for single or multiple distributed SDN controllers facing severe bottleneck issues. Our initial research created a reference model for the traditional network, using the standard SDN (referred to as SDN hereafter) in a network simulator called NetSim. Based on the network traffic, the reference models consisted of light, modest and heavy networks depending on the number of connected IoT devices. Furthermore, a priority scheduling and congestion control algorithm is proposed in the standard SDN, named extended SDN (eSDN), which minimises congestion and performs better than the standard SDN. However, the enhancement was suitable only for the small-scale network because, in a large-scale network, the eSDN does not support dynamic SDN controller mapping. Often, the same SDN controller gets overloaded, leading to a single point of failure. Our literature review shows that most proposed solutions are based on static SDN controller deployment without considering flow fluctuations and traffic bursts that lead to a lack of load balancing among the SDN controllers in real-time, eventually increasing the network latency. Therefore, to maintain the Quality of Service (QoS) in the network, it becomes imperative for the static SDN controller to neutralise the on-the-fly traffic burst. Thus, our novel dynamic controller mapping algorithm with multiple-controller placement in the SDN is critical to solving the identified issues. In dSDN, the SDN controllers are mapped dynamically with the load fluctuation. If any SDN controller reaches its maximum threshold, the rest of the traffic will be diverted to another controller, significantly reducing delay and enhancing the overall performance. Our technique considers the latency and load fluctuation in the network and manages the situations where static mapping is ineffective in dealing with the dynamic flow variation.
Association of NK Cells with the Severity of Fibrosis in Patients with Chronic Hepatitis C
Authors: Kleczka Anna , Mazur Bogdan , Tomaszek Krzysztof , Gabriel Andrzej , Dzik Radosław , Kabała-Dzik Agata
Published: June 2023

Some NK cell subpopulations may be involved in the modulation of fibrogenesis in the liver. The aim of the study was to evaluate the relationship between the number and phenotype of NK cell subsets in peripheral blood (PB) and total NK cell percentage, population density and the degree of liver fibrosis of patients infected with hepatitis C virus (HCV+). The study group consisted of 56 HCV+ patients, divided into two subgroups: patients with mild or moderate fibrosis and patients with advanced liver fibrosis or cirrhosis (F ≥ 3 in METAVIR classification). The preparations were stained with H-E and AZAN staining. NK cells were targeted with anti-CD56 antibody and identified automatically in situ using the DakoVision system. Assessment of different NK cell subsets in PB was performed with the flow cytometry technique. In the PB of HCV+ patients with advanced liver fibrosis, there was a lower proportion of CD62L+; CD62L+/CD94++; CD27+; CD127+/CD27+ and CXCR3+/CD27+ NK subsets, as compared to patients with mild/moderate liver fibrosis. The results also showed no association between total PB NK cell level and total intrahepatic NK cell population density between patients with mild/moderate fibrosis and with advanced liver fibrosis. However, positive correlations between the PB levels of CD94+ and CD62L+ NK cell subsets and the intrahepatic total NK cell percentage and population density in the liver, irrespectively to the extent of fibrosis, were observed. Additionally, positive correlation was found between the PB CXCR3+/CD94+ NK cell percentages and intrahepatic NK cell percentages in patients with advanced hepatic fibrosis. Lower blood availability of specific NK subsets in patients with chronic type C hepatitis might be a cause of progression of liver fibrosis via insufficient control over hepatic stellate cells.
Coarctation of the Aorta: Diagnosis and Management
Authors: Raza Sadaf , Aggarwal Suneil , Jenkins Petra , Kharabish Ahmed , Anwer Shehab , Cullington Damien , Jones Julia , Dua Jaspal , Papaioannou Vasileios , Ashrafi Reza , Moharem-Elgamal Sarah
Published: June 2023

