bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrocardiographic Fragmented Activity (I): Physiological Meaning of Multivariate Signal Decompositions
Authors: Melgarejo-Meseguer Francisco-Manuel , Gimeno-Blanes Francisco-Javier , Salar-Alcaraz María-Eladia , Gimeno-Blanes Juan-Ramón , Martínez-Sánchez Juan , García-Alberola Arcadi , Rojo-Álvarez José-Luis
Published: September 2019

Recent research has proven the existence of statistical relation among fragmented QRS and several highly prevalence diseases, such as cardiac sarcoidosis, acute coronary syndrome, arrythmogenic cardiomyopathies, Brugada syndrome, and hypertrophic cardiomyopathy. One out of five hundred people suffer from hypertrophic cardiomyopathies. The relation among the fragmentation and arrhythmias drives the objective of this work, which is to propose a valid method for QRS fragmentation detection. With that aim, we followed a two-stage approach. First, we identified the features that better characterize the fragmentation by analyzing the physiological interpretation of multivariate approaches, such as principal component analysis (PCA) and independent component analysis (ICA). Second, we created an invariant transformation method for the multilead electrocardiogram (ECG), by scrutinizing the statistical distributions of the PCA eigenvectors and of the ICA transformation arrays, in order to anchor the desired elements in the suitable leads in the feature space. A complete database was compounded incorporating real fragmented ECGs, surrogate registers by synthetically adding fragmented activity to real non-fragmented ECG registers, and standard clean ECGs. Results showed that the creation of beat templates together with the application of PCA over eight independent leads achieves 0.995 fragmentation enhancement ratio and 0.07 dispersion coefficient. In the case of ICA over twelve leads, the results were 0.995 fragmentation enhancement ratio and 0.70 dispersion coefficient. We conclude that the algorithm presented in this work constructs a new paradigm, by creating a systematic and powerful tool for clinical anamnesis and evaluation based on multilead ECG. This approach consistently consolidates the inconspicuous elements present in multiple leads onto designated variables in the output space, hence offering additional and valid visual and non-visual information to standard clinical review, and opening the door to a more accurate automatic detection and statistically valid systematic approach for a wide number of applications. In this direction and within the companion paper, further developments are presented applying this technique to fragmentation detection.
Non-Linear Vibration Isolators with Unknown Excitation and Unmodelled Dynamics: Sliding Mode Active Control
Authors: Zhang Ke-Wei , Hu Zhi-Gang , Liu Hai-Min , Ouyang Huajiang , Zhang Jia-Fan
Published: September 2019

For a class of single-degree-of-freedom non-linear passive vibration isolators with unknown excitation and unmodelled dynamics, two sliding mode control methods—a conventional one and the other using a super-twisting algorithm—were proposed to complement and improve the performances and the robustness of the passive isolators. The proposed control methods only require the estimation of the loading and measured velocities of the isolators. Numerical simulations for a non-linear isolator with quasi-zero stiffness demonstrated that both methods were effective and easy to implement, and the one using a super-twisting algorithm was more promising from the perspective of practical application.
The Rapid Detection Technology of Lamb Wave for Microcracks in Thin-Walled Tubes
Authors: Yang Shunmin , Wang Mingquan , Yang Lu
Published: September 2019

Thin-walled tubes are a kind of pressure vessel formed by a stamping and drawing process, which must withstand a great deal of sudden pressure during use. When microcrack defects of a certain depth are present on its inner and outer surfaces, severe safety accidents may occur, such as cracking and crushing. Therefore, it is necessary to carry out nondestructive testing of thin-walled tubes in the production process to eliminate the potential safety hazards. To realize the rapid detection of microcracks in thin-walled tubes, this study could be summarized as follows: (i) Because the diameters of the thin-walled tubes were much larger than their thicknesses, Lamb wave characteristics of plates with equal thicknesses were used to approximate the dispersion characteristics of thin-walled tubes. (ii) To study the dispersion characteristics of Lamb waves in thin plates, the detection method of the A 0 mode was determined using the particle displacement–amplitude curve. (iii) Using a multi-channel parallel detection method, rapid detection equipment for Lamb wave microcracks in thin-walled tubes was developed. (iv) The filtering peak values for defect signal detection with different depths showed that the defect detection peak values could reflect the defect depth information. (v) According to the minimum defect standard of a 0.045-mm depth, 100,000 thin-walled tubes were tested. The results showed that the missed detection rate was 0%, the reject rate was 0.3%, and the detection speed was 5.8 s/piece, which fully meets the actual detection requirements of production lines. Therefore, this study not only solved the practical issues for the rapid detection of microcracks in thin-walled tubes but also provided a reference for the application of ultrasonic technology for the detection of other components.
Graphene Nanoplatelets Impact on Concrete in Improving Freeze-Thaw Resistance
Authors: Chen Guofang , Yang Mingqian , Xu Longjun , Zhang Yingzi , Wang Yanze
Published: September 2019

