bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical and Mechanical Properties of Composite Scaffolds with or without Collagen Impregnation
Authors: Marcos José Joaquín López , Perrotti Vittoria , Iaculli Flavia , Aragones Águedo , Benfatti Cesar Augusto Magalhães , Magrin Gabriel Leonardo , Piattelli Adriano , Bianchini Marco Aurélio
Published: October 2019

This in vitro study aimed at evaluating the physical and mechanical properties of newly developed scaffolds of poly (lactic-co-glycolic acid) (PLGA) and biphasic ceramic (Hydroxyapatite HA + beta-tricalciumphosphate β-TCP) with or without collagen impregnation to be used for bone regeneration in the oral and maxillofacial district. Solvent casting and particle leaching techniques were used to produce the scaffolds, which were then divided into six groups according to PLGA/HA + β-TCP ratio and impregnation with collagen: G1 (50/50) + collagen; G2 (60/40) + collagen; G3 (40/60) + collagen; G4 (50/50); G5 (60/40); G6 (40/60). As control group, inorganic xenogenous bone was used. Structure and porosity were evaluated by scanning electron microscopy, and a chemical analysis was performed through an energy-dispersive spectrometer. Moreover, to evaluate the hydrophilicity of the samples, a wettability test was conceived, and finally, mechanical properties were examined by a compression test. High porosity and interconnectivity, resulting in a large surface area and great fluid retention capacity, were presented by the PLGA/HA + β-TCP scaffolds. In the composite groups, collagen increased the wettability and the mechanical resistance, although the latter was not statistically affected by the percentage of HA + β-TCP added. Further in vitro and in vivo studies are needed for a deeper understanding of the influence of collagen on the biological behavior of the developed composite materials and their potential, namely biocompatibility and bioactivity, for bone tissue regeneration.
Optimization of Nonspherical Gold Nanoparticles for Photothermal Therapy
Authors: Tuersun Paerhatijiang , Yakupu Xiayiding , Han Xiang’e , Yin Yingzeng
Published: October 2019

Previous investigations devoted to the optimization of nonspherical gold nanoparticles for photothermal therapy (PTT) encountered two issues, namely, the appropriate selection of objective functions and the processing of particle random orientations. In this study, these issues were resolved, and accurate optimization results were obtained for the three typical nonspherical gold nanoparticles (nanospheroid, nanocylinder, and nanorod) by using the T-matrix method. The dependence of the optimization results on the excitation wavelength and the refractive index of tissue was investigated. Regardless of the excitation wavelength and tissue type, gold nanospheroids were found to be the most effective therapeutic agents for PTT. The light absorption ability of optimized nanoparticles could be enhanced by using a laser with a longer wavelength. Finally, the design tolerance for the different sizes of nanoparticles was provided.
A Review on Bitumen Rejuvenation: Mechanisms, Materials, Methods and Perspectives
Authors: Loise Valeria , Caputo Paolino , Porto Michele , Calandra Pietro , Angelico Ruggero , Oliviero Rossi Cesare
Published: October 2019

This review aims to explore the state of the knowledge and the state-of-the-art regarding bitumen rejuvenation. In particular, attention was paid to clear things up about the rejuvenator mechanism of action. Frequently, the terms rejuvenator and flux oil, or oil (i.e., softening agent) are used as if they were synonymous. According to our knowledge, these two terms refer to substances producing different modifications to the aged bitumen: they can decrease the viscosity (softening agents), or, in addition to this, restore the original microstructure (real rejuvenators). In order to deal with the argument in its entirety, the bitumen is investigated in terms of chemical structure and microstructural features. Proper investigating tools are, therefore, needed to distinguish the different mechanisms of action of the various types of bitumen, so attention is focused on recent research and the use of different investigation techniques to distinguish between various additives. Methods based on organic synthesis can also be used to prepare ad-hoc rejuvenating molecules with higher performances. The interplay of chemical interaction, structural changes and overall effect of the additive is then presented in terms of the modern concepts of complex systems, which furnishes valid arguments to suggest X-ray scattering and Nuclear Magnetic Resonance relaxometry experiments as vanguard and forefront tools to study bitumen. Far from being a standard review, this work represents a critical analysis of the state-of-the-art taking into account for the molecular basis at the origin of the observed behavior. Furnishing a novel viewpoint for the study of bitumen based on the concepts of the complex systems in physics, it constitutes a novel approach for the study of these systems.
Interval Analysis and Calculus for Interval-Valued Functions of a Single Variable—Part II: Extremal Points, Convexity, Periodicity
Authors: Stefanini Luciano , Sorini Laerte , Amicizia Benedetta
Published: October 2019