Coarctation of the aorta (CoA) accounts for approximately 5–8% of all congenital heart defects. Depending on the severity of the CoA and the presence of associated cardiac lesions, the clinical presentation and age vary. Developments in diagnosis and management have improved outcomes in this patient population. Even after timely repair, it is important to regularly screen for hypertension. Patients with CoA require lifelong follow-up with a congenital heart disease specialist as these patients may develop recoarctation and complications at the repair site and remain at enhanced cardiovascular risk throughout their lifetime.
‘A Different Voice’ in Peer Feedback: Gender Specificity in Students’ Willingness to Provide Peer Feedback
Authors: Seroussi Dominique-Esther , Peled Yehuda , Sharon Rakefet , Rothschild Nathan , Halperin Barlev Osnat , Weissblueth Eyal , Harpaz Gal
Published: June 2023

In the context of the efforts to reach equity in the classroom, peer feedback (PFB) is used, among other participative learning methods, as it is considered to minimize gender differences. Yet, recent studies have reported gender discrepancies in students’ willingness to provide feedback to their peers. Building on Gilligan’s theory of moral development, we tried to refine the source of this difference. We conducted a semi-experimental study during which education students of both genders performing a PFB activity in a face-to-face course were asked to fill out a questionnaire. This allowed us to estimate the link between, on the one hand, the comfort in providing PFB and the willingness to provide PFB, and on the other hand, personal characteristics like self-esteem, self-efficacy, and empathic concern, and intellectual characteristics like self-efficacy in the learned discipline and the proficiency to write and understand feedback. The linear regression analysis of 57 students’ answers to the questionnaire did not reveal gender differences in comfort in providing PFB and willingness to do so, but showed that the comfort in providing PFB was linked to cognitive proficiency in students of both genders, whereas the willingness to provide PFB was independent of any other variables in men and linked to self-esteem, empathic concern, and comfort in providing feedback in women. This result indicates a differential sensitivity to social factors in male and female students, aligning with Gilligan’s model of women’s ‘ethics of care’. Possible applications in education would be the use of PFB to train women in self-esteem or, inversely, the improvement of psychological safety in PFB exercises in groups including female students.
A New Method for Graph-Based Representation of Text in Natural Language Processing
Authors: Probierz Barbara , Hrabia Anita , Kozak Jan
Published: June 2023

Natural language processing is still an emerging field in machine learning. Access to more and more data sets in textual form, new applications for artificial intelligence and the need for simple communication with operating systems all simultaneously affect the importance of natural language processing in evolving artificial intelligence. Traditional methods of textual representation, such as Bag-of-Words, have some limitations that result from the lack of consideration of semantics and dependencies between words. Therefore, we propose a new approach based on graph representations, which takes into account both local context and global relationships between words, allowing for a more expressive textual representation. The aim of the paper is to examine the possibility of using graph representations in natural language processing and to demonstrate their use in text classification. An innovative element of the proposed approach is the use of common cliques in graphs representing documents to create a feature vector. Experiments confirm that the proposed approach can improve classification efficiency. The use of a new text representation method to predict book categories based on the analysis of its content resulted in accuracy, precision, recall and an F1-score of over 90%. Moving from traditional approaches to a graph-based approach could make a big difference in natural language processing and text analysis and could open up new opportunities in the field.
TGA: A Novel Network Intrusion Detection Method Based on TCN, BiGRU and Attention Mechanism
Authors: Song Yangyang , Luktarhan Nurbol , Shi Zhaolei , Wu Haojie
Published: June 2023

With the increasing complexity of the network environment, the types of network attacks are gradually increasing. Network intrusion detection systems can detect and identify network attacks effectively. However, the existing methods have some limitations, focusing only on local or global temporal features of network traffic. To address the above issues, we present a novel network intrusion detection model (TGA) based on Temporal Convolutional Network (TCN), Bidirectional Gated Recurrent Unit (BiGRU), and self-attention mechanism. TCN extracts local temporal information from network traffic sequences, while BiGRU extracts global temporal information from network traffic sequences. However, TCN and BiGRU do not consider the weights of features when extracting them, so an attention mechanism is added. The feature vectors obtained in TCN and BiGRU are fused and then input into the self-attention mechanism to capture the correlation between different positions in the sequence and reassign the weights of the temporal features to further enhance the model’s capabilities. Lastly, it is delivered to the classifier to classify different network traffic classes. Our method achieves 97.83% accuracy on the public CSE-CIC-IDS2018 dataset. After extensive experiments, our idea proved to be reasonable and practical.
Adaptive Multi-Scale Difference Graph Convolution Network for Skeleton-Based Action Recognition
Authors: Wang Xiaojuan , Gan Ziliang , Jin Lei , Xiao Yabo , He Mingshu
Published: June 2023