Graphene nanoplatelets (GNP) is a newly nanomaterial with extraordinary properties. This paper investigated the effect of GNP on the addition on freeze–thaw (F–T) resistance of concrete. In this experimental study, water to cement ratio remained unchanged, a control mixture without GNP materials and the addition of GNP was ranging from 0.02% to 0.4% by weight of ordinary Portland cement was prepared. Specimens were carried out by the rapid freeze-thaw test, according to the current Chinese standard. The workability, compressive strength, visual deterioration and mass loss of concrete samples were evaluated. Scanning electron microscopy also applied in order to investigate the micromorphology inside of the concrete. The results showed that GNP concrete has a finer pore structure than ordinary concrete; moreover, the workability of GNP concrete reduced, and the compressive strength of specimens was enhanced within the appropriate range of GNP addition; in addition, GNP concrete performed better than the control concrete in the durability of concrete exposed to F-T actions. Specimens with 0.05% GNP exhibited the highest compressive property after 200 F–T cycles compared with other samples.
Performance Analysis and Parameter Optimization of the Optimal Fixed-Point Quantum Search
Authors: Bao Tianyi , Huang Duan
Published: September 2019

The optimal fixed-point quantum search (OFPQS) algorithm [Phys. Rev. Lett. 113, 210501 (2014)] achieves both the fixed-point property and quadratic speedup over classical algorithms, which gives a sufficient condition on the number of iterations to ensure the success probability is no less than a given lower bound (denoted by 1 − δ 2 ). However, this condition is approximate and not exact. In this paper, we derive the sufficient and necessary condition on the number of feasible iterations, based on which the exact least number of iterations can be obtained. For example, when δ = 0 . 8 , iterations can be saved by almost 25%. Moreover, to find a target item certainly, setting directly 1 − δ 2 = 100 % , the quadratic advantage of the OFPQS algorithm will be lost, then, applying the OFPQS algorithm with 1 − δ 2 < 100 % requires multiple executions, which leads to a natural problem of choosing the optimal parameter δ . For this, we analyze the extreme and minimum properties of the success probability and further analytically derive the optimal δ which minimizes the query complexity. Our study can be a guideline for both the theoretical and application research on the fixed-point quantum search algorithms.
A Distributed Energy Resources Aggregation Model Based on Multi-Scenario and Multi-Objective Methodology
Authors: Li Hong , Duan Jie , Zhang Dengyue , Yang Jinghui
Published: September 2019

Aggregation technology can integrate distributed energy resources (DERs) into resource aggregation (RA) to achieve efficient utilization of resources. This paper studies a DERs aggregation model to construct a RA. Firstly, considering the uncertainty of the output of distributed generation (DG), the characteristics of DG are analyzed and the daily eigenvalues are extracted. The contour coefficient is introduced and the improved K-means algorithm is used to cluster the daily eigenvectors to get the multiple probability scenarios in a single season. Then, in order to obtain a RA with lower daily average cost, better power generation characteristics and higher regional aggregation degree, the DERs aggregation model based on multi-scenario and multi-objective is established considering multiple constraints. To obtain a compromise optimal solution, the cellular bat algorithm based on fuzzy membership degree (FMD-CBA) is used to solve the model. Finally, the validity of the multi-scenario and multi-objective model in a single season is verified by an example.
Parameter Optimization of Geogrid-Reinforced Foundations Based on Model Experiments and Numerical Simulations
Authors: Zhang Guolong , Yang Yuyou , Su Fei
Published: September 2019

Dynamic compaction and geogrid reinforcement are two of the well-known methods used in improving the mechanical properties of fill foundations. In order to investigate their mutual restriction when used simultaneously and optimize the design parameters, model experiments and numerical simulations were conducted. First, three factors (embedded ratio of reinforced geogrid, number of reinforced layers and interval of reinforced layers) that are related to performance of reinforced geogrid were analyzed by model experiments with dynamic compaction. Then, orthogonal analysis was performed by numerical simulation (dynamic analysis in FLAC3D) to take into account five different elastic moduli and internal angle of friction along with the aforementioned three factors. Last, range analysis and variance analysis were performed on the orthogonal results to optimize the five factors by the calculated indicators. Additionally, linear regression analysis reflecting the relationships between five factors and four indicators was presented. The displacement field, compaction effect, earth pressure, and geogrid deformation of the reinforced soil under different combinations of the five factors were explored. Experiment and simulation results provide practical guides to the design of reinforced methods and a reference for the stability and deformation of other earth reinforcement projects under dynamic loads.
Mathematical and Numerical Modeling of On-Threshold Modes of 2-D Microcavity Lasers with Piercing Holes
Authors: Spiridonov Alexander O. , Karchevskii Evgenii M. , Nosich Alexander I.
Published: September 2019

This study considers the mathematical analysis framework aimed at the adequate description of the modes of lasers on the threshold of non-attenuated in time light emission. The lasers are viewed as open dielectric resonators equipped with active regions, filled in with gain material. We introduce a generalized complex-frequency eigenvalue problem for such cavities and prove important properties of the spectrum of its eigensolutions. This involves reduction of the problem to the set of the Muller boundary integral equations and their discretization with the Nystrom technique. Embedded into this general framework is the application-oriented lasing eigenvalue problem, where the real emission frequencies and the threshold gain values together form two-component eigenvalues. As an example of on-threshold mode study, we present numerical results related to the two-dimensional laser shaped as an active equilateral triangle with a round piercing hole. It is demonstrated that the threshold of lasing and the directivity of light emission, for each mode, can be efficiently manipulated with the aid of the size and, especially, the placement of the piercing hole, while the frequency of emission remains largely intact.
Flavonoids and Their Anti-Diabetic Effects: Cellular Mechanisms and Effects to Improve Blood Sugar Levels
Authors: AL-Ishaq Raghad Khalid , Abotaleb Mariam , Kubatka Peter , Kajo Karol , Büsselberg Dietrich
Published: September 2019

