bluuebunny/crossref_metadata_2025 huggingface dataset:
Reviving the Autopsy for Modern Cancer Evolution Research
Authors: Robb Tamsin Joy , Tse Rexson , Blenkiron Cherie
Published: January 2021

Outstanding questions plaguing oncologists, centred around tumour evolution and heterogeneity, include the development of treatment resistance, immune evasion, and optimal drug targeting strategies. Such questions are difficult to study in limited cancer tissues collected during a patient’s routine clinical care, and may be better investigated in the breadth of cancer tissues that may be permissible to collect during autopsies. We are starting to better understand key tumour evolution challenges based on advances facilitated by autopsy studies completed to date. This review article explores the great progress in understanding that cancer tissues collected at autopsy have already enabled, including the shared origin of metastatic cells, the importance of early whole-genome doubling events for amplifying genes needed for tumour survival, and the creation of a wealth of tissue resources powered to answer future questions, including patient-derived xenografts, cell lines, and a wide range of banked tissues. We also highlight the future role of these programmes in advancing our understanding of cancer evolution. The research autopsy provides a special opportunity for cancer patients to give the ultimate gift—to selflessly donate their tissues towards better cancer care.
Diet as a Potential Moderator for Genome Stability and Immune Response in Pediatric Leukemia
Authors: Wang Shanshan , Maxwell Christopher A. , Akella Neha M.
Published: January 2021

Pediatric leukemias are the most prevalent cancers affecting children in developed societies, with childhood acute lymphoblastic leukemia (ALL) being the most common subtype. As diet is a likely modulator of many diseases, this review focuses on the potential for diet to influence the incidence and progression of childhood ALL. In particular, the potential effect of diets on genome stability and immunity during the prenatal and postnatal stages of early childhood development are discussed. Maternal diet plays an integral role in shaping the bodily composition of the newborn, and thus may influence fetal genome stability and immune system development. Indeed, higher birth weights of newborns are associated with increased risk of ALL, which suggests in-utero biology may shape the evolution of preleukemic clones. Postnatally, the ingestion of maternal breastmilk both nourishes the infant, and provides essential components that strengthen and educate the developing immune system. Consistently, breast-feeding associates with decreased risk of ALL development. For children already suffering from ALL, certain dietary regimens have been proposed. These regimens, which have been validated in both animals and humans, alter the internal hormonal environment. Thus, hormonal regulation by diet may shape childhood metabolism and immunity in a manner that is detrimental to the evolution or expansion of preleukemic and leukemic ALL clones.
Interaction between ERAP Alleles and HLA Class I Types Support a Role of Antigen Presentation in Hodgkin Lymphoma Development
Authors: Jiang Peijia , Veenstra Rianne N. , Seitz Annika , Nolte Ilja M. , Hepkema Bouke G. , Visser Lydia , van den Berg Anke , Diepstra Arjan
Published: January 2021

Genetic variants in the HLA region are the strongest risk factors for developing Hodgkin lymphoma (HL), suggesting an important role for antigen presentation. This is supported by another HL-associated genomic region which contains the loci of two enzymes that process endogenous proteins to peptides to be presented by HLA class I, i.e., endoplasmic reticulum aminopeptidase 1 (ERAP1) and ERAP2. We hypothesized that ERAP and HLA class I type interact in HL susceptibility, as shown previously for several autoimmune diseases. We detected ERAP1 and ERAP2 expression in tumor cells and cells in the microenvironment in primary HL tissue samples. Seven ERAP SNPs and ERAP1 haplotypes showed strong associations with RNA and protein levels of ERAP1 and ERAP2 in LCLs and HL cell lines. Analysis of HLA class I types, ERAP SNPs and ERAP haplotypes by direct genotyping or imputation from genome-wide association data in 390 HL patients revealed significant interactions between HLA-A11, rs27038 and the rs27038 associated ERAP haplotype, as well as between HLA-Cw2 and rs26618. In conclusion, our results show that ERAP and HLA class I interact in genetic susceptibility to HL, providing further evidence that antigen presentation is an important process in HL susceptibility and pathogenesis.
Binder-Free Construction of a Methanol Tolerant Pt/TiO2/Carbon Paper Anode by Atomic Layer Deposition
Authors: Ballai Gergő , Gyenes Tamás , Haspel Henrik , Vásárhelyi Lívia , Szenti Imre , Sebők Dániel , Kónya Zoltán , Kukovecz Ákos
Published: January 2021

Direct liquid fuel cells are very appealing alternatives for fighting climate change, particularly in the field of personal mobility solutions. This is especially true for direct methanol fuel cells (DMFCs) that use and burn safe fuels that are readily available from sustainable sources using well-established C1 chemistry. However, DMFCs also have some serious competitive disadvantages, like the high cost of the noble metal catalysts, the difficulties of the catalyst application, and the poisoning of the catalyst due to carbon monoxide formation. Here we demonstrate that depositing platinum on TiO2 by atomic layer deposition (ALD) is an easy, reproducible method for the synthesis of TiO2-supported platinum catalyst for methanol oxidation with superior anti-poisoning properties.
Recent Progress in Plasmonic Hybrid Photocatalysis for CO2 Photoreduction and C–C Coupling Reactions
Authors: Shin Hyeon Ho , Suh Yung Doug , Lim Dong-Kwon
Published: January 2021