Graph convolutional networks (GCNs) have obtained remarkable performance in skeleton-based action recognition. However, previous approaches fail to capture the implicit correlations between joints and handle actions across varying time intervals. To address these problems, we propose an adaptive multi-scale difference graph convolution Network (AMD-GCN), which comprises an adaptive spatial graph convolution module (ASGC) and a multi-scale temporal difference convolution module (MTDC). The first module is capable of acquiring data-dependent and channel-wise graphs that are adaptable to both samples and channels. The second module employs the multi-scale approach to model temporal information across a range of time scales. Additionally, the MTDC incorporates an attention-enhanced module and difference convolution to accentuate significant channels and enhance temporal features, respectively. Finally, we propose a multi-stream framework for integrating diverse skeletal modalities to achieve superior performance. Our AMD-GCN approach was extensively tested and proven to outperform the current state-of-the-art methods on three widely recognized benchmarks: the NTU-RGB+D, NTU-RGB+D 120, and Kinetics Skeleton datasets.
Experimental Study on U-Beam Separator Device for Separating Solids from Gases
Authors: Aubry Rémy , Debal Matthieu , Aubert Stéphane , Rogaume Yann
Published: June 2023

The inertial separator, developed for fluidized beds, is a key component for optimizing large installations that separate solids from gases. Despite industrial interest and numerous patents, few studies have been conducted on this subject. In this paper, the geometric arrangement conditions were studied and evaluated. The efficiency of separating solids from gas depends on several factors, such as the granulometry, density, particle size distribution, velocity, humidity, and temperature of the system. For the mid-range of fluidized bed boilers (1–20 MWth), the experimental study selected all data to be in the same condition as the industrial technology. The global performance of the system can be increased by 15% by selecting a better combination of the U-beam. Three rows of U-beams are a good compromise between performance and cost for high Reynolds numbers, while only two rows seem to be enough for lower Reynolds numbers.
The Intersection of Fuel and Transport Policy in Scotland: A Review of Policy, Definitions and Metrics
Authors: Boyd Keran Sarah , Calvillo Christian , Mueller Tanja , Mu Xiaoyi , Zhu Tong
Published: June 2023

This paper is a literature review of fuel and transport poverty in the U.K. with a focus on contextualising this challenge in Scotland. Building on the discussion in the literature, we see that the objective of policy interventions should be to provide a mechanism for identifying vulnerable households. First, we analyse the definitions of fuel, energy, and transport poverty and observe that definitions in policy have been used to limit the scope of the issue to make it more easily addressable. In contrast, academic research points out that fuel poverty should not only encompass all energy use, including household heating, but that transport poverty should be considered under the same umbrella as the drivers overlap. We then consider the indicators used to measure fuel and transport poverty, finding that the thresholds set are arbitrary and only measure one of many possible drivers, namely expenditure. Through an analysis of the drivers, it is clear that both fuel and transport poverty are complex multidimensional challenges requiring a combination of indicators to allow the policy to accurately identify vulnerable households.
A Systematic Review of Uncertainty Handling Approaches for Electric Grids Considering Electrical Vehicles
Authors: Auza Anna , Asadi Ehsan , Chenari Behrang , Gameiro da Silva Manuel
Published: June 2023

This paper systematically reviews the techniques and dynamics to study uncertainty modelling in the electric grids considering electric vehicles with vehicle-to-grid integration. Uncertainty types and the most frequent uncertainty modelling approaches for electric vehicles are outlined. The modelling approaches discussed in this paper are Monte Carlo, probabilistic scenarios, stochastic, point estimate method and robust optimisation. Then, Scopus is used to search for articles, and according to these categories, data from articles are extracted. The findings suggest that the probabilistic techniques are the most widely applied, with Monte Carlo and scenario analysis leading. In particular, 19% of the cases benefit from Monte Carlo, 15% from scenario analysis, and 10% each from robust optimisation and the stochastic approach, respectively. Early articles consider robust optimisation relatively more frequent, possibly due to the lack of historical data, while more recent articles adopt the Monte Carlo simulation approach. The uncertainty handling techniques depend on the uncertainty type and human resource availability in aggregate but are unrelated to the generation type. Finally, future directions are given.
Strategic Priorities for Green Diversification of Oil and Gas Companies
Authors: Cherepovitsyn Alexey , Kazanin Aleksei , Rutenko Evgeniya
Published: June 2023

