bluuebunny/crossref_metadata_2025 huggingface dataset:
Visual Language-Aided Construction Fire Safety Planning Approach in Building Information Modeling
Authors: Khan Numan , Ali Ahmed Khairadeen , Van-Tien Tran Si , Lee Doyeop , Park Chansik
Published: March 2020

Fires pose an enormous threat to human safety and many spectacular fires in under-construction buildings were reported over the past few years. Many construction sites only rely on fire extinguishers, as under-construction buildings do not contain a permanent fire protection system. Traditional safety planning lacks a justified approach for the firefighting equipment installation planning in the construction job site. Even though many government agencies made safety regulations for firefighting equipment installations, it is still a challenge to translate and execute these rules at the job site. Currently, the construction industry is devoted to discovering all the possible applications of Building Information Modelling (BIM) technology in the entire phases of the project life cycle. BIM technology enables the presentation of facilities in 3-D and offers rule-based modeling through visual programming tools. Therefore, this paper focuses on a visual language approach for rule translation and a multi-agent-based construction fire safety planning simulation in BIM. The proposed approach includes three core modules, namely: (a) Rule Extraction and Logic Development (RELD) Module, (b) Design for Construction Fire Safety (DCFS) Module, and (c) Con-fire Safety Plan Simulation (CSPS) Module. In addition, the DCFS module further includes three submodules, named as (1) Firefighting Equipment Installation (FEI) Module, (2) Bill of Quantities (BoQs) for firefighting Equipment (BFE) Module, and (3) Escape Route Plan (ERP) Module. The RELD module converts the OSHA fire safety rule into mathematical logic, and the DCFS module presents the development of the Con-fire Safety Planning approach by translating the rules from mathematical logic into computer-readable language. The three sub-modules of the DCFS module visualize the outputs of this research work. The CSPS module uses a multi-agent simulation to verify the safety rule compliance of the portable firefighting equipment installation plan the system in a BIM environment. A sample project case study has been implemented to validate the proof of concept. It is anticipated that the proposed approach has the potential to helps the designers through its effectiveness and convenience while it could be helpful in the field for practical use.
Big Data Analytics and Processing Platform in Czech Republic Healthcare
Authors: Štufi Martin , Bačić Boris , Stoimenov Leonid
Published: March 2020

Big data analytics (BDA) in healthcare has made a positive difference in the integration of Artificial Intelligence (AI) in advancements of analytical capabilities, while lowering the costs of medical care. The aim of this study is to improve the existing healthcare eSystem by implementing a Big Data Analytics (BDA) platform and to meet the requirements of the Czech Republic National Health Service (Tender-Id. VZ0036628, No. Z2017-035520). In addition to providing analytical capabilities on Linux platforms supporting current and near-future AI with machine-learning and data-mining algorithms, there is the need for ethical considerations mandating new ways to preserve privacy, all of which are preconditioned by the growing body of regulations and expectations. The presented BDA platform, has met all requirements (N > 100), including the healthcare industry-standard Transaction Processing Performance Council (TPC-H) decision support benchmark in compliance with the European Union (EU) and the Czech Republic legislations. Currently, the presented Proof of Concept (PoC) that has been upgraded to a production environment has unified isolated parts of Czech Republic healthcare over the past seven months. The reported PoC BDA platform, artefacts, and concepts are transferrable to healthcare systems in other countries interested in developing or upgrading their own national healthcare infrastructure in a cost-effective, secure, scalable and high-performance manner.
Shear Tests of Deep Hollow Core Slabs Strengthened by Core-Filling
Authors: Joo Hyo-Eun , Han Sun-Jin , Park Min-Kook , Kim Kang Su
Published: March 2020

Prestressed hollow core slabs (PHCSs) have commonly been applied to long-span structures, due to their excellent flexural capacity and deflection control performance. However, in quite a few cases, the web-shear strength at member ends subjected to high shear forces is insufficient, because the web of the PHCS is very thin, making it difficult to place shear reinforcement, and the prestress is not fully effective in transfer length regions. Accordingly, a variety of shear strengthening methods have been proposed to improve the web-shear strength of PHCS ends. In this study, experimental research was conducted to investigate the shear resistance mechanism of PHCS strengthened by core-filling method, which has been most widely used in the construction field. The number of filled cores and the shear reinforcement ratio were set as the main test variables, and the patterns and angles of shear cracks that occurred in the PHCS units and filled cores, respectively, and the strain behavior of the shear reinforcement, were measured and analyzed in detail. This study also analyzed the test results based on the current design codes, and proposed a modified shear strength equation that can be applied to the core-filled PHCS.
An Integrated Approach to Biomedical Term Identification Systems
Authors: López-Úbeda Pilar , Díaz-Galiano Manuel Carlos , Montejo-Ráez Arturo , Martín-Valdivia María-Teresa , Ureña-López L. Alfonso
Published: March 2020

