bluuebunny/crossref_metadata_2025 huggingface dataset:
Extending the Functionality of Marine-origin Polysaccharides Through Chemical Modification for Biomedical Applications
Authors: Rodrigues J. M. M. , Castanheira E. J. , Costa D. C. S. , Rocha D. H. A. , Borges J. , Mano J. F.
Published: June 2021

Natural polysaccharides are a major class of biomacromolecules with a high degree of biocompatibility, biodegradability, and ability to mimic the natural extracellular matrix (ECM) microenvironment and, therefore, have been receiving increasing attention. Polysaccharides often exhibit interesting and advantageous properties, including bioactivity, different functional groups, and bioadhesive properties, as well as easiness in being tailored to different applications by chemical modification. Their bioactivity depends on the chemical structure, monosaccharide composition, and spatial conformation. The chemical modification of polysaccharides and the introduction of specific functional groups significantly increase their structural diversity, by promoting or adding new (bio)functionalities. Polysaccharide-based biomaterials are an emerging class in multiple biomedical applications, including in tissue engineering and regenerative medicine (TERM) and drug delivery. Most of the polysaccharides used in biomedical applications derive from natural sources, mainly from marine environments, particularly, alginate and chitin (CH). This chapter focuses on the recent progress in the field of chemical modification of marine-origin polysaccharides, including i) chitosan (CHT), ii) hyaluronic acid (HA), iii) alginate (ALG), iv) glycosaminoglycans (GAGs) and sulfated glycans, v) laminarin (LAM), and vi) agarose, for the development of biomaterials for biomedical applications.
Recent Advances in the Design of Surface-initiated Polymer Brushes for Biomedical Applications
Authors: Qu F. , Raynold A. M. , Gautrot J. E.
Published: June 2021

Polymer brushes allow the surface functionalisation of a wide range of substrates with polymer chains with controlled chemistry, therefore enabling the precise control of physico-chemical properties of corresponding interfaces. Such level of control has clear implications for the design of biomaterials, implants, scaffolds and devices in the biomedical field. For example, this enables the regulation of protein adsorption and the biofunctionalisation of biomaterials to promote cell adhesion, regulate signalling, confer bactericidal properties or targeting of specific cells or tissues. In addition, the temperature- and salt-responsive properties of some polymer brushes enable the capture and controlled release of therapeutics, including for gene delivery applications. Importantly, such control of surface chemistry can be achieved independently of the inherent properties and chemistry of the core substrate, whether it is an implant, scaffold or nanoparticle. Indeed, synthetic approaches to the tethering of polymer brushes are particularly versatile. In this chapter, we review recent progress in the design of polymer brushes in the biomedical field.
Long range interactions and related carbon–carbon bond reconstruction between interior and surface defects in nanodiamonds
Authors: D. W. Boukhvalov , Osipov V. Yu. , Takai K.
Published: June 2021

Interactions between interior substitutional nitrogen defects and surface unsaturated dangling bonds in synthetic nanodiamonds of ∼25 nm size were explored experimentally and theoretically.
Isocratic reporter-exclusion immunoassay using restricted-access adsorbents
Authors: Dhamane Sagar , Patil Ujwal , Smith Maxwell , Adhikari Meena , Nazem Ahmad , Conrad Jacinta C. , Kourentzi Katerina , Willson Richard C.
Published: June 2021

We introduce analyte-dependent exclusion of reporter reagents from restricted-access adsorbents as the basis of an isocratic reporter-exclusion immunoassay for viruses, proteins, and other analytes.
Development of a novel radiotheranostic platform with a DOTA-based trifunctional chelating agent
Authors: Nakashima Kazuma , Iikuni Shimpei , Watanabe Hiroyuki , Ono Masahiro
Published: June 2021

We designed and synthesized a novel DOTA-based trifunctional agent containing a click ligation moiety and a pharmacological modifier for the development of a radiotheranostic platform.
Mimicking reactive high-valent diiron-μ2-oxo intermediates of nonheme enzymes by an iron tetracarbene complex
Authors: Schlachta Tim P. , Anneser Markus R. , Schlagintweit Jonas F. , Jakob Christian H. G. , Hintermeier Carolin , Böth Alexander D. , Haslinger Stefan , Reich Robert M. , Kühn Fritz E.
Published: June 2021

The first diiron(iii,iv)-μ2-oxo tetracarbene complex is isolated and characterized, representing a scarce mimic of reactive high-valent diiron-μ2-oxo intermediates of nonheme enzymes.
Chalcogen-atom abstraction reactions of a Di-iron imidophosphorane complex
Authors: Aguirre Quintana Luis M. , Yang Yan , Ramanathan Arun , Jiang Ningxin , Bacsa John , Maron Laurent , La Pierre Henry S.
Published: June 2021

The synthesis of a diiron tris(piperidinyl)imidophosphorane complex and its reactions with N2O, S8, and Se0 are reported.
Nonenzymatic catalytic assembly of valency-controlled DNA architectures for nanoparticles and live cell assembly
Authors: Wang Jing , Ma Jia-Yi , Wang Dong-Xia , Liu Bo , Tang An-Na , Kong De-Ming
Published: June 2021

Using tetrahedral DNA nanostructures as building blocks, valency-controlled DNA architectures were assembled in a bottom-up manner.
Retraction: Chemical synthesis and antigenic activity of a phosphatidylinositol mannoside epitope from Mycobacterium tuberculosis
Authors: Zhao Shi-Yuan , Li Na , Luo Wan-Yue , Zhang Nan-Nan , Zhou Rong-Ye , Li Chen-Yu , Wang Jin
Published: June 2021