Diabetes mellitus (DM) is a prevailing global health metabolic disorder, with an alarming incidence rate and a huge burden on health care providers. DM is characterized by the elevation of blood glucose due either to a defect in insulin synthesis, secretion, binding to receptor, or an increase of insulin resistance. The internal and external factors such as obesity, urbanizations, and genetic mutations could increase the risk of developing DM. Flavonoids are phenolic compounds existing as secondary metabolites in fruits and vegetables as well as fungi. Their structure consists of 15 carbon skeletons and two aromatic rings (A and B) connected by three carbon chains. Flavonoids are furtherly classified into 6 subclasses: flavonols, flavones, flavanones, isoflavones, flavanols, and anthocyanidins. Naturally occurring flavonoids possess anti-diabetic effects. As in vitro and animal model’s studies demonstrate, they have the ability to prevent diabetes and its complications. The aim of this review is to summarize the current knowledge addressing the antidiabetic effects of dietary flavonoids and their underlying molecular mechanisms on selected pathways: Glucose transporter, hepatic enzymes, tyrosine kinase inhibitor, AMPK, PPAR, and NF-κB. Flavonoids improve the pathogenesis of diabetes and its complications through the regulation of glucose metabolism, hepatic enzymes activities, and a lipid profile. Most studies illustrate a positive role of specific dietary flavonoids on diabetes, but the mechanisms of action and the side effects need more clarification. Overall, more research is needed to provide a better understanding of the mechanisms of diabetes treatment using flavonoids.
Comparative Analysis of MicroRNA and mRNA Profiles of Sperm with Different Freeze Tolerance Capacities in Boar (Sus scrofa) and Giant Panda (Ailuropoda melanoleuca)
Authors: Ran Ming-Xia , Zhou Ying-Min , Liang Kai , Wang Wen-Can , Zhang Yan , Zhang Ming , Yang Jian-Dong , Zhou Guang-Bin , Wu Kai , Wang Cheng-Dong , Huang Yan , Luo Bo , Qazi Izhar Hyder , Zhang He-Min , Zeng Chang-Jun
Published: September 2019

Post-thawed sperm quality parameters vary across different species after cryopreservation. To date, the molecular mechanism of sperm cryoinjury, freeze-tolerance and other influential factors are largely unknown. In this study, significantly dysregulated microRNAs (miRNAs) and mRNAs in boar and giant panda sperm with different cryo-resistance capacity were evaluated. From the result of miRNA profile of fresh and frozen-thawed giant panda sperm, a total of 899 mature, novel miRNAs were identified, and 284 miRNAs were found to be significantly dysregulated (195 up-regulated and 89 down-regulated). Combined analysis of miRNA profiling of giant panda sperm and our previously published data on boar sperm, 46, 21 and 4 differentially expressed (DE) mRNAs in boar sperm were believed to be related to apoptosis, glycolysis and oxidative phosphorylation, respectively. Meanwhile, 87, 17 and 7 DE mRNAs in giant panda were associated with apoptosis, glycolysis and oxidative phosphorylation, respectively. Gene ontology (GO) analysis of the targets of DE miRNAs showed that they were mainly distributed on membrane related pathway in giant panda sperm, while cell components and cell processes were tied to the targets of DE miRNAs in boar sperm. Finally, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of DE mRNAs indicated that most of these DE mRNAs were distributed in membrane signal transduction-related pathways in giant panda sperm, while those in boar sperm were mainly distributed in the cytokine-cytokine receptor interaction pathway and inflammatory related pathways. In conclusion, although the different freezing extenders and programs were used, the DE miRNAs and mRNAs involved in apoptosis, energy metabolism, olfactory transduction pathway, inflammatory response and cytokine-cytokine interactions, could be the possible molecular mechanism of sperm cryoinjury and freeze tolerance.
Synthesis and Different Effects of Biotinylated PAMAM G3 Dendrimer Substituted with Nimesulide in Human Normal Fibroblasts and Squamous Carcinoma Cells
Authors: Uram Łukasz , Filipowicz-Rachwał Aleksandra , Misiorek Maria , Winiarz Aleksandra , Wałajtys-Rode Elżbieta , Wołowiec Stanisław
Published: September 2019