We continue the presentation of new results in the calculus for interval-valued functions of a single real variable. We start here with the results presented in part I of this paper, namely, a general setting of partial orders in the space of compact intervals (in midpoint-radius representation) and basic results on convergence and limits, continuity, gH-differentiability, and monotonicity. We define different types of (local) minimal and maximal points and develop the basic theory for their characterization. We then consider some interesting connections with applied geometry of curves and the convexity of interval-valued functions is introduced and analyzed in detail. Further, the periodicity of interval-valued functions is described and analyzed. Several examples and pictures accompany the presentation.
Host Plant-Derived miRNAs Potentially Modulate the Development of a Cosmopolitan Insect Pest, Plutella xylostella
Authors: Zhang Ling-ling , Jing Xiao-dong , Chen Wei , Wang Yue , Lin Jun-han , Zheng Ling , Dong Yu-hong , Zhou Li , Li Fei-fei , Yang Fei-ying , Peng Lu , Vasseur Liette , He Wei-yi , You Min-sheng
Published: October 2019

Plant microRNAs (miRNAs) have recently been reported to be involved in the cross-kingdom regulation of specific cellular and physiological processes in animals. However, little of this phenomenon is known for the communication between host plant and insect herbivore. In this study, the plant-derived miRNAs in the hemolymph of a cruciferous specialist Plutella xylostella were identified by small RNAs sequencing. A total of 39 miRNAs with typical characteristics of plant miRNAs were detected, of which 24 had read counts ≥ 2 in each library. Three plant-derived miRNAs with the highest read counts were validated, and all of them were predicted to target the hemocyanin domains-containing genes of P. xylostella. The luciferase assays in the Drosophila S2 cell demonstrated that miR159a and novel-7703-5p could target BJHSP1 and PPO2 respectively, possibly in an incomplete complementary pairing mode. We further found that treatment with agomir-7703-5p significantly influenced the pupal development and egg-hatching rate when reared on the artificial diet. The developments of both pupae and adults were severely affected upon their transfer to Arabidopsis thaliana, but this might be independent of the cross-kingdom regulation of the three plant-derived miRNAs on their target genes in P. xylostella, based on expression analysis. Taken together, our work reveals that the plant-derived miRNAs could break the barrier of the insect mid-gut to enter the circulatory system, and potentially regulate the development of P. xylostella. Our findings provide new insights into the co-evolution of insect herbivore and host plant, and novel direction for pest control using plant-derived miRNAs.
Trafficking and Function of the Voltage-Gated Sodium Channel β2 Subunit
Authors: Cortada Eric , Brugada Ramon , Verges Marcel
Published: October 2019

The voltage-gated sodium channel is vital for cardiomyocyte function, and consists of a protein complex containing a pore-forming α subunit and two associated β subunits. A fundamental, yet unsolved, question is to define the precise function of β subunits. While their location in vivo remains unclear, large evidence shows that they regulate localization of α and the biophysical properties of the channel. The current data support that one of these subunits, β2, promotes cell surface expression of α. The main α isoform in an adult heart is NaV1.5, and mutations in SCN5A, the gene encoding NaV1.5, often lead to hereditary arrhythmias and sudden death. The association of β2 with cardiac arrhythmias has also been described, which could be due to alterations in trafficking, anchoring, and localization of NaV1.5 at the cardiomyocyte surface. Here, we will discuss research dealing with mechanisms that regulate β2 trafficking, and how β2 could be pivotal for the correct localization of NaV1.5, which influences cellular excitability and electrical coupling of the heart. Moreover, β2 may have yet to be discovered roles on cell adhesion and signaling, implying that diverse defects leading to human disease may arise due to β2 mutations.
Unsupervised and Supervised Learning over the Energy Landscape for Protein Decoy Selection
Authors: Akhter Nasrin , Chennupati Gopinath , Kabir Kazi Lutful , Djidjev Hristo , Shehu Amarda
Published: October 2019

The energy landscape that organizes microstates of a molecular system and governs the underlying molecular dynamics exposes the relationship between molecular form/structure, changes to form, and biological activity or function in the cell. However, several challenges stand in the way of leveraging energy landscapes for relating structure and structural dynamics to function. Energy landscapes are high-dimensional, multi-modal, and often overly-rugged. Deep wells or basins in them do not always correspond to stable structural states but are instead the result of inherent inaccuracies in semi-empirical molecular energy functions. Due to these challenges, energetics is typically ignored in computational approaches addressing long-standing central questions in computational biology, such as protein decoy selection. In the latter, the goal is to determine over a possibly large number of computationally-generated three-dimensional structures of a protein those structures that are biologically-active/native. In recent work, we have recast our attention on the protein energy landscape and its role in helping us to advance decoy selection. Here, we summarize some of our successes so far in this direction via unsupervised learning. More importantly, we further advance the argument that the energy landscape holds valuable information to aid and advance the state of protein decoy selection via novel machine learning methodologies that leverage supervised learning. Our focus in this article is on decoy selection for the purpose of a rigorous, quantitative evaluation of how leveraging protein energy landscapes advances an important problem in protein modeling. However, the ideas and concepts presented here are generally useful to make discoveries in studies aiming to relate molecular structure and structural dynamics to function.
Emerging Roles of Lysyl Oxidases in the Cardiovascular System: New Concepts and Therapeutic Challenges
Authors: Martínez-González José , Varona Saray , Cañes Laia , Galán María , Briones Ana , Cachofeiro Victoria , Rodríguez Cristina
Published: October 2019

