bluuebunny/crossref_metadata_2025 huggingface dataset:
Noble Metal Nanoparticles-Based Colorimetric Biosensor for Visual Quantification: A Mini Review
Authors: Yu Lu , Li Na
Published: October 2019

Nobel metal can be used to form a category of nanoparticles, termed noble metal nanoparticles (NMNPs), which are inert (resistant to oxidation/corrosion) and have unique physical and optical properties. NMNPs, particularly gold and silver nanoparticles (AuNPs and AgNPs), are highly accurate and sensitive visual biosensors for the analytical detection of a wide range of inorganic and organic compounds. The interaction between noble metal nanoparticles (NMNPs) and inorganic/organic molecules produces colorimetric shifts that enable the accurate and sensitive detection of toxins, heavy metal ions, nucleic acids, lipids, proteins, antibodies, and other molecules. Hydrogen bonding, electrostatic interactions, and steric effects of inorganic/organic molecules with NMNPs surface can react or displacing capping agents, inducing crosslinking and non-crosslinking, broadening, or shifting local surface plasmon resonance absorption. NMNPs-based biosensors have been widely applied to a series of simple, rapid, and low-cost diagnostic products using colorimetric readout or simple visual assessment. In this mini review, we introduce the concepts and properties of NMNPs with chemical reduction synthesis, tunable optical property, and surface modification technique that benefit the development of NMNPs-based colorimetric biosensors, especially for the visual quantification. The “aggregation strategy” based detection principle of NMNPs colorimetric biosensors with the mechanism of crosslinking and non-crosslinking have been discussed, particularly, the critical coagulation concentration-based salt titration methodology have been exhibited by derived equations to explain non-crosslinking strategy be applied to NMNPs based visual quantification. Among the broad categories of NMNPs based biosensor detection analyses, we typically focused on four types of molecules (melamine, single/double strand DNA, mercury ions, and proteins) with discussion from the standpoint of the interaction between NMNPs surface with molecules, and DNA engineered NMNPs-based biosensor applications. Taken together, NMNPs-based colorimetric biosensors have the potential to serve as a simple yet reliable technique to enable visual quantification.
Refugee and Asylum-Seeking Children: Interrupted Child Development and Unfulfilled Child Rights
Authors: Vaghri Ziba , Tessier Zoë , Whalen Christian
Published: October 2019

The 21st century phenomenon of “global displacement” is particularly concerning when it comes to children. Childhood is a critical period of accelerated growth and development. These processes can be negatively affected by the many stressors to which refugee and asylum-seeking children are subjected. The United Nations Convention on the Rights of the Child (CRC) is the most ratified human rights treaty in history, with 196 States Parties (SPs). The CRC provides a framework of 54 articles outlining government responsibilities to ensure the protection, promotion, and fulfillment of rights of all children within their jurisdictions. Among these are the rights of refugee and asylum-seeking children, declared under Article 22 of the CRC. Refugee and asylum-seeking children, similarly to all other children, are entitled to their rights under the CRC and do not forgo any right by virtue of moving between borders. The hosting governments, as SPs to the CRC, are the primary duty bearers to fulfill these rights for the children entering their country. This manuscript provides an overview of the health and developmental ramification of being displaced for refugee and asylum-seeking children. Then, an in-depth analysis of the provisions under Article 22 is presented and the responsibilities of SPs under this article are described. The paper provides some international examples of strengths and shortcomings relating to these responsibilities and closes with a few concluding remarks and recommendations.
Chemical Safety of Furniture Products
Authors: Rybin Boris , Safin Ruslan , Zavrazhnova Irina , Mukhametzyanov Shamil , Rybin Dmitry , Gazizulina Albina
Published: October 2019

At present, technical regulations are adopted for furniture products of various types, establishing the protection of human health from the influence of harmful substances in the parts and assemblies of wood products and wood materials. The technical regulation adopted the requirements for ensuring chemical safety in the design and manufacture of furniture. The technical regulation is based on the condition of furniture products, eliminating the risk of harm to human health due to exceeding the maximum permissible concentration of harmful chemicals in indoor air. Such substances include free formaldehyde, migrating from the volume of chipboard and glue interlayers when gluing and veneering furniture parts and assemblies. Harmful chemicals are vapor-gas mixtures of solvents, the migration of which is observed from solid lacquer membrane of protective and decorative coatings of parts and components of furniture into the indoor air environment. These chemicals are present in the construction and auxiliary materials in the development of furniture. It is desirable that manufacturers of furniture products determine in advance, at the stage of its design, the level of safety when using certain raw materials. For this purpose, a technique is proposed that allows us to determine the concentration of harmful substances in the air of the premises with the selected materials, design and manufacturing technology of furniture products. Preliminary calculations based on the proposed method, allows us to determine the life of the furniture, in which the harmful substances migrating into the air environment of the premises will be within the permissible concentrations. This allows certifying the manufactured furniture products for chemical safety with the assignment of certain quality parameters. The proposed technique may be useful for enterprises focused on the production of furniture products.
Fatty Acid-Derived Ionic Liquid Lubricant. Protic Ionic Liquid Crystals as Protic Ionic Liquid Additives
Authors: Avilés María-Dolores , Pamies Ramón , Sanes José , Carrión Francisco-José , Bermúdez María-Dolores
Published: October 2019