Plasmonic hybrid nanostructures have been investigated as attractive heterogeneous photocatalysts that can utilize sunlight to produce valuable chemicals. In particular, the efficient photoconversion of CO2 into a stable hydrocarbon with sunlight can be a promising strategy to achieve a sustainable human life on Earth. The next step for hydrocarbons once obtained from CO2 is the carbon–carbon coupling reactions to produce a valuable chemical for energy storage or fine chemicals. For these purposes, plasmonic nanomaterials have been widely investigated as a visible-light-induced photocatalyst to achieve increased efficiency of photochemical reactions with sunlight. In this review, we discuss recent achievements involving plasmonic hybrid photocatalysts that have been investigated for CO and CO2 photoreductions to form multi-carbon products and for C–C coupling reactions, such as the Suzuki–Miyaura coupling reactions.
Healing Anthropocene Syndrome: Planetary Health Requires Remediation of the Toxic Post-Truth Environment
Authors: Logan Alan C. , Berman Susan H. , Berman Brian M. , Prescott Susan L.
Published: January 2021

The term “Anthropocene Syndrome” describes the wicked interrelated challenges of our time. These include, but are not limited to, unacceptable poverty (of both income and opportunity), grotesque biodiversity losses, climate change, environmental degradation, resource depletion, the global burden of non-communicable diseases (NCDs), health inequalities, social injustices, the spread of ultra-processed foods, consumerism and incivility in tandem with a diminished emphasis on the greater potential of humankind, efforts toward unity, or the value of fulfilment and flourishing of all humankind. Planetary health is a concept that recognizes the interdependent vitality of all natural and anthropogenic ecosystems—social, political and otherwise; it blurs the artificial lines between health at scales of person, place and planet. Promoting planetary health requires addressing the underlying pathology of “Anthropocene Syndrome” and the deeper value systems and power dynamics that promote its various signs and symptoms. Here, we focus on misinformation as a toxin that maintains the syndromic status quo—rapid dissemination of falsehoods and dark conspiracies on social media, fake news, alternative facts and medical misinformation described by the World Health Organization as an “infodemic”. In the context of planetary health, we explore the historical antecedents of this “infodemic” and underscore an urgent need to remediate the misinformation mess. It is our contention that education (especially in early life) emphasizing mindfulness and understanding of the mechanisms by which propaganda is spread (and unhealthy products are marketed) is essential. We expand the discourse on positive social contagion and argue that empowerment through education can help lead to an information transformation with the aim of flourishing along every link in the person, place and planet continuum.
Primary Immunodeficiency Disease Mimicking Pediatric Bechet’s Disease
Authors: Shiraki Mayuka , Kadowaki Saori , Kadowaki Tomonori , Kawamoto Norio , Ohnishi Hidenori
Published: January 2021

Behcet’s disease (BD) is a chronic inflammatory disease with multisystemic involvement. Its etiology is considered to involve complex environmental and genetic factors. Several susceptibility genes for BD, such as human leukocyte antigen (HLA)-A26, IL23R-IL12RB2, IL10 and ERAP1, in addition to the well-studied HLA-B51, were mainly identified by genome-wide association studies. A heterozygous mutation in TNFAIP3, which leads to A20 haploinsufficiency, was found to cause an early-onset autoinflammatory disease resembling BD in 2016. Several monogenic diseases associated with primary immunodeficiency disease and trisomy 8 have recently been reported to display BD-like phenotypes. Among the genes causing these diseases, TNFAIP3, NEMO, RELA, NFKB1 and TNFRSF1A are involved in the NF-κB (nuclear factor κ light-chain enhancer of activated B cells) signaling pathway, indicating that this pathway plays an important role in the pathogenesis of BD. Because appropriate treatment may vary depending on the disease, analyzing the genetic background of patients with such diseases is expected to help elucidate the etiology of pediatric BD and assist with its treatment. Here, we summarize recently emerging knowledge about genetic predisposition to BD.
Formative Evaluation of a Home-Based Physical Activity Intervention for Adolescent Girls—The HERizon Project: A Randomised Controlled Trial
Authors: Cowley Emma S. , Watson Paula M. , Foweather Lawrence , Belton Sarahjane , Mansfield Chiara , Whitcomb-Khan Gabriella , Cacciatore Isabella , Thompson Andrew , Thijssen Dick , Wagenmakers Anton J. M.
Published: January 2021

