bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Multi-Shell Free Water Correction on Glioma Characterization
Authors: Starck Lea , Zaccagna Fulvio , Pasternak Ofer , Gallagher Ferdia A. , Grüner Renate , Riemer Frank
Published: December 2021

Diffusion MRI is a useful tool to investigate the microstructure of brain tumors. However, the presence of fast diffusing isotropic signals originating from non-restricted edematous fluids, within and surrounding tumors, may obscure estimation of the underlying tissue characteristics, complicating the radiological interpretation and quantitative evaluation of diffusion MRI. A multi-shell regularized free water (FW) elimination model was therefore applied to separate free water from tissue-related diffusion components from the diffusion MRI of 26 treatment-naïve glioma patients. We then investigated the diagnostic value of the derived measures of FW maps as well as FW-corrected tensor-derived maps of fractional anisotropy (FA). Presumed necrotic tumor regions display greater mean and variance of FW content than other parts of the tumor. On average, the area under the receiver operating characteristic (ROC) for the classification of necrotic and enhancing tumor volumes increased by 5% in corrected data compared to non-corrected data. FW elimination shifts the FA distribution in non-enhancing tumor parts toward higher values and significantly increases its entropy (p ≤ 0.003), whereas skewness is decreased (p ≤ 0.004). Kurtosis is significantly decreased (p < 0.001) in high-grade tumors. In conclusion, eliminating FW contributions improved quantitative estimations of FA, which helps to disentangle the cancer heterogeneity.
New Approaches and Technologies to Improve Accuracy of Acute Otitis Media Diagnosis
Authors: Esposito Susanna , Bianchini Sonia , Argentiero Alberto , Gobbi Riccardo , Vicini Claudio , Principi Nicola
Published: December 2021

Several studies have shown that in recent years incidence of acute otitis media (AOM) has declined worldwide. However, related medical, social, and economic problems for patients, their families, and society remain very high. Better knowledge of potential risk factors for AOM development and more effective preventive interventions, particularly in AOM-prone children, can further reduce disease incidence. However, a more accurate AOM diagnosis seems essential to achieve this goal. Diagnostic uncertainty is common, and to avoid risks related to a disease caused mainly by bacteria, several children without AOM are treated with antibiotics and followed as true AOM cases. The main objective of this manuscript is to discuss the most common difficulties that presently limit accurate AOM diagnosis and the new approaches and technologies that have been proposed to improve disease detection. We showed that misdiagnosis can be dangerous or lead to relevant therapeutic mistakes. The need to improve AOM diagnosis has allowed the identification of a long list of technologies to visualize and evaluate the tympanic membrane and to assess middle-ear effusion. Most of the new instruments, including light field otoscopy, optical coherence tomography, low-coherence interferometry, and Raman spectroscopy, are far from being introduced in clinical practice. Video-otoscopy can be effective, especially when it is used in association with telemedicine, parents’ cooperation, and artificial intelligence. Introduction of otologic telemedicine and use of artificial intelligence among pediatricians and ENT specialists must be strongly promoted in order to reduce mistakes in AOM diagnosis.
Preimplantation Genetic Diagnosis in Hereditary Hearing Impairment
Authors: Chen Hsin-Lin , Lin Pei-Hsuan , Chiang Yu-Ting , Huang Wen-Jie , Lin Chi-Fang , Ma Gwo-Chin , Chang Shun-Ping , Fan Jun-Yang , Lin Shin-Yu , Wu Chen-Chi , Chen Ming
Published: December 2021

Sensorineural hearing impairment is a common sensory deficit in children and more than 50% of these cases are caused by genetic etiologies, that is, hereditary hearing impairment (HHI). Recent advances in genomic medicine have revolutionized the diagnostics of, and counseling for, HHI, including preimplantation genetic diagnosis (PGD), thus providing parents-to-be with better reproductive choices. Over the past decade, we have performed PGD using the amplification refractory mutation system quantitative polymerase chain reaction (ARMS-qPCR) technique in 11 couples with a history of HHI, namely eight with GJB2 variants, one with OTOF variants, one with SLC26A4 variants, and one with an MITF variant. We demonstrated that PGD can be successfully applied to HHI of different inheritance modes, namely autosomal dominant or recessive, and phenotypes, namely syndromic or non-syndromic HHI. However, certain ethical concerns warrant scrutiny before PGD can be widely applied to at-risk couples with a history of HHI.
State-of-Art in the Age Determination of Venous Thromboembolism: A Systematic Review
Authors: Di Fazio Nicola , Delogu Giuseppe , Ciallella Costantino , Padovano Martina , Spadazzi Federica , Frati Paola , Fineschi Vittorio
Published: December 2021