Fatty acids are natural products which have been studied as green lubricants. Ionic liquids are considered efficient friction reducing and wear preventing lubricants and lubricant additives. Fatty acid-derived ionic liquids have shown potential as neat lubricant and additives. Protic ionic liquid crystals (PILCs) are protic ionic liquids (PILs) where cations and anions form ordered mesophases that show liquid crystalline behavior. The adsorption of carboxylate units on sliding surfaces can enhance the lubricant performance. Ionic liquid crystal lubricants with longer alkyl chains can separate sliding surfaces more efficiently. However, they are usually solid at room temperature and, when used as additives in water, transitions to high friction coefficients and wear rates, with tribocorrosion processes occur when water evaporation takes place at the interface. In order to avoid these inconveniences, in the present work, a protic ammonium palmitate (DPA) ionic liquid crystal has been added in 1 wt.% proportion to a short chain citrate ionic liquid (DCi) with the same protic ammonium cation. A spin coated layer of (DCi + DPA) was deposited on AISI316L steel surface before the sliding test against sapphire ball. Synergy between DCi PIL and DPA PILC additive reduces friction coefficient and wear rate, without tribocorrosion processes, as shown by scanning electron microscopy (SEM)/energy dispersive X-ray microanalysis (EDX) and X-ray photoelectron spectroscopy (XPS) results.
Hardness and Roughness of Overlaid Wood Composites Exposed to a High-Humidity Environment
Authors: Salca Emilia-Adela , Hiziroglu Salim
Published: October 2019

The objective of this experimental study was to evaluate the surface roughness and hardness of laminated wood-based composite panels as a function of exposure to high relative humidity (RH). All samples were conditioned in a room having a temperature of 20 °C and a relative humidity of 65% before the tests were carried out. Surface roughness, Janka hardness and mass change rate of the raw and overlaid samples were determined before and after humidity exposure. The surface of the overlaid samples was also investigated by SEM. The stylus method was used to determine the fluctuations of the surface quality of the raw and overlaid composites. The surface quality and hardness of the samples were influenced by increases of the RH level and exposure time. The mass rate change was higher for the raw samples compared with the overlaid ones. The findings of this study can be applied to improve production techniques in furniture manufacturing and to enhance the use of overlaid composite panels.
Influence of Sputtering Power on the Electrical Properties of In-Sn-Zn Oxide Thin Films Deposited by High Power Impulse Magnetron Sputtering
Authors: Li Zhi-Yue , Chen Sheng-Chi , Huo Qiu-Hong , Liao Ming-Han , Dai Ming-Jiang , Lin Song-Sheng , Yang Tian-Lin , Sun Hui
Published: October 2019

In-Sn-Zn oxide (ITZO) thin films have been studied as a potential material in flat panel displays due to their high carrier concentration and high mobility. In the current work, ITZO thin films were deposited on glass substrates by high-power impulse magnetron sputtering (HiPIMS) at room temperature. The influence of the sputtering power on the microstructures and electrical performance of ITZO thin films was investigated. The results show that ITZO thin films prepared by HiPIMS were dense and smooth. There were slight variations in the composition of ITZO thin films deposited at different sputtering powers. With the sputtering power increasing from 100 W to 400 W, the film’s crystallinity was enhanced. When the sputtering power was 400 W, an In2O3 (104) plane could be detected. Films with optimal electrical properties were produced at a sputtering power of 300 W, a carrier mobility of 31.25 cm2·V−1·s−1, a carrier concentration of 9.11 × 1018 cm−3, and a resistivity of 2.19 × 10−4 Ω·m.
Highly Textured Seed Layers for the Growth of Vertically Oriented ZnO Nanorods
Authors: Basinova Nikola , Cernohorsky Ondrej , Grym Jan , Kucerova Sarka , Faitova Hana , Yatskiv Roman , Vanis Jan , Vesely Jozef , Maixner Jaroslav
Published: October 2019

One dimensional ZnO nanostructures prepared by favorable and simple solution growth methods are at the forefront of this research. Vertically oriented ZnO nanorods with uniform physical properties require high-quality seed layers with a narrow size distribution of the crystallites, strong c-axis orientation, and low surface roughness and porosity. It has been shown that high quality seed layers can be prepared by the sol–gel process. The sol–gel process involves three essential steps: preparation of the sol, its deposition by dip coating, and thermal treatment comprising preheating and annealing. We put emphasis on the investigation of the heat treatment on the properties of the seed layers and on the vertical alignment of the nanorods. It was demonstrated that for the vertical alignment of the nanorods, the preheating step is crucial and that the temperatures reported in the literature have been too low. With higher preheating temperatures, conditions for the vertical alignment of the nanorods were achieved in both investigated annealing atmospheres in air and in argon.
Two-Dimensional Hydrogen-Bonded Crystal Structure, Hirshfeld Surface Analysis and Morphology Prediction of a New Polymorph of 1H-Nicotineamidium Chloride Salt
Authors: Ferjani Hela , Chebbi Hammouda , Guesmi Abderrahmen , AlRuqi Obaid S. , Al-Hussain Sami A.
Published: October 2019