Retraction of ‘Chemical synthesis and antigenic activity of a phosphatidylinositol mannoside epitope from Mycobacterium tuberculosis’ by Shi-Yuan Zhao et al., Chem. Commun., 2020, 56, 14067–14070, DOI: 10.1039/D0CC05573E.
Elastic deformability and luminescence of crystals of polyhalogenated platinum(ii)–bipyridine complexes
Authors: Yoshida Masaki , Makino Yusuke , Sasaki Toshiyuki , Sakamoto Shunichi , Takamizawa Satoshi , Kobayashi Atsushi , Kato Masako
Published: June 2021

A series of polyhalogenated platinum(ii)–bipyridine complexes showed solvent-of-crystallisation-dependent elastic flexibility and luminescence.
A theoretical insight into the formation of chalcogen bonding (ChB) interactions involving coordinated DMSO molecules as σ-hole donors and benzoate groups as σ-hole acceptors in a dinuclear copper(ii) complex
Authors: Thakur Snehasish , Gomila Rosa M. , Frontera Antonio , Chattopadhyay Shouvik
Published: June 2021

The formation of two chalcogen bonding (ChB) interactions involving coordinated DMSO molecules as σ-hole donors and the O atoms of carboxylate groups as acceptors in a dimeric copper(ii) complex has been described.
3D supramolecular chiral crystal structures of radical anion salts of (−)-NDI-Δ and possible magnetic phase diagrams
Authors: Mizuno Asato , Shuku Yoshiaki , Suizu Rie , Tsuchiizu Masahisa , Awaga Kunio
Published: June 2021

Supramolecular chiral crystals of radical anion salts of a triangular chiral electron acceptor, (−)-naphthalene diimide (NDI)-Δ, were electrochemically grown in propylene carbonate electrolyte solutions in the presence of cyclic multidentate ligands.
The structure of isolated thalidomide as reference for its chirality-dependent biological activity: a laser-ablation rotational study
Authors: Blanco Susana , Macario Alberto , López Juan Carlos
Published: June 2021

Using the gas-phase structure of laser-ablated thalidomide as reference confirms the high distortion of the (R)-enantiomer bound to cereblon in agreement with the enhanced teratogenicity of the (S) enantiomer.
Molecular oxygen-mediated oxygenation reactions involving radicals
Authors: Tang Conghui , Qiu Xu , Cheng Zengrui , Jiao Ning
Published: June 2021

Molecular oxygen as a green, inexpensive oxidant and oxygen source has displayed lots of advantages compared to other oxidants. This review introduces the recent advances of radical processes in molecular oxygen-mediated oxygenation reactions.
Application of ReOx/TiO2 catalysts with excellent SO2 tolerance for the selective catalytic reduction of NOx by NH3
Authors: Yu Yanke , Yi Xianfang , Zhang Jiali , Tong Zhaojian , Chen Changwei , Ma Mudi , He Chi , Wang Jinxiu , Chen Jinsheng , Chen Bingbing
Published: June 2021

The adsorption of SO2 on ReOx/TiO2 catalysts was rather weak; thus, ReOx/TiO2 catalysts exhibited excellent SO2 tolerance in the NH3-SCR reaction.
A surface-alkalinized Ti3C2MXene as an efficient cocatalyst for enhanced photocatalytic CO2reduction over ZnO
Authors: Li Junyue , Wang Ziyi , Chen Huayu , Zhang Qiqi , Hu Huilin , Liu Lequan , Ye Jinhua , Wang Defa
Published: June 2021

Surface alkalinized Ti3C2MXene with high electronic conductivity and CO2adsorption/activation ability is used as an efficient co-catalyst for boosting the photocatalytic activity of ZnO for CO2reduction into hydrocarbon solar fuels.
Understanding nanoplastic toxicity and their interaction with engineered cationic nanopolymers in microalgae by physiological and proteomic approaches
Authors: Tamayo-Belda Miguel , Vargas-Guerrero Juan José , Martín-Betancor Keila , Pulido-Reyes Gerardo , González-Pleiter Miguel , Leganés Francisco , Rosal Roberto , Fernández-Piñas Francisca
Published: June 2021

This study reveals novel mechanisms and potential biomarkers of nanopolymer toxicity (polystyrene nanoplastics and PAMAM dendrimers) singly and in combination in a relevant aquatic primary producer, essential for sustaining the food chain.
The alleviating effect and mechanism of Bilobalide on ulcerative colitis
Authors: Zhang Haolong , Wang Yan , Su Yingchun , Fang Xuedong , Guo Wenjin
Published: June 2021

Bilobalide alleviates ulcerative colitis by inhibiting inflammatory response, protecting the intestinal epithelial barrier, and improving the composition of intestinal flora.
Quantifying nanotherapeutic penetration using a hydrogel-based microsystem as a new 3D in vitro platform
Authors: Goodarzi Saba , Prunet Audrey , Rossetti Fabien , Bort Guillaume , Tillement Olivier , Porcel Erika , Lacombe Sandrine , Wu Ting-Di , Guerquin-Kern Jean-Luc , Delanoë-Ayari Hélène , Lux François , Rivière Charlotte
Published: June 2021

We present a simple yet highly flexible 3D-model microsystem for the investigation of nanotherapeutics transport, ahead of in vivo studies, allowing to follow the penetration and distribution of nanoparticles within spheroids over space and time.
Surface-enhanced Raman scattering-based molecular encoding with gold nanostars for anticounterfeiting applications
Authors: Huo Yifeng , Curry Samantha , Trowbridge Andrew , Xu Xurong , Jiang Chaoyang
Published: June 2021

Star-shaped gold nanoparticles with encoded molecular information can be used in security inks for anticounterfeiting applications.
Engineered ε-decalactone lipomers bypass the liver to selectively in vivo deliver mRNA to the lungs without targeting ligands
Authors: Abd Elwakil Mahmoud M. , Gao Tianle , Isono Takuya , Sato Yusuke , Elewa Yaser H. A. , Satoh Toshifumi , Harashima Hideyoshi
Published: June 2021