Venous thromboembolism (VTE), consisting of deep vein thrombosis (DVT) and pulmonary embolism (PE), requires a forensic age determination to ascertain their causal relationship with recent events, such as trauma or medical treatment. The main objective of this systematic review is to identify the current state-of-the-art immunohistochemical methods for age determination of fatal VTE. A literature search was performed through different databases, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Within the study, we have selected only cases represented by deceased patients for DVT and/or PTE in which thromboembolic material was collected during an autoptic examination and then subjected to a histological and an immunohistochemical investigation. Studies based on animal models were not included. We assessed bias risk. A database-based search produced a total of 19 articles. After excluding duplicate items from the selection, 14 articles were reviewed. Ten articles were excluded because they did not meet the inclusion criteria. The results have pointed out 4 studies that were included in the present analysis for a total of 157 samples of DVT and 171 PTE samples. These were analyzed using traditional histological and immunohistochemical techniques. The results must be interpreted with a critical eye because of their heterogeneity in terms of time, geography, and study design. The present review highlights the importance of associating specific immunohistochemical markers with a histological analysis for the timing of DVT/PTE fatal events. Further future experiences will hopefully endorse actual knowledge on the subject to increase the accuracy in the assessment of thrombus-embolus age.
Assessment of Retinal Capillary Dropout after Transcatheter Aortic Valve Implantation by Optical Coherence Tomography Angiography
Authors: Gunzinger Jeanne , Ibrahimi Burbuqe , Baur Joel , Wiest Maximilian , Piccirelli Marco , Pangalu Athina , Straumann Dominik , Nietlispach Fabian , Moarof Igal , Zweifel Sandrine
Published: December 2021

Transcatheter aortic valve implantation (TAVI) is an alternative to open heart surgery in the treatment of symptomatic aortic valve stenosis, which is often the treatment of choice in elderly and frail patients. It carries a risk of embolic complications in the whole cerebral vascular bed, which includes the retinal vasculature. The main objective was the evaluation of retinal emboli visible on optical coherence tomography angiography (OCTA) following TAVI. This is a prospective, single center, observational study enrolling consecutive patients over two years. Patients were assessed pre- and post-TAVI. Twenty-eight patients were included in the final analysis, 82.1% were male, median age was 79.5 (range 52–88), median BCVA was 82.5 letters (range 75–93). Eight patients (28.6%) presented new capillary dropout lesions in their post-TAVI OCTA scans. There was no statistically significant change in BCVA. Quantitative analysis of macular or peripapillary OCTA parameters did not show any statistically significant difference in pre- and post-intervention. In conclusion, capillary dropout lesions could frequently be found in patients after TAVI. Quantitative measurements of macular and peripapillary flow remained stable, possibly indicating effective ocular blood flow regulation within the range of left ventricular ejection fraction in our cohort.
A Retrospective Analysis of the Correlation between Functional Imaging and Clinical Outcomes in Grade 3 Neuroendocrine Tumors (NETs G3)
Authors: Laffi Alice , Colandrea Marzia , Buonsanti Giuseppe , Frassoni Samuele , Bagnardi Vincenzo , Spada Francesca , Pisa Eleonora , Barberis Massimo , Rubino Manila , Grana Chiara Maria , Ceci Francesco , Fazio Nicola
Published: December 2021

Grade 3 (G3) neuroendocrine tumors (NETs) are a novel category among digestive neuroendocrine neoplasms, characterized by Ki-67 >20% and a well-differentiated morphology, presenting high intra-tumor heterogeneity. We aimed to explore the role of dual-tracer PET imaging (68Gallium (Ga)-DOTATOC and 18Fluorodeoxyglucose (FDG)) as overall survival (OS) predictor in NET G3 patients. We performed a retrospective analysis in NET G3 patients treated at our institution between 2003 and 2021. Accordingly, 30 NET G3 patients were analyzed. 68Ga-DOTA-TOC and 18F-FDG uptake were assessed by tumor/non-tumor (T-nonT) ratio. We reported a slightly better OS for patients with ≥75% concordance between 68Ga-DOTA-TOC and 18F-FDG PET/CT (p = 0.42). Among patients with discordant functional imaging, we reported a better 5-y OS rate for patients with a prevalent 68Ga-DOTATOC vs. 18F-FDG PET/CT (p = 0.016). In positive 18F-FDG PET/CT cases, we reported a better OS for <4 vs. ≥4 T/non-T ratio (p = 0.021). Among upfront-NET G3 patients with concordant exams, 5-y OS rate was 83.3% (95% CI: 27.3–97.5). Among patients with discordant exams, 5-y OS rate was 81.3% (52.5–93.5), 100% for those with prevalent receptor expression, and 50% (11.1–80.4) for those with prevalent 18F-FDG uptake. Our findings suggest that dual-tracer PET/CT can be considered as a predictor of patient outcome, able to stratify NET G3 patients with poorer prognosis.
MFF-Net: Deepfake Detection Network Based on Multi-Feature Fusion
Authors: Zhao Lei , Zhang Mingcheng , Ding Hongwei , Cui Xiaohui
Published: December 2021