Squamous cell carcinoma (SCC) remains a main cause of mortality in patients with neck and head cancers, with poor prognosis and increased prevalence despite of available therapies. Recent studies have identified a role of cyclooxygenases, particularly inducible isoform cyclooxygenase-2 (COX-2) and its metabolite prostaglandin E2 (PGE2) in cancer cell proliferation, and its inhibition become a target for control of cancer development, particularly in the view of recognized additive or synergic action of COX-2 inhibitors with other forms of therapy. Nimesulide (N), the selective COX-2 inhibitor, inhibits growth and proliferation of various types of cancer cells by COX-2 dependent and independent mechanisms. In the presented study, the conjugates of biotinylated third generation poly(amidoamine) dendrimer (PAMAM) with covalently linked 18 (G3B18N) and 31 (G3B31N) nimesulide residues were synthesized and characterized by NMR spectroscopy. Biological properties of conjugates were evaluated, including cytotoxicity, proliferation, and caspase 3/7 activities in relation to COX-2/PGE2 axis signaling in human normal fibroblast (BJ) and squamous cell carcinoma (SCC-15). Both conjugates exerted a selective cytotoxicity against SCC-15 as compared with BJ cells at low 1.25–10 µM concentration range and their action in cancer cells was over 250-fold stronger than nimesulide alone. Conjugates overcome apoptosis resistance and sensitized SCC-15 cells to the apoptotic death independently of COX-2/PGE2 axis. In normal human fibroblasts the same concentrations of G3B31N conjugate were less effective in inhibition of proliferation and induction of apoptosis, as measured by caspase 3/7 activity in a manner depending on increase of PGE2 production by either COX-1/COX-2.
Exploring Tumor Heterogeneity Using PET Imaging: The Big Picture
Authors: Bailly Clément , Bodet-Milin Caroline , Bourgeois Mickaël , Gouard Sébastien , Ansquer Catherine , Barbaud Matthieu , Sébille Jean-Charles , Chérel Michel , Kraeber-Bodéré Françoise , Carlier Thomas
Published: September 2019

Personalized medicine represents a major goal in oncology. It has its underpinning in the identification of biomarkers with diagnostic, prognostic, or predictive values. Nowadays, the concept of biomarker no longer necessarily corresponds to biological characteristics measured ex vivo but includes complex physiological characteristics acquired by different technologies. Positron-emission-tomography (PET) imaging is an integral part of this approach by enabling the fine characterization of tumor heterogeneity in vivo in a non-invasive way. It can effectively be assessed by exploring the heterogeneous distribution and uptake of a tracer such as 18F-fluoro-deoxyglucose (FDG) or by using multiple radiopharmaceuticals, each providing different information. These two approaches represent two avenues of development for the research of new biomarkers in oncology. In this article, we review the existing evidence that the measurement of tumor heterogeneity with PET imaging provide essential information in clinical practice for treatment decision-making strategy, to better select patients with poor prognosis for more intensive therapy or those eligible for targeted therapy.
The Influence of Cell Type and Culture Medium on Determining Cancer Selectivity of Cold Atmospheric Plasma Treatment
Authors: Biscop Eline , Lin Abraham , Van Boxem Wilma , Van Loenhout Jinthe , De Backer Joey , Deben Christophe , Dewilde Sylvia , Smits Evelien , Bogaerts Annemie
Published: September 2019

Increasing the selectivity of cancer treatments is attractive, as it has the potential to reduce side-effects of therapy. Cold atmospheric plasma (CAP) is a novel cancer treatment that disrupts the intracellular oxidative balance. Several reports claim CAP treatment to be selective, but retrospective analysis of these studies revealed discrepancies in several biological factors and culturing methods. Before CAP can be conclusively stated as a selective cancer treatment, the importance of these factors must be investigated. In this study, we evaluated the influence of the cell type, cancer type, and cell culture medium on direct and indirect CAP treatment. Comparison of cancerous cells with their non-cancerous counterparts was performed under standardized conditions to determine selectivity of treatment. Analysis of seven human cell lines (cancerous: A549, U87, A375, and Malme-3M; non-cancerous: BEAS-2B, HA, and HEMa) and five different cell culture media (DMEM, RPMI1640, AM, BEGM, and DCBM) revealed that the tested parameters strongly influence indirect CAP treatment, while direct treatment was less affected. Taken together, the results of our study demonstrate that cell type, cancer type, and culturing medium must be taken into account before selectivity of CAP treatment can be claimed and overlooking these parameters can easily result in inaccurate conclusions of selectivity.
Insulin Receptor Isoform A Modulates Metabolic Reprogramming of Breast Cancer Cells in Response to IGF2 and Insulin Stimulation
Authors: Vella Veronica , Nicolosi Maria Luisa , Giuliano Marika , Morrione Andrea , Malaguarnera Roberta , Belfiore Antonino
Published: September 2019