Background. This is a formative evaluation study of the HERizon Project, a home-based multi-component physical activity (PA) intervention for adolescent girls in the UK and Ireland. Although not intended, this study coincided with the initial COVID-19 lockdown restrictions. Methods. A total of 42 female participants, aged 13 to 16 years old (mean = 14.2, SD = 1.1), were randomly allocated to: (i) the HERizon group (n = 22) or (ii) the wait-list control group (n = 20). Participants in the six-week HERizon group were asked to complete three PA sessions each week and engage in weekly behaviour change support video calls. The primary outcome measure was self-reported habitual PA. Secondary outcomes measures included cardiorespiratory fitness (20 m shuttle run), muscular strength (standing long jump), muscular endurance (push up test), and psychosocial outcomes (Perceived Competence Scale, Body Appreciation Scale, Self-Esteem Questionnaire, Behavioural Regulation in Exercise Questionnaire). Quantitative and qualitative process evaluation data were also collected. Outcome measures were assessed at baseline and after the six-week intervention. Results. There was no significant change in habitual PA between groups (LMM group*time interaction: p = 0.767). The HERizon group had significantly increased cardiorespiratory fitness (p = 0.001), muscular endurance (p = 0.022), intrinsic motivation (p = 0.037), and body appreciation (p < 0.003) in comparison to the wait-list control group. All participants in the intervention group completed the intervention and compliance to the intervention was high (participants completed 18 ± 2 sessions). Conclusions. Although no change in PA was observed, HERizon resulted in improved physical fitness and psychosocial outcomes. These preliminary findings, alongside positive findings for feasibility and acceptability, highlight potential benefits from the home-based intervention, thus further investigation is warranted.
Laser Surface Texturing for Biomedical Applications: A Review
Authors: Shivakoti Ishwer , Kibria Golam , Cep Robert , Pradhan Bal Bahadur , Sharma Ashis
Published: January 2021

For generating a texture or pattern on a work surface, one of the emerging processes is laser surface texturing (LST). It is an effective method for producing texture on a work surface. Literature shows that various lasers have been applied to generate textures on the surface of work materials. Recently, LST has shown tremendous potential in the field of biomedical applications. Applying the LST process, the efficacy of the biomaterial has been drastically improved. This paper presents an in-depth review of laser surface texturing for biomedical applications. The effect of LST on important biomaterial has been thoroughly studied; it was found that LST has extreme potential for surface modification of biomaterial and can be utilized for biomedical applications.
Using a Modified Polyamidoamine Fluorescent Dendrimer for Capturing Environment Polluting Metal Ions Zn2+, Cd2+, and Hg2+: Synthesis and Characterizations
Authors: A. Adam Abdel Majid , Altalhi Tariq A. , El-Megharbel Samy M. , Saad Hosam A. , Refat Moamen S.
Published: January 2021

One of the most pressing global concerns is how to provide a clean environment for future generations given the exacerbation of urban, agricultural, industrial, and economic activities due to the escalating size of the global population. A polyamidoamine (PAMAM) dendrimer peripherally modified with 4-N,N′-dimethylethylenediamine-1,8-naphthalmide as a chromophore was synthesized and utilized to capture hazardous heavy metal ions. This modified fluorescent dendrimer (FCD) was complexed with Group 12 metal ions (Zn2+, Cd2+, and Hg2+) at a 2:1 (metal: FCD) ratio. Electronic absorption, fluorescence emission, Infra-red (IR), and nuclear magnetic resonance (1H NMR) spectroscopies, conductivity, CHN elemental, thermogravimetry, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses were used to characterize the resulting metal complexes. These assays revealed that the synthesized complexes were yellow-colored, thermally stable, nanoscale-sized, and composed of [M2FCD]·4Cl2. Considerable spectral shifts were observed in the emission and absorption spectra of the FCD molecule after binding the Zn2+ ions, which can be used to differentiate the Zn2+ complex from the other two complexes. This work provides basic data to facilitate the detection, quantification, and removal of environmentally hazardous heavy metal ions through complexation with a fluorescent dendrimer.
Fast-Response Liquid Crystal for Spatial Light Modulator and LiDAR Applications
Authors: Zou Junyu , Yang Qian , Hsiang En-Lin , Ooishi Haruki , Yang Zhuo , Yoshidaya Kifumi , Wu Shin-Tson
Published: January 2021

We report a new nematic mixture for liquid-crystal-on-silicon spatial light modulator (SLM) and light detection and ranging (LiDAR) applications. The mixture exhibits a relatively high birefringence (Δn), moderate dielectric anisotropy (Δɛ), low viscosity, and reasonably good photostability. To achieve 2π phase change at 5 V, the response time (on + off) is 2.5 ms at 40 °C with λ = 633 nm, and 5.9 ms with λ = 905 nm. After exposure by a blue laser (λ = 465 nm) with a total dosage up to 20 MJ/cm2, this mixture shows no sign of photodegradation. Widespread applications of this material for high brightness SLMs, LiDAR, near-eye displays, and head-up displays are foreseeable.
Angiogenesis Inhibitors as Anti-Cancer Therapy Following Renal Transplantation: A Case Report and Review of the Literature
Authors: Kasherman Lawrence , Doi Jeffrey , Karakasis Katherine , Schiff Jeffrey , Kitchlu Abhijat , Lheureux Stephanie , Oza Amit M.
Published: January 2021

Solid organ transplant recipients on long-term immunosuppressive medication are at increased risk of developing malignancy, and treatment of advanced cancers with angiogenesis inhibitors in this context has not been widely studied. We present a case of recurrent high-grade serous ovarian carcinoma treated with paclitaxel and bevacizumab in the context of prior renal transplantation where the patient responded well to treatment with controlled toxicities, discussing the potential for increased rates of adverse events and drug interactions in this select population.
Exurbia East and West: Responses of Bird Communities to Low Density Residential Development in Two North American Regions
Authors: Glennon Michale J. , Kretser Heidi E.
Published: January 2021