Significant progress has been made in generating counterfeit images and videos. Forged videos generated by deepfaking have been widely spread and have caused severe societal impacts, which stir up public concern about automatic deepfake detection technology. Recently, many deepfake detection methods based on forged features have been proposed. Among the popular forged features, textural features are widely used. However, most of the current texture-based detection methods extract textures directly from RGB images, ignoring the mature spectral analysis methods. Therefore, this research proposes a deepfake detection network fusing RGB features and textural information extracted by neural networks and signal processing methods, namely, MFF-Net. Specifically, it consists of four key components: (1) a feature extraction module to further extract textural and frequency information using the Gabor convolution and residual attention blocks; (2) a texture enhancement module to zoom into the subtle textural features in shallow layers; (3) an attention module to force the classifier to focus on the forged part; (4) two instances of feature fusion to firstly fuse textural features from the shallow RGB branch and feature extraction module and then to fuse the textural features and semantic information. Moreover, we further introduce a new diversity loss to force the feature extraction module to learn features of different scales and directions. The experimental results show that MFF-Net has excellent generalization and has achieved state-of-the-art performance on various deepfake datasets.
Hypothetical Control of Fatal Quarrel Variability
Authors: West Bruce J.
Published: December 2021

Wars, terrorist attacks, as well as natural catastrophes typically result in a large number of casualties, whose distributions have been shown to belong to the class of Pareto’s inverse power laws (IPLs). The number of deaths resulting from terrorist attacks are herein fit by a double Pareto probability density function (PDF). We use the fractional probability calculus to frame our arguments and to parameterize a hypothetical control process to temper a Lévy process through a collective-induced potential. Thus, the PDF is shown to be a consequence of the complexity of the underlying social network. The analytic steady-state solution to the fractional Fokker-Planck equation (FFPE) is fit to a forty-year fatal quarrel (FQ) dataset.
Encoding Individual Source Sequences for the Wiretap Channel
Authors: Merhav Neri
Published: December 2021

We consider the problem of encoding a deterministic source sequence (i.e., individual sequence) for the degraded wiretap channel by means of an encoder and decoder that can both be implemented as finite-state machines. Our first main result is a necessary condition for both reliable and secure transmission in terms of the given source sequence, the bandwidth expansion factor, the secrecy capacity, the number of states of the encoder and the number of states of the decoder. Equivalently, this necessary condition can be presented as a converse bound (i.e., a lower bound) on the smallest achievable bandwidth expansion factor. The bound is asymptotically achievable by Lempel–Ziv compression followed by good channel coding for the wiretap channel. Given that the lower bound is saturated, we also derive a lower bound on the minimum necessary rate of purely random bits needed for local randomness at the encoder in order to meet the security constraint. This bound too is achieved by the same achievability scheme. Finally, we extend the main results to the case where the legitimate decoder has access to a side information sequence, which is another individual sequence that may be related to the source sequence, and a noisy version of the side information sequence leaks to the wiretapper.
Security Analysis of a Passive Continuous-Variable Quantum Key Distribution by Considering Finite-Size Effect
Authors: Xu Shengjie , Li Yin , Wang Yijun , Mao Yun , Wu Xiaodong , Guo Ying
Published: December 2021

We perform security analysis of a passive continuous-variable quantum key distribution (CV-QKD) protocol by considering the finite-size effect. In the passive CV-QKD scheme, Alice utilizes thermal sources to passively make preparation of quantum state without Gaussian modulations. With this technique, the quantum states can be prepared precisely to match the high transmission rate. Here, both asymptotic regime and finite-size regime are considered to make a comparison. In the finite-size scenario, we illustrate the passive CV-QKD protocol against collective attacks. Simulation results show that the performance of passive CV-QKD protocol in the finite-size case is more pessimistic than that achieved in the asymptotic case, which indicates that the finite-size effect has a great influence on the performance of the single-mode passive CV-QKD protocol. However, we can still obtain a reasonable performance in the finite-size regime by enhancing the average photon number of the thermal state.
SpotFuzz: Fuzzing Based on Program Hot-Spots
Authors: Pang Haibo , Jian Jie , Zhuang Yan , Ye Yingyun , Li Zhanbo
Published: December 2021

AFL is the most widely used coverage-guided fuzzer, which relies on rough execution information to assign seeds energy, which can lead to waste. We track the program executed by AFL and discover that the hit counts of each edge might vary greatly when using different seeds as inputs. Some seeds, which are continuously given too much energy, experience very high hit counts of several edges without new crashes or edges being explored, which results in invalid execution and waste of performance. We also define time-consuming edges and discover that they only occupy a small part of the program. In this paper, we define invalid execution edges and time-consuming edges as hot-spots and propose a fuzzing solution SpotFuzz to solve energy waste caused by the above hot-spot phenomenon. It allocates seeds with more hot-spots during execution and uses less energy to reduce energy waste. Moreover, it preferentially selects seeds with less time-consuming edges as test cases, allowing for more edges to be explored in a limited time. We implement an SpotFuzz prototype based on AFL and test it on several real programs for 600 CPU days. The experimental results show that minimizing the invalid and time-consuming execution of edges can improve the fuzzing efficiency. On average, SpotFuzz could find 42.96% more unique crashes and 14.25% more edges than AFL on GNU Binutils and tcpdump.
Privacy-Preserving Tampering Detection in Automotive Systems
Authors: Roman Adrian-Silviu , Genge Béla , Duka Adrian-Vasile , Haller Piroska
Published: December 2021