Engineered lipomers coming from sustainable sources can efficiently bypass the liver to deliver a genetic message to the lungs after systemic administration without targeting ligands.
A thermally insulating vermiculite nanosheet–epoxy nanocomposite paint as a fire-resistant wood coating
Authors: Sethurajaperumal Abimannan , Manohar Anagha , Banerjee Arghya , Varrla Eswaraiah , Wang Hao , Ostrikov Kostya (Ken)
Published: June 2021

A nanocomposite made of exfoliated vermiculite nanosheets and epoxy is developed for extinguishing fire and protecting wood from fire degradation.
Ultrafine Co0.85Se nanocrystals dispersed in 3D CNT network as a flexible free-standing anode for high-performance lithium-ion battery
Authors: Li Huapeng , Wei Tongye , Huang Shouji , Xu Guobao , Liu Xiong , Tian Jiao , Yang Liwen , Cao Juexian , Wei Xiaolin
Published: June 2021

A flexible free-standing film electrode with high pseudocapacitive contribution and strengthened cyclic stability was successfully prepared.
Modulating the ferroelectric performance by altering halogen anions in the crystals of tetranuclear copper-clusters
Authors: Liu Meiying , Liang Jingjing , Liu Zhiliang
Published: June 2021

The ferroelectric performance of tetranuclear copper clusters can be modulated by altering the free halogen anions existing in the crystal structure.
High-throughput thermal plasma synthesis of FexCo1−x nano-chained particles with unusually high permeability and their electromagnetic wave absorption properties at high frequency (1–26 GHz)
Authors: Jang Min-Sun , Chang Mi Se , Kwon Young-tae , Yang Sangsun , Gwak Jina , Kwon Suk Jin , Lee Joonsik , Song Kyung , Park Chong Rae , Lee Sang Bok , Park Byeongjin , Jeong Jae Won
Published: June 2021

Novel 1-D nano-chained FeCo particles with unusually-high permeability are prepared by a thermal plasma synthesis and an electromagnetic wave absorber with exceptionally low reflection loss in the high-frequency regime (1–26 GHz) are demonstrated.
Synthesis, biological evaluation and molecular modeling of urea-containing MraY inhibitors
Authors: Oliver Martin , Le Corre Laurent , Poinsot Mélanie , Corio Alessandra , Madegard Léa , Bosco Michaël , Amoroso Ana , Joris Bernard , Auger Rodolphe , Touzé Thierry , Bouhss Ahmed , Calvet-Vitale Sandrine , Gravier-Pelletier Christine
Published: June 2021

The synthesis and biological evaluation of a panel of 11 aminoribosyl uridines substituted by a 5′-methylene-urea are described. Molecular modeling studies were performed to rationalize their activity against the bacterial transferase MraY.
Cycloaddition of cyclopropanes for the elaboration of medium-sized carbocycles
Authors: Caillé Julien , Robiette Raphaël
Published: June 2021

In this review, we describe the important advances in cycloaddition methodologies involving cyclopropanes for the construction of seven-, eight- and nine-membered carbocycles, with a particular attention to the variety of the mechanisms involved.
Synthesis of trisubstituted hydrazine via MnO2-promoted oxidative coupling of N,N-disubstituted hydrazine and boronic ester
Authors: Wang Jiaoyang , Wang Danfeng , Tong Xiaofeng
Published: June 2021

A MnO2-promoted oxidative coupling process between N,N-disubstituted hydrazine and boronic ester is reported.
Controllable chemoselectivity in the reaction of 2H-indazoles with alcohols under visible-light irradiation: synthesis of C3-alkoxylated 2H-indazoles and ortho-alkoxycarbonylated azobenzenes
Authors: Sun Mingli , Li Laiqiang , Wang Lei , Huo Jie , Sun Manman , Li Pinhua
Published: June 2021

A high chemoselectivity in the visible-light-induced reaction of 2H-indazoles with alcohols controlled by the reaction atmosphere was achieved, providing C3-alkoxylated 2H-indazoles and ortho-alkoxycarbonylated azobenzenes.
Copper-catalyzed 1,6-conjugate addition of para-quinone methides with diborylmethane
Authors: Li Xin , Gao Guoliang , He Songtao , Song Qiuling
Published: June 2021

Presented herein is the first 1,6-conjugate addition of diborylmethane. This reaction features high yields, mild reaction conditions, and broad functional group compatibilities.
Visible-light-induced iodine-anion-catalyzed decarboxylative/deaminative C–H alkylation of enamides
Authors: Wang Jia-Xin , Wang Ya-Ting , Zhang Hao , Fu Ming-Chen
Published: June 2021

An efficient method for photo-induced iodine-anion-catalyzed C–H alkylation of enamides has been developed. Redox-active esters and Katritzky salts of amino acids are amenable, successfully delivering various functionalized enamides.
Current perspectives on supercharging reagents in electrospray ionization mass spectrometry
Authors: Abaye Daniel A. , Agbo Irene A. , Nielsen Birthe V.
Published: June 2021

A simple illustration of the positive electrospray ionization (ESI) environment.
Au–Ag core–shell composite nanoparticles as a selective and sensitive plasmonic chemical probe for l-cysteine detection in Lens culinaris (lentils)
Authors: Saha Anushree , Khalkho Beeta Rani , Deb Manas Kanti
Published: June 2021

The present work reported is a simple and selective method for the colorimetrical detection of l-cysteine in Lens culinaris (or lentils) using Au–Ag core–shell (Au core Ag shell) composite nanoparticles as a chemical probe.
Detecting hypoxia in vitro using 18F-pretargeted IEDDA “click” chemistry in live cells
Authors: Allott Louis , Chen Cen , Braga Marta , Leung Sau Fung Jacob , Wang Ning , Barnes Chris , Brickute Diana , Carroll Laurence , Aboagye Eric O.
Published: June 2021

