bluuebunny/crossref_metadata_2025 huggingface dataset:
An on‐chain trading model of real world asset backed digital assets
Authors: Hou Dongsheng , Ma Wenjing , Zhang Wei , Li Yixuan , Du Yu , Hao Yukun
Published: September 2023

Metaverse is a digital value interaction network based on blockchain technology, with an important economic system component. While both traditional financial industries and crypto‐native industries have made significant progress by leveraging blockchain, the value stream of each remains limited to separate ecosystems. To bridge this gap between off‐chain and on‐chain economic systems, an on‐chain trading model was proposed using HD key derivation technique for direct uploading onto chains without going through centralized services for IoT data transmission. To improve the current status of NFTs as static assets, a token protocol binding each NFT with a unique account address was proposed. Additionally, oracle technique was leveraged with a decentralized and distributed trust model spanning across on‐chain and off‐chain components which securely pushes data between smart contracts and Web‐APIs. A decentralized trading model was developed based on smart contracts implementing automated market makers according to CFMM algorithm. Parallel transaction computing was executed based on the DAG model to ensure high operational performance and security standards of underlying blockchain. Finally, the on‐chain trading system of real world asset backed digital assets was developed integrating all the above key techniques that correspond to crucial functions of a complete economic system in Metaverse.
Reliable control of cyber‐physical systems under state attack: An adaptive integral sliding‐mode control approach
Authors: Li Jian , Yang Defu , Su Qingyu , Shen Xueqiang
Published: September 2023

This paper is concerned with optimal security problem of cyber‐physical systems with state attacks. Consider a linear physical system, assuming that the control input signal of the network layer is vulnerable to state attack. For a system that cannot measure all states, by combining output integral sliding mode, robust observer, and adaptive methods, an adaptive output integral sliding mode control method is proposed to maintain the safe operation of cyber physical systems under state attacks. Moreover, by optimizing the linear control gain matrix, the control strategy the authors designed can use the minimum cost to compensate the impact on the CPS system. Different from the existing results, (1) It is assumed that the system information of the attack signal is not fully known, we assume that the attacker can only measure a small amount of state information. (2) Not only the stability of ideal sliding mode is proved, but also the upper bound of the augmented state composed of system states and the error dynamic is given. (3) The sliding mode compensator can eliminate the impact of state attack, on the one hand, the damage caused by the state attack has been eliminated by using the upper bound of error, and on the other hand, the cost is reduced by optimizing the linear control gain. Finally, a power system with 3 generators and 6 buses is used to prove the effectiveness of the adaptive output integral sliding mode control scheme.
A symbolic approach to the verification and enforcement of current‐state opacity using labelled Petri nets
Authors: Peng Kun , Chen Yufeng , Li Zhiwu
Published: September 2023

This work proposes a symbolic method to verify and enforce the current‐state opacity of labelled Petri nets (LPNs). The notion of basis markings of partially observed Petri nets currently dominates the development of opacity verification and enforcement for discrete event systems. However, the related computational efficiency, to a great extent, depends on the number of basis markings in a system, which increases exponentially with respect to the size of its corresponding LPN model. Binary decision diagrams (BDDs) are capable of computing a set of basis markings in a compact shared structure. To mitigate the computational overheads, a BDD‐based method to efficiently model the structure and behaviour of an LPN is proposed. Then, the current‐state opacity of LPNs is verified and enforced in a symbolic manner. Finally, a number of examples are provided to demonstrate the effectiveness and efficiency of the proposed method.
Robust adaptive event‐triggered ILC scheme design for discrete‐time non‐repetitive nonlinear systems
Authors: Chai Sheng , Yu Miao , Zhao Kai
Published: September 2023