The inconsistency of arguments regarding the value of diversification strategies means that there is a lack of a unified methodological approach and a method for evaluating the impact on efficiency and competitive ability of companies. Research shows that diversification was crucially important for oil and gas companies during the economic shocks of 1998, 2009, and 2015. Nowadays, oil and gas companies apply the strategy of green diversification to solve climate change problems and adapt to energy transition trends. The goals of 14 global oil and gas companies with regard to carbon neutrality were analyzed in this study. This research expands the theoretical studies of diversification processes and outcomes in the oil and gas industry and contributes to the discussion of the feasibility of companies implementing renewable energy projects. The factors that prompt oil and gas companies to adopt green diversification were formulated, and their key strategic priorities were determined depending on the volume of proven resources. The research suggests that global shocks in the international energy market and a reduction in the significance of oil and gas resources in the overall power balance stimulate companies to diversify their asset portfolios, but such strategy does not protect against negative impacts. In addition, important issues were identified for further analysis.
Study on the Effect of Structural Parameters of Volume Control Tank on Gas–Liquid Mass Transfer
Authors: Hu Jian , Li Weiguang , Chi Xiangyu , Wang Naihua
Published: June 2023

The volume control tank (VCT) is an important facility in the primary circuit of nuclear power plants. During the normal operation of nuclear power plants, the mass transfer between the gas and liquid phases occurs in the VCT at all times. It is driven by submerged jets, which may cause potential risks to the operational safety of nuclear power plants. It is necessary to conduct an in-depth study to gain a deeper understanding of the gas–liquid mass transfer behavior in the VCT. In this paper, a new gas–liquid mass transfer model is developed that combines a surface divergence model with a CFD model to accurately simulate the mass transfer process of the gas phase into the liquid phase. The simulation data were verified by the experimental results. The deviation between the simulation results and experimental results is less than 6.55%. Based on this model, a simulation study was carried out for the effect of structural parameters of the VCT on gas–liquid mass transfer. The results show that the double-vortex structure above the jet inlet, the surface jet at the gas–liquid interface, and the vortex at the end of the jet are the three factors dominating the gas–liquid mass transfer in the VCT. The gas–liquid mass transfer can be influenced by the jet diameter since the jet diameter has a remarkable effect on the Kolmogorov scale and the macroscopic flow field structure. Moreover, both the Kolmogorov scale and the macroscopic flow field structure can be affected by the jet height. However, these two effects cancel each other out. Thus, the influence of the jet height on the gas–liquid mass transfer rate is negligible.
Microfluidic Studies on Minimum Miscibility Pressure for n-Decane and CO2
Authors: Pereponov Dmitrii , Tarkhov Michael , Dorhjie Desmond Batsa , Rykov Alexander , Filippov Ivan , Zenova Elena , Krutko Vladislav , Cheremisin Alexey , Shilov Evgeny
Published: June 2023

Oil production is a complex process that can be made more efficient by applying gas enhanced oil recovery (EOR) methods. Thus, it is essential to know the minimum miscibility pressure (MMP) and minimum miscibility enrichment (MME) of gas in oil. Conventional slim-tube experiments for the measurement of MMP require hundreds of millilitres of real or recombined oil and last over 30 days. Advances in microfluidic technology allow the reduction of the amount of fluid and the time required in determining MMP (or MME), hence making the process rapid. In this study, we developed a microfluidic model with a stochastically distributed pore network, porosity of 74.6% and volume of 83.26 nanolitres. Although the volume was six orders of magnitude smaller than the slim tube, it retained the same proportions, guaranteeing a proper comparison between the tests. This microfluidic chip allowed the study of the MMP of n-decane with carbon dioxide at two different temperature conditions. The experimental results coincided with the results received both from conventional and microfluidic experiments. Furthermore, a numerical simulation of a section of the microfluidic model under the experimental conditions presented results within acceptable margins of the experimental ones. The results of the presented methodology indicate the potential to replace conventional technology for the measurement of MMP with microfluidic technology. Its promise lies in accelerating laboratory tests and increasing the reliability of experimental results and, subsequently, the quality of field gas EOR operations.
Determination of the Risk of Failures of Locomotive Diesel Engines in Maintenance
Authors: Baranovskyi Denys , Bulakh Maryna , Michajłyszyn Adam , Myamlin Sergey , Muradian Leonty
Published: June 2023