Exurban development is a prevalent cause of habitat loss and alteration throughout the globe and is a common land-use pattern in areas of high natural amenity value. We investigated the response of bird communities to exurban development in two contrasting North American regions, the Adirondack Park (New York) in the eastern US, and the Greater Yellowstone Ecosystem (Montana) in the Rocky Mountain West. We combined social and ecological data collection methods to compare the effects of exurban development on avian communities between the two landscapes, and, in exurban residential areas within them, to compare the relative roles of habitat structure, resource provisioning, and human disturbance in influencing avian habitat use. Contrasting with an earlier pilot study, we found differential effects of exurban development in the two regions, with birds generally more responsive in the Adirondack Park. Characteristics of habitat context and structure had larger influences on bird habitat use than human-associated resource provisioning or disturbance in both landscapes. The smaller magnitude and high variability in the responses of birds to landowner stewardship and/or disturbance suggest that broader geographical factors are highly important and that careful siting of developments on the landscape may be more successful at protecting wildlife communities than attempts to influence the behaviors of their inhabitants once built.
The Effect of Preprocessing Techniques, Applied to Numeric Features, on Classification Algorithms’ Performance
Authors: Alshdaifat Esra’a , Alshdaifat Doa’a , Alsarhan Ayoub , Hussein Fairouz , El-Salhi Subhieh Moh’d Faraj S.
Published: January 2021

It is recognized that the performance of any prediction model is a function of several factors. One of the most significant factors is the adopted preprocessing techniques. In other words, preprocessing is an essential process to generate an effective and efficient classification model. This paper investigates the impact of the most widely used preprocessing techniques, with respect to numerical features, on the performance of classification algorithms. The effect of combining various normalization techniques and handling missing values strategies is assessed on eighteen benchmark datasets using two well-known classification algorithms and adopting different performance evaluation metrics and statistical significance tests. According to the reported experimental results, the impact of the adopted preprocessing techniques varies from one classification algorithm to another. In addition, a statistically significant difference between the considered data preprocessing techniques is demonstrated.
A Systematic Survey of ML Datasets for Prime CV Research Areas—Media and Metadata
Authors: Castro Helder F. , Cardoso Jaime S. , Andrade Maria T.
Published: January 2021

The ever-growing capabilities of computers have enabled pursuing Computer Vision through Machine Learning (i.e., MLCV). ML tools require large amounts of information to learn from (ML datasets). These are costly to produce but have received reduced attention regarding standardization. This prevents the cooperative production and exploitation of these resources, impedes countless synergies, and hinders ML research. No global view exists of the MLCV dataset tissue. Acquiring it is fundamental to enable standardization. We provide an extensive survey of the evolution and current state of MLCV datasets (1994 to 2019) for a set of specific CV areas as well as a quantitative and qualitative analysis of the results. Data were gathered from online scientific databases (e.g., Google Scholar, CiteSeerX). We reveal the heterogeneous plethora that comprises the MLCV dataset tissue; their continuous growth in volume and complexity; the specificities of the evolution of their media and metadata components regarding a range of aspects; and that MLCV progress requires the construction of a global standardized (structuring, manipulating, and sharing) MLCV “library”. Accordingly, we formulate a novel interpretation of this dataset collective as a global tissue of synthetic cognitive visual memories and define the immediately necessary steps to advance its standardization and integration.
Is the 1-Minute Sit-To-Stand Test a Good Tool to Evaluate Exertional Oxygen Desaturation in Chronic Obstructive Pulmonary Disease?
Authors: Fernandes Ana L. , Neves Inês , Luís Graciete , Camilo Zita , Cabrita Bruno , Dias Sara , Ferreira Jorge , Simão Paula
Published: January 2021

Background: Chronic obstructive pulmonary disease (COPD) is frequently associated with exertional oxygen desaturation, which may be evaluated using the 6-minute walking test (6MWT). However, it is a time-consuming test. The 1-minute sit-to-stand test (1STST) is a simpler test, already used to evaluate the functional status. The aim of this study was to compare the 1STST to the 6MWT in the evaluation of exertional desaturation. Methods: This was a cross-sectional study including 30 stable COPD patients who performed the 6MWT and 1STST on the same day. Six-minute walking distance (6MWD), number of 1STST repetitions (1STSTr), and cardiorespiratory parameters were recorded. Results: A significant correlation was found between the 6MWD and the number of 1STSTr (r = 0.54; p = 0.002). The minimum oxygen saturation (SpO2) in both tests showed a good agreement (intraclass correlation coefficient (ICC) 0.81) and correlated strongly (r = 0.84; p < 0.001). Regarding oxygen desaturation, the total agreement between the tests was 73.3% with a fair Cohen’s kappa (κ = 0.38; p = 0.018), and 93.33% of observations were within the limits of agreement for both tests in the Bland–Altman analysis. Conclusion: The 1STST seems to be a capable tool of detecting exercise-induced oxygen desaturation in COPD. Because it is a less time- and resources-consuming test, it may be applied during the outpatient clinic consultation to regularly evaluate the exercise capacity and exertional desaturation in COPD.
Intra- and Interobserver Reliability of Bone Volume Estimation Using OsiriX Software in Patients with Cleft Lip and Palate Using Cone Beam Computed Tomography
Authors: Kochhar Anuraj Singh , Sidhu Maninder Singh , Prabhakar Mona , Bhasin Ritasha , Kochhar Gulsheen Kaur , Dadlani Himanshu , Spagnuolo Gianrico , Mehta Viral Vijay
Published: January 2021