Lysyl oxidases (LOX and LOX-likes (LOXLs) isoenzymes) belong to a family of copper-dependent enzymes classically involved in the covalent cross-linking of collagen and elastin, a pivotal process that ensures extracellular matrix (ECM) stability and provides the tensile and elastic characteristics of connective tissues. Besides this structural role, in the last years, novel biological properties have been attributed to these enzymes, which can critically influence cardiovascular function. LOX and LOXLs control cell proliferation, migration, adhesion, differentiation, oxidative stress, and transcriptional regulation and, thereby, their dysregulation has been linked to a myriad of cardiovascular pathologies. Lysyl oxidase could modulate virtually all stages of the atherosclerotic process, from endothelial dysfunction and plaque progression to calcification and rupture of advanced and complicated plaques, and contributes to vascular stiffness in hypertension. The alteration of LOX/LOXLs expression underlies the development of other vascular pathologies characterized by a destructive remodeling of the ECM, such as aneurysm and artery dissections, and contributes to the adverse myocardial remodeling and dysfunction in hypertension, myocardial infarction, and obesity. This review examines the most recent advances in the study of LOX and LOXLs biology and their pathophysiological role in cardiovascular diseases with special emphasis on their potential as therapeutic targets.
Development of Aptamer-Based TID Assays Using Thermophoresis and Microarrays
Authors: Kurth Tracy , Witt Sandra , Bolten Svenja , Waniek Janice-Joy , Kortmann Carlotta , Lavrentieva Antonina , Scheper Thomas , Walter Johanna-Gabriela
Published: October 2019

Aptamers are single-stranded oligonucleotides which can be used as alternative recognition elements for protein detection, because aptamers bind their targets with a high affinity similar to antibodies. Due to the target-induced conformational changes of aptamers, these oligonucleotides can be applied in various biosensing platforms. In this work, aptamers directed against the vascular endothelial growth factor (VEGF) were used as a model system. VEGF plays a key role in physiological angiogenesis and vasculogenesis. Furthermore, VEGF is involved in the development and growth of cancer and other diseases like age-related macular degeneration, rheumatoid arthritis, diabetes mellitus, and neurodegenerative disorders. Detecting the protein biomarker VEGF is therefore of great importance for medical research and diagnostics. In this research, VEGF-binding aptamers were investigated for the systematic development of a target-induced dissociation (TID) assay utilizing thermophoresis and microarrays. The established aptamer-microarray allowed for the detection of 0.1 nM of VEGF. Furthermore, the systematic development of the TID method using the VEGF model protein could help to develop further TID assays for the detection of various protein biomarkers.
Analysis of the Thermal Characteristics of a Composite Ceramic Product Filled with Phase Change Material
Authors: Krasoń Joanna , Miąsik Przemysław , Lichołai Lech , Dębska Bernardeta , Starakiewicz Aleksander
Published: October 2019

The article presents a comparative analysis carried out using three methods, determining the heat transfer coefficient U for a ceramic product modified with a phase change material (PCM). The purpose of the article is to determine the convergence of the resulting thermal characteristics, obtained using the experimental method, numerical simulation, and standard calculation method according to the requirements of PN-EN ISO 6946. The heat transfer coefficient is one of the basic parameters characterizing the thermal insulation of a building partition. Most often, for the thermal characteristics of the partition, we obtain from the manufacturer the value of the thermal conductivity coefficient λ for individual homogeneous materials or the heat transfer coefficient U for the finished (prefabricated) partition. In the case of a designed composite element modified with a phase change material or other material, it is not possible to obtain direct information on the above parameter. In such a case, one of the methods presented in this article should be used to determine the U factor. The U factor in all analyses was determined in stationary conditions. Research has shown a significant convergence of the resulting value of the heat transfer coefficient obtained by the assumed methods. Thanks to obtaining similar values, it is possible to continue tests of thermal characteristics of partitions by means of numerical simulation, limiting the number of experimental tests (due to the longer test time required) in assumed different partition configurations, in stationary and dynamic conditions.
Cocktail Strategy Based on NK Cell-Derived Exosomes and Their Biomimetic Nanoparticles for Dual Tumor Therapy
Authors: Wang Guosheng , Hu Weilei , Chen Haiqiong , Shou Xin , Ye Tingting , Xu Yibing
Published: October 2019

Successful cancer therapy requires drugs being precisely delivered to tumors. Nanosized drugs have attracted considerable recent attention, but their toxicity and high immunogenicity are important obstacles hampering their clinical translation. Here we report a novel “cocktail therapy” strategy based on excess natural killer cell-derived exosomes (NKEXOs) in combination with their biomimetic core–shell nanoparticles (NNs) for tumor-targeted therapy. The NNs were self- assembled with a dendrimer core loading therapeutic miRNA and a hydrophilic NKEXOs shell. Their successful fabrication was confirmed by transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). The resulting NN/NKEXO cocktail showed highly efficient targeting and therapeutic miRNA delivery to neuroblastoma cells in vivo, as demonstrated by two-photon excited scanning fluorescence imaging (TPEFI) and with an IVIS Spectrum in vivo imaging system (IVIS), leading to dual inhibition of tumor growth. With unique biocompatibility, we propose this NN/NKEXO cocktail as a new avenue for tumor therapy, with potential prospects for clinical applications.
Developing a Novel Enzyme Immobilization Process by Activation of Epoxy Carriers with Glucosamine for Pharmaceutical and Food Applications
Authors: Serra Immacolata , Benucci Ilaria , Robescu Marina Simona , Lombardelli Claudio , Esti Marco , Calvio Cinzia , Pregnolato Massimo , Terreni Marco , Bavaro Teodora
Published: October 2019

