bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacological analysis of transmission activation of two aphid-vectored plant viruses, turnip mosaic virus and cauliflower mosaic virus
Authors: Berthelot Edwige , Macia Jean-Luc , Martinière Alexandre , Morisset Alexandre , Gallet Romain , Blanc Stéphane , Khelifa Mounia , Drucker Martin
Published: June 2019

Turnip mosaic virus (TuMV, family Potyviridae) and cauliflower mosaic virus (CaMV, family Caulimoviridae) are transmitted by aphid vectors. They are the only viruses shown so far to undergo transmission activation (TA) immediately preceding plant-to-plant propagation. TA is a recently described phenomenon where viruses respond to the presence of vectors on the host by rapidly and transiently forming transmissible complexes that are efficiently acquired and transmitted. Very little is known about the mechanisms of TA and on whether such mechanisms are alike or distinct in different viral species. We use here a pharmacological approach to initiate the comparison of TA of TuMV and CaMV. Our results show that both viruses rely on calcium signaling and reactive oxygen species (ROS) for TA. However, whereas application of the thiol-reactive compound N-ethylmaleimide (NEM) inhibited, as previously shown, TuMV transmission it did not alter CaMV transmission. On the other hand, sodium azide, which boosts CaMV transmission, strongly inhibited TuMV transmission. Finally, wounding stress inhibited CaMV transmission and increased TuMV transmission. Taken together, the results suggest that transmission activation of TuMV and CaMV depends on initial calcium and ROS signaling that are generated during the plant’s immediate responses to aphid manifestation. Interestingly, downstream events in TA of each virus appear to diverge, as shown by the differential effects of NEM, azide and wounding on TuMV and CaMV transmission, suggesting that these two viruses have evolved analogous TA mechanisms.
The medical AI insurgency: what physicians must know about data to practice with intelligent machines
Authors: Miller D. Douglas
Published: June 2019

Machine learning (ML) and its parent technology trend, artificial intelligence (AI), are deriving novel insights from ever larger and more complex datasets. Efficient and accurate AI analytics require fastidious data science—the careful curating of knowledge representations in databases, decomposition of data matrices to reduce dimensionality, and preprocessing of datasets to mitigate the confounding effects of messy (i.e., missing, redundant, and outlier) data. Messier, bigger and more dynamic medical datasets create the potential for ML computing systems querying databases to draw erroneous data inferences, portending real-world human health consequences. High-dimensional medical datasets can be static or dynamic. For example, principal component analysis (PCA) used within R computing packages can speed & scale disease association analytics for deriving polygenic risk scores from static gene-expression microarrays. Robust PCA of k-dimensional subspace data accelerates image acquisition and reconstruction of dynamic 4-D magnetic resonance imaging studies, enhancing tracking of organ physiology, tissue relaxation parameters, and contrast agent effects. Unlike other data-dense business and scientific sectors, medical AI users must be aware that input data quality limitations can have health implications, potentially reducing analytic model accuracy for predicting clinical disease risks and patient outcomes. As AI technologies find more health applications, physicians should contribute their health domain expertize to rules-/ML-based computer system development, inform input data provenance and recognize the importance of data preprocessing quality assurance before interpreting the clinical implications of intelligent machine outputs to patients.
Discovery of piperidine-substituted thiazolo[5,4-d]pyrimidine derivatives as potent and orally bioavailable HIV-1 non-nucleoside reverse transcriptase inhibitors
Authors: Kang Dongwei , Zhao Tong , Wang Zhao , Feng Da , Zhang Heng , Huang Boshi , Wu Gaochan , Wei Fenju , Zhou Zhongxia , Jing Lanlan , Zuo Xiaofang , Tian Ye , Poongavanam Vasanthanathan , Kongsted Jacob , De Clercq Erik , Pannecouque Christophe , Zhan Peng , Liu Xinyong
Published: June 2019

HIV-1 reverse transcriptase offers a key target for antiviral therapy. However, the rapid emergence of drug-resistant mutations in reverse transcriptase as well as the poor pharmacokinetic properties of HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) limits their clinical use. Starting from a previous piperidine-substituted thiophene[3,2-d]pyrimidine compound (K-5a2), here we explore the chemical space around the thiophene ring located in the solvent-exposed regions of the NNRTI binding pocket in detail. Bioisosterism-based structural modification leads to the discovery of a number of compounds as potent in vitro reverse transcriptase inhibitors, providing improved drug resistance profiles compared to the listed drug Etravirine. Furthermore, 14a and 19a are identified as lead compounds with good solubility, appropriate ligand efficiency, and lower cytochrome P450 liability. Compound 19a exhibits useful in vivo pharmacokinetic properties in rat and safety in mice, suggesting that it may have the potential to be an effective drug candidate for treating AIDS.
Quantum teleportation-based state transfer of photon polarization into a carbon spin in diamond
Authors: Tsurumoto Kazuya , Kuroiwa Ryota , Kano Hiroki , Sekiguchi Yuhei , Kosaka Hideo
Published: June 2019