The objective of the current study was to evaluate intra- and interobserver bone volume measurements and effect of orientation on the reliability of bone volume evaluation in as-acquired vis-à-vis oriented cone beam computed tomography scans using Osirix software and possible correlation between gender, age, and bone volume required. For this, 31 cone beam computed tomography (CBCT) scans of 14 girls and 17 boys (aged 9–13) with unilateral cleft lip and/or palate who met the inclusion criteria were analyzed. Efficacy and reliability of third party software Osirix for bone volume calculation was assessed using as acquired and oriented volumes by three specialists (a radiologist, an orthodontist, and an oral maxillofacial surgeon). The dataset and readings were anonymized to prevent any bias. Two-way mixed model analysis on as-acquired and oriented observations exhibited intra-class coefficient (ICC) values ≥ 0.90. Wilcoxon signed rank test (p = 0.10) and Kruskal–Wallis ANOVA (p = 0.46) indicated that although a clinical difference in volume assessment was seen between as-acquired and oriented observations (inter-observer and intra-observer), it was statistically insignificant. Spearman’s bi-variate correlation analysis revealed a significant relation between the type (side) of cleft and bone volume required to fill the defect (p < 0.05). Although there was clinical difference in bone volume measurement by the three observers, it was insignificant statistically. Clefts on the left side in the patients had significantly more bone required than the right side, whereas age and gender had no relation with bone needed to fill the defect. OsiriX software provided good reliability in measurements of bone volume.
Increase in Axial Compressibility in a Spinning Van der Waals Gas
Authors: Liu Yun , Liu Hao , Fu Zhen-Guo , Zhou Weimin
Published: January 2021

We investigated the adiabatic compression along the axial direction of a spinning Van der Waals gas by applying theoretical analysis and molecular dynamics (MD) simulations. Based on the analytical results, the rotation-induced compressibility increase effect is significant in a Van der Waals gas, while the attraction term in the Van der Waals equation of states (EOS) contributes significantly to the compressibility increase in a spinning system. We conducted MD simulations to the axial compression of a spinning gas, whose state is far from the ideal gas state, and further demonstrated that the rotation-induced compressibility increase effect in a dense state is robust, implying that such a phenomenon can be detected in experiments under high-energy-density conditions.
Electronic Wave-Packets in Integer Quantum Hall Edge Channels: Relaxation and Dissipative Effects
Authors: Rebora Giacomo , Ferraro Dario , Rodriguez Ramiro H. , Parmentier François D. , Roche Patrice , Sassetti Maura
Published: January 2021

We theoretically investigate the evolution of the peak height of energy-resolved electronic wave-packets ballistically propagating along integer quantum Hall edge channels at filling factor equal to two. This is ultimately related to the elastic scattering amplitude for the fermionic excitations evaluated at different injection energies. We investigate this quantity assuming a short-range capacitive coupling between the edges. Moreover, we also phenomenologically take into account the possibility of energy dissipation towards additional degrees of freedom—both linear and quadratic—in the injection energy. Through a comparison with recent experimental data, we rule out the non-dissipative case as well as a quadratic dependence of the dissipation, indicating a linear energy loss rate as the best candidate for describing the behavior of the quasi-particle peak at short enough propagation lengths.
Accessing Young Children’s Ideas about Energy
Authors: Detken Franziska , Brückmann Maja
Published: January 2021

We present a multi-method design for elucidating young, mostly illiterate children’s (grades 1 and 2 of Swiss elementary school, ages 6–8) ideas about energy. The design uses semi-structured interviews and video recordings as the main methods of data generation and collection, respectively. A plurality of tasks, including drawing, sorting and a newly developed picture stories task, target core aspects of the scientific energy concept in selected contexts. These tasks provide various opportunities for the children to connect to their prior experiences and express ideas verbally and non-verbally in age-adequate ways, e.g., by gestures or drawings. We illustrate the level of detail and complexity of the children’s responses and show how these reflect the children’s associations with energy and their patterns of argumentation. These rich data enable analysis regarding various aspects of the scientific energy concept, including sources, users, forms, and the transfer of energy, and the identification of possible starting points for early energy instruction.
Hacking Higher Education: Rethinking the EduHack Course
Authors: Barpi Fabrizio , Dalmazzo Davide , De Blasio Antonella , Vinci Fiorella
Published: January 2021

The paper presents a report that discuss the experience of participation of the authors in the EduHack, an online course designed to train university teachers in the use of digital techniques and learning strategies. This study highlights two issues of great interest in pandemic times. The first one is the structure and the organization of the EduHack course with some suggestions related to its improvement; the second one is Drag&Fly, the project idea of an e-learning web platform developed by the authors during the collaborative part of the course. The experience of participation to EduHack course has been analyzed by authors using concepts and categories of analysis widespread in the pragmatic theoretical tradition, enhancing the possibility of changing the teachers’ approach to the design and the implementation of a higher education e-learning course.
Designing Online Platforms Supporting Emotions and Awareness
Authors: Collazos César A. , Fardoun Habib , AlSekait Deema , Pereira Carla Santos , Moreira Fernando
Published: January 2021