In this paper a novel architecture to build biomedical term identification systems is presented. The architecture combines several sources of information and knowledge bases to provide practical and exploration-enabled biomedical term identification systems. We have implemented a system to evidence the convenience of the different modules considered in the architecture. Our system includes medical term identification, retrieval of specialized literature and semantic concept browsing from medical ontologies. By applying several Natural Language Processing (NLP) technologies, we have developed a prototype that offers an easy interface for helping to understand biomedical specialized terminology present in Spanish medical texts. The result is a system that performs term identification of medical concepts over any textual document written in Spanish. It is possible to perform a sub-concept selection using the previously identified terms to accomplish a fine-tune retrieval process over resources like SciELO, Google Scholar and MedLine. Moreover, the system generates a conceptual graph which semantically relates all the terms found in the text. In order to evaluate our proposal on medical term identification, we present the results obtained by our system using the MANTRA corpus and compare its performance with the Freeling-Med tool.
4-Hexylresorcinol Exhibits Different Characteristics to Estrogen
Authors: Kang Yei-Jin , Oh Ji-Hyeon , Seok Hyun , Jo You-Young , Kim Dae-Won , Garagiola Umberto , Choi Je-Yong , Kim Seong-Gon
Published: March 2020

4-Hexylresorcinol (4HR) has been used as a food additive and antiseptic. The aim of this study was to evaluate whether the application of 4HR in breast cancer cells and ovariectomized rats showed estrogen-like effects. MCF-7 and SK-BR-3 cells were treated by solvent, 1–100 µM bisphenol-A (BPA), or 1–100 µM 4HR, respectively. 3-(4, 5-Dimethylthiazole-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay and Western blot for extracellular signal-regulated kinase-1/-2 (ERK1/2), phosphorylated ERK1/2 (p-ERK1/2), estrogen receptor-α (ERα), and ERβ were done. As an in vivo study, ovariectomized rats (n = 15) received solvent, 125 mg/kg of 4HR, or 10 µg of 17-β estradiol via daily subcutaneous injection for 7 days. Blood samples were obtained for evaluation of prolactin levels. Pituitary glands and uteruses were biopsied for histological evaluation and Western blot analysis. Compared with the control group, the application of 4HR decreased the proliferation of MCF-7 and SK-BR-3 cells, while the application of BPA increased (p < 0.05). The application of BPA increased the expression of ERα, ERβ, and p-ERK1/2, but 4HR did not change the expression of ERα, ERβ, or p-ERK1/2 in MCF-7 cells. In an animal model, the 4HR group showed similar levels of ERα, ERβ, and prolactin expression in the pituitary gland compared to the solvent only group, while the estradiol group showed higher levels. Serum prolactin levels were similar between the 4HR and solvent only groups. Taken together, 1–100 µM 4HR did not show BPA-like behavior in MCF-7 cells, and 125 mg/kg of 4HR daily subcutaneous injection for 7 days did not demonstrate estradiol-like effects in ovariectomized rats. Collectively, 4HR has no estrogen-like effects on both ERα-positive cells and estrogen-deficient rat models.
Year 2020: A Snapshot of the Last Progress in Flexible Printed Gas Sensors
Authors: Fioravanti Ambra , Carotta Maria Cristina
Published: March 2020

A review of recent advances in flexible printed gas sensors is presented. During the last years, flexible electronics has started to offer new opportunities in terms of sensors features and their possible application fields. The advent of this technology has made sensors low-cost, thin, with a large sensing area, lightweight, wearable, flexible, and transparent. Such new characteristics have led to the development of new gas sensor devices. The paper makes some statistical remarks about the research and market of the sensors and makes a shot of the printing technologies, the flexible organic substrates, the functional materials, and the target gases related to the specific application areas. The conclusion is a short notice on perspectives in the field.
Software Defect Prediction Using Heterogeneous Ensemble Classification Based on Segmented Patterns
Authors: Alsawalqah Hamad , Hijazi Neveen , Eshtay Mohammed , Faris Hossam , Radaideh Ahmed Al , Aljarah Ibrahim , Alshamaileh Yazan
Published: March 2020

Software defect prediction is a promising approach aiming to improve software quality and testing efficiency by providing timely identification of defect-prone software modules before the actual testing process begins. These prediction results help software developers to effectively allocate their limited resources to the modules that are more prone to defects. In this paper, a hybrid heterogeneous ensemble approach is proposed for the purpose of software defect prediction. Heterogeneous ensembles consist of set of classifiers of different learning base methods in which each of them has its own strengths and weaknesses. The main idea of the proposed approach is to develop expert and robust heterogeneous classification models. Two versions of the proposed approach are developed and experimented. The first is based on simple classifiers, and the second is based on ensemble ones. For evaluation, 21 publicly available benchmark datasets are selected to conduct the experiments and benchmark the proposed approach. The evaluation results show the superiority of the ensemble version over other well-regarded basic and ensemble classifiers.
Skill Assessment of an Atmosphere–Wave Regional Coupled Model over the East China Sea with a Focus on Typhoons
Authors: Li Delei , Staneva Joanna , Grayek Sebastian , Behrens Arno , Feng Jianlong , Yin Baoshu
Published: March 2020