Quantum teleportation is a key principle for quantum information technology. It permits the transfer of quantum information into an otherwise inaccessible space, while also permitting the transfer of photon information into a quantum memory without revealing or destroying the stored quantum information. Here, we show reliable quantum state transfer of photon polarization into a carbon isotope nuclear spin coupled to a nitrogen-vacancy center in diamond based on photon-electron Bell state measurement by photon absorption. The carbon spin is first entangled with the electron spin, which is then permitted to absorb a photon into a spin-orbit correlated eigenstate. Detection of the electron after relaxation into the spin ground state allows post-selected transfer of arbitrary photon polarization into the carbon memory. The quantum state transfer scheme allows individual addressing of integrated quantum memories to realize scalable quantum repeaters for long-haul quantum communications, and distributed quantum computers for large-scale quantum computation and metrology.
A sensitive photoluminescent chemosensor for cyanide in water based on a zinc coordination polymer bearing ditert-butyl-bipyridine
Authors: Rosales-Vázquez Luis D. , Valdes-García Josue , Bazany-Rodríguez Iván J. , Germán-Acacio Juan M. , Martínez-Otero Diego , Vilchis-Néstor Alfredo R. , Morales-Luckie Raúl , Sánchez-Mendieta Víctor , Dorazco-González Alejandro
Published: June 2019

Sensitive and direct sensing of cyanide in buffered aqueous solutions at pH = 7.0 by three new blue photoluminescent zinc-1,4-cyclohexanedicarboxylato coordination polymers bearing di-alkyl-2,2′-bipyridines has been achieved.
Room-temperature liquid metal and alloy systems for energy storage applications
Authors: Guo Xuelin , Zhang Leyuan , Ding Yu , Goodenough John B. , Yu Guihua
Published: June 2019

Liquid metals and alloy systems that feature inherent deformability, high electronic conductivity, and superior electrochemical properties have enabled further development of next-generation energy storage devices.
Oxidation pathways, kinetics and branching ratios of chloromethyl ethyl ether (CMEE) initiated by OH radicals and the fate of its product radical: an insight from a computational study
Authors: Paul Subrata , Gour Nand Kishor , Deka Ramesh Ch.
Published: June 2019

Primary and secondary reaction pathways of CMEE initiated by OH radicals.
Biomimetic nanoparticle technology for cardiovascular disease detection and treatment
Authors: Park Joon Ho , Dehaini Diana , Zhou Jiarong , Holay Maya , Fang Ronnie H. , Zhang Liangfang
Published: June 2019

Biomimetic nanoparticle technology has the potential to significantly improve the clinical management of cardiovascular disease.
Dendrimer-based micelles as cyto-compatible nanocarriers
Authors: Parshad Badri , Yadav Preeti , Kerkhoff Yannic , Mittal Ayushi , Achazi Katharina , Haag Rainer , Sharma Sunil K.
Published: June 2019

The aim of the present study is to compare the synthesized dendritic architectures in terms of self-assembly and transport potential for hydrophobic guest molecules.
A concise construction of 4-alkynylquinazolines via [4 + 2] annulation of 4-alkynylbenzoxazinanones with acylhydroxamates under transition-metal-free conditions
Authors: Yuan Wen-Kui , Sun Sheng-Zheng , Zhang Lin-Bao , Wen Li-Rong , Li Ming
Published: June 2019

A concise and highly efficient method for the construction of valuable 4-alkynylquinazolines under transition-metal-free conditions was developed via [4 + 2] annulation of 4-alkynylbenzoxazinanones with acylhydroxamates in good to excellent yields.
Reaction of antiaromatic porphyrinoid with active methylene compounds
Authors: Ren Demin , Fu Xinliang , Li Xiaofang , Koniarz Sebastian , Chmielewski Piotr J.
Published: June 2019

Antiaromatic norcorrolatonickel(ii) reacts regioselectively under basic conditions with active methylene compounds, yielding mono-substituted derivatives in which spectroscopic and redox properties of the starting macrocycle are retained.
Platinum on 2-aminoethanethiol functionalized MIL-101 as a catalyst for alkene hydrosilylation
Authors: Xie Zhikai , Chen Weiwen , Chen Xiuying , Zhou Xinhua , Hu Wenbin , Shu Xugang
Published: June 2019

Ptδ+was uniformly dispersed in AET-MIL-101 as a highly efficient catalyst for a catalytic hydrosilylation reaction.
Investigation of synergistic effects between silica nanoparticles, biosurfactant and salinity in simultaneous flooding for enhanced oil recovery
Authors: Khademolhosseini Rasoul , Jafari Arezou , Mousavi Seyyed Mohammad , Manteghian Mehrdad
Published: June 2019

The purpose of this study was to investigate the effect of process parameters (silica nanoparticle concentration (NP), biosurfactant (BS) concentration and salinity) as well as their synergistic effects on oil recovery in simultaneous flooding.
Improved antibacterial performance using hydrogel-immobilized lysozyme as a catalyst in water
Authors: Ye Yuemei , Klimchuk Stanislav , Shang Mingwei , Niu Junjie
Published: June 2019

Hydrogel-immobilized lysozyme for antibacterial membrane modification.
Dual-scale TiO2 and SiO2 particles in combination with a fluoroalkylsilane and polydimethylsiloxane superhydrophobic/superoleophilic coating for efficient solvent–water separation
Authors: Heale Frances L. , Einhorn Maud , Page Kristopher , Parkin Ivan P. , Carmalt Claire J.
Published: June 2019