In this paper, we describe the development of an efficient enzyme immobilization procedure based on the activation of epoxy carriers with glucosamine. This approach aims at both creating a hydrophilic microenvironment surrounding the biocatalyst and introducing a spacer bearing an aldehyde group for covalent attachment. First, the immobilization study was carried out using penicillin G acylase (PGA) from Escherichia coli as a model enzyme. PGA immobilized on glucosamine activated supports has been compared with enzyme derivatives obtained by direct immobilization on the same non-modified carriers, in the synthesis of different 3′-functionalized cephalosporins. The derivatives prepared by immobilization of PGA on the glucosamine-carriers performed better than those prepared using the unmodified carriers (i.e., 90% versus 79% cefazolin conversion). The same immobilization method has been then applied to the immobilization of two other hydrolases (neutral protease from Bacillus subtilis, PN, and bromelain from pineapple stem, BR) and one transferase (γ-glutamyl transpeptidase from Bacillus subtilis, GGT). Immobilized PN and BR have been exploited in the synthesis of modified nucleosides and in a bench-scale packed-bed reactor for the protein stabilization of a Sauvignon blanc wine, respectively. In addition, in these cases, the new enzyme derivatives provided improved results compared to those previously described.
Conversion of 5-Methyl-3-Heptanone to C8 Alkenes and Alkane over Bifunctional Catalysts
Authors: Al-Auda Zahraa , Al-Atabi Hayder , Li Xu , Thapa Prem , Hohn Keith
Published: October 2019

A one-step catalytic process was used to catalyze the hydrodeoxygenation of 5-methyl-3-heptanone (C8 ketone) to a mixture of 5-methyl-3-heptene, 5-methyl-2-heptene (C8 alkenes), and 3-methyl heptane (C8 alkane). High conversion of C8 ketone to the desired products was achieved over a single bed of a supported catalyst (bifunctional heterogeneous catalyst) consisting of one transition metal (copper (Cu) or platinum (Pt)) loaded on alumina (Al2O3) under mild operating conditions (reaction temperatures were varied between 180 °C to 260 °C, and the pressure was 1 atm). The C8 ketone was hydrogenated to 5-methyl-3-heptanol (C8 alcohol) over metal sites, followed by dehydration of the latter on acid sites on the support to obtain a mixture of C8 alkenes. These C8 alkenes can be further hydrogenated on metal sites to make a C8 alkane. The results showed that the main products over copper loaded on alumina (20 wt% Cu–Al2O3) were a mixture of C8 alkenes and C8 alkane in different amounts depending on the operating conditions (the highest selectivity for C8 alkenes (~82%) was obtained at 220 °C and a H2/C8 ketone molar ratio of 2). However, over platinum supported on alumina (1 wt% Pt–Al2O3), the major product was a C8 alkane with a selectivity up to 97% and a conversion of 99.9% at different temperatures and all H2/C8 ketone ratios.
Enzymatic Production of Biodiesel Using Immobilized Lipase on Core-Shell Structured Fe3O4@MIL-100(Fe) Composites
Authors: Xie Wenlei , Huang Mengyun
Published: October 2019

In this research, core–shell structured Fe3O4@MIL-100(Fe) composites were prepared by coating Fe3O4 magnetite with porous MIL-100(Fe) metal-organic framework (MOF) material, which were then utilized as magnetic supports for the covalent immobilization of the lipase from Candida rugosa through amide linkages. By using the carbodiimide/hydroxysulfosuccinimide (EDC/NHS) activation strategy, the lipase immobilization efficiency could reach 83.1%, with an activity recovery of 63.5%. The magnetic Fe3O4@MIL-100(Fe) composite and immobilized lipase were characterized by several techniques. The characterization results showed that the Fe3O4 core was coated with MIL-100(Fe) shell with the formation of perfect core–shell structured composites, and moreover, the lipase was covalently tethered on the magnetic carrier. The immobilized lipase displayed a strong magnetic response and could be facilely separated by an external magnetic field. With this magnetic biocatalyst, the maximum biodiesel conversion attained 92.3% at a methanol/oil molar ratio of 4:1, with a three-step methanol addition manner, and a reaction temperature of 40 °C. Moreover, the biocatalyst prepared in the present study was recycled easily by magnetic separation without significant mass loss, and displayed 83.6% of its initial activity as it was reused for five runs, thus allowing its potential application for the cleaner production of biodiesel.
Application of Phase Transfer Catalysis in the Esterification of Organic Acids: The Primary Products from Ring Hydrocarbon Oxidation Processes
Authors: Wang Hui , Lin Hongfei , Li Xiaohu , Ren Rui , Pu Jianglong , Zhang Haiping , Zheng Ying , Zhao Jianshe , Ng Siauw , Zhang Hui
Published: October 2019