Bioorthogonal IEDDA “click” can interrogate intracellular hypoxia using a radioactive reporter molecule.
Improved efficiency and air stability of two-dimensional p-i-n inverted perovskite solar cells by Cs doping
Authors: Hsieh Tzu-Chien , Shih Chung-Yueh , Chao Yu-Chiang , Cheng I-Chun , Chen Jian-Zhang
Published: June 2021

Improved efficiency and air stability of two-dimensional p-i-n inverted perovskite solar cells by 10% Cs doping.
A Cu(ii)-MOF based on a propargyl carbamate-functionalized isophthalate ligand
Authors: Cassani Maria Cristina , Gambassi Francesca , Ballarin Barbara , Nanni Daniele , Ragazzini Ilaria , Barreca Davide , Maccato Chiara , Guagliardi Antonietta , Masciocchi Norberto , Kovtun Alessandro , Rubini Katia , Boanini Elisa
Published: June 2021

A copper-based metal–organic framework with a novel 5-substituted isophthalic linker bearing a propargyl carbamate group protruding from the material surface.
Different view of solvent effect on the synthesis methods of zeolitic imidazolate framework-8 to tuning the crystal structure and properties
Authors: Akhundzadeh Tezerjani Arezoo , Halladj Rouein , Askari Sima
Published: June 2021

One of the important aims in the synthesis of zeolite imidazolate framework-8 is to prepare crystals with predictable structures and valuable properties.
Tobacco mosaic virus for the targeted delivery of drugs to cells expressing prostate-specific membrane antigen
Authors: Shukla Sourabh , Marks Isaac , Church Derek , Chan Soo-Khim , Pokorski Jonathan K. , Steinmetz Nicole F.
Published: June 2021

Prostate-specific membrane antigen (PSMA) is a membrane-bound protein that is preferentially expressed in the prostate gland and induced in many prostate cancers, making it an important target for new diagnostics and therapeutics.
Precursor accumulation on nanocarbons for the synthesis of LaCoO3 nanoparticles as electrocatalysts for oxygen evolution reaction
Authors: Sakamaki Aoi , Ogihara Hitoshi , Yoshida-Hirahara Miru , Kurokawa Hideki
Published: June 2021

A simple synthetic process for LaCoO3 nanoparticles based on the accumulation of precursors on nanocarbon supports was presented. The LaCoO3 nanoparticles showed excellent OER activity owing to their high surface area and perovskite structure.
Cell–cell interactions via non-covalent click chemistry
Authors: Plumet Chad , Mohamed Achmet Said , Vendeuvre Tanguy , Renoux Brigitte , Clarhaut Jonathan , Papot Sébastien
Published: June 2021

We designed complementary artificial markers that were introduced on the surface of cells previously modified by metabolic glycoengineering. These recognition markers enable unnatural cell–cell adhesion through non-covalent click chemistry.
Photoredox-catalyzed aminofluorosulfonylation of unactivated olefins
Authors: Zhong Tao , Yi Ji-Tao , Chen Zhi-Da , Zhuang Quan-Can , Li Yong-Zhao , Lu Gui , Weng Jiang
Published: June 2021

A three-component aminofluorosulfonylation of unactivated alkenes has been developed by merging photocatalytic PCET with radical relay processes, affording various aliphatic sulfonyl fluorides featuring medicinally privileged heterocyclic scaffolds.
Photoinduced 1,2-dicarbofunctionalization of alkenes with organotrifluoroborate nucleophilesviaradical/polar crossover
Authors: Cabrera-Afonso María Jesús , Sookezian Anasheh , Badir Shorouk O. , El Khatib Mirna , Molander Gary A.
Published: June 2021

Alkene 1,2-dicarbofunctionalizations increase molecular complexity. Herein, the carboallylation, carboalkenylation, carboalkynylation, and carboarylation of olefins is accomplished through radical/polar crossover with organotrifluoroborates.
PANI/g-C3N4 composite over ZnCo2O4/Ni-foam, a bi-functional electrode as a supercapacitor and electrochemical glucose sensor
Authors: Kumar Sanath , Fu Yen-Pei
Published: June 2021

The ternary composite ZnCo2O4/g-C3N4/PANI is a potential and promising electrode material for supercapacitor and electrochemical glucose sensor applications.
Radiation curable polysiloxane: synthesis to applications
Authors: T. Muthamil Selvan , Mondal Titash
Published: June 2021

Radiation curable polysiloxanes is a class of specialty polymer that can be cured by UV, electron beam and gamma radiation. These polymers find applications in different segments like healthcare, automotive, aerospace,etc.
Soluble porous carbon cage-encapsulated highly active metal nanoparticle catalysts
Authors: Liu Hangyu , Chen Liyu , Hou Chun-Chao , Wei Yong-Sheng , Xu Qiang
Published: June 2021

Metal nanoparticles are encapsulated within soluble porous carbon cages by a silica-shelled metal–organic framework pyrolysis approach. The catalyst shows high catalytic activities for hydrogen peroxide decomposition and ammonia borane hydrolysis.
Environmentally friendly thermoelectric sulphide Cu2ZnSnS4 single crystals achieving a 1.6 dimensionless figure of merit ZT
Authors: Nagaoka Akira , Yoshino Kenji , Masuda Taizo , Sparks Taylor D. , Scarpulla Michael A. , Nishioka Kensuke
Published: June 2021

A record high dimensionless figure of merit ZT = 1.6 has been achieved in totally environmentally benign Cu2ZnSnS4 (CZTS) single crystal.
A facile and broadly applicable CdBr2-passivating strategy for halide migration-inhibiting perovskite films and high-performance solar cells
Authors: Sun Xiangnan , Li Xitao , Li Haotong , Li Yao , Li Siqi , Zheng Yan-Zhen , Tao Xia
Published: June 2021