Surfaces that have unique wettabilities and are simultaneously superhydrophobic with water contact angles > 150°, and superoleophilic with oil contact angles < 5°, are of critical importance in the oil/solvent–water separation field.
Fly ash based robust biocatalyst generation: a sustainable strategy towards enhanced green biosurfactant production and waste utilization
Authors: Zhu Zhiwen , Zhang Baiyu , Chen Bing , Ling Jingjing , Cai Qinghong , Husain Tahir
Published: June 2019

Biosurfactants have been well recognized as an environmentally friendly alternative to chemical surfactants.
Inorganic carbonate composites as potential high temperature CO2 sorbents with enhanced cycle stability
Authors: Vall Maria , Hultberg Jonas , Strømme Maria , Cheung Ocean
Published: June 2019

A Ca/Mg/Al oxide composite was synthesised and showed a high CO2 uptake of 0.537 g g−1 at 650 °C with high uptake even after 100 cycles.
A review of the applications of ion floatation: wastewater treatment, mineral beneficiation and hydrometallurgy
Authors: Chang Luping , Cao Yijun , Fan Guixia , Li Chao , Peng Weijun
Published: June 2019

The applications, progress and outlook of ion flotation are discussed.
Preparation of a novel curcumin nanoemulsion by ultrasonication and its comparative effects in wound healing and the treatment of inflammation
Authors: Ahmad Niyaz , Ahmad Rizwan , Al-Qudaihi Ali , Alaseel Salman Edrees , Fita Ibrahim Zuhair , Khalid Mohammed Saifuddin , Pottoo Faheem Hyder
Published: June 2019

The aim of this study was to develop and evaluate a curcumin (Cur) nanoemulsion (NE) and enhance transdermal drug delivery.
Nickel-metalated porous organic polymer for Suzuki–Miyaura cross-coupling reaction
Authors: Dong Ying , Jv Jing-Jing , Li Yue , Li Wen-Han , Chen Yun-Qi , Sun Qian , Ma Jian-Ping , Dong Yu-Bin
Published: June 2019

A porous organic polymer with Ni(ii) α-diimine moiety, which can be a highly active reusable heterogeneous catalyst to promote the Suzuki–Miyaura coupling reaction, was reported.
Electrokinetic energy conversion in nanochannels grafted with pH-responsive polyelectrolyte brushes modelled using augmented strong stretching theory
Authors: Sachar Harnoor Singh , Sivasankar Vishal Sankar , Das Siddhartha
Published: June 2019

Augmented strong stretching theory has been employed to establish that functionalization of nanochannels with polyelectrolyte brushes enhances electrokinetic energy conversion.
A CO2-responsive hydrogel film for optical sensing of dissolved CO2
Authors: Wang Ruiqin , Zhang Mengxin , Guan Ying , Chen Mao , Zhang Yongjun
Published: June 2019

BPEI/PO-Dex LBL film swells in response of dissolved CO2and reports CO2levelviathe shift of Fabry–Perot fringes.
Semiconductor TiO2 thin film as an electrolyte for fuel cells
Authors: Dong Wenjing , Tong Yuzhu , Zhu Bin , Xiao Haibo , Wei Lili , Huang Chao , Wang Baoyuan , Wang Xunying , Kim Jung-Sik , Wang Hao
Published: June 2019

An SOFC using semiconductor TiO2 thin film as an electrolyte was designed using the energy band theory to prevent short-circuiting problem.
Planar all-solid-state rechargeable Zn–air batteries for compact wearable energy storage
Authors: Cao Zhiqian , Hu Haibo , Wu Mingzai , Tang Kun , Jiang Tongtong
Published: June 2019

Planar all-solid-state rechargeable Zn–air batteries with superior energy efficiency demonstrate a novel design for compact all-solid-state rechargeable ZABs towards next-generation wearable energy storage devices with high energy density and safety.
A multistimuli-responsive fluorescent switch in the solution and solid states based on spiro[fluorene-9,9′-xanthene]-spiropyran
Authors: Wang Lingyun , Xiong Wei , Tang Hao , Cao Derong
Published: June 2019

A solid state stimuli-responsive fluorescent switch based on spiro[fluorene-9,9′-xanthene]-spiropyran (SFX-2SP) was reported.
Association of smoking with coronary artery disease in Nepalese populations: a case control study
Authors: Basnet Til Bahadur , Xu Cheng , Mallah Manthar Ali , Indayati Wiwik , Shi Cheng , Xu Jin , Gu Aihua
Published: June 2019

There are well-known traditional risk factors for coronary artery disease (CAD). Among them, smoking is one of the most prominent and modifiable risk factors. This study aims to determine the magnitude of smoking as a risk factor for CAD in the Nepalese population. A hospital-based age- and sex-matched case–control study was carried out with a total of 612 respondents. Bivariate analysis showed that the risk of developing CAD in ex-smokers and current smokers was higher (odds ratio (OR): 1.81 (confidence interval (CI): 1.21–2.7) and OR: 5.2 (CI: 3.4–7.97)), with p-values less than 0.004 and <0.00001, respectively, compared to the risk in never smokers. From stratified socio-demographic, cardio-metabolic, behavioural and psychosocial risk factor analysis, smoking was found to be associated with CAD in almost all subgroups. In the subsequent multivariate analysis, adjustment for socio-demographic, cardio-metabolic and psychosocial risk factors showed a steady increase in risk. However, further adjustment for behavioural risk factors (alcohol use and physical activity) showed that the risk was attenuated by 59% in current smokers. After adjusting for the covariates, current smokers and ex-smokers had an increased risk of CAD (OR: 6.64, 95% CI: 3.64–12.12, p < 0.00001; OR: 1.89, 95% CI: 1.08–3.31, p < 0.012, respectively) compared with non-smokers. In conclusion, smoking was found to increase the risk of CAD in the Nepalese population.
Book Club Experiences, Engagement, and Reading Support Use by People With Aphasia
Authors: Knollman-Porter Kelly , Julian Samantha K.
Published: June 2019