This study performed several sensitivity experiments to investigate the impact of atmosphere–wave coupling on the simulated wind and waves over the East China Sea (ECS) with a focus on typhoon events. These experiments include stand-alone regional atmosphere model (CCLM) simulations, stand-alone spectral wave model (WAM) simulations driven by the regional atmospheric model CCLM or ERA5 reanalysis, and two-way (CCLM-WAM) coupled simulations. We assessed the simulated wind speed and significant wave height against in situ observations and remote sensing data and focused on typhoon events in 2010. We analyzed the differences between the experiments in capturing the surface pressure, wind speed, and roughness length. Both ERA5 reanalysis data and our regional model simulations demonstrate high quality in capturing wind and wave conditions over the ECS. The results show that downscaled simulations tend to be closer to in situ observations than ERA5 reanalysis data in capturing wind variability and probability distribution, dominant wind and wave directions, strong typhoon intensity and related extreme significant wave height. In comparison with satellite observations, the CCLM-WAM simulation outperforms the CCLM in reducing wind bias. The coupled and uncoupled simulations are very similar in terms of other wind and wave statistics. Though there is much improvement in capturing typhoon intensity to ERA5, regional downscaled simulations still underestimate the wind intensity of tropical cyclones.
Behavior of Battery Metals Lithium, Cobalt, Manganese and Lanthanum in Black Copper Smelting
Authors: Dańczak Anna , Klemettinen Lassi , Kurhila Matti , Taskinen Pekka , Lindberg Daniel , Jokilaakso Ari
Published: March 2020

Recycling of metals from different waste streams must be increased in the near future for securing the availability of metals that are critical for high-tech applications, such as batteries for e-mobility. Black copper smelting is a flexible recycling route for many different types of scrap, including Waste Electrical and Electronic Equipment (WEEE) and some end-of-life energy storage materials. Fundamental thermodynamic data about the behavior of battery metals and the effect of slag additives is required for providing data necessary for process development, control, and optimization. The goal of our study is to investigate the suitability of black copper smelting process for recycling of battery metals lithium, cobalt, manganese, and lanthanum. The experiments were performed alumina crucibles at 1300 °C, in oxygen partial pressure range of 10−11–10−8 atm. The slags studied contained 0 to 6 wt% of MgO. Electron probe microanalysis (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) techniques were utilized for phase composition quantifications. The results reveal that most cobalt can be recovered into the copper alloy in extremely reducing process conditions, whereas lithium, manganese, and lanthanum deport predominantly in the slag at all investigated oxygen partial pressures.
Galectin-3 as a Next-Generation Biomarker for Detecting Early Stage of Various Diseases
Authors: Hara Akira , Niwa Masayuki , Noguchi Kei , Kanayama Tomohiro , Niwa Ayumi , Matsuo Mikiko , Hatano Yuichiro , Tomita Hiroyuki
Published: March 2020

Galectin-3 is a β-galactoside-binding lectin which is important in numerous biological activities in various organs, including cell proliferation, apoptotic regulation, inflammation, fibrosis, and host defense. Galectin-3 is predominantly located in the cytoplasm and expressed on the cell surface, and then often secreted into biological fluids, like serum and urine. It is also released from injured cells and inflammatory cells under various pathological conditions. Many studies have revealed that galectin-3 plays an important role as a diagnostic or prognostic biomarker for certain types of heart disease, kidney disease, viral infection, autoimmune disease, neurodegenerative disorders, and tumor formation. In particular, it has been recognized that galectin-3 is extremely useful for detecting many of these diseases in their early stages. The purpose of this article is to review and summarize the recent literature focusing on the biomarker characteristics and long-term outcome predictions of galectin-3, in not only patients with various types of diseases, but associated animal models.
Wolkenstein’s Model of Size Effects in CO Oxidation by Gold Nanoparticles
Authors: Turaeva Nigora , Krueger Herman
Published: March 2020

The Wolkenstein’s theory of catalysis and the d-band theory of formation chemical bonds between transition metal catalysts and adsorbates were used to develop the approach applied to the kinetics of CO oxidation by gold nanoparticles. In the model, within the framework of the mechanism of the reaction going through dissociative adsorption of oxygen molecules and reaction with gas-phase CO molecules, weak and strong chemisorption states of intermediates (O, CO2) were taken into account in the kinetic equations by introducing reversible electronic steps corresponding to electron transfers between the intermediates and the catalyst. As a result, we obtain the expression for the reaction rate, which exhibits a volcano-shape dependence upon the size of the gold nanoparticles at the conditions when the intermediates fractions are not small compared to the empty active sites of the catalyst. It is supposed that the approach can be also applied to the Langmuir-Hinshelwood mechanism.
Apelin Affects the Progression of Osteoarthritis by Regulating VEGF-Dependent Angiogenesis and miR-150-5p Expression in Human Synovial Fibroblasts
Authors: Wang Yu-Han , Kuo Shu-Jui , Liu Shan-Chi , Wang Shih-Wei , Tsai Chun-Hao , Fong Yi-Chin , Tang Chih-Hsin
Published: March 2020