A universally-applicable strategy to reduce the defects in various compositional perovskite films (MAPbI3, Cs0.15FA0.85PbI3, and CsPbI2Br) by a simple CdBr2 post-treatment.
Regulating glucose metabolism using nanomedicines for cancer therapy
Authors: Tang Ming , Ren Xiangling , Fu Changhui , Ding Minghui , Meng Xianwei
Published: June 2021

The application of glucose metabolism regulation with nanomedicine in cancer therapy.
3D bioprinting of dual-crosslinked nanocellulose hydrogels for tissue engineering applications
Authors: Monfared Marzieh , Mawad Damia , Rnjak-Kovacina Jelena , Stenzel Martina H.
Published: June 2021

Dual crosslinked PEG-CNFs inks, designedviaa two-step strategy based on ionic interaction and subsequent visible light photoreaction, can be used for 3D printing of bioscaffolds with tailored viscoelastic and mechanical properties.
Heterovalent cations substitution to design asymmetric chalcogenides with promising nonlinear optical performances
Authors: Li Ya-Nan , Chen Zi-Xia , Yao Wen-Dong , Tang Ru-Ling , Guo Sheng-Ping
Published: June 2021

Two Sn-based chalcogenides BaZnSnQ4 (Q = S, Se) synthesized based on the idea of heterovalent cations co-substitution exhibit good SHG effects and large LIDTs.
A data‐driven network optimisation approach to coordinated control of distributed photovoltaic systems and smart buildings in distribution systems
Authors: Bai Linquan , Xue Yaosuo , Xu Guanglin , Dong Jin , Olama Mohammed M. , Kuruganti Teja
Published: June 2021

The increasing integration of distributed energy resources, including demand‐side resources and distributed photovoltaics (PVs), into distribution systems has resulted in more complicated power system operation. A data‐driven network optimisation approach is proposed to coordinate the control of distributed PVs and smart buildings in distribution networks considering the uncertainties of solar power, outdoor temperature and heat gain associated with building thermal dynamics. These uncertain parameters have a significant impact on the operation and control of distributed PVs and smart buildings, bringing challenges to the distribution system operation. In the proposed data‐driven distributionally robust optimisation (DRO) approach, the Wasserstein ball is used to construct an ambiguity set for the uncertain parameters, which does not require the probability distributions to be known. Furthermore, a conditional value‐at‐risk is incorporated into the Wasserstein‐based DRO model and converted into a computationally tractable mixed‐integer convex optimisation problem. Benchmarked with robust optimisation and chance‐constrained programming, the proposed data‐driven model can give a less conservative robust solution.
Track Segment Association via track graph representation learning
Authors: Xiong Wei , Xu Pingliang , Cui Yaqi , Xiong Zhenyu , Gu Xiangqi , Lv Yafei
Published: June 2021

Traditional Track Segment Association (TSA) methods used track position vectors or other track information to get association results. However, simply extracting the track position information to form track vectors will lead to the loss of irregular structure information. To solve this problem, a Track Graph Representation Association (TGRA) method is proposed. Through node‐level local track point embedding and graph‐level track graph embedding, representations of track segments can be obtained and irregular structure information can be retained simultaneously. Then, by the constraint of loss function, track segments belonging to the same target become closer, track segments belonging to different targets become farther in representation space. Finally, the nearest neighbour embedding in representation space is picked as associated tracks. Simulation results demonstrate that TGRA has good adaptability and anti‐noise ability, and it can outperform other TSA methods in both quality and efficiency. Compared with the best performance, the average true association rate of TGRA can be increased by 2.8% in short interrupt intervals and 1.3% in long interrupt intervals, respectively.
New constraints on the magnetic field in cosmic web filaments
Authors: Locatelli N. , Vazza F. , Bonafede A. , Banfi S. , Bernardi G. , Gheller C. , Botteon A. , Shimwell T.
Published: June 2021

Strong accretion shocks are expected to illuminate the warm–hot intergalactic medium encompassed by the filaments of the cosmic web, through synchrotron radio emission. Given their high sensitivity, large low-frequency radio facilities may already be able to detect signatures of this extended radio emission from the region between two close and massive galaxy clusters. In this work we exploit the non-detection of such diffuse emission by deep observations of two pairs of relatively close (≃10 Mpc) and massive (M500 ≥ 1014 M⊙) galaxy clusters using the LOw-Frequency ARray. By combining the results from the two putative inter-cluster filaments, we derive new independent constraints on the median strength of intergalactic magnetic fields: B10 Mpc < 2.5 × 102 nG (95% confidence level). Based on cosmological simulations and assuming a primordial origin of the B-fields, these estimates can be used to limit the amplitude of primordial seed magnetic fields: B0 ≤ 10 nG. We recommend the observation of similar cluster pairs as a powerful tool to set tight constraints on the amplitude of extragalactic magnetic fields.
Kinetic electrostatic waves and their association with current structures in the solar wind
Authors: Graham D. B. , Khotyaintsev Yu. V. , Vaivads A. , Edberg N. J. T. , Eriksson A. I. , Johansson E. P. G. , Sorriso-Valvo L. , Maksimovic M. , Souček J. , Píša D. , Bale S. D. , Chust T. , Kretzschmar M. , Krasnoselskikh V. , Lorfèvre E. , Plettemeier D. , Steller M. , Štverák Š. , Trávníček P. , Vecchio A. , Horbury T. S. , O’Brien H. , Evans V. , Angelini V.
Published: June 2021

Context.A variety of kinetic electrostatic and electromagnetic waves develop in the solar wind and the relationship between these waves and larger scale structures, such as current sheets and ongoing turbulence, remain a topic of investigation. Similarly, the instabilities producing ion-acoustic waves in the solar wind are still an open question.