Modern auto-vehicles are built upon a vast collection of sensors that provide large amounts of data processed by dozens of Electronic Control Units (ECUs). These, in turn, monitor and control advanced technological systems providing a large palette of features to the vehicle’s end-users (e.g., automated parking, autonomous vehicles). As modern cars become more and more interconnected with external systems (e.g., cloud-based services), enforcing privacy on data originating from vehicle sensors is becoming a challenging research topic. In contrast, deliberate manipulations of vehicle components, known as tampering, require careful (and remote) monitoring of the vehicle via data transmissions and processing. In this context, this paper documents an efficient methodology for data privacy protection, which can be integrated into modern vehicles. The approach leverages the Fast Fourier Transform (FFT) as a core data transformation algorithm, accompanied by filters and additional transformations. The methodology is seconded by a Random Forest-based regression technique enriched with further statistical analysis for tampering detection in the case of anonymized data. Experimental results, conducted on a data set collected from the On-Board Diagnostics (OBD II) port of a 2015 EUR6 Skoda Rapid 1.2 L TSI passenger vehicle, demonstrate that the restored time-domain data preserves the characteristics required by additional processing algorithms (e.g., tampering detection), showing at the same time an adjustable level of privacy. Moreover, tampering detection is shown to be 100% effective in certain scenarios, even in the context of anonymized data.
Factors Influencing Students’ Acceptance of M-Learning in Higher Education: An Application and Extension of the UTAUT Model
Authors: Alyoussef Ibrahim Youssef
Published: December 2021

The goal of this study was to develop a new model and conduct confirmatory factor analysis to learn more about how students use M-learning in higher education. The study is theoretically based on the unified theory of acceptance and use of technology (UTAUT) theory and the technology acceptance model (TAM). Theoretically, the factors related to the adoption of M-learning in higher education, identified as contributory to perceived ease of use, perceived usefulness, and attitudes towards M-learning and actual use of M-learning, were analyzed. A questionnaire survey was distributed to 362 university students who were randomly selected. Structural Equation Modeling (SEM)-AMOS was used for data analysis. Based on the findings, M-learning appears to be one of the most promising educational technologies for development in educational environments. Perceived facilitating conditions, performance expectancy, effort expectancy, social influence, and perceived enjoyment have a significant positive effect on the perceived ease of use and perceived usefulness, while performance expectancy has a negative effect on the perceived ease of use. Perceived ease of use and perceived usefulness have a positive and significant effect on attitudes towards using M-learning and actual use of M-learning. Therefore, we recommend lecturers encourage students to utilize M-learning for educational purposes in higher education.
Generation of Beam Tilt through Three-Dimensional Printed Surface
Authors: Shrestha Sujan , Zahra Hijab , Abbas Syed Muzahir , Kiyani Arslan , Mohamadzade Bahare , Asadnia Mohsen
Published: December 2021

In this paper, 3D printed surfaces are presented to study this technology’s application in generating beam tilt for the electromagnetic waves in the Ku-band. Additionally, the input source is maintained by a feed horn that is additively manufactured and is coated with copper spray paint to add conductivity, which is fed by a WR-75 waveguide. The proposed beam tilt generating surface is also referred to as a Beam Deviating Surface (BDS). There is no relative gap between the BDS and the aperture of the horn, which eventually decreased the overall antenna height. The BDS layer is able to deviate the beam for a fixed elevation angle of 22.5∘ and could be consequently rotated along with the rotation of the BDS prototype. The voltage standing wave ratio value is less than two over the operating frequency range, which depicts the wideband behavior. The measured and simulated radiation patterns show that we can tilt the electromagnetic waves in ranges of up to +/−22.5∘ with a minimum side lobe level of −5 dB at frequencies from 10 to 15 GHz. This signifies the wideband characteristic of the proposed prototype, which is achieved by Vero material from Multijet Printing that is a low-cost and rapid manufacturing 3D printing technology.
Axial-Flux Permanent-Magnet Generator Design for Hybrid Electric Propulsion Drone Applications
Authors: Lee Ji-Young , Lee Ji-Heon , Nguyen Tung Khanh
Published: December 2021

This paper presents the design of an axial-flux permanent-magnet (AFPM) generator used for hybrid electric propulsion drone applications. The design objectives of the AFPM generator are high power density, which is defined as output power per generator weight, and high efficiency. In order to satisfy the requirements for the target application and consider the practical problems in the manufacturing process, the structure of the AFPM generator comprising a double-rotor single-stator (DR-SS) was studied. In order to determine the rotor topology and stator winding specifications that had the greatest impact on performance in the DR-SS type design process, we selected three rotor models according to the arrangement of the magnetization direction and three stator models according to the coreless winding specifications. These models were first compared and analyzed. Then, a 3-D finite element method was performed to calculate the magnetic, mechanical, and thermal characteristics of the designed models. By consideration of the output power, efficiency, temperature, and mechanical stability, etc., a topology suitable for the design of generators for UAV systems was determined and manufactured. The reliability of the design result was confirmed through the test.
A Review on Advanced Manufacturing for Hydrogen Storage Applications
Authors: Free Zach , Hernandez Maya , Mashal Mustafa , Mondal Kunal
Published: December 2021