Synovium-induced angiogenesis is central to osteoarthritis (OA) pathogenesis and thus a promising therapeutic target. The adipokine apelin (APLN) is involved in both OA pathogenesis and angiogenesis. We examined the role of APLN in synovium-induced angiogenesis by investigating the crosstalk between APLN and vascular endothelial growth factor (VEGF) expression in human OA synovial fibroblasts (OASFs). We found higher levels of APLN and VEGF expression in OA samples compared with normal samples. APLN-induced stimulation of VEGF expression and VEGF-dependent angiogenesis in OASFs was mitigated by FAK/Src/Akt signaling. APLN also inhibited levels of microRNA-150-5p (miR-150-5p), which represses VEGF production and angiogenesis. Analyses of an OA animal model showed that shAPLN transfection of OASFs rescued pathologic changes in OA cartilage and histology. Here, we found APLN enhances VEGF expression and angiogenesis via FAK/Src/Akt cascade and via downstream suppression of miR-150-5p expression. These findings help to clarify the pathogenesis of adipokine-induced angiogenesis in OA synovium.
Melatonin’s Antineoplastic Potential Against Glioblastoma
Authors: Moretti Enrico , Favero Gaia , Rodella Luigi Fabrizio , Rezzani Rita
Published: March 2020

Glioblastoma (GBM) is one of the most intransigent and aggressive brain tumors, and its treatment is extremely challenging and ineffective. To improve patients’ expectancy and quality of life, new therapeutic approaches were investigated. Melatonin is an endogenous indoleamine with an incredible variety of properties. Due to evidence demonstrating melatonin’s activity against several cancer hallmarks, there is growing interest in its use for preventing and treating cancer. In this review, we report on the potential effects of melatonin, alone or in combination with anticancer drugs, against GBM. We also summarize melatonin targets and/or the intracellular pathways involved. Moreover, we describe melatonin’s epigenetic activity responsible for its antineoplastic effects. To date, there are too few clinical studies (involving a small number of patients) investigating the antineoplastic effects of melatonin against GBM. Nevertheless, these studies described improvement of GBM patients’ quality of life and did not show significant adverse effects. In this review, we also report on studies regarding melatonin-like molecules with the tumor-suppressive properties of melatonin together with implemented pharmacokinetics. Melatonin effects and mechanisms of action against GBM require more research attention due to the unquestionably high potential of this multitasking indoleamine in clinical practice.
Astrocyte and Oligodendrocyte Cross-Talk in the Central Nervous System
Authors: Nutma Erik , van Gent Démi , Amor Sandra , Peferoen Laura A. N.
Published: March 2020

Over the last decade knowledge of the role of astrocytes in central nervous system (CNS) neuroinflammatory diseases has changed dramatically. Rather than playing a merely passive role in response to damage it is clear that astrocytes actively maintain CNS homeostasis by influencing pH, ion and water balance, the plasticity of neurotransmitters and synapses, cerebral blood flow, and are important immune cells. During disease astrocytes become reactive and hypertrophic, a response that was long considered to be pathogenic. However, recent studies reveal that astrocytes also have a strong tissue regenerative role. Whilst most astrocyte research focuses on modulating neuronal function and synaptic transmission little is known about the cross-talk between astrocytes and oligodendrocytes, the myelinating cells of the CNS. This communication occurs via direct cell-cell contact as well as via secreted cytokines, chemokines, exosomes, and signalling molecules. Additionally, this cross-talk is important for glial development, triggering disease onset and progression, as well as stimulating regeneration and repair. Its critical role in homeostasis is most evident when this communication fails. Here, we review emerging evidence of astrocyte-oligodendrocyte communication in health and disease. Understanding the pathways involved in this cross-talk will reveal important insights into the pathogenesis and treatment of CNS diseases.
Designing Novel Therapies to Mend Broken Hearts: ATF6 and Cardiac Proteostasis
Authors: Blackwood Erik A. , Bilal Alina S. , Stauffer Winston T. , Arrieta Adrian , Glembotski Christopher C.
Published: March 2020

The heart exhibits incredible plasticity in response to both environmental and genetic alterations that affect workload. Over the course of development, or in response to physiological or pathological stimuli, the heart responds to fluctuations in workload by hypertrophic growth primarily by individual cardiac myocytes growing in size. Cardiac hypertrophy is associated with an increase in protein synthesis, which must coordinate with protein folding and degradation to allow for homeostatic growth without affecting the functional integrity of cardiac myocytes (i.e., proteostasis). This increase in the protein folding demand in the growing cardiac myocyte activates the transcription factor, ATF6 (activating transcription factor 6α, an inducer of genes that restore proteostasis. Previously, ATF6 has been shown to induce ER-targeted proteins functioning primarily to enhance ER protein folding and degradation. More recent studies, however, have illuminated adaptive roles for ATF6 functioning outside of the ER by inducing non-canonical targets in a stimulus-specific manner. This unique ability of ATF6 to act as an initial adaptive responder has bolstered an enthusiasm for identifying small molecule activators of ATF6 and similar proteostasis-based therapeutics.
Propranolol Suppresses the T-Helper Cell Depletion-Related Immune Dysfunction in Cirrhotic Mice
Authors: Tsai Hung-Cheng , Hsu Chien-Fu , Huang Chia-Chang , Huang Shiang-Fen , Li Tzu-Hao , Yang Ying-Ying , Lin Ming-Wei , Lee Tzung-Yan , Liu Chih-Wei , Huang Yi-Hsiang , Hou Ming-Chih , Lin Han-Chieh
Published: March 2020