Background

People with chronic aphasia often exhibit a decrease in social engagement and reading ability that negatively influences quality of life. Book clubs can provide a supportive environment that facilitates both socialization and reading. However, limited data exist examining the use of book clubs for individuals with chronic aphasia.

Purpose

The purpose of this qualitative descriptive study was to describe the experiences, engagement, and reading supports used by people with aphasia participating for the 1st time in a book club.

Method and Procedure

Ten people with chronic aphasia and co-occurring reading deficits engaged in 7 book club sessions. Participants first completed a questionnaire about pre- and poststroke reading experiences. Individualized interviews with participants during and post–book club explored the experiences, preferences, and reading comprehension strategies used within the structure of the book club.

Results

Three main categories of findings emerged from the data analysis: (a) perceived changes in attitudes regarding reading and club participation post–book club,(b) variations in use of reading supports and strategies across participants, and (c) perceived social benefits of the book club.

Conclusion

The current study provides evidence that people with varying types and severities of chronic aphasia and reading comprehension challenges can successfully increase reading and social engagement through book club participation. The results from this study highlight the need to provide evidence to support services that extend beyond standard rehabilitation protocols and identify engaging ways to facilitate active participation in functional reading activities for people with chronic aphasia.
Gesture Frequency and Function in Infants With Fragile X Syndrome and Infant Siblings of Children With Autism Spectrum Disorder
Authors: Hughes K. R. , Hogan Abigail L. , Roberts Jane E. , Klusek Jessica
Published: June 2019

Purpose

Infant siblings of children with autism spectrum disorder (ASIBs) and infants with fragile X syndrome (FXS) are both at risk for developing autism spectrum disorder (ASD) and communication disorders; however, very few studies have examined 1 of the earliest forms of intentional communication in infants from these groups: gestures. This study examined the frequency and function of gesture use across 12-month-old infant ASIBs, infants with FXS, and low-risk controls.

Method

Participants included 23 ASIBs who did not later meet diagnostic criteria for ASD, 18 infants with FXS, and 21 low-risk controls. Gestures were coded from a semistructured play-based interaction.

Results

Overall, infants with FXS displayed fewer gestures than low-risk infants, whereas ASIBs did not differ from the FXS or low-risk groups in overall gesture frequency. In terms of the communicative function of the gestures used, the FXS and ASIB groups displayed significantly fewer social interaction gestures than the low-risk controls, with large effect sizes.

Conclusion

This study contributes to scant knowledge of early communication phenotypes of infant ASIBs who do not meet criteria for ASD and infants with FXS. Results indicated that gesture function, not frequency, best discriminated at-risk infants from low-risk infants at 12 months of age. Findings have implications for the clinical evaluation and treatment of infants at high risk for ASD and communication disorders.
Vocal and Tactile Input to Children Who Are Deaf or Hard of Hearing
Authors: Abu-Zhaya Rana , Kondaurova Maria V. , Houston Derek , Seidl Amanda
Published: June 2019

Purpose

Caregivers may show greater use of nonauditory signals in interactions with children who are deaf or hard of hearing (DHH). This study explored the frequency of maternal touch and the temporal alignment of touch with speech in the input to children who are DHH and age-matched peers with normal hearing.

Method

We gathered audio and video recordings of mother–child free-play interactions. Maternal speech units were annotated from audio recordings, and touch events were annotated from video recordings. Analyses explored the frequency and duration of touch events and the temporal alignment of touch with speech.

Results

Greater variance was observed in the frequency of touch and its total duration in the input to children who are DHH. Furthermore, touches produced by mothers of children who are DHH were significantly more likely to be aligned with speech than touches produced by mothers of children with normal hearing.

Conclusion

Caregivers' modifications in the input to children who are DHH are observed in the combination of speech with touch. The implications for such patterns and how they may impact children's attention and access to the speech signal are discussed.
Performance analysis of the LS Prony method for estimating parameters of damped sinusoids
Authors: Lee Joon‐Ho , Cho Yun Seong , Jeong Joon‐Ho
Published: June 2019

The authors address the performance analysis of the least squares (LS) Prony method for estimating the natural frequencies of radar target in the study. Based on the perturbation theory and the Taylor series expansion, the authors get explicit expressions of the mean square error (MSE) of the LS solution, the MSE of the z‐plane natural frequencies and the MSE of the s‐plane natural frequencies. The validity of the derived expressions is demonstrated by comparing the analytic results with simulation results. For further validation of the results, simulation results of the GPOF method have been used for comparison.
Dual‐loop control strategy applied to PV/battery‐based islanded DC microgrids for swarm electrification of developing regions
Authors: Nasir Mashood , Khan Hassan Abbas , Niazi Kamran Ali Khan , Jin Zheming , Guerrero Josep M.
Published: June 2019