Hydrogen is a notoriously difficult substance to store yet has endless energy applications. Thus, the study of long-term hydrogen storage, and high-pressure bulk hydrogen storage have been the subject of much research in the last several years. To create a research path forward, it is important to know what research has already been done, and what is already known about hydrogen storage. In this review, several approaches to hydrogen storage are addressed, including high-pressure storage, cryogenic liquid hydrogen storage, and metal hydride absorption. Challenges and advantages are offered based on reported research findings. Since the project looks closely at advanced manufacturing, techniques for the same are outlined as well. There are seven main categories into which most rapid prototyping styles fall. Each is briefly explained and illustrated as well as some generally accepted advantages and drawbacks to each style. An overview of hydrogen adsorption on metal hydrides, carbon fibers, and carbon nanotubes are presented. The hydrogen storage capacities of these materials are discussed as well as the differing conditions in which the adsorption was performed under. Concepts regarding storage shape and materials accompanied by smaller-scale advanced manufacturing options for hydrogen storage are also presented.
Scenarios Analysis on Electric Power Planning Based on Multi-Scale Forecast: A Case Study of Taoussa, Mali from 2020 to 2035
Authors: Kanté Moussa , Li Yang , Deng Shuai
Published: December 2021

The increase in electricity demand is caused by population density, gross domestic product growth and technological conditions. A long-term forecast study on the electricity demand could be a promising alternative to the investment planning of power systems and distribution. In this study, the main aim is to forecast and understand the long-term electricity demand of the Taoussa area for the sustainable development of the regions of northern Mali, by using the Model for Analysis of Energy Demand (MAED) from the International Atomic Energy Agency. To fill such a knowledge gap, the long-term evolution of electricity demand is calculated separately for four consumption sectors: industry, transportation, service and household from 2020 to 2035. The demand for each end-use category of electricity is driven by one or several socioeconomic and technological parameters development of the country, which are given as part of the reference scenario (RS) and two alternative scenarios (Low and High). These scenarios were developed based on four groups of coherent hypotheses concerning demographic evolution, economic development, lifestyle change and technological change. The results showed that the annual growth rate of electricity demand in Taoussa area in all scenarios is expected to increase by only 8.13% (LS), 10.31% (RS) and 12.56% (HS). According to the seasonal variations of electricity demand, dry season electricity demand was higher than the demand in cool season during the study period. Such a conclusion demonstrates that the proposed long-term method and related results could provide powerful sustainable solutions to the electricity development challenges of Africa.
Development of a Platform for Securing Interoperability between Components in a Carbon-Free Island Microgrid Energy Management System
Authors: Hwang Jihui , Oh Yun-Sik , Song Jin-Uk , An Jae-Guk , Jeon Jin-Hong
Published: December 2021

The rigidity of information technology (IT) has been hindering the development of various businesses regarding energy management systems (EMSs) of power networks, although this area has become more diversified, resulting in changes of elements in the systems due to the introduction of renewable energy (RE) and the new energy industry. In order to effectively accommodate these changes, EMSs should be developed in a structure with a standard-based interface, which can secure interoperability between components in the EMS. In previous studies, the common information model (CIM) proposed by IEC TC57 has been utilized for developing EMSs of power networks, but there are gaps between the existing CIM and an information model for the EMSs of carbon-free island microgrids (MGs), which are a newly introduced form of power network covering multiple islands for reducing carbon emissions. This paper proposes a CIM-based software platform for a carbon-free island MG-EMS to efficiently operate the power network and secure interoperability between components in the MG-EMS. Concerning service restoration of the power network, use cases and business objects representing information exchanged between the components in the EMS are derived, and the existing CIM is extended based on the results of the gap analysis in order to provide necessary information on the MG-EMS. The validity of the proposed platform is verified by exchanging payloads between components in the MG-EMS based on the profile extracted from the extended CIM. Furthermore, the performance of the proposed platform regarding data size and speed of data exchange is presented. Based on the case study results, it is concluded that the proposed platform based on the extended CIM can exchange data between the components in the MG-EMS, achieving reasonable data size and speed of data exchange with the help of the interoperability between components in the carbon-free island MG-EMS.
Air to Water Generator Integrated Systems: The Proposal of a Global Evaluation Index—GEI Formulation and Application Examples
Authors: Cattani Lucia , Cattani Paolo , Magrini Anna
Published: December 2021

Due to water scarcity, in the last few decades, air-to-water generator (AWG) technology, whose useful effect is the extraction of water from air, has been improved. In particular, in the last few years, advanced AWG integrated systems have been developed. Such systems permit, not only to condense water from air, but also the smart use of the by-side effects of the process in order to partially or totally cover the heating ventilation air conditioning (HVAC) needs of a building. Presently, there are no evaluation tools that permit a complete comparison among AWG machines, taking into account all the useful effects that can be obtained at the same time and with the same energy input. The current work, starting from the need for such a tool, proposes a global index whose formulation considers all useful effects of an integrated system, the energy required to obtain them, and the integration degree of the machine. The index translates into a single number the system global efficiency, by means of a particular combination of existing efficiency indicators. In its extended formulation, it can be applied, not only to AWGs, but also to other HVAC integrated systems, as well as to combinations of non-integrated and integrated solutions. In addition to equations, the paper provides calculation examples and a case study in order to show the practical application and advantages of GEI.
Social Learning for Energy Transition—A Literature Review
Authors: Rozkwitalska Malgorzata
Published: December 2021