For enhancing the cetane number (CN) of diesel fraction, the selective oxidative ring opening method was applied to upgrade ring hydrocarbons. Organic acids, one of the main products from this oxidative reaction, being esterified by the phase transfer catalysis (PTC) approach were studied. Adipic acid, benzoic acid, and phthalic acid were used as model compounds. Reaction time, reaction temperature, the amount of water, and the amount of catalyst in the esterification process were investigated and optimized using orthogonal experimental design method. The kinetics of esterification process was then conducted under the optimal condition. The types of catalysts and organic acids, the amount of catalyst and water were also investigated. The PTC esterification was one rate controlling reaction on the interface between the aqueous phase and the oil phase. Hydrophobicity is a key factor for converting benzoic acid, adipic acid, and phthalic acid to the corresponding esters. It was found that around 5–8% water is the optimal quantity for the given reaction system. Two cases of esterification processes of PTC were proposed.
The Bright and Dark Side of DNA Methylation: A Matter of Balance
Authors: Borchiellini Marta , Ummarino Simone , Di Ruscio Annalisa
Published: October 2019

DNA methylation controls several cellular processes, from early development to old age, including biological responses to endogenous or exogenous stimuli contributing to disease transition. As a result, minimal DNA methylation changes during developmental stages drive severe phenotypes, as observed in germ-line imprinting disorders, while genome-wide alterations occurring in somatic cells are linked to cancer onset and progression. By summarizing the molecular events governing DNA methylation, we focus on the methods that have facilitated mapping and understanding of this epigenetic mark in healthy conditions and diseases. Overall, we review the bright (health-related) and dark (disease-related) side of DNA methylation changes, outlining how bulk and single-cell genomic analyses are moving toward the identification of new molecular targets and driving the development of more specific and less toxic demethylating agents.
Correction: Yamamuro et al. Power Generation in Slope-Type Thin-Film Thermoelectric Generators by the Simple Contact of a Heat Source. Coatings 2019, 9, 63
Authors: Yamamuro Hiroki , Takashiri Masayuki
Published: October 2019

In the original version of article [...]
Microstructure, Mechanical Properties, Abrasive Wear, and Corrosion Behavior in Molten Zinc of Boride-Based Coatings in Situ Synthesized by an HVOF Spraying Process
Authors: Chen Xiao , Li Chengdi , Bai Xiaobo , Wang Hongtao , Xu Shunjian , Song Su
Published: October 2019

Hot-dip galvanizing has been used for anti-corrosion of various steel products; however, the corrosion of molten zinc in the galvanizing industry is the key problem to be solved. Three kinds of Mo–B–Co–Cr, Mo–B–Ni–Cr, and Ti–B–Co–Cr mixture powders were deposited on the surface of a 316L stainless-steel substrate by a HVOF spraying method to prepare MoB/CoCr, MoB/NiCr, and TiB/CoCr coatings. The microstructure, mechanical properties, abrasive wear, and corrosion behavior in molten zinc of the in situ synthesized boride-based coatings were investigated. The experimental results showed that MoB/NiCr coating with a denser microstructure had the lowest porosity (0.811%). The in situ synthesized boride-phase compositions of MoB/CoCr, MoB/NiCr, and TiB/CoCr coatings were CoMoB and CoMo2B2, NiMo2B2, and TiB2, respectively. The MoB/NiCr coating had the highest boride content among the coatings. The presence of binary (TiB2) or ternary boride phases (CoMoB, CoMo2B2, and NiMo2B2) with their excellent mechanical properties could obviously increase the microhardness values in the coatings. The in situ synthesized borides in the coatings also could improve the wear resistance properties; MoB/NiCr coating with shallower grooves and smaller craters/pits had the smoothest worn surface and the lowest weight loss (6.8 ± 0.84 mg) among the coatings. After immersion test in molten zinc for 360 h, no presence of zinc or intermetallic compounds in the three kinds of the coatings (MoB/CoCr, MoB/NiCr, and TiB/CoCr), and the element compositions of the three kinds of coatings after the immersion test were the same as the as-sprayed coatings. Compared to the other coatings, MoB/NiCr coatings had the higher durability in molten zinc.
Fitness Gain of Individually Sensed Information by Cells
Authors: Kobayashi Tetsuya J. , Sughiyama Yuki
Published: October 2019

Mutual information and its causal variant, directed information, have been widely used to quantitatively characterize the performance of biological sensing and information transduction. However, once coupled with selection in response to decision-making, the sensing signal could have more or less evolutionary value than its mutual or directed information. In this work, we show that an individually sensed signal always has a better fitness value, on average, than its mutual or directed information. The fitness gain, which satisfies fluctuation relations (FRs), is attributed to the selection of organisms in a population that obtain a better sensing signal by chance. A new quantity, similar to the coarse-grained entropy production in information thermodynamics, is introduced to quantify the total fitness gain from individual sensing, which also satisfies FRs. Using this quantity, the optimizing fitness gain of individual sensing is shown to be related to fidelity allocations for individual environmental histories. Our results are supplemented by numerical verifications of FRs, and a discussion on how this problem is linked to information encoding and decoding.
Multi-Sensor Accurate Forklift Location and Tracking Simulation in Industrial Indoor Environments
Authors: Barral Valentín , Suárez-Casal Pedro , Escudero Carlos J. , García-Naya José A.
Published: October 2019