In this work, a dual‐loop control strategy is applied to a highly distributed architecture of photovoltaic (PV)/battery‐based DC microgrid, suitable for swarm electrification of developing regions. Typically, in such schemes, resource sharing among the spatially dispersed PV generation and battery storage resources is enabled via communication‐based control methodologies, which adds cost and complexity to the overall system. Alternately, a communication‐less and decentralised control methodology is proposed which utilises inner loop current control and outer loop voltage droop (V–I droop) control for the coordinated resource sharing among the distributed resources. Various scenarios of power sharing among the contributing households are evaluated and the efficacy of the proposed control scheme is validated through simulations on MATLAB/Simulink. Results show that the proposed decentralised control strategy is capable of ensuring stable and coordinated operation without any dedicated layer of communication among the dispersed generation/storage resources.
Thermal modelling of a small wind turbine gearbox for condition monitoring
Authors: Corley Becky , Carroll James , McDonald Alasdair
Published: June 2019

This study details the development of a mathematical thermal model of a small wind turbine gearbox for use in condition monitoring. The model was optimised and partially validated using experimental data from a wind turbine drivetrain test rig. The model was then used to mimic bearing faults, by simulating additional heat losses at respective faulty components. The extent to which the thermal behaviour changed as a result of a fault was studied, with a view to use such an approach to detect and locate faults.
Delivering combined droop and inertial response from wind plant for power system frequency stability
Authors: Wu Lei , Infield David , Yangfei Zhang , Sipeng Hao
Published: June 2019

As wind penetration level into power systems increases, provision of frequency support from wind plant is anticipated to become a requirement in grid codes. In addition to the virtual inertial response, two different approaches to delivering droop response from wind plant are presented and compared in this paper. The combination of droop and inertial response from wind plant has been assessed for a frequency time series. Simulation results show that the proposed approaches to delivering combined droop and inertial response can provide superior performance to either inertial or droop response alone.
Complex forward scattering coefficient for signal characterisation
Authors: Chen Jing , Liu Xiangrong , Liu Changjiang , Dong Xichao
Published: June 2019

In this study, modelling and characteristics analysis of forward scattering coefficients and echoes are investigated. Traditional ground‐target forward scattering signal model has not considered the impact of scattering phase; thus it is not accurate enough for describing air‐target echoes. To solve this problem, a novel echo model was proposed based on the analytical deduction of complex forward scattering coefficient. The novel model separately expresses the target scattering characteristics and Doppler, greatly facilitating the theoretical analyses of echo characteristics. Then, theoretical and simulation investigations on the amplitude and phase characteristics of forward scattering echoes were made based on the complex forward scattering coefficient model. Theoretical explanations for the periodical fluctuation of far‐field echo amplitude, periodical saltation of far‐field echo phase, shadow blocking of near‐field echo amplitude, and slow variation of near‐field echo phase were given, respectively. Meanwhile, the boundary between near‐field forward scattering and far‐field forward scattering was quantitatively defined, which laid the theoretical foundation for the corresponding signal processing algorithms. Finally, with CST simulation results the accuracy of the echo model is verified and impacts of objects' real shapes are analysed.
Random forest‐based track initiation method
Authors: Liu Shuo , Li Hongbo , Zhang Yun , Zou Bin , Zhao Jian
Published: June 2019

In this study, a novel method based on the random forest is presented to solve the problem of track initiation in the air‐traffic‐control (ATC) radar system. ATC radar is the most common civilian surveillance radar. There are dense targets with different moving models in its observation area. When implementing track initiation, previous heuristic methods often fail to meet its high requirements for target detection rate and false track suppression. In the method proposed in this study, the general track initiation problem is modelled as a two‐category classification problem of measurement sequences. From the historical data, the sample set is constructed. The classification function is derived by Breiman's random forest. Simulation experiments and measurement experiments show that the proposed method outperforms conventional heuristic methods in the scene of the ATC system.
Multiple hypothesis method for tracking move‐stop‐move target
Authors: Liu Shuo , Li Hongbo , Zhang Yun , Zou Bin
Published: June 2019

This study presents a new approach to track the move‐stop‐move targets. In the presence of the radar Doppler blind area, a move‐stop‐move target may lead to track breakages, which has some adverse effects on estimating the number of targets in the surveillance area. The authors develop a mode switching‐based multiple hypothesis tracking (MHT) method to solve this problem. In each association, MHT generates three types of hypotheses: moving and detected, moving and undetected and stopped. In the first two types of hypotheses, the target is in the mode of move and tracked with interacting multiple model (IMM)‐extended Kalman filter (EKF) estimator, while in the third kind of hypotheses, the target is in the mode of stop and tracked by EKF with a stop model. The mode probabilities are calculated using the kinematic state statistics from the estimator and the Markov transfer probability of the target movement stage. The track discontinuity event in the classical log‐likelihood ratio of MHT is modified as well. The results of simulation experiment show that the proposed MHT‐based tracker outperforms the conventional MHT‐based method when tracking move‐stop‐move target.
New robust Taylor series method for target localisation based on external emitter radar
Authors: Wang Jun , Zhu Zhenguo , Qin Zhaotao , Zhang Yuxi , Wei Shaoming
Published: June 2019