Aims.The goals of this paper are to investigate electrostatic Langmuir and ion-acoustic waves in the solar wind at 0.5 AU and determine whether current sheets and associated streaming instabilities can produce the observed waves. The relationship between these waves and currents observed in the solar wind is investigated statistically.

Methods.Solar Orbiter’s Radio and Plasma Waves instrument suite provides high-resolution snapshots of the fluctuating electric field. The Low Frequency Receiver resolves the waveforms of ion-acoustic waves and the Time Domain Sampler resolves the waveforms of both ion-acoustic and Langmuir waves. Using these waveform data, we determine when these waves are observed in relation to current structures in the solar wind, estimated from the background magnetic field.

Results.Langmuir and ion-acoustic waves are frequently observed in the solar wind. Ion-acoustic waves are observed about 1% of the time at 0.5 AU. The waves are more likely to be observed in regions of enhanced currents. However, the waves typically do not occur at current structures themselves. The observed currents in the solar wind are too small to drive instability by the relative drift between single ion and electron populations. When multi-component ion or electron distributions are present, the observed currents may be sufficient for instabilities to occur. Ion beams are the most plausible source of ion-acoustic waves in the solar wind. The spacecraft potential is confirmed to be a reliable probe of the background electron density when comparing the peak frequencies of Langmuir waves with the plasma frequency calculated from the spacecraft potential.
First light observations of the solar wind in the outer corona with the Metis coronagraph
Authors: Romoli M. , Antonucci E. , Andretta V. , Capuano G. E. , Da Deppo V. , De Leo Y. , Downs C. , Fineschi S. , Heinzel P. , Landini F. , Liberatore A. , Naletto G. , Nicolini G. , Pancrazzi M. , Sasso C. , Spadaro D. , Susino R. , Telloni D. , Teriaca L. , Uslenghi M. , Wang Y.-M. , Bemporad A. , Capobianco G. , Casti M. , Fabi M. , Frassati F. , Frassetto F. , Giordano S. , Grimani C. , Jerse G. , Magli E. , Massone G. , Messerotti M. , Moses D. , Pelizzo M.-G. , Romano P. , Schühle U. , Slemer A. , Stangalini M. , Straus T. , Volpicelli C. A. , Zangrilli L. , Zuppella P. , Abbo L. , Auchère F. , Aznar Cuadrado R. , Berlicki A. , Bruno R. , Ciaravella A. , D’Amicis R. , Lamy P. , Lanzafame A. , Malvezzi A. M. , Nicolosi P. , Nisticò G. , Peter H. , Plainaki C. , Poletto L. , Reale F. , Solanki S. K. , Strachan L. , Tondello G. , Tsinganos K. , Velli M. , Ventura R. , Vial J.-C. , Woch J. , Zimbardo G.
Published: June 2021

In this work, we present an investigation of the wind in the solar corona that has been initiated by observations of the resonantly scattered ultraviolet emission of the coronal plasma obtained with UVCS-SOHO, designed to measure the wind outflow speed by applying Doppler dimming diagnostics. Metis on Solar Orbiter complements the UVCS spectroscopic observations that were performed during solar activity cycle 23 by simultaneously imaging the polarized visible light and the H I Lyman-α corona in order to obtain high spatial and temporal resolution maps of the outward velocity of the continuously expanding solar atmosphere. The Metis observations, taken on May 15, 2020, provide the first H I Lyman-α images of the extended corona and the first instantaneous map of the speed of the coronal plasma outflows during the minimum of solar activity and allow us to identify the layer where the slow wind flow is observed. The polarized visible light (580–640 nm) and the ultraviolet H I Lyα (121.6 nm) coronal emissions, obtained with the two Metis channels, were combined in order to measure the dimming of the UV emission relative to a static corona. This effect is caused by the outward motion of the coronal plasma along the direction of incidence of the chromospheric photons on the coronal neutral hydrogen. The plasma outflow velocity was then derived as a function of the measured Doppler dimming. The static corona UV emission was simulated on the basis of the plasma electron density inferred from the polarized visible light. This study leads to the identification, in the velocity maps of the solar corona, of the high-density layer about ±10° wide, centered on the extension of a quiet equatorial streamer present at the east limb – the coronal origin of the heliospheric current sheet – where the slowest wind flows at about 160 ± 18 km s−1 from 4 R⊙ to 6 R⊙. Beyond the boundaries of the high-density layer, the wind velocity rapidly increases, marking the transition between slow and fast wind in the corona.
Resuspension processes in a wide range of particle sizes
Authors: Vidales Ana María , Benito Jesica , Uñac Rodolfo , Oger Luc , Ippolito Irene
Published: June 2021

Particulate matter offers a broad spectrum of phenomena, well known in the granular matter community. This fact is not only related to the individual or collective behaviour that grains can present depending on the external boundary conditions and/or internal interactions but, to the wide range of particle sizes. This feature confers the possibility of studying a particular phenomenon in different size scales. The main goal of this paper is to describe the detachment of particles from surfaces, where particles go from tens of microns to several millimetres, in a variety of scenarios. All the studied systems presented here have in common the need to determine the critical conditions to lose the equilibrium balance, initiating incipient motion. Solving the right time moment for particle resuspension, consideration of the local interactions between particle, surface and external applied forces can be achieved from different modelling approaches, from deterministic dynamics to statistical mechanics. This paper focuses on some of these approaches performed recently on grains through different size scales.
Stress and force measurement uncertainties in 3D granular materials
Authors: Hurley Ryan C.
Published: June 2021