With increasing concerns regarding environmental sustainability, energy transition has emerged as a vital subtopic in transition studies. Such socio-technical transition requires social learning, which, however, is poorly conceptualized and explained in transition research. This paper overviews transition research on social learning. It attempts to portray how social learning has been studied in the context of energy transition and how research could be advanced. Due to the underdevelopment of the field, this paper employs a narrative review method. The review indicates two clusters of studies, which portray both direct and indirect links concerning the phenomena. The overview reveals that social learning is a force in energy transition and may occur at different levels of analysis, i.e., micro, meso, and macro, as well as different orders of learning. The author proposes to develop the academic research on the topic through quantitative and mixed-methods research as well as contributions and insights from disciplines other than sociology and political science. Some relevant topics for further inquiry can be clustered around: orders of social learning and their antecedents in energy transition; boundary-spanning roles in social learning in the context of energy transition; social learning triggered by stories about energy transition; and other theoretical underpinnings of energy transition research on social learning.
Analysis of Induced Voltage on Pipeline Located Close to Parallel Distribution System
Authors: Kim Hyoun-Su , Min Hae-Yeol , Chase J. Geoffrey , Kim Chul-Hwan
Published: December 2021

Gas and oil pipelines are widely used to supply customers. They are often laid in parallel with high voltage power lines, sharing right of way. When the pipeline is located near overhead high-voltage power, corrosion caused by induced voltages from AC power lines can occur in utility pipelines. Therefore, the calculation of induced voltage is always required for both interference and maintenance workers as well as pipeline facility safety. For parallel distribution lines, the calculation method for the induced voltage is not suitable due to the excessive error caused by using the screening factors of the neutral current. For a more practical analysis of the induced voltage, a new analysis is needed using the actual neutral current and which also considers the overhead ground conductor and the neutral conductor. This paper analyzed the induced voltage from a parallel distribution system using Carson’s formula and vector analysis. Simulation analysis results are verified by separate Electromagnetic Transient Program (EMTP) simulation.
Investigation of Dynamic Loads in Wind Turbine Drive Trains Due to Grid and Power Converter Faults
Authors: Röder Julian , Jacobs Georg , Duda Tobias , Bosse Dennis , Herzog Fabian
Published: December 2021

Electrical faults can lead to transient and dynamic excitations of the electromagnetic generator torque in wind turbines. The fast changes in the generator torque lead to load oscillations and rapid changes in the speed of rotation. The combination of dynamic load reversals and changing rotational speeds can be detrimental to gearbox components. This paper shows, via simulation, that the smearing risk increases due to the electrical faults for cylindrical roller bearings on the high speed shaft of a wind turbine research nacelle. A grid fault was examined for the research nacelle with a doubly fed induction generator concept. Furthermore, a converter fault was analyzed for the full size converter concept. Both wind turbine grid connection concepts used the same mechanical drive train. Thus, the mechanical component loading was comparable. During the grid fault, the risk of smearing increased momentarily by a maximum of around 1.8 times. During the converter fault, the risk of smearing increased by around 4.9 times. Subsequently, electrical faults increased the risk of damage to the wind turbine gearbox bearings, especially on the high speed stage.
Improving Thermoeconomic and Environmental Performance of District Heating via Demand Pooling and Upscaling
Authors: Fitó Jaume , Dimri Neha , Ramousse Julien
Published: December 2021

This study evaluates the effects of pooling heat demands in a district for the purpose of upscaling heat production units by means of energy, exergy, economic, exergoeconomic, and environmental indicators, as well as the sensitivity to investment and fuel costs. The following production systems to satisfy the heat demands (domestic hot water production and space heating) of a mixed district composed of office (80%), residential (15%), and commercial (5%) buildings are considered: gas- and biomass-fired boilers, electric boilers and heat pumps (grid-powered or photovoltaic -powered), and solar thermal collectors. For comparison, three system sizing approaches are examined: at building scale, at sector scale (residential, office, and commerce), or at district scale. For the configurations studied, the upscaling benefits were up to 5% higher efficiency (energy and exergy), there was lower levelized cost of heat for all systems (between 20% and 54%), up to 55% lower exergy destruction costs, and up to 5% greater CO2 mitigations. In conclusion, upscaling and demand pooling tend to improve specific efficiencies, reduce specific costs, reduce total investment through the peak power sizing method, and mitigate temporal mismatch in solar-driven systems. Possible drawbacks are additional heat losses due to the distribution network and reduced performance in heat pumps due to the higher temperatures required. Nevertheless, the advantages outweigh the drawbacks in most cases.
Experiments with Pyrotechnic Compositions Based on a Mathematical Model—Part I Evaluation of the Applicability of Mathematical Models in Developing Pyrotechnic Compositions Producing an Acoustic Effect
Authors: Biegańska Jolanta , Barański Krzysztof
Published: December 2021