A new polymorph of 1H-nicotineamidium chloride salt, (C6H7N2O)+·Cl−, was grown by slow evaporation at room temperature. It crystallizes in the monoclinic space group P21/m. The crystal structure study shows that the organic cations (C6H7N2O)+ and chloride anions are organized into 2D-layers packed along the b-axis. The structural components interact by N–H···O, N–H···Cl and C–H···Cl hydrogen bonds building up a two-dimensional network. The protonated organic cations and the chloride anions show a π–Cl− interaction enhancing stability to the crystal structure. A description of the hydrogen-bonding network and comparison with similar related compounds of nicotinamide and isonicotineamide are presented. The bulk morphology was also predicted and it was found that the simulated morphology predicted by Bravais–Friedel–Donnay–Harker (BFDH) model matches with the morphology of as grown single crystal. Moreover, to illustrate the intermolecular interactions in the new studied polymorph, we report also the analysis of the Hirshfeld surface and its fingerprint polts.
Thermo-Optical Generation of Particle-Like Structures in Frustrated Chiral Nematic Film
Authors: Shvetsov Sergey , Orlova Tetiana , Emelyanenko Alexander V. , Zolot’ko Alexander
Published: October 2019

The creation of metastable particle-like structures in frustrated (unwound) chiral nematic film containing light-absorbing additive is studied. It is shown that such localized structures can be generated by the thermo-optical action of a focused laser beam or arise spontaneously at a phase transition from an isotropic to a liquid crystal state. Observed axisymmetric patterns resemble cholesteric spherulites with toroidal double-twisted director-field configuration.
Functional Traits Co-Occurring with Mobile Genetic Elements in the Microbiome of the Atacama Desert
Authors: Sáenz Johan S. , Airo Alessandro , Schulze-Makuch Dirk , Schloter Michael , Vestergaard Gisle
Published: October 2019

Mobile genetic elements (MGEs) play an essential role in bacterial adaptation and evolution. These elements are enriched within bacterial communities from extreme environments. However, very little is known if specific genes co-occur with MGEs in extreme environments and, if so, what their function is. We used shotgun-sequencing to analyse the metagenomes of 12 soil samples and characterized the composition of MGEs and the genes co-occurring with them. The samples ranged from less arid coastal sites to the inland hyperarid core of the Atacama Desert, as well as from sediments below boulders, protected from UV-irradiation. MGEs were enriched at the hyperarid sites compared with sediments from below boulders and less arid sites. MGEs were mostly co-occurring with genes belonging to the Cluster Orthologous Group (COG) categories “replication, recombination and repair,” “transcription” and “signal transduction mechanisms.” In general, genes coding for transcriptional regulators and histidine kinases were the most abundant genes proximal to MGEs. Genes involved in energy production were significantly enriched close to MGEs at the hyperarid sites. For example, dehydrogenases, reductases, hydrolases and chlorite dismutase and other enzymes linked to nitrogen metabolism such as nitrite- and nitro-reductase. Stress response genes, including genes involved in antimicrobial and heavy metal resistance genes, were rarely found near MGEs. The present study suggests that MGEs could play an essential role in the adaptation of the soil microbiome in hyperarid desert soils by the modulation of housekeeping genes such as those involved in energy production.
HIV Capsid Inhibitors Beyond PF74
Authors: McArthur Carole , Gallazzi Fabio , Quinn Thomas P. , Singh Kamal
Published: October 2019

Human immunodeficiency virus (HIV) capsid plays important roles at multiple stages of viral replication. At the initial stages, controlled uncoating (disassembly) of the capsid ensures efficient reverse transcription of the single-stranded RNA genome, into the double-stranded DNA. Whereas at later stages, a proper assembly of capsid ensures the formation of a mature infectious virus particle. Hence, the inhibition of capsid assembly and/or disassembly has been recognized as a potential therapeutic strategy, and several capsid inhibitors have been reported. Of these, PF-3450074 (PF74) has been extensively studied. Recently reported GS-CA inhibitors (GS-CA1 and GS-6207), have shown a strong potential and appear to contain a PF74 scaffold. The location of resistance mutations and the results of structural studies further suggest that GS-CA compounds and PF74 share the same binding pocket, which is located between capsid monomers. Additionally, phenylalanine derivatives containing the PF74 scaffold show slightly enhanced capsid inhibiting activity. A comparison of capsid structures in complex with host factors and PF74, reveals the presence of common chemical entities at topologically equivalent positions. Here we present the status of capsid inhibitors that contain PF74 scaffolds and propose that the PF74 scaffold may be used to develop strong and safe capsid inhibitors.
Multi-Sensor UAV Tracking of Individual Seedlings and Seedling Communities at Millimetre Accuracy
Authors: Buters Todd , Belton David , Cross Adam
Published: October 2019