Due to the global pandemic (COVID-19) currently facing humanity, a new environment that promotes teaching–learning is now emerging. This environment that challenges traditional teaching practices created an opportunity for the technology industry to capitalize on by developing creative e-learning platforms that empowers the teaching–learning process, during this ‘emergency’ situation. E-learning scenario is an important element to be considered, as it offers a host of benefits, such as reducing costs, allowing for education on-demand, etc., to its adopters. However, the application of this could bring some challenges, as some of the existing online platforms are not conducive to support clear communication among academic staff. This paper describes a report identifying the main problems faced by teachers and students from different countries in Latin America, when using e-learning platforms in a lockdown scenario, reporting the importance to include aspects related with emotions and awareness.
Intelligent Cognitive Radio Ad-Hoc Network: Planning, Learning and Dynamic Configuration
Authors: Lee Kwang-Eog , Park Joon Goo , Yoo Sang-Jo
Published: January 2021

Cognitive radio (CR) is an adaptive radio technology that can automatically detect available channels in a wireless spectrum and change transmission parameters to improve the radio operating behavior. A CR ad-hoc network (CRAHN) should be able to coexist with primary user (PU) systems and other CR secondary systems without causing harmful interference to licensed PUs as well as dynamically configure autonomous and decentralized networks. Therefore, an intelligent system structure is required for efficient spectrum use. In this paper, we present a learning-based distributed autonomous CRAHN network system model for network planning, learning, and dynamic configuration. Based on the system model, we propose machine learning-based optimization algorithms for spectrum sensing, cluster-based ad-hoc network configuration, and context-aware signal classification. Using the sensing engine and the cognitive engine, the surrounding spectrum usage and the neighbor network operation status can be analyzed. The proposed policy engine can create network operation policies for the dynamically changing surrounding wireless environment, detect policy conflicts, and infer the optimal policy for the current situation. The decision engine finally determines and configures the optimal CRAHN configuration parameters through cooperation with a learning engine, in which we implement the proposed machine-learning algorithms. The simulation results show that the proposed machine-learning CRAHN algorithms can construct CR cluster networks that have a long network lifetime and high spectrum utility. Additionally, with high signal context recognition performance, we can ensure coexistence with neighboring systems.
Investigations on Quench Recovery Characteristics of High-Temperature Superconducting Coated Conductors for Superconducting Fault Current Limiters
Authors: Chen Wei , Song Peng , Jiang Hao , Zhu Jiahui , Zou Shengnan , Qu Timing
Published: January 2021

Superconducting fault current limiters (SFCLs) are attracting increasing attention due to their potential for use in modern smart grids or micro grids. Thanks to the unique non-linear properties of high-temperature-superconducting (HTS) tapes, an SFCL is invisible to the grid with faster response compared to traditional fault current limiters. The quench recovery characteristic of an HTS tape is fundamental for the design of an SFCL. In this work, the quench recovery time of an HTS tape was measured for fault currents of different magnitudes and durations. A global heat transfer model was developed to describe the quench recovery characteristic and compared with experiments to validate its effectiveness. Based on the model, the influence of tape properties on the quench recovery time was discussed, and a safe margin for the impact energy was proposed.
A Nonlinear Viscoelastic Model for the Yielding of Gelled Waxy Crude Oil
Authors: Sun Mengran , Jou David , Wang Zhihui
Published: January 2021

We explore some rheological aspects of the yielding of gelled waxy crude oil on the basis of a fractal model for the structural description of the waxy gel and Marrucci’s model for the time evolution of the stress with mixed elastic and viscous effects. With some parameters of the model directly obtained from classic rheometry, and others by fitting the parameters to the experimental data of one shear-rate condition, the flow curves for another shear-rate condition are predicted. Both theoretical curves—the fitting and the predicted ones—share the basic features of the experimental ones. Comparison with results of Maxwell model shows that Marrucci’s model used here leads to much better results, as it incorporates nonlinear viscoelasticity of waxy crude gels in the stress evolution equation. The strain dependence of the elastic modulus also plays a relevant role on the prediction of the model, suggesting a double-network contribution for very small strain values. Due to the inertia of rheometric device, the actual shear rate is often found to depart from the setting one, and modification of shear rate history can be necessary in model validation.
Analysis of Corrosion of Hastelloy-N, Alloy X750, SS316 and SS304 in Molten Salt High-Temperature Environment
Authors: Sandhi Ketan Kumar , Szpunar Jerzy
Published: January 2021