This study addresses the target localisation problem using bistatic range (BR) measurements in a multi‐base system based on external emitter radar. An asymptotically efficient Taylor series method is proposed for target localisation. The initial value for Taylor series method is provided by some algebraic closed‐form positioning algorithms, rather than priori initial guesses. The localisation convergence problem can also be avoided unless in an extremely large measurement noise. The proposed method can be applied to both critically determined and over‐determined conditions. The performance is verified and evaluated through simulations. The results show that the method can realise Cramer‐Rao lower bound (CRLB) precision under Gaussian measurement noise. In addition, the method is superior to the existing localisation estimation in positioning accuracy and robustness.
A joint XMM-NuSTAR observation of the galaxy cluster Abell 523: Constraints on inverse Compton emission
Authors: Cova F. , Gastaldello F. , Wik D. R. , Boschin W. , Botteon A. , Brunetti G. , Buote D. A. , De Grandi S. , Eckert D. , Ettori S. , Feretti L. , Gaspari M. , Ghizzardi S. , Giovannini G. , Girardi M. , Govoni F. , Molendi S. , Murgia M. , Rossetti M. , Vacca V.
Published: June 2019

Aims. We present the results of a joint XMM-Newton and NuSTAR observation (200 ks) of the galaxy cluster Abell 523 at z = 0.104. The peculiar morphology of the cluster radio halo and its outlier position in the radio power P(1.4 GHz) – X-ray luminosity plane make it an ideal candidate for the study of radio and X-ray correlations and for the search of inverse Compton (IC) emission.

Methods. We constructed bi-dimensional maps for the main thermodynamic quantities (i.e., temperature, pressure and entropy) derived from the XMM observations to describe the physical and dynamical state of the cluster’s intracluster medium (ICM) in detail. We performed a point-to-point comparison in terms of surface brightness between the X-ray and radio emissions to quantify their morphological discrepancies. Making use of NuSTAR’s unprecedented hard X-ray focusing capability, we looked for IC emission both globally and locally after properly modeling the purely thermal component with a multi-temperature description.

Results. The thermodynamic maps obtained from the XMM observation suggest the presence of a secondary merging process that could be responsible for the peculiar radio halo morphology. This hypothesis is supported by the comparison between the X-ray and radio surface brightnesses, which shows a broad intrinsic scatter and a series of outliers from the best-fit relation, corresponding to those regions that could be influenced by a secondary merger. The global NuSTAR spectrum can be explained by purely thermal gas emission, and there is no convincing evidence that an IC component is needed. The 3σ upper limit on the IC flux in the 20−80 keV band is in the [2.2−4.0] × 10−13 erg s−1 cm−2 range, implying a lower limit on the magnetic field strength in the B >  [0.23 − 0.31] μG range. Locally, we looked for IC emission in the central region of the cluster radio halo finding a 3σ upper limit on the 20−80 keV nonthermal flux of 3.17 × 10−14 erg s−1 cm−2, corresponding to a lower limit on the magnetic field strength of B ≳ 0.81 μG.
The Fornax Deep Survey with the VST
Authors: Raj M. A. , Iodice E. , Napolitano N. R. , Spavone M. , Su H-S. , Peletier R. F. , Davis T. A. , Zabel N. , Hilker M. , Mieske S. , Falcon Barroso J. , Cantiello M. , van de Ven G. , Watkins A. E. , Salo H. , Schipani P. , Capaccioli M. , Venhola A.
Published: June 2019

Context. We present the study of a magnitude limited sample (mB ≤ 16.6 mag) of 13 late type galaxies (LTGs), observed inside the virial radius, Rvir ∼ 0.7 Mpc, of the Fornax cluster within the Fornax Deep Survey (FDS).

Aims. The main objective is to use surface brightness profiles and g − i colour maps to obtain information on the internal structure of these galaxies and find signatures of the mechanisms that drive their evolution in high-density environments inside the virial radius of the cluster.

Methods. By modelling galaxy isophotes, we extract the azimuthally averaged surface brightness profiles in four optical bands. We also derive g − i colour profiles, and relevant structural parameters like total magnitude and effective radius. For ten of the galaxies in this sample, we observe a clear discontinuity in their typical exponential surface brightness profiles, derive their “break radius”, and classify their disc-breaks into Type II (down-bending) or Type III (up-bending).

Results. We find that Type II galaxies have bluer average (g − i) colour in their outer discs while Type III galaxies are redder. The break radius increases with stellar mass and molecular gas mass while it decreases with molecular gas-fractions. The inner and outer scale-lengths increase monotonically with absolute magnitude, as found in other works. For galaxies with CO(1-0) measurements, there is no detected cold gas beyond the break radius (within the uncertainties). In the context of morphological segregation of LTGs in clusters, we also find that, in Fornax, galaxies with morphological type 5 <  T ≤ 9 (∼60% of the sample) are located beyond the high-density, ETG-dominated regions, however there is no correlation between T and the disc-break type. We do not find any correlation between the average (g − i) colours and cluster-centric distance, but the colour-magnitude relation holds true.