The increasing spatial and temporal scales of ecological recovery projects demand more rapid and accurate methods of predicting restoration trajectory. Unmanned aerial vehicles (UAVs) offer greatly improved rapidity and efficiency compared to traditional biodiversity monitoring surveys and are increasingly employed in the monitoring of ecological restoration. However, the applicability of UAV-based remote sensing in the identification of small features of interest from captured imagery (e.g., small individual plants, <100 cm2) remains untested and the potential of UAVs to track the performance of individual plants or the development of seedlings remains unexplored. This study utilised low-altitude UAV imagery from multi-sensor flights (Red-Green-Blue and multispectral sensors) and an automated object-based image analysis software to detect target seedlings from among a matrix of non-target grasses in order to track the performance of individual target seedlings and the seedling community over a 14-week period. Object-based Image Analysis (OBIA) classification effectively and accurately discriminated among target and non-target seedling objects and these groups exhibited distinct spectral signatures (six different visible-spectrum and multispectral indices) that responded differently over a 24-day drying period. OBIA classification from captured imagery also allowed for the accurate tracking of individual target seedling objects through time, clearly illustrating the capacity of UAV-based monitoring to undertake plant performance monitoring of individual plants at very fine spatial scales.
Impact of Misclassification Rates on Compression Efficiency of Red Blood Cell Images of Malaria Infection Using Deep Learning
Authors: Dong Yuhang , Pan W. David , Wu Dongsheng
Published: October 2019

Malaria is a severe public health problem worldwide, with some developing countries being most affected. Reliable remote diagnosis of malaria infection will benefit from efficient compression of high-resolution microscopic images. This paper addresses a lossless compression of malaria-infected red blood cell images using deep learning. Specifically, we investigate a practical approach where images are first classified before being compressed using stacked autoencoders. We provide probabilistic analysis on the impact of misclassification rates on compression performance in terms of the information-theoretic measure of entropy. We then use malaria infection image datasets to evaluate the relations between misclassification rates and actually obtainable compressed bit rates using Golomb–Rice codes. Simulation results show that the joint pattern classification/compression method provides more efficient compression than several mainstream lossless compression techniques, such as JPEG2000, JPEG-LS, CALIC, and WebP, by exploiting common features extracted by deep learning on large datasets. This study provides new insight into the interplay between classification accuracy and compression bitrates. The proposed compression method can find useful telemedicine applications where efficient storage and rapid transfer of large image datasets is desirable.
Non-Equilibrium Quantum Brain Dynamics: Super-Radiance and Equilibration in 2 + 1 Dimensions
Authors: Nishiyama Akihiro , Tanaka Shigenori , Tuszynski Jack A.
Published: October 2019

We derive time evolution equations, namely the Schrödinger-like equations and the Klein–Gordon equations for coherent fields and the Kadanoff–Baym (KB) equations for quantum fluctuations, in quantum electrodynamics (QED) with electric dipoles in 2 + 1 dimensions. Next we introduce a kinetic entropy current based on the KB equations in the first order of the gradient expansion. We show the H-theorem for the leading-order self-energy in the coupling expansion (the Hartree–Fock approximation). We show conserved energy in the spatially homogeneous systems in the time evolution. We derive aspects of the super-radiance and the equilibration in our single Lagrangian. Our analysis can be applied to quantum brain dynamics, that is QED, with water electric dipoles. The total energy consumption to maintain super-radiant states in microtubules seems to be within the energy consumption to maintain the ordered systems in a brain.
Wideband Performance Comparison between the 40 GHz and 60 GHz Frequency Bands for Indoor Radio Channels
Authors: Riobó Miguel , Hofman Rob , Cuiñas Iñigo , García Sánchez Manuel , Verhaevert Jo
Published: October 2019

When 5G networks are to be deployed, the usability of millimeter-wave frequency allocations seems to be left out of the debate. However, there is an open question regarding the advantages and disadvantages of the main candidates for this allocation: The use of the licensed spectrum near 40 GHz or the unlicensed band at 60 GHz. Both bands may be adequate for high performance radio communication systems, and this paper provides insight into such alternatives. A large measurement campaign supplied enough data to analyze and to evaluate the network performance for both frequency bands in different types of indoor environments: Both large rooms and narrow corridors, and both line of sight and obstructed line of sight conditions. As a result of such a campaign and after a deep analysis in terms of wideband parameters, the radio channel usability is analyzed with numerical data regarding its performance.
Implementation of SOH Estimator in Automotive BMSs Using Recursive Least-Squares
Authors: Sung Woosuk , Lee Jaewook
Published: October 2019

This paper presents a computationally efficient state-of-health (SOH) estimator that is readily applicable to automotive battery management systems (BMSs). The proposed scheme uses a recursive estimator to improve the original scheme based on a batch estimator. In the batch process, state estimation requires significantly longer CPU time than data measurement, and the original scheme may fail to satisfy real-time guarantees. To prevent this problem, we apply recursive least-squares. By replacing the batch process to solve the normal equation with a recursive update, the proposed scheme can spread CPU utilization and reduce memory footprint. The benefits of the recursive estimator are quantitatively validated by comparing its CPU time and memory footprint with those of the batch estimator. A similar level of SOH estimation accuracy is achievable with over 60% less memory usage, and the CPU time stabilizes around 5 ms. This enables implementation of the proposed scheme in automotive BMSs.
Efficient Implementation on Low-Cost SoC-FPGAs of TLSv1.2 Protocol with ECC_AES Support for Secure IoT Coordinators
Authors: Bellemou Ahmed Mohamed , García Antonio , Castillo Encarnación , Benblidia Nadjia , Anane Mohamed , Álvarez-Bermejo José Antonio , Parrilla Luis
Published: October 2019