Previously published work has demonstrated that overexpression of the insulin receptor isoform A (IR-A) might play a role in cancer progression and metastasis. The IR has a predominant metabolic role in physiology, but the potential role of IR-A in cancer metabolic reprogramming is unknown. We aimed to characterize the metabolic impact of IR-A and its ligand insulin like growth factor 2 (IGF2) in human breast cancer (BC) cells. To establish autocrine IGF2 action, we generated human BC cells MCF7 overexpressing the human IGF2, while we focused on the metabolic effect of IR-A by stably infecting IGF1R-ablated MCF7 (MCF7IGF1R-ve) cells with a human IR-A cDNA. We then evaluated the expression of key metabolism related molecules and measured real-time extracellular acidification rates and oxygen consumption rates using the Seahorse technology. MCF7/IGF2 cells showed increased proliferation and invasion associated with aerobic glycolysis and mitochondrial biogenesis and activity. In MCF7IGF1R-ve/IR-A cells insulin and IGF2 stimulated similar metabolic changes and were equipotent in eliciting proliferative responses, while IGF2 more potently induced invasion. The combined treatment with the glycolysis inhibitor 2-deoxyglucose (2DG) and the mitochondrial inhibitor metformin blocked cell invasion and colony formation with additive effects. Overall, these results indicate that IGF2 and IR-A overexpression may contribute to BC metabolic reprogramming.
Effect of Chronic Corticosterone Treatment on Depression-Like Behavior and Sociability in Female and Male C57BL/6N Mice
Authors: Berger Stefanie , Gureczny Sarah , Reisinger Sonali N. , Horvath Orsolya , Pollak Daniela D.
Published: September 2019

Depression is a very common psychiatric disorder affecting approximately 300 million people worldwide with the prevalence being twice as high in women as in men. Despite intense research efforts in recent decades, the neurobiological basis underlying depression remains incompletely understood. However, the exposure to chronic stress is widely accepted to constitute a precipitating factor for the development of this mental disorder. Several animal models for the investigation of the pathogenetic link between chronic stress and depression exist and have yielded important insights. The present study aimed at comparing two published protocols for the induction of depression-like behavior in mice based on chronic oral glucocorticoid application. Given the gender distribution in the prevalence of depression, the second goal of this study was to reveal possible differences in the behavioral responses of female and male mice to corticosterone (CORT) treatment. CORT treatment was found to modulate depression-like behavior in selected behavioral paradigms in a sex- and protocol-specific manner. These data are of relevance for the experimental design and interpretation of future studies in the field and further highlight the relevance of “sex as biological variable” to be considered an important parameter for experimental planning and interpretation of results.
Usability of Cr-Doped Alumina in Dosimetry
Authors: Einbergs Ernests , Zolotarjovs Aleksejs , Bite Ivita , Laganovska Katrina , Auzins Krisjanis , Smits Krisjanis , Trinkler Laima
Published: September 2019

Dosimetry is a widespread material science field dealing with detection and quantification of ionizing radiation using electronic processes in materials. One of the main aspects that determines the performance of dosimeters is the type of defects the material contains. Crystalline lattice imperfections are formed around impurity ions, which may have a smaller or larger size, or different oxidation states compared to host ions. In this study, we show what effects Cr impurities have on the luminescent properties of alumina. Porous Al 2 O 3 : Cr microceramics synthesized using the sol-gel method showed a higher thermoluminescence response than a single crystal ruby. We have found that Cr 2 O 3 concentration of 0.2 wt% was optimal; it yielded the highest X-ray luminescence and thermostimulated luminescence readout of all studied additive concentrations added to alumina during synthesis. Our results show that Cr doped alumina could potentially be used as a promising new material for dosimetry of ionizing radiation.
Using the Cahn–Hilliard Theory in Metastable Binary Solutions
Authors: Tran Duc Viet-Nhien , Chan Philip K.
Published: September 2019

A solution may be in one of three states: stable, unstable, or metastable. If the solution is unstable, phase separation is spontaneous and proceeds by spinodal decomposition. If the solution is metastable, the solution must overcome an activation barrier for phase separation to proceed spontaneously. This mechanism is called nucleation and growth. Manipulating morphology using phase separation has been of great research interest because of its practical use to fabricate functional materials. The Cahn–Hilliard theory, incorporating Flory–Huggins free energy, has been used widely and successfully to model phase separation by spinodal decomposition in the unstable region. This model is used in this paper to mathematically model and numerically simulate the phase separation by nucleation and growth in the metastable state for a binary solution. Our numerical results indicate that Cahn–Hilliard theory is able to predict phase separation in the metastable region but in a region near the spinodal line.
Increasing Access to Clean Fuels and Clean Technologies: A Club Convergence Approach
Authors: Cary Michael
Published: September 2019

In this paper we test for convergence in access to clean energy and clean technology among nations in order to study the economic determinants of access to clean energy and clean technologies. This is important because without access to clean fuels, no global development strategy can be environmentally sustainable. After obtaining an estimated convergence rate under a conditional β -convergence model, we use a more sophisticated club convergence econometric framework and ultimately reject the hypothesis of β -convergence in favor of subgroups exhibiting intra-group convergence tendencies that are distinct from the other groups. We then employ a club convergence algorithm which groups the 93 nations studied into 8 convergence clubs based on characteristics including the percentage of the population with access to clean energy in the household and the growth rate of this percentage. Evidence that household access to clean energy and clean technology is tied to economic development and institutional quality is provided by showing that the convergence clubs not only reflect distinct strata in access to clean energy but are also strongly tied to important indicators of institutional quality.
Mindfulness-Based Attention Training: Feasibility and Preliminary Outcomes of a Digital Course for High School Students
Authors: Mrazek Alissa J. , Mrazek Michael D. , Reese Jordan V. , Kirk Arianna C. , Gougis Lefeba J. , Delegard Alex M. , Cynman David J. , Cherolini Casey M. , Carr Peter C. , Schooler Jonathan W.
Published: September 2019