This article presents a mathematical model of the risk of failures, depending on the operating parameters, of locomotive diesel engines. The purpose of this study is to determine the risk of failures of locomotive diesel engines in maintenance. The theory of probability and the theory of logic and reliability are used in this theoretical study. The innovations and main works are the first approaches to calculating the risk of failures of locomotive diesel engines by hourly fuel consumption, which, under operational conditions, allows for extending the life of locomotive diesel engines during maintenance. As a result, a maintenance process for 5D49 diesel engines is developed in a locomotive depot. When managing the maintenance processes of 5D49 diesel engines in the locomotive depot, it is determined that the optimal mileage is 45,000 km. The resource of 5D49 diesel engines in the locomotive depot increased by 2.4% in the management of the maintenance process compared to the existing maintenance system.
Validation of the Eulerian–Eulerian Two-Fluid Method and the RPI Wall Partitioning Model Predictions in OpenFOAM with Respect to the Flow Boiling Characteristics within Conventional Tubes and Micro-Channels
Authors: Vontas Konstantinos , Pavarani Marco , Miché Nicolas , Marengo Marco , Georgoulas Anastasios
Published: June 2023

Flow boiling within conventional, mini and micro-scale channels is encountered in a wide range of engineering applications such as nuclear reactors, steam engines and cooling of electronic devices. Due to the high complexity and importance of the boiling process, several numerical and experimental investigations have been conducted for the better understanding of the underpinned physics and heat transfer characteristics. One of the most widely used numerical approaches that can analyse such phenomena is the Eulerian–Eulerian two-fluid method in conjunction with the RPI model. However, according to the current state-of-the-art methods this modelling approach heavily relies on empirical closure relationships derived for conventional channels, limiting its applicability to mini- and micro-scale channels. The present paper aims to give further insights into the applicability of this modelling approach for non-conventional channels. For this purpose, a numerical investigation utilising the Eulerian–Eulerian two-fluid model and the RPI wall heat flux partitioning model in OpenFOAM 8.0 is conducted. Initially the parameters comprising the empirical closure relationships used in the RPI sub-models are tuned against the DEBORA experiments on conventional channels, through an extensive sensitivity analysis. In the second part of the investigation, numerical simulations against flow boiling experiments within micro-channels are performed, utilising the previously optimised and validated model setup. Furthermore the importance of including a bubble coalescence and break-up sub-model to capture parameters such as the radial velocity profiles, is also illustrated. However, when the optimal model setup, in conventional tubes, is used against micro-channel experiments, the need to develop new correlations from data obtained from mini and micro-scale channel studies, not from experimental data on conventional channels, is revealed.
Comparison of Evaporite-Related Source Rocks and Implications for Petroleum Exploration: A Case Study of the Dongying Depression, Bohai Bay Basin, Eastern China
Authors: Chen Yong , Han Yun , Zhang Pengfei , Wang Miao , Qiu Yibo , Zhu Xuelei , Zhang Xuejun
Published: June 2023