Location and tracking needs are becoming more prominent in industrial environments nowadays. Process optimization, traceability or safety are some of the topics where a positioning system can operate to improve and increase the productivity of a factory or warehouse. Among the different options, solutions based on ultra-wideband (UWB) have emerged during recent years as a good choice to obtain highly accurate estimations in indoor scenarios. However, the typical harsh wireless channel conditions found inside industrial environments, together with interferences caused by workers and machinery, constitute a challenge for this kind of system. This paper describes a real industrial problem (location and tracking of forklift trucks) that requires precise internal positioning and presents a study on the feasibility of meeting this challenge using UWB technology. To this end, a simulator of this technology was created based on UWB measurements from a set of real sensors. This simulator was used together with a location algorithm and a physical model of the forklift to obtain estimations of position in different scenarios with different obstacles. Together with the simulated UWB sensor, an additional inertial sensor and optical sensor were modeled in order to test its effect on supporting the location based on UWB. All the software created for this work is published under an open-source license and is publicly available.
Design and Construction of a Cost-Effective Didactic Robotic Arm for Playing Chess, Using an Artificial Vision System
Authors: del Toro Cristian , Robles-Algarín Carlos , Rodríguez-Álvarez Omar
Published: October 2019

This paper presents the design and construction of a robotic arm that plays chess against a human opponent, based on an artificial vision system. The mechanical design was an adaptation of the robotic arm proposed by the rapid prototyping laboratory FabLab RUC (Fabrication Laboratory of the University of Roskilde). Using the software Solidworks, a gripper with 4 joints was designed. An artificial vision system was developed for detecting the corners of the squares on a chessboard and performing image segmentation. Then, an image recognition model was trained using convolutional neural networks to detect the movements of pieces on the board. An image-based visual servoing system was designed using the Kanade–Lucas–Tomasi method, in order to locate the manipulator. Additionally, an Arduino development board was programmed to control and receive information from the robotic arm using Gcode commands. Results show that with the Stockfish chess game engine, the system is able to make game decisions and manipulate the pieces on the board. In this way, it was possible to implement a didactic robotic arm as a relevant application in data processing and decision-making for programmable automatons.
Design of a Wide-Band Voltage-Controlled Ring Oscillator Implemented in 180 nm CMOS Technology
Authors: Tlelo-Cuautle Esteban , Castañeda-Aviña Perla Rubi , Trejo-Guerra Rodolfo , Carbajal-Gómez Victor Hugo
Published: October 2019

The design of a wide-band voltage-controlled oscillator (VCO) modified as a VCO with programmable tail currents is introduced herein. The VCO is implemented by using CMOS current-mode logic stages, which are based on differential pairs that are connected in a ring topology. SPICE simulation results show that the VCO operates within the frequency ranges of 2.65–5.65 GHz, and when it is modified, the VCO with programmable tail currents operates between 1.38 GHz and 4.72 GHz. The design of the CMOS differential stage is detailed along with the symbolic approximation of its dominant pole, which is varied to increase the frequency response in order to achieve a higher oscillation frequency when implementing the ring oscillator structure. The layout of the VCO is described and pre- and post-layout simulations are provided, which are in good agreement using CMOS technology of 180 nm. Finally, process, voltage and temperature variations are performed to guarantee robustness of the designed CMOS ring oscillator.
Probabilistic Evaluation and Improvement Measures of Power Supply Capability Considering Massive EV Integration
Authors: Sun Weiqing , Zhang Jie , Yang Jingyuan , Liu Wei , Zhang Wei
Published: October 2019

Massive electric vehicle (EV) integration has been an inevitable trend for future power distribution networks. However, the spatial-temporal randomness of EV charging behavior may cause insufficiency of power supply capability. This paper simulates the charging loads with massive EV integration, proposes a probabilistic evaluation index to evaluate the probability of insufficient power supply capability, and gives improvement measures for power distribution networks without hardware upgrading. First, the spatial-temporal distribution of EV charging loads is simulated via Monte Carlo method, which particularly divides EVs into three categories, private cars, buses, and taxis. Then, aggregated with conventional loads, total supply capacity of a power distribution network can be calculated on different time periods. Second, for the uncertainty of EV charging loads both in time and space, a probabilistic evaluation index is addressed to evaluate the probability of power supply capability insufficiency. After that, several improvement measures of the charging strategy are given to relieve the insufficiency of power supply capability. Finally, taking the simplified distribution network of a typical power supply mode in China’s Fujian province as an example, three scenarios with different vehicle quantities and parameters are designed, and the effectiveness of the evaluation index and improvement measures proposed are identified. The results can provide evidences for constraining EV charging behaviors with massive integration.
Comparison of the Financial Standing of Companies Generating Electricity from Renewable Sources and Fossil Fuels: A New Hybrid Approach
Authors: Tomczak Sebastian Klaudiusz
Published: October 2019