Bacterial translocation (BT) and splenomegaly contribute to cirrhosis-associated immune dysfunction (CAID) including T cell depletion, infection, and chronic inflammation. β-blockers have been reported to decrease BT and improve splenomegaly. This study explores the modulation of β1 and β2 adrenergic receptors (ADRB1/ADRB2) by propranolol treatment on the peripheral and splenic immune dysfunction of cirrhotic mice. In vivo experiments were performed in bile duct ligation (BDL)- and thioacetamide (TAA)-cirrhotic mice receiving two weeks of propranolol treatment. Acute effects of propranolol were evaluated in T-helper (Th) cells isolated from spleen of cirrhotic mice. Over-expression of β1 and β2 adrenergic receptors (ADRB1/ADRB2) in spleen and T lymphocytes was associated with high peripheral/splenic lipopolysaccharide binding protein levels. Moreover, a decrease in Th cells percentage, increase in Treg subset, and cytokines were accompanied by increased apoptosis, proliferation, and reduced white pulp hyperplasia in cirrhotic mice, which were counteracted by propranolol treatment. The Th-cell depletion, systemic inflammation, BT, and infection were improved by chronic propranolol treatment. Acute propranolol treatment inhibited apoptosis, Treg-conditioned differentiation, and promoted Th2-conditioned differentiation through ADRB-cyclic adenosine monophosphate (cAMP) signals in cirrhotic mice. In conclusion, suppression of ADRB1 and ADRB2 expressions in spleen and splenic T lymphocytes by acute and chronic propranolol treatment ameliorate systemic and splenic immune dysfunction in cirrhosis.
Fluorinated Galactoses Inhibit Galactose-1-Phosphate Uridyltransferase and Metabolically Induce Galactosemia-like Phenotypes in HEK-293 Cells
Authors: Janes Verena , Grabany Simona , Delbrouck Julien , Vincent Stephane P. , Gottschalk Johannes , Elling Lothar , Hanisch Franz-Georg
Published: March 2020

Genetic defects of human galactose-1-phosphate uridyltransferase (hGALT) and the partial loss of enzyme function result in an altered galactose metabolism with serious long-term developmental impairment of organs in classic galactosemia patients. In search for cellular pathomechanisms induced by the stressor galactose, we looked for ways to induce metabolically a galactosemia-like phenotype by hGALT inhibition in HEK293 cells. In kinetic studies, we provide evidence for 2-fluorinated galactose-1-phosphate (F-Gal-1-P) to competitively inhibit recombinant hGALT with a KI of 0.9 mM. Contrasting with hepatic cells, no alterations of N-glycoprofiles in MIG (metabolic induction of galactosemia)-HEK293 cells were revealed for an inducible secretory netrin-1 probe by MALDI-MS. Differential fluorescence-activated cell sorting demonstrated reduced surface expression of N-glycosylated CD109, EGFR, DPP4, and rhMUC1. Membrane raft proteomes exhibited dramatic alterations pointing to an affection of the unfolded protein response, and of targeted protein traffick. Most prominent, a negative regulation of oxidative stress was revealed presumably as a response to a NADPH pool depletion during reduction of Gal/F-Gal. Cellular perturbations induced by fluorinated galactoses in normal epithelial cells resemble proteomic changes revealed for galactosemic fibroblasts. In conclusion, the metabolic induction of galactosemia-like phenotypes in healthy epithelial/neuronal cells could support studies on the molecular pathomechanisms in classic galactosemia, in particular under conditions of low galactose stress and residual GALT activity.
Left Atrial Structural Remodelling in Non-Valvular Atrial Fibrillation: What Have We Learnt from CMR?
Authors: Floria Mariana , Radu Smaranda , Gosav Evelina Maria , Cozma Dragos , Mitu Ovidiu , Ouatu Anca , Tanase Daniela Maria , Scripcariu Viorel , Serban Lacramioara Ionela
Published: March 2020

Left atrial structural, functional and electrical remodelling are linked to atrial fibrillation (AF) pathophysiology and mirror the phrase “AF begets AF”. A structurally remodelled left atrium (LA) is fibrotic, dysfunctional and enlarged. Fibrosis is the hallmark of LA structural remodelling and is associated with increased risk of stroke, heart failure development and/or progression and poorer catheter ablation outcomes with increased recurrence rates. Moreover, increased atrial fibrosis has been associated with higher rates of stroke even in sinus-rhythm individuals. As such, properly assessing the fibrotic atrial cardiomyopathy in AF patients becomes necessary. In this respect, late-gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging is the gold standard in imaging myocardial fibrosis. LA structural remodelling extension offers both diagnostic and prognostic information and influences therapeutic choices. LGE-CMR scans can be used before the procedure to better select candidates and to aid in choosing the ablation technique, during the procedure (full CMR-guided ablations) and after the ablation (to assess the ablation scar). This review focuses on imaging several LA structural remodelling CMR parameters, including size, shape and fibrosis (both extension and architecture) and their impact on procedure outcomes, recurrence risk, as well as their utility in relation to the index procedure timing.
Exploring Students’ Metacognitive Knowledge: The Case of Integral Calculus
Authors: Radmehr Farzad , Drake Michael
Published: March 2020