Digital mindfulness-based interventions (d-MBIs) present an unprecedented opportunity to share mindfulness training at scale. However, the feasibility of digital mindfulness training for high schools remains unknown. Using a one-group pre–post design, this feasibility study evaluated the adoption of a digital mindfulness course in a public high school. The 22-day course was delivered on laptops, tablets, or phones via a custom digital learning platform. The course included a total of 2.25 h of instruction designed to improve focus, stress management, and emotion regulation. The intervention was implemented across 11 classrooms with 9th–12th grade students. On average across all classes, students completed 80% of lessons and 77% of daily exercises. Although the one-group design precludes definitive conclusions about the intervention’s effects, paired t-tests from pretest to post-test (N = 190) revealed improved emotional regulation and stress management despite students experiencing significantly increased life demands toward the end of the academic term. Results suggest that students also adopted a stronger growth mindset about their ability to focus, and they felt more motivated and confident to train this ability. A total of 64% of students indicated that the course improved their focus. Among the 81.6% of students who reported at baseline that they paid attention in class less than they should, focus during class increased significantly. This investigation supports the feasibility of digital mindfulness training for high schools and highlights strategies for increasing fidelity of implementation of digital interventions in school settings.
Teaching Ecosystem Design: Teachers’ Satisfaction with the Integrated Course Service System
Authors: Li Meng-Hua , Hung Ming-Chien , Hsian Wen-Hsu , Heung Won-Fu , Chiu Mai-Lun , Wang Shen-Tsu
Published: September 2019

In order to support teachers preparing their teaching resources, a teaching ecosystem for developing an online service system to acquire teaching materials, the Ministry of Education (MOE) in Taiwan, implemented an Integrated Course Service System (ICSS) to assist teachers in searching for instructional resources from distributed Educational Six Learning Networks (ESLN) of MOE. The study designed the ICSS and developed an instrument to investigate the satisfaction for the teachers of primary schools, junior high schools and senior high schools. By analyzing 253 teachers, the results show that demographics, such as age, school level, teaching experience and position, have significant effects on the ICSS satisfaction. Further, the teachers were found to be satisfied with the system content, system accuracy, report format, ease of use, system timeliness and community building offered by the ICSS that helps us to understand the teachers’ online behavior in more detail for the popularization of the course service system.
CFD Simulation of an Industrial Spiral Refrigeration System
Authors: Khenien A. , Benattayallah A. , Tabor G.
Published: September 2019

In the food industry, heating and cooling are key processes where CFD can play an important role in improving quality, productivity and reducing energy costs. Cooling products after baking is crucial for storage and transportation; the product has to be cooled efficiently to a specified temperature (often to fulfill regulatory requirements) whilst preserving its quality. This study involves the analysis of spiral cooling refrigerators used in cooling food products, in this case, Cornish Pasties. Three separate sets of CFD models were developed and validated against experimental data taken in the laboratory and measurements taken in use in industry. In the first set of models a full CFD model was developed of a refrigeration spiral including the pasties, and used to study the heat transfer from the products to the air. Further simulations were carried out on individual pasties to explore the pasty cooling and heat transfer to the air in more detail, with the pasty geometry being determined from MRI scans. In the final set of simulations, Image Based Meshing (IBM) was used to determine the interior structure of the pasty and develop a full heat conduction model of the interior, which was compared with separate laboratory experiments using jets of cold air to cool the pasty. In all cases, good agreement was obtained between the CFD results and experimental data, whilst the CFD simulations provide valuable information about the air flows and cooling in the industrial system.
Energy Modelling and Calibration of Building Simulations: A Case Study of a Domestic Building with Natural Ventilation
Authors: Aparicio-Fernández Carolina , Vivancos José-Luis , Cosar-Jorda Paula , Buswell Richard A.
Published: September 2019

In this paper, the building energy performance modelling tools TRNSYS (TRaNsient SYstem Simulation program) and TRNFlow (TRaNsient Flow) have been used to obtain the energy demand of a domestic building that includes the air infiltration rate and the effect of natural ventilation by using window operation data. An initial model has been fitted to monitoring data from the case study, building over a period when there were no heat gains in the building in order to obtain the building infiltration air change rate. After this calibration, a constant air-change rate model was established alongside two further models developed in the calibration process. Air change rate has been explored in order to determine air infiltrations caused by natural ventilation due to windows being opened. These results were compared to estimates gained through a previously published method and were found to be in good agreement. The main conclusion from the work was that the modelling ventilation rate in naturally ventilated residential buildings using TRNSYS and TRNSFlow can improve the simulation-based energy assessment.
Cost–Benefit Analysis of Energy Storage in Distribution Networks
Authors: Ji Yu , Hou Xiaogang , Kou Lingfeng , Wu Ming , Zhang Ying , Xiong Xiong , Ding Baodi , Xue Ping , Li Junlong , Xiang Yue
Published: September 2019