This paper presents research on the development of pyrotechnic compositions producing an acoustic effect. These types of compositions are used in firecrackers to imitate a cannon shot—they are most frequently used during military exercises. The research was based on a mathematical model of an experiment. For environmental reasons, the replacement of the harmful oxidant Ba(NO3)2 by KClO4 and NH4ClO4 was modelled. The compositions were tested for reliability and evaluated in terms of friction sensitivity and burning rate. This allowed for the verification of the effectiveness of the modelling carried out. Optimum compositions were selected for further research.
Physicochemical Analysis of the Particulate Matter Emitted from Road Vehicle Engines
Authors: Jasiński Remigiusz , Strzemiecka Beata , Koltsov Iwona , Mizeracki Jan , Kurzawska Paula
Published: December 2021

Air pollution with particulate matter from transport sources is a serious problem in terms of air quality and its impact on human health. The article attempts to test the emitted particles from piston engines in terms of their physical properties and chemical composition. The research test objects were a diesel engine with Euro 5 emission class and a petrol engine, which was a part of the scooter drive system. The conducted research consisted in the analysis of the number, mass, and volume of particles, as well as chemical analysis, using the methods: Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope with Energy Dispersive Spectroscopy (SEM-EDS), and Evolved gas analysis (EGA). The diesel engine emitted particles in the range of 50–120 nm. With the increase in the engine load, the specific emission of particulate matter increased. In the case of a gasoline engine running without load, the emission of particles smaller than 30 nm was mainly observed. Increasing load of the gasoline engine resulted in an increase in both the concentration of particles and their diameter (average diameter to 90 nm). FTIR analysis showed higher black carbon content in the case of the sample taken from the diesel engine. In order to carry out a more detailed chemical analysis, the EGA and SEM methods were used. On their basis, the chemical composition of particles was presented, and a greater ability to agglomerate of a gasoline engine particles was found.
Integration of Electric Vehicles and Energy Storage System in Home Energy Management System with Home to Grid Capability
Authors: Mohammad Arshad , Zuhaib Mohd , Ashraf Imtiaz , Alsultan Marwan , Ahmad Shafiq , Sarwar Adil , Abdollahian Mali
Published: December 2021

In this paper, we proposed a home energy management system (HEMS) that includes photovoltaic (PV), electric vehicle (EV), and energy storage systems (ESS). The proposed HEMS fully utilizes the PV power in operating domestic appliances and charging EV/ESS. The surplus power is fed back to the grid to achieve economic benefits. A novel charging and discharging scheme of EV/ESS is presented to minimize the energy cost, control the maximum load demand, increase the battery life, and satisfy the user’s-traveling needs. The EV/ESS charges during low pricing periods and discharges in high pricing periods. In the proposed method, a multi-objective problem is formulated, which simultaneously minimizes the energy cost, peak to average ratio (PAR), and customer dissatisfaction. The multi-objective optimization is solved using binary particle swarm optimization (BPSO). The results clearly show that it minimizes the operating cost from 402.89 cents to 191.46 cents, so that a reduction of 52.47% is obtained. Moreover, it reduces the PAR and discomfort index by 15.11% and 16.67%, respectively, in a 24 h time span. Furthermore, the home has home to grid (H2G) capability as it sells the surplus energy, and the total cost is further reduced by 29.41%.
Study of the Influence of Nonlinear Dynamic Loads on Elastic Modulus of Carbonate Reservoir Rocks
Authors: Riabokon Evgenii , Turbakov Mikhail , Popov Nikita , Kozhevnikov Evgenii , Poplygin Vladimir , Guzev Mikhail
Published: December 2021

The paper presents the results of the experimental investigation of carbonate reservoir rocks subjected to quasistatic and nonlinear dynamic loads. During the quasistatic loading the zones of linear elasticity were determined. Dynamic loading of samples was performed at several frequencies and load amplitudes using a testing system. There were two zones found in which the elastic modulus changes nonlinearly in terms of dynamic load frequency. While the frequency of the dynamic load increases from 0 to 10 Hz the dynamic elastic modulus rises according to logarithmic law; while the frequency increases from 10 to 60 Hz elastic modulus rises according to a power law for each load amplitude. The amplitude of the longitudinal strain and phase shift decreases with increasing frequency of the dynamic load. Under the higher strain rates the rock gets stiffer in comparison with rock subjected to smaller strain rate dynamic loading. Saturation of rock samples with distilled water flattening the dependencies of dynamic Young’s modulus on frequency.
Potential Energy Savings from Circular Economy Scenarios Based on Construction and Agri-Food Waste in Italy
Authors: Ghisellini Patrizia , Ncube Amos , D’Ambrosio Gianni , Passaro Renato , Ulgiati Sergio
Published: December 2021