Companies operating in the energy sector are under pressure to boost the level of green energy production. The use of renewable energy sources will have a positive impact on the environment, but the basic question is whether power plants that produce electricity using renewable energy sources are in better financial condition than those that use only traditional energy sources. We address the latter using a new hybrid approach that extends prior research by combining three analyses: ratio analysis with a large set of indicators, the Altman model and cluster analysis. To test the statistical significance of differences between groups, Student’s t-test is applied. The sample concerns companies from the Baltic States and Central Europe in the years 2008–2017. The results indicate that in most cases there is no statistical difference in the financial standing of companies that use renewable energy sources and those that generate only fossil fuel-based energy.
A Formulation of the Thrust Coefficient for Representing Finite-Sized Farms of Tidal Energy Converters
Authors: Soto-Rivas Karina , Richter David , Escauriaza Cristian
Published: October 2019

Tidal energy converter (TEC) arrays in tidal channels generate complex flow phenomena due to interactions with the local environment and among devices. Models with different resolutions are thus employed to study flows past TEC farms, which consider multiple spatial and temporal scales. Simulations over tidal cycles use mesoscale ocean circulation models, incorporating a thrust coefficient to model the momentum sink that represents the effects of the array. In this work, we propose an expression for a thrust coefficient to represent finite-sized farms of TEC turbines at larger scales, C t F a r m , which depends on the spatial organization of the devices. We use a coherent-structure resolving turbulence model coupled with the actuator disk approach to simulate staggered turbine configurations in more detail, varying the separation among devices and the ratios between the channel depths and hub heights. Based on these simulations, we calculate the resultant force for various subsets of devices within the farm, and their corresponding effective thrust coefficient, C t F a r m . We conclude that the thrust coefficient depends solely on the lateral separation of the devices, S y , for farms with only two rows. For farms with more than two rows, the streamwise distance, S x , must be considered as well. With the proposed expression, it is possible to calculate efficiently the effects of finite-sized TEC farms and incorporate a momentum sink into ocean circulation models, without assuming a constant coefficient derived from an infinite farm approximation.
Design Considerations of Switched Flux Memory Machine with Partitioned Stators
Authors: Lei Jiaxing , Wei Chaofan , Yang Hui , Zheng Hao , Wang Wenjia , Feng Shuang
Published: October 2019

This paper presents general design considerations of a partitioned stator switched flux hybrid magnet memory machine (PS-SF-HMMM). The armature windings and permanent magnets (PMs) are placed on two separate stators, respectively, in the PS-SF-HMMM, and thus both high torque density and wide flux regulation capability can be obtained. The topology and working principle of the machine are introduced briefly first, and then different magnet arrangements and stator/rotor pole combinations are investigated. In addition, various design parameters are optimized based on finite element (FE) methods. Finally, a prototype is fabricated to experimentally validate the FE results.
Merit Order Effect Modeling: The Case of the Hellenic Electricity Market
Authors: Loumakis Stelios , Giannini Eugenia , Maroulis Zacharias
Published: October 2019

A simple effective model is proposed for the day-ahead electricity market. The model considers the main factors which govern the process, predicts the seasonal and daily variation of electricity demand, renewable production, system marginal price, and merit order effect. The accuracy of the model is increased by fitting to historic data of the Hellenic electricity market. During the period between October 2016 and December 2018, the Hellenic electricity market calculated explicitly the merit order effect using an innovative mechanism to directly charge the electricity suppliers (retailers). On the basis of the proposed model and the market recorded data, the effect of the renewable penetration on the wholesale Hellenic electricity prices is revealed. The model is further used to analyze the market future behavior when basic factors (electricity demand, conventional power, and renewable penetration) are known or estimated. The effect of merit order effect on the Hellenic legislation is discussed and the appropriate measures adopted by the Hellenic authorities are analyzed and evaluated.
High-Resolution Household Load Profiling and Evaluation of Rooftop PV Systems in Selected Houses in Qatar
Authors: Alrawi Omar , Bayram I. Safak , Al-Ghamdi Sami G. , Koc Muammer
Published: October 2019