Nickel superalloy Hastelloy-N, alloy X-750, stainless steel 316 (SS316), and stainless steel 304 (SS304) are among the alloys used in the construction of molten salt reactor (MSR). These alloys were analyzed for their corrosion resistance behavior in molten fluoride salt, a coolant used in MSR reactors with 46.5% LiF+ 11.5% NaF+ 42% KF. The corrosion tests were run at 700 °C for 100 h under the Ar cover gas. After corrosion, significant weight loss was observed in the alloy X750. Weight loss registered in SS316 and SS304 was also high. However, Hastelloy-N gained weight after exposure to molten salt corrosion. This could be attributed to electrochemical plating of corrosion products from other alloys on Hastelloy-N surface. SEM–energy-dispersive X-ray spectroscopy (EDXS) scans of cross-section of alloys revealed maximum corrosion damage to the depth of 250 µm in X750, in contrast to only 20 µm on Hastelloy-N. XPS wide survey scans revealed the presence of Fe, Cr, and Ni elements on the surface of all corroded alloys. In addition, Cr clusters were formed at the triple junctions of grains, as confirmed by SEM–EBSD (Electron Back Scattered Diffraction) analysis. The order of corrosion resistance in FLiNaK environment was X750 < SS316 < SS304 < Hastelloy-N.
A Game-Theoretic Analysis of Incentive Effects for Agribiomass Power Generation Supply Chain in China
Authors: Wu Juanjuan , Zhang Jian , Yi Weiming , Cai Hongzhen , Li Yang , Su Zhanpeng
Published: January 2021

The undersupplies of feedstock and high costs have hindered the development of China’s biomass power generation. In this paper, the noncooperative game, farmer–broker cooperative game, and broker–biomass power plant cooperative game, under government incentives, are constructed and analyzed. The optimal decision strategies and profits for these three cases are obtained, while numerical examples and sensitivity analysis are conducted, aiming at illustrating some specific features of the games. It is shown that the government plays a critical role in the development of utilizing agribiomass for power generation and can work better in cooperative games. In addition, both agribiomass supply quantity and profits of supply chain members are higher in cooperative than in noncooperative game. Meanwhile, farmers can get the maximum profit in the broker–biomass power plant cooperative game, while biomass power plant makes the maximum profit in the farmer–broker cooperative game. To guide the healthy development of the industry, there is an urgent need for further exploration of the biomass supply chain management and coordination issue. Specifically, the cooperative game for establishing optimal feedstock price subsidy policy will be done by way of adjusting government incentives and alliance profit distribution.
Investigating the Interaction Effects between Reservoir Deformation and Hydrate Dissociation in Hydrate-Bearing Sediment by Depressurization Method
Authors: Li Lijia , Li Xiaosen , Wang Yi , Qin Chaozhong , Li Bo , Luo Yongjiang , Feng Jingchun
Published: January 2021

Natural gas hydrate (NGH) has been widely focused on having great potential for alternative energy. Numerous studies on gas production from hydrate-bearing sediments have been conducted in both laboratory and field. Since the strength of hydrate-bearing sediments depends on the saturation of NGH, the decomposition of NGH may cause the failure of sediments, then leading to reservoir deformation and other geological hazards. Plenty of research has shown that the reservoir deformation caused by hydrate decomposition is considerable. In order to investigate this, the influence of sediment deformation on the production of NGH, a fully coupled thermo-hydro-chemo-mechanical (THMC) model is established in this study. The interaction effects between reservoir deformation and hydrate dissociation are discussed by comparing the simulation results of the mechanical coupling and uncoupled models on the laboratory scale. Results show that obvious differences in behaviors between gas and water production are observed among these two models. Compared to the mechanical uncoupled model, the mechanical coupling model shows a significant compaction process when given a load equal to the initial pore pressure, which leads to a remarkable decrease of effective porosity and reservoir permeability, then delays the pore pressure drop rate and reduces the maximum gas production rate. It takes a longer time for gas production in the mechanical coupling model. Since the reservoir temperature is impacted by the comprehensive effects of the heat transfer from the boundary and the heat consumption of hydrate decomposition, the reduced maximum gas production rate and extended gas production process for the mechanical coupling model lead to the minimum reservoir temperature in the mechanical coupling model larger than that of the mechanical uncoupled model. The reduction of the effective porosity for the mechanical coupling model causes a larger cumulative water production. The results of this paper indicate that the reservoir deformation in the gas production process should be taken into account by laboratory and numerical methods to accurately predict the behaviors of gas production on the field scale.
A Novel Design Portable Plugged-Type Soil Microbial Fuel Cell for Bioelectricity Generation
Authors: Nguyen Hoang-Uyen-Dung , Nguyen Dang-Trang , Taguchi Kozo
Published: January 2021

Soil microbial fuel cells (SMFCs) are a promising cost-effective power source for on-demand electricity generation applications. So far, reported SMFC configurations are usually bulky and hard to setup. In this study, a low-cost portable plugged-type SMFC (PSMFC) was designed and fabricated for on-demand micropower generation. The PSMFC can be activated just by plugging into natural wet soil, which is easy to access in the natural condition. The PSMFC uses carbon-based electrodes for cost-effectiveness. After setting the PSMFC into the soil to activate, it started to produce electricity after 1 h and reached the power density of 7.3 mW/m2 after 48 h. The proposed PSMFC can potentially generate electricity for remote sensors or soil sensing systems.
Numerical Analysis of the Combustion Dynamics of Passively Controlled Jets Issuing from Polygonal Nozzles
Authors: Kuban Łukasz , Stempka Jakub , Tyliszczak Artur
Published: January 2021