Security management for IoT applications is a critical research field, especially when taking into account the performance variation over the very different IoT devices. In this paper, we present high-performance client/server coordinators on low-cost SoC-FPGA devices for secure IoT data collection. Security is ensured by using the Transport Layer Security (TLS) protocol based on the TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 cipher suite. The hardware architecture of the proposed coordinators is based on SW/HW co-design, implementing within the hardware accelerator core Elliptic Curve Scalar Multiplication (ECSM), which is the core operation of Elliptic Curve Cryptosystems (ECC). Meanwhile, the control of the overall TLS scheme is performed in software by an ARM Cortex-A9 microprocessor. In fact, the implementation of the ECC accelerator core around an ARM microprocessor allows not only the improvement of ECSM execution but also the performance enhancement of the overall cryptosystem. The integration of the ARM processor enables to exploit the possibility of embedded Linux features for high system flexibility. As a result, the proposed ECC accelerator requires limited area, with only 3395 LUTs on the Zynq device used to perform high-speed, 233-bit ECSMs in 413 µs, with a 50 MHz clock. Moreover, the generation of a 384-bit TLS handshake secret key between client and server coordinators requires 67.5 ms on a low cost Zynq 7Z007S device.
Research on Linear Active Disturbance Rejection Control in DC/DC Boost Converter
Authors: Li Hui , Liu Xinxiu , Lu Junwei
Published: October 2019

This paper proposes a cascade control strategy based on linear active disturbance rejection control (LADRC) for a boost DC/DC converter. It solves the problem that the output voltage of boost converter is unstable due to non-minimum phase characteristics, input voltage and load variation. Firstly, the average state space model of boost converter is established. Secondly, a new output variable is selected, and a cascade control is adopted to solve the problems of narrow bandwidth and poor dynamic performance caused by non-minimum phase. LADRC is used to estimate and compensate the fluctuations of input voltage and loads in time. Linear state error feedback (LSEF) is used to achieve smaller errors than traditional control method, which ensures the stability and robustness of the system under internal uncertainty and external disturbance. Subsequently, the stability of the system is determined by frequency domain analysis. Finally, the feasibility and superiority of the proposed strategy is verified by simulation and hardware experiment.
Melody Extraction and Encoding Method for Generating Healthcare Music Automatically
Authors: Li Shuyu , Jang Sejun , Sung Yunsick
Published: October 2019

The strong relationship between music and health has helped prove that soft and peaceful classical music can significantly reduce people’s stress; however, it is difficult to identify and collect examples of such music to build a library. Therefore, a system is required that can automatically generate similar classical music selections from a small amount of input music. Melody is the main element that reflects the rhythms and emotions of musical works; therefore, most automatic music generation research is based on melody. Given that melody varies frequently within musical bars, the latter are used as the basic units of composition. As such, there is a requirement for melody extraction techniques and bar-based encoding methods for automatic generation of bar-based music using melodies. This paper proposes a method that handles melody track extraction and bar encoding. First, the melody track is extracted using a pitch-based term frequency–inverse document frequency (TFIDF) algorithm and a feature-based filter. Subsequently, four specific features of the notes within a bar are encoded into a fixed-size matrix during bar encoding. We conduct experiments to determine the accuracy of track extraction based on verification data obtained with the TFIDF algorithm and the filter; an accuracy of 94.7% was calculated based on whether the extracted track was a melody track. The estimated value demonstrates that the proposed method can accurately extract melody tracks. This paper discusses methods for automatically extracting melody tracks from MIDI files and encoding based on bars. The possibility of generating music through deep learning neural networks is facilitated by the methods we examine within this work. To help the neural networks generate higher quality music, which is good for human health, the data preprocessing methods contained herein should be improved in future works.
Feedback Control for Transition Suppression in Direct Numerical Simulations of Channel Flow
Authors: Sun Yiyang , Hemati Maziar S.
Published: October 2019

For channel flow at subcritical Reynolds numbers ( R e < 5772 ), a laminar-to-turbulent transition can emerge due to a large transient amplification in the kinetic energy of small perturbations, resulting in an increase in drag at the walls. The objectives of the present study are three-fold: (1) to study the nonlinear effects on transient energy growth, (2) to design a feedback control strategy to prevent this subcritical transition, and (3) to examine the control mechanisms that enable transition suppression. We investigate transient energy growth of linear optimal disturbance in plane Poiseuille flow at a subcritical Reynolds number of R e = 3000 using linear analysis and nonlinear simulation. Consistent with previous studies, we observe that the amplification of the given initial perturbation is reduced when the nonlinear effect is substantial, with larger perturbations being less amplified in general. Moreover, we design linear quadratic optimal controllers to delay transition via wall-normal blowing and suction actuation at the channel walls. We demonstrate that these feedback controllers are capable of reducing transient energy growth in the linear setting. The performance of the same controllers is evaluated for nonlinear flows where a laminar-to-turbulent transition emerges without control. Nonlinear simulations reveal that the controllers can reduce transient energy growth and suppress transition. Further, we identify and characterize the underlying physical mechanisms that enable feedback control to suppress and delay laminar-to-turbulent transition.
Electricity Market Empowered by Artificial Intelligence: A Platform Approach
Authors: Xu Yueqiang , Ahokangas Petri , Louis Jean-Nicolas , Pongrácz Eva
Published: October 2019