Conclusions. The main results of this work suggest that the disc-breaks of LTGs inside the virial radius of the Fornax cluster seem to have arisen through a variety of mechanisms (e.g. ram-pressure stripping, tidal disruption), which is evident in their outer-disc colours and the absence of molecular gas beyond their break radius in some cases. This can result in a variety of stellar populations inside and outside the break radii.
Heating and cooling vehicle seat via air conditioner coils
Authors: ATES Ali , CANLI Eyub
Published: June 2019

A real vehicle seat was modified in order to locate evaporator coils extended from a vehicle air conditioner system just beneath the back and cushion surfaces. The seat back and cushion surface temperatures were measured by several thermocouples. Air conditioner system was operated in heat pump and cooling modes for different compressor speeds. After steady operation of the air conditioner was attained, a live manikin sat to the seat and remained in sitting position for five minutes. The temperatures were recorded during the existence of the manikin and they were recorded for an additional five minutes after the manikin left the seat. The coils embedded under the seat surfaces were made of flexible hoses for the sake of usage due to the shape changing seat surfaces under the load of the manikin weight. Coils were in parallel configuration by the help of a distributer and collector. The temperatures of the seat surfaces were evaluated in respect of the thermal comfort and feasibility of the application. Air conditioner system was also monitored in respect of the COP and energy consumption values. At the instance of sitting, the transient response of the system is very significant due to the weight of the live manikin. However it settles quickly. Cooling was observed to be more realizable while heating seat surfaces had problems due to flow blockage. There were no significant discomfort issues due to the seat surface temperatures and the existence of the coils. The surface temperatures of the seat back exhibited differences from the seat cushion although the formations were same. The orientation of the coils and the weight of the passenger were concluded to be the reason for that. COP was found to be changing between 3 and 3.56 for cooling mode while the highest amount was found for 600 rev/min compressor speed in cooling operation. Heat pump operation had relatively higher COP values ranging between 3.31-3.64. 700 rev/min compressor speed gave the 3.64 COP value for heat pump operation. The difference between COP values of the working modes was concluded to be due to the seat coils and their effect on the additional pumping work. The potential of the application and possible field of studies were evaluated according to the conducted tests and the survey about the topic.
Methodology of using the Adjoint solver optimization tool during flow in the intercooler filling line to minimize pressure drop
Authors: Horová Veronika , Bojko Marian , Dobeš Josef
Published: June 2019

The paper deals with numerical modelling of the flow in the intercooler filling line by Adjoint solver to minimize pressure loss. The ANSYS Fluent software was used for the calculations. The basic flow calculation was performed in the first phase. Then the mathematical model with Adjoint solver optimization tool was defined. The numerical calculation was unstable and did not lead to a convergent solution, because of creation of vortexes. The mathematical model was simplified in the second phase. To suppress instabilities and vortices a dynamic viscosity of coolant was adjusted. The pressure gradients between inlet and outlet for unmodified geometry and for modified geometry were evaluated. The final evaluations of pressure drop changes were implemented for modified geometry with original dynamic viscosity of the coolant.
Preliminary computational study of turbulent flow in the boundary layer of the suction side of an inclined plate
Authors: Hurda Lukáš , Matas Richard
Published: June 2019

A turbulent flow behind a simple thin planar air foil with rounded edges at moderate angle of attack is studied. Reynolds number is about 65 000. First results of CFD analysis are presented, which will be validated with PIV measurements made by Institute of Thermomechanics of the Czech academy of Sciences. All the work is carried out to support the “New theory of flight” presented by Hoffman and Johnson [1]. Large eddy simulation is employed to verify the existence of streamwise vorticial structures and their description. The 3D transient simulation provides more information than the data from a set of PIV measurement planes and it offers also finer time resolution.
Pressure evaluation during dam break using weakly compressible SPH
Authors: Jančík Petr , Hyhlík Tomáš
Published: June 2019

This paper presents a solution of a dam break problem in two dimensions obtained with smoothed particle hydrodynamics (SPH) method. The main focus is on pressure evaluation during the impact on the wall. The used numerical method and the way of pressure evaluation are described in detail. The numerical results of the kinematics and dynamics of the flow are compared with experimental data from the literature. The abilities and limitations of the used methods are discussed.
Vorticity in the turbulent flow above variously rough surfaces
Authors: Kellnerová Radka , Jurčáková Klára , Procházka Pavel , Uruba Václav
Published: June 2019

Highly turbulent flows above variously rough surfaces were investigated by means of Time-Resolved Particle Image Velocimetry in a wind tunnel. Proper Orthogonal Decomposition was applied to both velocity and vorticity data in order to detect dominant features in the flow based on turbulent kinetic energy and enstrophy, respectively. While both the shape and location of the POD patterns exhibited similarity with other studies, a systematic inconsistency in terms of contribution from the features to the enstrophy between the previously published papers and our results were found.
Capability of air exchange rate to predict ventilation of three-dimensional street canyons
Authors: Kluková Zuzana , Nosek Štěpán , Fuka Vladimír
Published: June 2019