In the present work, the combustion of vitiated hydrogen jets issuing from differently shaped nozzles is modelled using the LES method. We investigate the impact of nozzle cross-sectional geometries (circular, square, triangular, hexagonal and hexagram) and the jet Reynolds numbers (Re= 18,000, 20,000 and 23,600) on the flame lift-off height, its structure, the locations of the temperature maxima and species distributions. The triangular nozzle yields the highest mixing rate and therefore the fastest decay of axial velocity and the fastest growth of the average temperature along the flame axis. It was found that for the largest Re, the zone of intense mixing and the reaction zone occur in distinct regions, while for the lower Re, these regions combine into an indistinguishable zone. Finally, it is shown that the lift-off height of the flames and the mean temperature field are non-linearly correlated with Re and strongly dependent on the nozzle shape.
Pathways toward a Decarbonized Future—Impact on Security of Supply and System Stability in a Sustainable German Energy System
Authors: Metzger Michael , Duckheim Mathias , Franken Marco , Heger Hans Joerg , Huber Matthias , Knittel Markus , Kolster Till , Kueppers Martin , Meier Carola , Most Dieter , Paulus Simon , Wyrwoll Lothar , Moser Albert , Niessen Stefan
Published: January 2021

Pathways leading to a carbon neutral future for the German energy system have to deal with the expected phase-out of coal-fired power generation, in addition to the shutdown of nuclear power plants and the rapid ramp-up of photovoltaics and wind power generation. An analysis of the expected impact on electricity market, security of supply, and system stability must consider the European context because of the strong coupling—both from an economic and a system operation point of view—through the cross-border power exchange of Germany with its neighbors. This analysis, complemented by options to improve the existing development plans, is the purpose of this paper. We propose a multilevel energy system modeling, including electricity market, network congestion management, and system stability, to identify challenges for the years 2023 and 2035. Out of the results, we would like to highlight the positive role of innovative combined heat and power (CHP) solutions securing power and heat supply, the importance of a network congestion management utilizing flexibility from sector coupling, and the essential network extension plans. Network congestion and reduced security margins will become the new normal. We conclude that future energy systems require expanded flexibilities in combination with forward planning of operation.
Combined Use of Solar and Biomass Energy for Sustainable and Cost-Effective Low-Temperature Drying of Food Processing Residues on Industrial-Scale
Authors: Mutlu Özge Çepelioğullar , Büchner Daniel , Theurich Steffi , Zeng Thomas
Published: January 2021

In this study, a low-temperature drying plant based on renewable energies to dry food processing wastes is investigated. The demand-oriented heat supply is realized by a solar wall in combination with a biomass boiler. Due to the operational complexity of such a system with different sub-units and process parameters, steady-state simulations were performed in Aspen Plus to provide an insight into the process. Moreover, a time-resolved energetic evaluation was conducted to analyze the influence of varying capacity of the heat sources and operational strategy in addition to economic calculations. The simulations showed that an overall control strategy needs to consider the air properties as well as the flow rate of wet input material. In the reference case, the boiler must be operated at full load through the year to supply as much heat as possible. The revenue from the dried material was the most crucial parameter on the drying economics. Although the current plant configuration operating at 12 h per day and five days per week enable feasible results, the drying process can be more profitable by doubling the boiler capacity and increasing operational hours to 24 h per day and five days per week. The proposed plant can provide an environmentally friendly and cost-effective solution for the re-valorization of food-processing wastes into added-value compounds.
Do Sandy Grasslands along the Danube in the Carpathian Basin Preserve the Memory of Forest-Steppes?
Authors: Penksza Károly , Saláta Dénes , Pápay Gergely , Péter Norbert , Bajor Zoltán , Lisztes-Szabó Zsuzsa , Fűrész Attila , Fuchs Márta , Michéli Erika
Published: January 2021

Research highlights: In the present survey we examined the sandy grasslands appearing in the steppe-forest-steppe vegetation in the central part of the Carpathian Basin along the Danube. Background and objectives: We aimed to answer the following questions: Is it possible to build a picture of the past form of the vegetation through the examination of these vegetation units based on dominant grass taxa? Is Festuca wagneri an element of open grasslands or steppes? According to our hypothesis, these surveys can help reveal the original or secondary woody, shrubby patches through clarifying dominant taxa. Materials and Methods: We studied the grasslands in terms of coenology, putting great emphasis on the dominant Festuca taxa. Based on our preliminary surveys and literature, three vegetation types can be separated based on one single dominant Festuca taxon in each. The survey was conducted in four different locations in the Carpathian Basin. The cover of dominant grass species was used as an indicator value. The pedological background was also examined. Results: F. vaginata grassland is an open vegetation type based on its coenosystematic composition and ecological values. It grows in very weakly developed calcareous soil with sandy texture, with its lowest and highest organic carbon content ranging from 0.2% to 11.3% (0.2%), and the highest carbonate content (11.3%). Where the grasslands were disturbed, F. pseudovaginata and the recently discovered F. tomanii appeared. These taxa were also found in forest patches. The soil under F. pseudovaginata was more developed, in the surface horizon with higher organic carbon content (1.1%) and lower carbonate content (6.9%). The soil profile under F. wagneri developed the most, as the presence of deep and humus rich soil material from deflation and degradation showed. Conclusions: the dominant Festuca taxa of these vegetation types are good indicators of the changes in the vegetation and their ecological background.