Artificial intelligence (AI) techniques and algorithms are increasingly being utilized in energy and renewable research to tackle various engineering problems. However, a majority of the AI studies in the energy domain have been focusing on solving specific technical issues. There is limited discussion on how AI can be utilized to enhance the energy system operations, particularly the electricity market, with a holistic view. The purpose of the study is to introduce the platform architectural logic that encompasses both technical and economic perspectives to the development of AI-enabled energy platforms for the future electricity market with massive and distributed renewables. A constructive and inductive approach for theory building is employed for the concept proposition of the AI energy platform by using the aggregated data from a European Union (EU) Horizon 2020 project and a Finnish national innovation project. Our results are presented as a systemic framework and high-level representation of the AI-enabled energy platform design with four integrative layers that could enable not only value provisioning but also value utilization for a distributed energy system and electricity market as the new knowledge and contribution to the extant research. Finally, the study discusses the potential use cases of the AI-enabled energy platform.
An Evaluation Method of Wind Power Integration in Power Systems with Flexible Combined Heat and Power Plant
Authors: Lyu Quan , Gong Haoyan , Yang Nan , Xu Xiandong , Zhang Na , Wang Haixia
Published: October 2019

During the heating period in Northeast China, the electricity generated by Combined Heat and Power (CHP) plants has caused a large amount of wind power curtailment. To avoid this curtailment, Heat Storages (HS) and Electric Boilers (EB) are being widely applied to CHP plants. However, the effectiveness of HS and EB on the curtailment of wind power has still not been well evaluated. This paper proposes a new evaluation method consisting of an operation boundary model and an internal coordinated operation model for each flexible CHP plant with HS and EB. Then a system power balance model based on hour-by-hour analysis is established to determine the wind power integration, down-regulation subsidy and the utilization degree of the flexible equipment. The models are validated by using field measured data of a province in China. The results show that the capacity change of the EB has a bigger impact on the down-regulation subsidy than that of the HS, while the EB is more effective when the level of wind power integration is high.
Modelling and Analysis of Plate Heat Exchangers for Flexible District Heating Systems
Authors: Chyhryn Serafym
Published: October 2019

Seamless integration of district heating (DH) and power systems implies their flexible operation, which extends their typical operational boundaries and, thus, affects performance of key components, such as plate heat exchangers (PHXs). Despite that the heat transfer in a PHX is regulated by mass flows, flexible operation and demand variations cause shifts in temperature levels, which affects the system operation and must be efficiently accounted for. In this paper, an overall heat transfer coefficient (OHTC) model with direct relation to temperature is proposed. The model is based on a linear approximation of thermophysical components of the forced convection coefficient (FCC). On one hand, it allows to account for temperature variations as compared to mass flow-based models, thus, improving accuracy. On the other hand, it does not involve iterative lookup of thermophysical properties and requires fewer inputs, hence, reducing computational effort. The proposed linear model is experimentally verified on a laboratory PHX against estimated correlations for FCC. A practical estimation procedure is proposed based on component data. Additionally, binding the correlation to one of varying parameters shows reduction in the heat transfer error. Finally, operational optimization test cases for a basic DH system demonstrate better performance of the proposed models as compared to those previously used.
Optical Performance Analysis of Single Flow Through and Concentric Tube Receiver Coupled with a Modified CPC Collector Under Different Configurations
Authors: Akhter Javed , Gilani Syed I. , Al-Kayiem Hussain H. , Ali Muzaffar
Published: October 2019

Compound parabolic concentrating (CPC) collectors have great potential to provide sustainable solar thermal energy for many applications operating in the medium temperature range. This paper presents the design, development and performance evaluation of a modified CPC collector integrated with an evacuated tube receiver. The optical performance of the designed CPC paired with concentric tube receiver is compared with that of a CPC coupled with single flow through evacuated tube receiver for stationary installation in the East-West and North-South directions. Ray tracing simulations of different configurations demonstrate that CPC coupled with single flow through receivers suffer high gap losses, especially at smaller incidence angles which are considerably alleviated by a concentric tube receiver arrangement. East-West installation of CPC paired with concentric tube receiver exhibited superior optical performance than all other configurations. The yearly average optical efficiency of CPC with concentric tube receiver was 5% higher than that of a single flow through receiver within the acceptance angle. A 60% truncated CPC coupled with concentric tube receiver emerged as the most effective design, which was fabricated for experimental testing. The tests conducted under actual outdoor tropical environmental conditions demonstrated that the experimental optical efficiency reached to about 69% in the case of N-S installation and 66.5% in an E-W arrangement. The experimental results closely match the simulation outcomes, which indicate the proposed performance prediction technique as instrumental for selecting the most effective configuration of CPC collectors for medium temperature heat supply.
Design of the Smart Grid Architecture According to Fractal Principles and the Basics of Corresponding Market Structure
Authors: ILO Albana
Published: October 2019