The Dongying Depression (Bohai Bay Basin, eastern China) was widely filled with evaporite (anhydrite and halite) layers during the Paleogene period, especially the middle of the fourth member of the Shahejie Formation (Es4). Most evaporite layers are interbedded with mudstone strata. The strata of Es4 are divided into three sections, referred to as the upper layers, evaporite layers, and lower layers, respectively. The analysis of elemental concentrations, elemental ratios, and Pr/Ph suggests that the lower layers were deposited in an intermittent saline lake environment within a relatively dry climate. The evaporite layers were formed in a highly saline lake environment, whereas the upper layers were formed in a brackish-saline to fresh-water environment. Organic matter (OM) abundance indices, including total organic carbon (TOC), chloroform extracts, total hydrocarbon content (HC), hydrocarbon generation potential (S1 + S2), and OM type, show that the source rock potential for petroleum generation in the upper layers is best, that in the evaporite layers is fair, and in the lower layers it is poor. Carbon isotopes (δ13C) of hydrocarbons in the evaporite and lower layers were heavier than those in the upper layers. Thermal maturity parameters show that the thermal evolution process of OM in the upper layers was faster where evaporite were present compared with evaporite-free areas, while the thermal evolution of OM in the lower layers was slower in these regions. The high thermal conductivity of evaporites may have accelerated the thermal evolution of source rocks in upper layers and allowed hydrocarbon generation at a shallower burial depth. This resulted in the earlier appearance of the petroleum generation window compared to in evaporite-free areas. Meanwhile, the thermal evolution of OM in the lower layers was restrained, and consequently the hydrocarbon generation window was widened, which implies the potential for petroleum exploration in deep strata under the evaporite sequence. This is a common phenomenon in evaporite-bearing basins, according to previous and present studies.
Study of the Effect of Tetrabutylammonium Halide Aqueous Solutions on the Gas Storage of Methane and Carbon Dioxide
Authors: Naeiji Parisa , Woo Tom K. , Ohmura Ryo , Alavi Saman
Published: June 2023

In this study, the effect of tetrabutylammonium halide aqueous solutions on the gas storage of CH4 and CO2 gases were studied with molecular dynamics (MD) simulations. The results show that the surface tension and the gas molecules adsorbed at the interface decreases and increases, respectively, in the presence of TBAX (X: Br, Cl, F) in the aqueous phase compared to pure water at similar gas pressures. Both of these factors may facilitate gas uptake into cages during semi-clathrate hydrate formation. CO2 showed a stronger intermolecular interaction with the water molecules since it was preferentially adsorbed at the interface, leading to a higher surface density as compared to CH4. Moreover, the relative increase in CH4 adsorption on the surface was because of the hydrophobic interactions between the CH4 molecules and the n-alkyl chains of the cation. The counter-ions of TBAXs can affect their surface activity. TBAX salts enhance the tetrahedral ordering of water molecules at the interface compared to the bulk, leading to a potential mechanism for forming semi-clathrate hydrates.
Optimal Scheduling of the Wind-Photovoltaic-Energy Storage Multi-Energy Complementary System Considering Battery Service Life
Authors: Li Yanpin , Wang Huiliang , Zhang Zichao , Li Huawei , Wang Xiaoli , Zhang Qifan , Zhou Tong , Zhang Peng , Chang Fengxiang
Published: June 2023

Under the background of “peak carbon dioxide emissions by 2030 and carbon neutrality by 2060 strategies” and grid-connected large-scale renewables, the grid usually adopts a method of optimal scheduling to improve its ability to cope with the stochastic and volatile nature of renewable energy and to increase economic efficiency. This article proposes a short-term optimal scheduling model for wind–solar storage combined-power generation systems in high-penetration renewable energy areas. After the comprehensive consideration of battery life, energy storage units, and load characteristics, a hybrid energy storage operation strategy was developed. The model uses the remaining energy in the system after deducting wind PV and energy storage output as the “generalized load”. An improved particle swarm optimization (PSO) is used to solve the scheduling schemes of different running strategies under different objectives. The optimization strategy optimizes the battery life-loss coefficient from 0.073% to 0.055% under the target of minimizing the mean squared deviation of “generalized load”, which was optimized from 0.088% to 0.053% under the minimized fluctuation of combined system output and optimized from 0.092% to 0.081% under the minimized generation costs of the combined system. The results show that the model can ensure a stable operation of the combined system, and the operation strategy proposed in this article effectively reduces battery life loss while reducing the total power generation cost of the system. Finally, the superiority of the improved PSO algorithm was verified.