In this study, a robust adaptive event‐triggered iterative learning control (ET‐ILC) method is developed for discrete‐time non‐repetitive nonlinear systems with both time‐varying system parameters and time‐iteration‐varying non‐parametric uncertainty. The proposed method utilizes an iteration‐varying dead‐zone function to estimate both parametric and non‐parametric uncertainties simultaneously. Moreover, an event‐triggered control mechanism including a mixed triggering strategy is employed to minimize the unnecessary usage of communication resource. This strategy updates the controller only when the triggering condition is met, thereby reducing the frequency of controller actions. The results are also extended to a class of multiple‐input–multiple‐output (MIMO) non‐repetitive nonlinear systems. The designed robust adaptive ET‐ILC algorithm not only guarantees perfect learning convergence in the iteration domain but also contributes to saving the system resources. The effectiveness of the presented method is demonstrated by virtue of the rigorous theoretical analysis and the illustrative simulation examples.
First end‐to‐end PQC protected DPU‐to‐DPU communications
Authors: Aguilera A. Cano , Clemente X. Arnal i , Lawo D.C. , Monroy I. Tafur , Olmos J.J. Vegas
Published: September 2023

The appearance of quantum computing in the short foreseeable future and its capability to break conventional cryptographic algorithms forces to change the paradigm of secure real‐time communications. Thus, government organizations, data centers, and enterprises among others are migrating their public key infrastructure towards using post‐quantum cryptography (PQC) algorithms in order to mitigate the security threats posed by quantum computers. This letter presents the first quantum resilient secure end‐to‐end communication link based on PQC algorithms operating between two data‐processing units DPU. Both data‐processing units employ on‐board ARM processors to perform the computationally expensive cryptographic building blocks—in that case CRYSTALS‐Kyber as a key encapsulation mechanism and CRYSTALS‐Dilithium for digital signature scheme in combination with advanced encryption standard with 256‐bit key.
6G energy‐efficient systems based on arrays combined with dielectric lenses
Authors: Wang Hairu , Castillo‐Tapia Pilar , Manholm Lars , Johansson Martin , Quevedo‐Teruel Oscar , Algaba‐Brazález Astrid
Published: September 2023

It is demonstrated that combining phased array antennas with dielectric lenses constitutes a suitable solution to increase the energy efficiency in next‐generation communication systems. A dielectric lens is designed to increase the gain of an array antenna working in the 3GPP n257 band (26.5–29.5 GHz). The simulated results demonstrate that the dielectric lens increases the gain between 0.4 and 1.3 dB in a large scanning range from 0° to 60° at 28 GHz; meaning that the output RF power can be decreased by up to 26% for a same equivalent isotropic radiated power required from the base station.
A hybrid half‐bridge submodule‐based DC–DC modular multilevel converter with a single bidirectional high‐voltage valve
Authors: Elserougi Ahmed , Abdelsalam Ibrahim , Massoud Ahmed
Published: September 2023

Modular Multilevel Converters (MMCs) are promising candidates for high‐voltage high‐power applications. The main challenge of the MMCs is the zero‐frequency operation. To achieve a successful DC–DC conversion process with balanced capacitors’ voltages with limited voltage ripple, this paper suggests the employment of the conventional two‐leg half‐bridge submodule‐based MMC structure in conjunction with a single bidirectional high‐voltage (HV) valve across the low‐voltage side. In the suggested structure, the HV valve is controlled on and off to ensure energy equalization for the MMC arms. In addition, soft‐switching for the HV valve is proposed to reduce the switching losses. Detailed illustration and design of the proposed concept are presented. Simulation and experimentation results are elucidated to show the effectiveness of the proposed DC–DC hybrid MMC. The results showed efficient performance of the suggested converter.
Sub‐array level structural compensation method for radiating and scattering performance of array antennas
Authors: Wang Yan , Yan Biaolin , Yu Rong , Fan Mengmeng , Duan Zhongxing , Ma Zongfa , Fu Hongping , Wang Zhihai , Yu Kunpeng , Wu Wenzhi , Wang Congsi
Published: September 2023