We have developed and employed a 3D particle stress tensor and contact force inference technique that employs synchrotron X-ray tomography and diffraction with an optimization algorithm. We have used this technique to study stress and force heterogeneity, particle fracture mechanics, contact-level energy dissipation, and the origin of wave phenomena in 3D granular media for the past five years. Here, we review the technique, describe experimental and numerical sources of uncertainty, and use experimental data and discrete element method simulations to study the method’s accuracy. We find that inferred forces in the strong force network of a 3D granular material are accurately determined even in the presence of noisy stress measurements.
Non-monotonic dependence of avalanche durations on particle velocities in the discharge of a silo
Authors: Gella Diego , Maza Diego , Zuriguel Iker
Published: June 2021

The distributions of avalanche times between successive clog events are analyzed in a silo discharged with a conveyor belt. In a previous work [Phys. Rev. Lett. 121, 138001 (2018)], we measured the distribution of avalanche sizes (in number of particles) for the same experiment, finding a monotonous influence of both the outlet size and the velocity of particles in the clogging probability. Nonetheless, if avalanche durations are analyzed instead of avalanche sizes, a minimum is observed when representing the mean avalanche time as function of the velocity of particles. This phenomenon is explained using kinematic arguments, which are validated by experimental data. At the same time, this work aims at highlighting the importance of discerning between measuring clogging avalanches in terms of times or doing it in terms of number of particles.
On the broad tails in breaking time distributions of vibrated clogging arches
Authors: Garcimartín Angel , Guerrero Bruno V. , Nicolas Alexandre , Barbosa da Silva Rodrigo C. , Zuriguel Iker
Published: June 2021

Flowing grains can clog an orifice by developing arches, an undesirable event in many cases. Several strategies have been put forward to avoid this. One of them is to vibrate the system in order to undo the clogging. Nevertheless, the time taken to break an arch under a constant vibration has a distribution displaying a heavy tail. This can lead to a situation where the average breaking time is not well defined. Moreover, it has been observed in some experiments that these tails tend to flatten for very long times, exacerbating the problem. Here we will review two conceptual frameworks that have been proposed to understand the phenomenon and discuss their physical implications.
Designing non-segregating granular mixtures
Authors: Duan Yifei , Umbanhowar Paul B. , Lueptow Richard M.
Published: June 2021

In dense flowing bidisperse particle mixtures varying in size or density alone, large particles rise (driven by percolation) and heavy particles sink (driven by buoyancy). When the two particle species differ from each other in both size and density, the two segregation mechanisms either enhance (large/light and small/heavy) or oppose (large/heavy and small/light) each other. In the latter case, an equilibrium condition exists in which the two mechanisms balance and the particles no longer segregate. This leads to a methodology to design non-segregating particle mixtures by specifying particle size ratio, density ratio, and mixture concentration to achieve the equilibrium condition. Using DEM simulations of quasi-2D bounded heap flow, we show that segregation is significantly reduced for particle mixtures near the equilibrium condition. In addition, the rise-sink transition for a range of particle size and density ratios matches the predictions of the combined size and density segregation model.
The performance of the µ(I)-rheology model on flat bottom silos discharge
Authors: Venier César , Binda Leonardo , Ramajo Damián , Márquez Damián Santiago , Ippolito Irene , Nigro Norberto
Published: June 2021

The aim of this work is to explore the capability of the µ(I)-rheology model and its numerical implementation in addressing a silo discharge problem by computational simulation. In order to do so, the model was implemented in the general structure of an Eulerian multiphase solver based on the Volume-Of-Fluid (VOF) method of the OpenFOAM(R) suite. First, the implementation is validated against the results of another Lagrangian and Eulerian codes in a two-dimensional discharge problem. After that, the model is tested against the experimental results of a lab-scale and industrial-scale discharge problem. While the results of the first one were satisfactory in terms of discharge rate, for the latter one, the model exhibits disagreements in the flow patterns inside the silo. The study shows the limits of applicability of the standard formulation of the model for real scale silos and sets the ground for further discussion and improvements.
Effect of dissipation in rapid-gravitational granular flows
Authors: Zhu Yajuan , Delannay Renaud , Valance Alexandre
Published: June 2021

We investigate numerically high speed granular flows down an incline and focus our attention on the influence of the restitution coefficient e of binary collisions on the nature of the flow regimes. We show in particular that e plays a major role in rapid flows. Decreasing e leads in general to denser flows but also quicker flows. The increase of the mean flow velocity with decreasing e is explained as the result of the clustering instability which produces a dense and cold core moving very fast as a plug.
Homogeneous cooling and heating states of dilute soft-core gases under nonlinear drag
Authors: Takada Satoshi
Published: June 2021

The temperature evolution of dilute soft inertial gas-solid suspensions is theoretically analyzed when the gas particles are influenced by a nonlinear drag force from a background fluid. The kinetic theory is extended to this system, and the time evolutions of the temperature and the kurtosis of the velocity distribution are derived. Molecular dynamics simulations are also performed to check the validity of the theory, and they show good agreement with the theoretical predictions.
Continuously heated granular gas of elongated particles
Authors: Pongó Tivadar , Puzyrev Dmitry , Harth Kirsten , Stannarius Ralf , Cruz Hidalgo Raúl
Published: June 2021