Previous studies of integral calculus have mainly explored students’ conceptual and procedural knowledge; only a few have focused on students’ metacognition in relation to integral calculus. The study reported here explored students’ metacognitive knowledge of integral calculus by interviewing nine first-year university and eight Year 13 students. The design of the interview questions was based on the structure of metacognitive knowledge in Revised Bloom’s Taxonomy. The findings suggest there are differences between students’ metacognitive knowledge at Year 13 and the first year of university. In particular, the importance of knowing the rationale behind the theorems and formulas was not obvious for Year 13 students. Moreover, students’ metacognitive knowledge could be developed further at both levels, particularly in terms of developing strategies to identify how integral calculus questions could be solved and to check the outcome of problem-solving.
Efficient FPSoC Prototyping of FCS-MPC for Three-Phase Voltage Source Inverters
Authors: Zafra Eduardo , Vazquez Sergio , Guzman Miranda Hipolito , Sanchez Juan A. , Marquez Abraham , Leon Jose I. , Franquelo Leopoldo G.
Published: March 2020

This work describes an efficient implementation in terms of computation time and resource usage in a Field-Programmable System-On-Chip (FPSoC) of a Finite Control Set Model Predictive Control (FCS-MPC) algorithm. As an example, the FCS-MPC implementation is used for the current reference tracking of a two-level three-phase power converter. The proposed solution is an enabler for using both complex control algorithms and digital controllers for high switching frequency semiconductor technologies. An original HW/SW (hardware and software) system architecture for an FPSoC is designed to take advantage of a modern operating system, while removing time uncertainty in real-time software tasks, and exploiting dedicated FPGA fabric for the most complex computations. In addition, two different architectures for the FPGA-implemented functionality are proposed and compared in order to study the area-speed trade-off. Experimental results show the feasibility of the proposed implementation, which achieves a speed hundreds of times faster than the conventional Digital Signal Processor (DSP)-based control platform.
The Influence of Compaction and Water Conditions on Shear Strength and Friction Resistance between Geotextiles and Ash-Slag Mixture
Authors: Gruchot Andrzej , Zydroń Tymoteusz , Michalska Agata
Published: March 2020

The paper presents the results of tests of the shear strength of the ash–slag mixture taken from the landfill located in Kraków (Poland) and the interfacial friction resistance at the contact between the ash–slag mixture and woven or nonwoven geotextiles. The tests were carried out in a direct shear apparatus on samples with and without water saturation. The samples for testing were formed in the apparatus box at the optimum moisture by compacting them to IS = 0.90 and 1.00. The test results reveal that the shear strength parameters of the ash-slag mixture were large. It was stated the significant influence of the compaction, the growth of which has resulted in an increase in the angle of internal friction (from 7% to 9%) and cohesion (from 60% to 97%). Whereas the saturation of the samples reduced the shear strength parameters (from 4% to 6%, of the internal friction angle and 30% to 43% of cohesion). The values of the interfacial friction resistance at the contact between the ash–slag mixture and the geotextiles were large as well, but slightly smaller than the values of the shear strength parameters of the mixture itself. The compaction caused an increase in the angle of interfacial friction (from 1% to 5%) and adhesion (from 31% to 127%). The water-saturation of the samples caused a change in the angle of interfacial friction (from −6% to 3%) and decline in the adhesion (from 22% to 69%). Values of the interaction coefficient were about 0.8–1.0 and they tended to rise with increasing the normal stress. Higher values of this parameter were obtained in tests with water saturation and for non-woven geotextiles.
Investigation of Ash Deposition Dynamic Process in an Industrial Biomass CFB Boiler Burning High-Alkali and Low-Chlorine Fuel
Authors: Zhang Hengli , Yu Chunjiang , Luo Zhongyang , Li Yu’an
Published: March 2020

The circulating fluidized bed (CFB) boiler is a mainstream technology of biomass combustion generation in China. The high flue gas flow rate and relatively low combustion temperature of CFB make the deposition process different from that of a grate furnace. The dynamic deposition process of biomass ash needs further research, especially in industrial CFB boilers. In this study, a temperature-controlled ash deposit probe was used to sample the deposits in a 12 MW CFB boiler. Through the analysis of multiple deposit samples with different deposition times, the changes in micromorphology and chemical composition of the deposits in each deposition stage can be observed more distinctively. The initial deposits mainly consist of particles smaller than 2 μm, caused by thermophoretic deposition. The second stage is the condensation of alkali metal. Different from the condensation of KCl reported by most previous literatures, KOH is found in deposits in place of KCl. Then, it reacts with SO2, O2 and H2O to form K2SO4. In the third stage, the higher outer layer temperature of deposits reduces the condensation rate of KOH significantly. Meanwhile, the rougher surface of deposits allowed more calcium salts in fly ash to deposit through inertial impact. Thus, the elemental composition of deposits surface shows an overall trend of K decreasing and Ca increasing.
Comparing Power-System and User-Oriented Battery Electric Vehicle Charging Representation and Its Implications on Energy System Modeling
Authors: Wulff Niklas , Steck Felix , Gils Hans Christian , Hoyer-Klick Carsten , van den Adel Bent , Anderson John E.
Published: March 2020