Nowadays, there is a dramatic upsurge in the use of renewable energy resources, ICT and digitalization that requires more than the straightforward refinements of an established power system structure. New solutions are required to perform dynamic optimizations in real time, closed loops and so on, taking into account the high requirements on data privacy and cyber security. The LINK-paradigm was designed to meet these requirements. It was developed on the basis of the bottom-up method that can lead to misinterpretations or wrong conclusions. This work mainly deals with the verification of the authenticity and correctness of LINK. Fractal analysis is used to identify the unique and independent elements of smart grids required for the design of an architectural paradigm. The signature of the fractal structure, the so-called fractal pattern, is founded and referred to as electrical appliances (ElA). The latter has proven to be the key component of the architectural LINK paradigm. The definition of the LINK paradigm is finally validated: It consists of unique and independent elements that avoid misinterpretation or the need for any changes in its definition. Additionally, the fractal analysis indicates two fractal anomalies in the existing power system structure, while the fractal dimension calculation insinuates the highest complexity in the fractal level of electrical devices. The LINK-based holistic architecture is given a finishing touch. A compact presentation of the control chain strategy is provided that should facilitate its practical implementation. The basis for the harmonization of the market structure with the grid link arrangements is established. The processes of demand response and conservation voltage reduction are presented under the new findings.
Accurate Evaluation of Steady-State Sheath Voltage and Current in HVDC Cable Using Electromagnetic Transient Simulation
Authors: Asif Mansoor , Lee Ho-Yun , Park Kyu-Hoon , Lee Bang-Wook
Published: October 2019

The current and voltage in High Voltage DC (HVDC) line is not pure DC but contain superimposed ripple components. The current ripple in core of HVDC cable magnetically induces a voltage in the sheath, whereas the voltage ripple causes the flow of charging current from core to sheath. The knowledge of sheath voltage is necessary to ensure compliance with the specification of utility companies. In this work, we have reported that the models available in commercial Electromagnetic Transient (EMT) simulation software erroneously introduce a DC bias in steady-state sheath voltage and sheath current. We have also demonstrated that by removing the DC bias accurate steady-state evaluation of sheath voltage and sheath current is possible. Additionally, we have analyzed the sheath voltage and currents in HVDC cable considering different cable lengths and sheath grounding schemes. It has been found that grounding the sheath at the terminal of HVDC cable can limit the sheath voltage to acceptable levels without causing substantial joule loss in the sheath.
The Removal Efficiencies of Several Temperate Tree Species at Adsorbing Airborne Particulate Matter in Urban Forests and Roadsides
Authors: Kwak Myeong Ja , Lee Jongkyu , Kim Handong , Park Sanghee , Lim Yeaji , Kim Ji Eun , Baek Saeng Geul , Seo Se Myeong , Kim Kyeong Nam , Woo Su Young
Published: October 2019

Although urban trees are proposed as comparatively economical and eco-efficient biofilters for treating atmospheric particulate matter (PM) by the temporary capture and retention of PM particles, the PM removal effect and its main mechanism still remain largely uncertain. Thus, an understanding of the removal efficiencies of individual leaves that adsorb and retain airborne PM, particularly in the sustainable planning of multifunctional green infrastructure, should be preceded by an assessment of the leaf microstructures of widespread species in urban forests. We determined the differences between trees in regard to their ability to adsorb PM based on the unique leaf microstructures and leaf area index (LAI) reflecting their overall ability by upscaling from leaf scale to canopy scale. The micro-morphological characteristics of adaxial and abaxial leaf surfaces directly affected the PM trapping efficiency. Specifically, leaf surfaces with grooves and trichomes showed a higher ability to retain PM as compared to leaves without epidermal hairs or with dynamic water repellency. Zelkova serrata (Thunb.) Makino was found to have significantly higher benefits with regard to adsorbing and retaining PM compared to other species. Evergreen needle-leaved species could be a more sustainable manner to retain PM in winter and spring. The interspecies variability of the PM adsorption efficiency was upscaled from leaf scale to canopy scale based on the LAI, showing that tree species with higher canopy density were more effective in removing PM. In conclusion, if urban trees are used as a means to improve air quality in limited open spaces for urban greening programs, it is important to predominantly select a tree species that can maximize the ability to capture PM by having higher canopy density and leaf grooves or trichomes.
An Aging Evaluation of the Bearing Performances of Glass Fiber Composite Laminate in Salt Spray Fog Environment
Authors: Calabrese Luigi , Fiore Vincenzo , Bruzzaniti Paolo Giovanni , Scalici Tommaso , Valenza Antonino
Published: October 2019