Some years ago, Harth et al. experimentally explored the steady state dynamics of a heated granular gas of rod-like particles in microgravity [K. Harth et al. Phys. Rev. Lett. 110, 144102 (2013)]. Here, we report numerical results that quantitatively reproduce their experimental findings and provide additional insight into the process. A system of sphero-cylinders is heated by the vibration of three flat side walls, resulting in one symmetrically heated direction, one non-symmetrically heated direction, and one non-heated direction. In the non-heated direction, the speed distribution follows a stretched exponential distribution $$p(\upsilon )\, \propto \,{\rm{exp}}\left( { - {{\left( {{{\left| \upsilon \right|} \mathord{\left/ {\vphantom {{\left| \upsilon \right|} C}} \right. \kern-\nulldelimiterspace} C}} \right)}^{1.5}}} \right)$$. In the symmetrically heated direction, the velocity statistics at low speeds is similar but it develops pronounced exponential tails at high speeds. In the non-symmetrically heated direction (not accessed experimentally), the distribution also follows $$p(\upsilon )\, \propto \,{\rm{exp}}\left( { - {{\left( {{{\left| \upsilon \right|} \mathord{\left/ {\vphantom {{\left| \upsilon \right|} C}} \right. \kern-\nulldelimiterspace} C}} \right)}^{1.5}}} \right)$$
, but the velocity statistics of rods moving toward the vibrating wall resembles the indirectly excited direction, whereas the velocity statistics of those moving away from the wall resembles the direct excited direction.
Dynamics of two particles on a vertically driven plate
Authors: Yang Kai , Sabey Alex , Olafsen Jeffrey
Published: June 2021

We experimentally investigate the dynamics of two particles driven vertically and free to collide in a nearly one-dimensional channel. Both spherical particles are Delrin with a diameter of d = 5.0 mm. We obtained data for driving frequencies, f, ranging from 26.06 to 29.52 HZ and acceleration magnitudes, Γ, from 1.79 to 2.42 g. High speed digital imaging is used to extract the positions of the two particles from experiment, with digital imaging analysis used to extract velocities and accelerations from sequential images. The total energy and the velocity of the particles before and after collisions are studied in both the lab frame and centre of mass frame. Most of the experimental results suggest a linear dependence for the relative velocity after collision on the relative velocity before collision with the coefficient of restitution approximately constant at 0.8. However, some data in the low impact velocity regime indicates the possibility of an occasional energy transfer between the rotational and translational degrees of freedom.
Shape or friction? Which of these characteristics drives the shear strength in granular systems?
Authors: Binaree Theechalit , Azéma Emilien , Estrada Nicolas , Renouf Mathieu , Preechawuttipong Itthichai
Published: June 2021

The shape of the particles and local friction, separately, are known to strongly affect the macroscopic properties of an assembly of grains. But the combined effects of these two parameters still remain poorly described. By means of extensive two dimensional contact dynamics simulations, we perform a systematic analysis of the interplay between friction and shape on strength properties of granular systems. The shape of the particles is varied from disks to triangles, while the friction is varied from 0 to 0.7. We find that the macroscopic friction first increases with angularity, but it may decline (for low friction values), saturate (for intermediates friction values), or continue to increase (for large friction values) for the most angular shapes. In other words, the effect of the particle’s angularity on the shear strength depends on the level of sliding friction. In contrast, the effect of local friction on the shear strength does not depend on the specific properties of shape. The results presented here highlight the subtle coupling existing between shape and friction effects.
Revisiting Hardin’s parameters for the quantification of particle breakage – A statistical entropy approach
Authors: Leak James , Barreto Daniel , Dimitriadi Vasiliki , Imre Emoke
Published: June 2021

It is well recognised that particle breakage in granular materials is affected by stress level, stress path, initial density, and particle size distribution (PSD), amongst others. Furthermore, it has been shown that breakage has a significant influence on the stress-strain behaviour of soils. This paper compares a commonly used breakage parameter with grading entropy coordinates. Such coordinates enable for the representation of any PSD as a single point in a Cartesian coordinate plane. Hence, the evolution of PSD changes may be easily tracked. This paper aims to demonstrate that grading entropy coordinates are as (or more) effective than other breakage parameters, whilst providing additional insight. On the basis of limited data it is shown that grading entropy coordinates are able to capture the dependence of breakage on stress level, stress path and initial PSD.
Evaluation of flowability for granulated powder using a test of powder discharge by pressurized air
Authors: Ogata Koichiro , Ariga Daigo
Published: June 2021

This study experimentally and theoretically examined the flowability and the cohesiveness for powder using a test of powder discharge through an orifice by the pressurized air. The powder used consisted of two kinds of Calcium hydroxide which have different particle sizes by granulation. These sizes are 11µm and 176µm, those called Ca(OH)2 -A and -B. Cohesiveness is characterized by the Bond number which is the ratio of separation force to the gravity force. Flowability is evaluated by the relationship between the mass flow rate and the average air pressure acting on the powder bed. We found that the Bond number of Ca(OH)2 -B was much lower than Ca(OH)2 -A. The relation between the mass flow rate of the powder and the average air pressure indicates Ca(OH)2 -B is easily flowing at the lower pressure region, and Ca(OH)2 -A was scattered at the higher pressure region. This means Ca(OH)2 -B has good flowability by the particle granulation in comparison with Ca(OH)2 -A.
Extending the Shields criterion to erosion of weakly cemented granular soils
Authors: Philippe Pierre , Benseghier Zeyd , Brunier-Coulin Florian , Luu Li-Hua , Cuéllar Pablo , Bonelli Stéphane
Published: June 2021

This contribution tackles the issue of incipient conditions for initiation of erosion by a fluid flow at the surface of cohesive materials. To this end, a typical assessment procedure consists of subjecting a soil sample to progressive hydrodynamic stresses induced by a submerged impinging jet flow whose injection velocity is gradually increased. This paper presents the results of an extensive use of this protocol both in experiments and numerical simulations, the latter being based on a coupled DEM and LBM approach. Here we consider the specific case of weakly cemented soils, either made experimentally of glass beads bonded by solid bridges or modelled numerically by a solid bond rheology with a parabolic yield condition involving the micromechanical traction, shearing and bending of the bonds. The results show that, as expected, the hydrodynamic stress for erosion onset substantially increases with solid cohesion as compared to cohesionless cases but can, however, be satisfactorily predicted by a simple extension of the usual Shields criterion that only applies for cohesion-less granular sediments. This extension includes a cohesion number, the granular Bond number, with a simple definition based on tensile yield values.