Battery electric vehicles (BEV) provide an opportunity to balance supply and demand in future power systems with high shares of fluctuating renewable energy. Compared to other storage systems such as pumped-storage hydroelectricity, electric vehicle energy demand is highly dependent on charging and connection choices of vehicle users. We present a model framework of a utility-based stock and flow model, a utility-based microsimulation of charging decisions, and an energy system model including respective interfaces to assess how the representation of battery electric vehicle charging affects energy system optimization results. We then apply the framework to a scenario study for controlled charging of nine million electric vehicles in Germany in 2030. Assuming a respective fleet power demand of 27 TWh, we analyze the difference between power-system-based and vehicle user-based charging decisions in two respective scenarios. Our results show that taking into account vehicle users’ charging and connection decisions significantly decreases the load shifting potential of controlled charging. The analysis of marginal values of equations and variables of the optimization problem yields valuable insights on the importance of specific constraints and optimization variables. Assumptions on fleet battery availability and a detailed representation of fast charging are found to have a strong impact on wind curtailment, renewable energy feed-in, and required gas power plant flexibility. A representation of fleet connection to the grid in high temporal detail is less important. Peak load can be reduced by 5% and 3% in both scenarios, respectively. Shifted load is robust across sensitivity analyses while other model results such as curtailment are more sensitive to factors such as underlying data years. Analyzing the importance of increased BEV fleet battery availability for power systems with different weather and electricity demand characteristics should be further scrutinized.
HEMS-IoT: A Big Data and Machine Learning-Based Smart Home System for Energy Saving
Authors: Machorro-Cano Isaac , Alor-Hernández Giner , Paredes-Valverde Mario Andrés , Rodríguez-Mazahua Lisbeth , Sánchez-Cervantes José Luis , Olmedo-Aguirre José Oscar
Published: March 2020

Energy efficiency has aroused great interest in research worldwide, because energy consumption has increased in recent years, especially in the residential sector. The advances in energy conversion, along with new forms of communication, and information technologies have paved the way for what is now known as smart homes. The Internet of Things (IoT) is the convergence of various heterogeneous technologies from different application domains that are used to interconnect things through the Internet, thus allowing for the detection, monitoring, and remote control of multiple devices. Home automation systems (HAS) combined with IoT, big data technologies, and machine learning are alternatives that promise to contribute to greater energy efficiency. This work presents HEMS-IoT, a big data and machine learning-based smart home energy management system for home comfort, safety, and energy saving. We used the J48 machine learning algorithm and Weka API to learn user behaviors and energy consumption patterns and classify houses with respect to energy consumption. Likewise, we relied on RuleML and Apache Mahout to generate energy-saving recommendations based on user preferences to preserve smart home comfort and safety. To validate our system, we present a case study where we monitor a smart home to ensure comfort and safety and reduce energy consumption.
Unsupervised Monitoring System for Predictive Maintenance of High Voltage Apparatus
Authors: Gianoglio Christian , Ragusa Edoardo , Bruzzone Andrea , Gastaldo Paolo , Zunino Rodolfo , Guastavino Francesco
Published: March 2020

The online monitoring of a high voltage apparatus is a crucial aspect for a predictive maintenance program. Partial discharges (PDs) phenomena affect the insulation system of an electrical machine and—in the long term—can lead to a breakdown, with a consequent, significant economic loss; wind turbines provide an excellent example. Embedded solutions are therefore required to monitor the insulation status. The paper presents an online system that adopts unsupervised methodologies for assessing the condition of the monitored machine in real time. The monitoring process does not rely on any prior knowledge about the apparatus; nonetheless, the method can identify the relevant drifts in the machine status. In addition, the system is specifically designed to run on low-cost embedded devices.
Determinants of the Forward Premium in the Nord Pool Electricity Market
Authors: Haugom Erik , Molnár Peter , Tysdahl Magne
Published: March 2020

Nord Pool is the leading power market in Europe. It has been documented that the forward contracts traded in this market exhibit a significant forward premium, which could be a sign of market inefficiency. Efficient power markets are important, especially when there is a goal to increase the share of the power mix stemming from renewable energy sources. We therefore contribute to the understanding of this topic by examining how the forward premium in the Nord Pool market depend on several economic and physical conditions. We utilise two methods: ordinary least squares and quantile regression. The results show that the reservoir level and the basis (the difference between the forward and spot price) have a significant impact on the forward premium. The realised volatility of futures prices and the implied volatility of the stock market have strong effects on both the conditional lower and upper tails of the forward premium. We also find that, as the market has matured, the forward premium has decreased, indicating an increase in market efficiency.
A Parallel Estimation System of Stator Resistance and Rotor Speed for Active Disturbance Rejection Control of Six-Phase Induction Motor
Authors: Heidari Hamidreza , Rassõlkin Anton , Holakooie Mohammad Hosein , Vaimann Toomas , Kallaste Ants , Belahcen Anouar , Lukichev Dmitry V.
Published: March 2020