The aim of the present paper is to assess the bearing performance evolution of pinned, glass-composite laminates due to environmental aging in salt-spray fog tests. Glass fibers/epoxy pinned laminates were exposed for up to 60 days in salt-spraying, foggy environmental conditions (according to ASTM B117 standard). In order to evaluate the relationship between mechanical failure mode and joint stability over increasing aging time, different single lap joints, measured by the changing hole diameter (D), laminate width (W) and hole free edge distance (E), were characterized at varying aging steps. Based on this approach, the property-structure relationship of glass-fibers/epoxy laminates was assessed under these critical environmental conditions. Furthermore, an experimental 2D failure map, clustering main failure modes in the plane E/D versus W/D ratios, was generated, and its cluster variation was analyzed at each degree of aging.
Vitellogenesis in Blue Gourami is Accompanied by Brain Transcriptome Changes
Authors: Degani Gad , Alon Amir , Hajouj Akram , Meerson Ari
Published: October 2019

The blue gourami (Trichogaster trichopterus) is a model for hormonal control of reproduction in Anabantidae fish, but also relevant to other vertebrates. We analyzed the female blue gourami brain transcriptome in two developmental stages: pre-vitellogenesis (PVTL) before yolk accumulation in the oocytes, and high vitellogenesis (HVTL) at the end of yolk accumulation in the oocytes. RNA sequencing of whole-brain transcriptome identified 34,368 unique transcripts, 23,710 of which could be annotated by homology with other species. We focused on the transcripts showing significant differences between the stages. Seventeen and fourteen annotated genes were found to be upregulated in PVTL and HVTL, respectively. Five nuclear transcripts, three of which contain the homeobox domain (ARX, DLX5, CERS6), were upregulated in PVTL. Additionally, several receptors previously known to be involved in reproduction were identified, and three of these, G-protein coupled receptor 54, Membrane progesterone receptor epsilon, and Gonadotropin-releasing hormone II receptor (GPCR, mPR, and GnRHR) were measured by quantitative RT-PCR in brain, pituitary, and ovary samples from PVTL and HVTL stage females. Of these, GPCR was highly expressed in the brain and pituitary as compared to the ovary in both PVTL and HVTL. GnRHR was highly expressed in the ovary compared to the brain and pituitary, and its levels in the brain were significantly higher in PVTL than HVTL. Brain mPR mRNA levels were likewise higher in PVTL than HVTL. In conclusion, this study details changes in the female blue gourami brain transcriptome through yolk accumulation in the oocytes and identifies key genes that may mediate this process.
Broccoli (Brassica oleracea L. var. italica) Sprouts as the Potential Food Source for Bioactive Properties: A Comprehensive Study on In Vitro Disease Models
Authors: Le Thanh Ninh , Luong Hong Quang , Li Hsin-Ping , Chiu Chiu-Hsia , Hsieh Pao-Chuan
Published: October 2019

Broccoli sprouts are an excellent source of health-promoting phytochemicals such as vitamins, glucosinolates, and phenolics. The study aimed to investigate in vitro antioxidant, antiproliferative, apoptotic, and antibacterial activities of broccoli sprouts. Five-day-old sprouts extracted by 70% ethanol showed significant antioxidant activities, analyzed to be 68.8 μmol Trolox equivalent (TE)/g dry weight by 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic (ABTS) assay, 91% scavenging by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, 1.81 absorbance by reducing power assay, and high phenolic contents by high-performance liquid chromatography (HPLC). Thereafter, sprout extract indicated considerable antiproliferative activities towards A549 (lung carcinoma cells), HepG2 (hepatocellular carcinoma cells), and Caco-2 (colorectal adenocarcinoma cells) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, with IC50 values of 0.117, 0.168 and 0.189 mg/mL for 48 h, respectively. Furthermore, flow cytometry confirmed that Caco-2 cells underwent apoptosis by an increase of cell percentage in subG1 phase to 31.3%, and a loss of mitochondrial membrane potential to 19.3% after 48 h of treatment. Afterward, the extract exhibited notable antibacterial capacities against Bacillus subtilis and Salmonella Typhimurium with minimum inhibition concentration (MIC) values of 0.39 and 0.78 mg/mL, appropriately, along with abilities against Staphylococcus aureus and Escherichia coli with an MIC value of 1.56 mg/mL. Thus, broccoli sprouts were confirmed as a potential food source for consumers’ selection and functional food industry.
Cabinet of Curiosities: The Interesting Geometry of the Angle β = arccos ((3ϕ − 1)/4)
Authors: Fang Fang , Irwin Klee , Kovacs Julio , Sadler Garrett
Published: October 2019

In this paper, we present the construction of several aggregates of tetrahedra. Each construction is obtained by performing rotations on an initial set of tetrahedra that either (1) contains gaps between adjacent tetrahedra, or (2) exhibits an aperiodic nature. Following this rotation, gaps of the former case are “closed” (in the sense that faces of adjacent tetrahedra are brought into contact to form a “face junction”), while translational and rotational symmetries are obtained in the latter case. In all cases, an angular displacement of β = arccos 3 ϕ − 1 / 4 (or a closely related angle), where ϕ = 1 + 5 / 2 is the golden ratio, is observed between faces of a junction. Additionally, the overall number of plane classes, defined as the number of distinct facial orientations in the collection of tetrahedra, is reduced following the transformation. Finally, we present several “curiosities” involving the structures discussed here with the goal of inspiring the reader’s interest in constructions of this nature and their attending, interesting properties.