Due to the challenges posed to power systems because of the variability and uncertainty in clean energy, the integration of energy storage devices (ESD) has provided a rigorous approach to improve network stability in recent years. Moreover, with the rapid development of the electricity market, an ESD operation strategy, which can maximize the benefits of ESD owners as well as the contribution to the electricity network stability, plays an important role in the marketization of ESDs. Although the benefits for ESD owners are discussed in many studies, the economic impact of ESD operation on distribution networks has not been commendably taken into account. Therefore, a cost–benefit analysis method of ESD which quantifies the economic impact of ESD operation on distribution networks is proposed in this paper. Considering the time-of-use (TOU) price and load demand, the arbitrage of ESD is realized through a strategy with low price charging and high price discharging. Then, the auxiliary service of ESD is realized by its capability of peak shaving and valley filling. In this paper, the long-run incremental cost (LRIC) method is adopted to calculate the network price based on the congestion cost. Based on the dynamic cost–benefit analysis method, the cost–benefit marginal analysis model in the ESD life cycle is proposed through the calculation of the present value of benefit. Subsequently, the optimal ESD capacity and charge/discharge rate is obtained to get the shortest payback period by analyzing different operation parameters. Finally, a case study is undertaken, where the ESD operation model mentioned above is simulated on a two-bus system and a 33-bus system, and the ESD cost–benefit analysis and the analysis of corresponding influence factors are carried out adequately.
Computational Fluid Dynamics Analysis of an Enhanced Tube with Backward Louvered Strip Insert
Authors: Wijayanta Agung Tri , Kristiawan Budi , Pranowo  , Premono Agung , Aziz Muhammad
Published: September 2019

A computational solution of an enhanced tube equipped with a backward louvered strip insert with various pitches was evaluated in this work. A k-ε renormalized group turbulence model has been applied for the turbulent model. Different pitches, S, of 40, 50, and 60 mm were investigated for the Reynolds number with a range of 10,000–17,500 using water as a working fluid. The extra louvered strip caused fluid flow disturbance, so that the flow pattern formed more turbulence. The turbulent flow was characterized by the flow pattern on the back of the inserts that form a vortex. The vortices formed caused a better heat transfer. The results of the computational analysis showed that the enhanced tube had a louvered strip with a pitch distance S = 40, 50, and 60 mm could increase the Nusselt numbers to 1.81, 1.75, and 1.72, and the friction factor to 7.59, 6.51, and 5.77 times greater than the plain tube, respectively.
Artificial Neural Network Control of Battery Energy Storage System to Damp-Out Inter-Area Oscillations in Power Systems
Authors: Lee Heung-Jae , Jhang Seong-Su , Yu Won-Kun , Oh Jung-Hyun
Published: September 2019

This paper proposed an ANN (Artificial Neural Network) controller to damp out inter-area oscillation of a power system using BESS (Battery Energy Storage System). The conventional lead-lag controller-based PSSs (Power System Stabilizer) have been designed using linear models usually linearized at heavy load conditions. This paper proposes a non-linear ANN based BESS controller as the ANN can emulate nonlinear dynamics. To prove the performance of this nonlinear PSS, two linear PSS are introduced at first which are linearized at the heavy load and light load conditions, respectively. It is then verified that each controller can damp out inter-area oscillations at its own condition but not satisfactorily at the other condition. Finally, an ANN controller, that learned the dynamics of these two controllers, is proposed. Case studies are performed using PSCAD/EMTDC and MATLAB. As a result, the proposed ANN PSS shows a promising robust nonlinear performance.
Optimization of Energy and Resource Efficiency in a Multistage Drying Process of Phosphate Pellets
Authors: Meshalkin Valery , Bobkov Vladimir , Dli Maksim , Dovì Vincenzo
Published: September 2019

The roasting of phosphate pellets is an energy-intensive process the optimization of which can give rise to considerable efficiency improvements. To this purpose, the mathematical modeling and the computer-aided simulation of a multi-stage process of phosphate pellets roasting have been developed. This process includes drying, dissociation reaction of carbonates and a sintering process in a moving, dense, multilayer mass of phosphate pellets in a special horizontal grate apparatus. A theoretical model for the physical-chemical processes of a mass of phosphate pellets moving in a multistage process and subject to external operation variables (i.e., temperatures and flowrates of the drying gas at different positions of the conveyor length) has been developed. By letting these control variables vary over suitable ranges limited by technical constraints, it is possible to construct an algorithm that minimizes the overall energy consumption subject to the attainment of the required quality indicators of the pellets. Therefore, the set of constraints includes bounds on both the operational variables and quality indicators of the final product. A dynamic programming algorithm subject to suitable penalty functions for avoiding constraints violation has been used. The results obtained show that the scientifically based operation described in this paper achieves the goal of attaining considerable energy savings while assuring the quality of the finished pellets. Furthermore, the results highlight the convenience of extending the general strategy developed in this article to other chemical energy engineering processes.
Assessment of Freeze-Dried Immobilized Lactobacillus casei as Probiotic Adjunct Culture in Yogurts
Authors: Dimitrellou Dimitra , Kandylis Panagiotis , Kourkoutas Yiannis
Published: September 2019