As most of the world’s population lives in cities, it is critical to understand dispersion processes of pollutants in urban areas. This study focuses on so called air exchange rate (ACH) index, which is frequently used by numerical studies to determine ventilation of street canyons without a simulation of a pollution source. These studies applied the ACH on idealised 2D street canyons, where the ventilation acts only through the one opening roof top. There are two pertinent questions: i) is the ACH really capable to predict the ventilation of a street canyon without knowing of a pollutant source; and ii) how much the ACH differs between 2D and 3D street canyons? To answer these questions, we performed large-eddy simulations of pollution of complex 3D street canyons from ground-level line sources. We computed ACHs and spatially-average concentrations for three different street canyons and compared these quantities with those from previous studies. Results clearly demonstrate that these quantities strongly depend not only on street-canyon geometry but also on geometry of surrounding buildings. It is also shown that 2D canyon gives unrealistic result for retention of pollutant within an urban street canyon. The ACH might lead to significant underestimation of the street-canyon ventilation if a source would be outside the canyon.
Transformations, threats and the bond of chlorine in the processes of burning the wastes
Authors: Król Danuta , Poskrobko Sławomir
Published: June 2019

The aim of the study was to present the possibility of reducing the emission of HCl to the atmosphere and the possibility of limiting the formation of PCDD/F in the technologies of incineration of waste fuels and incineration of animal waste. Waste fuel and animal biomass were burned in a two-stage system i.e.: Io-gasification and IIo-combustion of gas products of gasification. As part of the implementation, the reduction of HCl emissions to air was investigated when Ca(OH)2was added as an additive to the fuel from waste. Ca(OH)2bonded HCl releasing into the gas space in the combustion process. HCl binding in the combustion chamber not only limited its emission to the atmosphere. Its elimination also limited the possibility of creating PCDD/F. In case of animal waste, HCl was captured with CaO produced from the decomposition of bone material (hydroxyapatite). The efficiency of this process was low. It was thus necessary to remove it in the built-in exhaust purification plant.
The simulation of the atmospheric flow with emmisions
Authors: Kyncl Martin , Pelant Jaroslav
Published: June 2019

The aim of this work is to simulate the flow of the passive gas mixture and estimate the resulting concentration of the potentionally dangerous pollutant emmisions. We assume non-stationary compressible gas flow in the gravitational field described by the system of the RANS equations, equipped with the equation for the concentration of additional specie. Due to gravitational force eﬀect we modify the boundary conditions and data resulting admissible situations. The real simulations of the atmospheric flow require the use of the wall functions for the boundary condition simulating the ground surface with given roughness. We show the modification of such wall functions. The computational results are obtained with the own-developed CFD code for the compressible turbulent mixture flow. The originality of this work lies with the special handling of the boundary conditions, and own computational code.
Static and dynamic characteristics of proportional directional valve
Authors: Ledvoň Marian , Hružík Lumír , Bureček Adam , Vašina Martin
Published: June 2019

This article deals with experimental measurement and numerical simulation of static and dynamic characteristics of the proportional directional valve. The characteristics of the proportional directional valve are measured on experimental equipment. At the static characteristic, pressure drop on the proportional directional valve, flow and oil temperature are measured on this equipment. The spool position is measured to determine of the dynamic characteristic of the proportional directional valve. Mathematical model of the proportional directional valve is created using Matlab SimScape Fluids software and is complemented by a mathematical model of the experimental equipment. The simulation results on the mathematical model are compared with the results of the experimental measurement.
Dielectrophoretic classification of fibres: principles and application to glass fibres suspended in air
Authors: Lizal Frantisek , Maly Milan , Elcner Jakub , Farkas Arpad , Pech Ondrej , Misik Ondrej , Jedelsky Jan , Jicha Miroslav
Published: June 2019

Particles exposed to an electric field experience forces that influence their movement. This effect can be used for filtration of air, or for size classification of aerosols. The motion of charged particles in a non-uniform electric field is called electrophoresis. Two processes are involved in this phenomenon: 1) charging of particles and 2) electrical mobility separation. If fibres are exposed to electrophoresis, they are separated on the basis of two parameters: diameter and length. Regrettably, as naturally occurring fibres are polydisperse both in diameter and length, the electrophoresis is not very efficient in length classification. In contrast, dielectrophoresis is the motion of electrically neutral particles in a non-uniform electric field due to the induced charge separation within the particles. As deposition velocity of fibres induced by dielectrophoretic force strongly depends on length and only weakly on diameter, it can be used for efficient length classification.

Principles of length classification of conducting and non-conducting fibres are presented together with design of a fibre classifier. Lastly, images of motion of fibres recorded by high-speed camera are depicted.
Conditions at interfaces of layered flow with intense bed load transport
Authors: Matoušek Václav , Krupička Jan , Picek Tomáš , Zrostlík Štěpán
Published: June 2019

Intense bed load transport in open channel flow is typically associated with a layered structure of the flow, in which individual layers exhibit different mechanisms of support and friction of transported sediment grains. In the lowermost layer adjacent to the channel bed, the grains slide over each other and maintain virtually permanent contact. In the uppermost layer below the water surface, typically no grains are transported. In the central layer, the grains collide with each other producing typical distributions of granular concentration and velocity across the collisional layer. Mathematical models describing the layered flow with intense bed load (as models based on kinetic theory of granular flows) consider flow conditions at interfaces of the individual layers in their flow predictions. Usually, experimental verification of interfacial predictions is lacking. We exploit results of our new experiments with plastic cylindrical sediment to identify a variation of the conditions at the interfaces (local interfacial granular concentrations and velocities) with varying flow discharge, depth and slope in a laboratory tilting flume. The experimental results include local granular concentration using an improved laser stripe method. The experiments are compared with predictions using our kinetic-theory based transport model with the aim to evaluate a match for experimentally-determined and model-predicted interfacial parameters.