In this paper, a parallel estimation system of the stator resistance and the rotor speed is proposed in speed sensorless six-phase induction motor (6PIM) drive. First, a full-order observer is presented to provide the stator current and the rotor flux. Then, an adaptive control law is designed using the Lyapunov stability theorem to estimate the rotor speed. In parallel, a stator resistance identification scheme is proposed using more degrees of freedom of the 6PIM, which is also based on the Lyapunov stability theorem. The main advantage of the proposed method is that the stator resistance adaptation is completely decoupled from the rotor speed estimation algorithm. To increase the robustness of the drive system against external disturbances, noises, and parameter uncertainties, an active disturbance rejection controller (ADRC) is introduced in direct torque control (DTC) of the 6PIM. The experimental results clarify the effectiveness of the proposed approaches.
Interaction of Electrical Energy Storage, Flexible Bioenergy Plants and System-friendly Renewables in Wind- or Solar PV-dominated Regions
Authors: Tafarte Philip , Kanngießer Annedore , Dotzauer Martin , Meyer Benedikt , Grevé Anna , Millinger Markus
Published: March 2020

Wind and solar PV have become the lowest-cost alternatives for power generation in many countries and are expected to dominate the renewable power supply in many regions of the world. The temporal volatility in power production from these sources leads to new challenges for a stable and secure power supply system. Possible technologies to improve the integration of wind and solar PV are electrical energy storage and the flexible power provision by bioenergy. A third option is the system-friendly layout of wind and solar PV systems and the optimized mix of wind and solar PV capacities. To assess these different options at hand, a case study was conducted covering various scenarios for a regional power supply based on a high share of wind and solar PV. State-of-the-art concepts for all the stated technologies are modelled and a numerical optimization approach is applied on temporally-resolved time series data to identify the potential role of each option and their respective interactions. Power storage was found to be most relevant in solar dominated systems, due to the diurnal generation pattern, whereas bioenergy is more suitably combined with high wind power shares due to the less regular generation pattern. System-friendly wind and solar power can reduce the need for generation capacity and flexible options by fitting generation and demand patterns better.
How Much Energy Efficient are Renewable Energy Sources Cooperatives’ Initiatives?
Authors: Sifakis Nikolaos , Daras Tryfon , Tsoutsos Theocharis
Published: March 2020

In this paper is provided a systematic, in-depth, behavioral analysis of renewable energy sources cooperatives’ members. The analysis proved that in, on hand, there was a noticeable difference in the portion of affection of each proposed intervention on the actual energy consumption, which may be to even ten times more in some cases, and on the other hand, the difference in energy consumption between the analyzed groups was noticeable as well. So, implementing energy efficiency interventions of various types, such as technical support, special tariffs, energy generation schemes, and smart meters, seems to lead to substantial energy reductions to even more than 10%, cumulatively, and reduces the environmental footprint. Additionally, the majority of energy efficiency interventions applied by the renewable energy sources cooperatives are proved to be effective in achieving their primary goal, sensitizing members, and leading them to a more efficient energy consumption behavior (“greener”). The results of the analysis showed that each proposed intervention had played a different but nonetheless significant role in the diminishing of the energy consumption of the members and that there was a noticeable difference in energy consumption between the analyzed groups. The results of the analysis demonstrated more than 22 GWh totally in green consumption, and almost 4500 tons of CO2 saved.
Effects of Increasing Nitrogen Content on Process Stability and Reactor Performance in Anaerobic Digestion
Authors: Morozova Ievgeniia , Nikulina Nadiia , Oechsner Hans , Krümpel Johannes , Lemmer Andreas
Published: March 2020

The aim of this study was to analyse the effect of different nitrogen increase rates in feedstock on the process stability and conversion efficiency in anaerobic digestion (AD). The research was conducted in continuously stirred tank reactors (CSTR), initially filled with two different inocula: inocula #1 with low and #2 with high nitrogen (N) concentrations. Three N feeding regimes were investigated: the “0-increase” feeding regime with a constant N amount in feeding and the regimes “0.25-increase” and “0.5-increase” where the N concentrations in feedstock were raised by 0.25 and 0.5 g·kg−1, respectively, related to fresh matter (FM) every second week. The N concentration inside the reactors increased according to the feeding regimes. The levels of inhibition (Inhibition) in specific methane yields (SMY), related to the conversion efficiency of the substrates, were quantified. At the N concentration in digestate of 10.82 ± 0.52 g·kg−1 FM measured in the reactors with inoculum #2 and “0.5-increase” feeding regime, the level of inhibition was equal to 38.99% ± 14.99%. The results show that high nitrogen increase rates in feeding regime are negatively related to the efficiency of the AD process, even if low volatile fatty acid (VFA) concentrations indicate a stable process.