Freeze-dried immobilized Lactobacillus casei ATCC 393 on casein and apple pieces were assessed as a probiotic adjunct culture for novel probiotic yogurt production. The effect of probiotic culture on physicochemical characteristics, probiotic cell survival, volatile aroma compounds, and sensory quality were evaluated during 28 days of storage at 4 °C. The use of L. casei resulted in lower pH values (3.92–4.12), higher acidity (0.88–1.10 g lactic acid/100 g of yogurt), and lower syneresis (40.8%–42.6%) compared to traditionally produced yogurt (pH 4.29; acidity 0.83 g lactic acid/100 g of yogurt; syneresis 44.1%). Microbiological and strain-specific multiplex PCR (Polymerase Chain Reaction) analysis confirmed that immobilized L. casei ATCC 393 cells were detected in yogurts at levels >7 log cfu g−1 after 28 days. In addition, probiotic supplementation significantly affected the concentrations of key volatile compounds, like acetic and other organic acids, 2-ethyl-1-hexanol, acetoin, and 2-butanone, as revealed by GC-MS (Gas Chromatography–Mass Spectrometry) analysis. Finally, the sensory evaluation demonstrated that the new products exhibited improved characteristics compared to traditionally produced yogurts.
Nutritional Characteristics and Antimicrobial Activity of Australian Grown Feijoa (Acca sellowiana)
Authors: Phan Anh Dao Thi , Chaliha Mridusmita , Sultanbawa Yasmina , Netzel Michael E.
Published: September 2019

The present study determined the chemical composition, bioactive compounds and biological properties of Australian grown feijoa (Acca sellowiana), including whole fruit with peel, fruit peel and pulp, in order to assess the nutritional quality and antimicrobial activity of this emerging subtropical fruit. Polyphenolic compounds and vitamins were determined by UHPLC-PDA-MS/MS, showing that the feijoa fruit not only contains high amounts of antioxidant flavonoids, but is also a valuable source of vitamin C (63 mg/100 g FW (fresh weight)) and pantothenic acid (0.2 mg/100 g FW). Feijoa fruit is also a good source of dietary fibre (6.8 g/100 g FW) and potassium (255 mg/100 g FW). The edible fruit peel possesses significantly (p < 0.05) higher amounts of antioxidant flavonoids and vitamin C than the fruit pulp. This is most likely the reason for the observed strong antimicrobial activity of the peel-extracts against a wide-range of food-spoilage microorganism. The consumption of feijoa fruit can deliver a considerable amount of bioactive compounds such as vitamin C, flavonoids and fibre, and therefore, may contribute to a healthy diet. Furthermore, the potential use of feijoa-peel as a natural food perseverative needs to be investigated in follow-up studies.
Development of Healthy, Nutritious Bakery Products by Incorporation of Quinoa
Authors: Ballester-Sánchez Jaime , Millán-Linares M. Carmen , Fernández-Espinar M. Teresa , Haros Claudia Monika
Published: September 2019

The use of quinoa could be a strategy for the nutritional improvement of bakery products. The inclusion of this pseudocereal, with its suitable balance of carbohydrates, proteins, lipids and minerals, could contribute to attaining the adequate intake values proposed by the FAO (Food and Agriculture Organization) and/or EFSA (European Food Safety Authority) for suitable maintenance and improvement of the population’s health. Bakery products made with white, red or black royal quinoa significantly improved the contribution to an adequate intake of polyunsaturated fatty acids (linoleic and linolenic acids) and dietary fibre, which produced an improvement in the soluble/insoluble fibre ratio. There was also an increase in the contribution to the average requirement of Fe and Zn, although the increase in the phytate/mineral ratio would make absorption of them more difficult. Inclusion of flour obtained from the three quinoas studied slightly improved the protein quality of the products that were prepared and positively affected the reduction in their glycaemic index.
Genomic Prediction and Genome-Wide Association Studies of Flour Yield and Alveograph Quality Traits Using Advanced Winter Wheat Breeding Material
Authors: Kristensen Peter S. , Jensen Just , Andersen Jeppe R. , Guzmán Carlos , Orabi Jihad , Jahoor Ahmed
Published: September 2019

Use of genetic markers and genomic prediction might improve genetic gain for quality traits in wheat breeding programs. Here, flour yield and Alveograph quality traits were inspected in 635 F6 winter wheat breeding lines from two breeding cycles. Genome-wide association studies revealed single nucleotide polymorphisms (SNPs) on chromosome 5D significantly associated with flour yield, Alveograph P (dough tenacity), and Alveograph W (dough strength). Additionally, SNPs on chromosome 1D were associated with Alveograph P and W, SNPs on chromosome 1B were associated with Alveograph P, and SNPs on chromosome 4A were associated with Alveograph L (dough extensibility). Predictive abilities based on genomic best linear unbiased prediction (GBLUP) models ranged from 0.50 for flour yield to 0.79 for Alveograph W based on a leave-one-out cross-validation strategy. Predictive abilities were negatively affected by smaller training set sizes, lower genetic relationship between lines in training and validation sets, and by genotype–environment (G×E) interactions. Bayesian Power Lasso models and genomic feature models resulted in similar or slightly improved predictions compared to GBLUP models. SNPs with the largest effects can be used for screening large numbers of lines in early generations in breeding programs to select lines that potentially have good quality traits. In later generations, genomic predictions might be used for a more accurate selection of high quality wheat lines.