Even though Qatar’s per capita electricity consumption is one of the highest in the world, little is currently known about behind-the-meter power consumption. The residential sector is the largest consumer of electricity, accounting for approximately 59% of the overall consumption of electricity. As energy subsidies lead to budget deficits and overconsumption of carbon resources, there is a pressing need to examine the residential load profile to better understand consumption patterns and uncover potential solutions for more efficient usage. Residential load profiles are typically influenced by seasonal and socio-economic factors. Furthermore, household load profiles can be used to examine the viability of rooftop photovoltaic (PV) systems. In this study, a total of 10 houses in Qatar were chosen, and their power demand was monitored for over a year using smart energy monitors. This empirical research was conducted to achieve the following goals: (1) creation of the first high-resolution residential load profiles in Qatar and in the Gulf region; (2) analyses of the acquired load profiles and the determining factors that affect energy consumption; and (3) calculation of self-consumption values, analysis of the viability of household rooftop PV systems, and discussing potential use-cases for energy storage systems. Investigation of this topic is particularly important for Qatar as the country is adopting a sizable portion of PV systems (5% by 2021) and promotes sustainable energy options as a part of a national development strategy. Results show that there are significant differences between per-household and per-capita consumption due to factors such as electricity subsidies, household income and size, and air-conditioner type. Moreover, due to high electricity consumption, distributed energy storage units for bill management applications have limited applicability with current pricing tariffs. To the best of authors’ knowledge, this is the first study conducted in Qatar and in the Gulf region where a growing amount of interest is given to measure and improve building energy performance.
Experimental and Numerical Analysis of a Seawall’s Effect on Wind Turbine Performance
Authors: Kim Hyun-Goo , Jeon Wan-Ho
Published: October 2019

For the purposes of this study, a wind tunnel experiment and a numerical analysis during ebb and high tides were conducted to determine the positive and negative effects of wind flow influenced by a seawall structure on the performance of wind turbines installed along a coastal seawall. The comparison of the wind flow field between a wind tunnel experiment performed with a 1/100 scale model and a computational fluid dynamics (CFD) analysis confirmed that the MP k-turbulence model estimated flow separation on the leeside of the seawall the most accurately. The CFD analysis verified that wind speed-up occurred due to the virtual hill effect caused by the seawall’s windward slope and the recirculation zone of its rear face, which created a positive effect by mitigating wind shear while increasing the mean wind speed in the wind turbine’s rotor plane. In contrast, the turbulence effect of flow separation on the seawall’s leeside was limited to the area below the wind turbine rotor, and had no negative effect. The use of the CFD verified with the comparison with the wind tunnel experiment was extended to the full-scale seawall, and the results of the analysis based on the wind turbine Supervisory Control and Data Acquisition (SCADA) data of a wind farm confirmed that the seawall effect was equivalent to a 1.5% increase in power generation as a result of a mitigation of the wind profile.
Present Geothermal Characteristics and Influencing Factors in the Xiong’an New Area, North China
Authors: Guo Sasa , Zhu Chuanqing , Qiu Nansheng , Tang Boning , Cui Yue , Zhang Jiatang , Zhao Yuhang
Published: October 2019

The present geothermal characteristics and influencing factors are analyzed to conduct geothermal resource exploration in the Xiong’an New Area. Thermal conductivity data for 100 rock samples are obtained from different wells and a sedimentary strata thermal conductivity column is proposed. From these data, heat flow distribution in the area is mapped using equilibrium temperature logs obtained for 32 wells. The heat flow in this area is found to be 53.3–106.5 mW·m−2 (average: 73 mW·m−2). The uplift heat value in Niutuozhen and Rongcheng uplift is 106.5 and 90 mW·m−2, respectively. The sag heat flow is relatively low and the Baxian sag’s heat flow value is 48.9–61.6 mW·m−2. Thermal conductivity differences among Cenozoic caprock, Proterozoic carbonate reservoirs, and basement rock mainly affects the geothermal distribution. The low and high thermal conductivities of the caprock and thermal reservoir as well as basement, respectively, cause heat flow redistribution in the surface during conduction. Groundwater rises to geothermal reservoirs through heat-controlling faults, causing convective heat transfer and increasing the geothermal reservoir temperature; therefore, high-temperature groundwater accumulates in the shallow uplift areas. The caprock’s thin uplift area exhibits a high geothermal background due to water convergence. Understanding the geothermal characteristics and influencing factors is necessary for understanding the distribution law and factors influencing geothermal resources and guiding geothermal exploration and development in the Xiong’an New Area.
No Correlation between Endo- and Exoskeletal Regenerative Capacities in Teleost Species
Authors: Pápai Nóra , Kagan Ferenc , Csikós György , Kosztelnik Mónika , Vellai Tibor , Varga Máté
Published: October 2019

The regeneration of paired appendages in certain fish and amphibian lineages is a well established and extensively studied regenerative phenomenon. The teleost fin is comprised of a proximal endoskeletal part (considered homologous to the Tetrapod limb) and a distal exoskeletal one, and these two parts form their bony elements through different ossification processes. In the past decade, a significant body of literature has been generated about the biology of exoskeletal regeneration in zebrafish. However, it is still not clear if this knowledge can be applied to the regeneration of endoskeletal parts. To address this question, we decided to compare endo- and exoskeletal regenerative capacity in zebrafish (Danio rerio) and mudskippers (Periophthalmus barbarous). In contrast to the reduced endoskeleton of zebrafish, Periophthalmus has well developed pectoral fins with a large and easily accessible endoskeleton. We performed exo- and endoskeletal amputations in both species and followed the regenerative processes. Unlike the almost flawless exoskeletal regeneration observed in zebrafish, regeneration following endoskeletal amputation is often impaired in this species. This difference is even more pronounced in Periophthalmus where we could observe no regeneration in endoskeletal structures. Therefore, regeneration is regulated differentially in the exo- and endoskeleton of teleost species.