In this study, our aim was to explore the potential energy savings obtainable from the recycling of 1 tonne of Construction and Demolition Waste (C&DW) generated in the Metropolitan City of Naples. The main fraction composing the functional unit are mixed C&DW, soil and stones, concrete, iron, steel and aluminium. The results evidence that the recycling option for the C&DW is better than landfilling as well as that the production of recycled aggregates is environmentally sustainable since the induced energy and environmental impacts are lower than the avoided energy and environmental impacts in the life cycle of recycled aggregates. This LCA study shows that the transition to the Circular Economy offers many opportunities for improving the energy and environmental performances of the construction sector in the life cycle of construction materials by means of internal recycling strategies (recycling C&DW into recycled aggregates, recycled steel, iron and aluminum) as well as external recycling by using input of other sectors (agri-food by-products) for the manufacturing of construction materials. In this way, the C&D sector also contributes to realizing the energy and bioeconomy transition by disentangling itself from fossil fuel dependence.
Comparison of the Efficiency of Two Types of Heat Exchangers with Parallel Plates Made of Varied Materials
Authors: Grysa Krzysztof , Maciąg Artur , Ściana Artur
Published: December 2021

The paper discusses two mathematical models for the air flow through a plate heat exchanger with parallel plates. The first exhausts the used air and then supplies the fresh air. The second exhausts the used air above the plate and simultaneously supplies fresh air under it (counter-flow exchanger). In both cases, the exhaust air heat is used to heat the supply air. The purpose of the research is to verify which exchanger uses the exhaust air heat more efficiently. The method of the Trefftz function was used to determine approximate solutions of the analysed problems. The results obtained for 1.2 mm thick steel, aluminium, and copper plates and for external winter, summer, and spring–autumn temperatures are discussed. The results indicate that steel is the best material for a plate heat exchanger, and the counter-flow exchanger is more efficient of the two. Thanks to the use of thin steel plates and the reduction of the air exchange time to a few minutes, cheap and efficient counter-flow exchangers can be obtained.
Implementation of a Multi-Zone Numerical Blow-by Model and Its Integration with CFD Simulations for Estimating Collateral Mass and Heat Fluxes in Optical Engines
Authors: De Renzis Edoardo , Mariani Valerio , Bianchi Gian Marco , Cazzoli Giulio , Falfari Stefania , Antetomaso Christian , Irimescu Adrian
Published: December 2021

Nowadays reducing green-house gas emissions and pushing the fossil fuel savings in the field of light-duty vehicles is compulsory to slow down climate change. To this aim, the use of new combustion modes and dilution strategies to increase the stability of operations rich in diluent is an effective technique to reduce combustion temperatures and heat losses in throttled operations. Since the combustion behavior in those solutions highly differs from that of typical market systems, fundamental analyses in optical engines are mandatory in order to gain a deep understanding of those and to tune new models for improving the mutual support between experiments and simulations. However, it is known that optical accessible engines suffer from significant blow-by collateral flow due to the installation of the optical measure line. Thus, a reliable custom blow-by model capable of being integrated with both mono-dimensional and three-dimensional simulations was developed and validated against experimental data. The model can work for two different configurations: (a) stand-alone, aiming at providing macroscopic data on the ignitable mixture mass loss/recover through the piston rings; (b) combined, in which it is integrated in CFD engine simulations for the local analysis of likely collateral heat release induced by blow-by. Furthermore, once the model was validated, the effect of the engine speed and charge dilution on the blow-by phenomenon in the optical engine were simulated and discussed in the stand-alone mode.
Comparison of Tar Samples from Reaction Zone and Outlet in Ex-Situ Underground Coal Gasification Experiment
Authors: Feng Lele , Dong Maifan , Wu Yuxin , Gu Junping
Published: December 2021

Tar remaining in the gasification cavity during underground coal gasification (UCG) is an important pollution source, while the reported studies only focus on the tar behavior at the outlet. The present work aims to compare the tar properties from the reaction zone and the outlet, analyze the tar evolution during gasification, and discuss possible measures to control tar pollution. Tar was sampled with a self-developed equipment from an ex-situ underground coal gasification experimental system and analyzed by GC-MS. The gas composition, temperature, and PM10 were also compared for the reaction zone and the outlet. Compared with the tar from reaction zone, the tar from outlet has a smaller percentage of high boiling point content, PAHs, C, O, N, S, Cl, Si, and a larger percentage of H. The PAHs percentage in tar at the outlet in this work is closer to the field data than the lab data from literature, indicating the experimental system gives a good simulation of tar behavior in underground coal gasification. Condensation due to a fast temperature drop is one of the main reasons for PAHs decreasing. Tar cracking and soot formation also cause the decrease of heavy tar, proven by the light gas and particulate matter results.
Effects of High-Temperature Milk Processing
Authors: Deeth Hilton C.
Published: December 2021

In this entry, high temperature is defined as 90 to 150 °C. Many dairy processes, including extended shelf-life (ESL) and ultra-high-temperature (UHT) processing, in-container sterilization, yogurt milk heat treatment, pre-heating or forewarming milk for production of sterile concentrated milk and powders, manufacture of co-precipitate and dolce de leche, involve heat treatments in this temperature range. Pasteurization is not included in this entry as it is generally performed at 72–75 °C.