The detection and stealth abilities of array antennas depend mainly on the antennas' radiating and scattering performance, respectively. However, the operating environmental loads and assembly lead to serious structural errors, including deformation and random errors, which affect both the radiating and scattering performance. As the demand to guarantee high performance in detection as well as in stealth, a new sub‐array level structural compensation method is presented to simultaneously guarantee the radiating and scattering performance of array antennas in service. First, a statistical model of scattering performance with structural deformation and random position error is established to quickly evaluate the impact of a random structural error on scattering performance. Then, the effects of structural errors in different directions on radiating and scattering performance are analysed to determine the structural adjustment direction. Moreover, the multi‐objective problem considering the comprehensive compensation of radiating and scattering performance is converted into a single‐object problem by constructing a fitness function to realise the sub‐array level structural compensation. Finally, a typical case is used to verify the effectiveness of the compensation method. The results show that the presented method can guarantee both the radiating and scattering performance effectively, providing advantageous guidance for structural design and performance compensation for array antennas.
Quantum Key Distribution for V2I communications with software‐defined networking
Authors: Stavdas Alexandros , Kosmatos Evangelos , Maple Carsten , Hugues‐Salas Emilio , Epiphaniou Gregory , Fowler Daniel S. , Razak Shadi A. , Matrakidis Chris , Yuan Hu , Lord Andrew
Published: September 2023

The evolution of Connected and Autonomous Vehicles (CAVs) promises improvements in our travel experience and the potential to enhance road safety and reduce environmental impact. This will be utilising highly diverse traffic environments that enable several advanced mobility applications. A secure, efficient, reliable, and resilient communications infrastructure is required to support developments in these CAV systems. Next generation of telecommunication networks will seamlessly integrate terrestrial, satellite, and airborne networks into a single wireless system satisfying the requirements of trustworthy future transport systems. Given the increasing importance of CAVs, coupled with their attractiveness as a cyber‐attack for threat agents (e.g., disruption of transportation systems by nation states), security is paramount. Future communications systems offer an opportunity to integrate Quantum Key Distribution (QKD) into vehicular environments, protecting against advances in quantum computation that render many of the classical algorithms that underpin Public Key Infrastructure obsolete. This paper proposes a method for the integration of QKD in V2I networks to enable secure data communication. Quantum Key Distribution is used in the end‐to‐end path of vehicle‐to‐infrastructure (V2I) networks. Furthermore, an overarching Software‐Defined Network, with integrated QKD, is introduced. We have investigated the security performance of QKD in a V2I network over an urban environment.
Beyond small-scale transients: A closer look at the diffuse quiet solar corona
Authors: Gorman J. , Chitta L. P. , Peter H. , Berghmans D. , Auchère F. , Aznar Cuadrado R. , Teriaca L. , Solanki S. K. , Verbeeck C. , Kraaikamp E. , Stegen K. , Gissot S.
Published: September 2023

Aims. Within the quiet Sun corona imaged at 1 MK, much of the field of view consists of diffuse emission that appears to lack the spatial structuring that is so evident in coronal loops or bright points. Our aim is to determine if these diffuse regions are categorically different in terms of their intensity fluctuations and spatial configuration from the better-studied dynamic coronal features.

Methods. We analyzed a time series of observations from Solar Orbiter’s High Resolution Imager in the extreme ultraviolet to quantify the characterization of the diffuse corona at high spatial and temporal resolutions. We then compared this to the dynamic features within the field of view, mainly a coronal bright point.

Results. We find that the diffuse corona lacks visible structuring, such as small embedded loops, and that this is persistent over the 25 min duration of the observation. The intensity fluctuations of the diffuse corona, which are within ±5%, are significantly smaller in comparison to the coronal bright point; however, the total intensity observed in the diffuse corona is on the same order as the bright point.

Conclusions. It seems inconsistent with our data that the diffuse corona is a composition of small loops or jets or that it is driven by discrete small heating events that follow a power-law-like distribution. We speculate that small-scale processes such as magnetohydrodynamic turbulence might be energizing the diffuse regions, but at this point we cannot offer a conclusive explanation for the nature of this feature.
The ALMA-ALPAKA survey
Authors: Rizzo F. , Roman-Oliveira F. , Fraternali F. , Frickmann D. , Valentino F. M. , Brammer G. , Zanella A. , Kokorev V. , Popping G. , Whitaker K. E. , Kohandel M. , Magdis G. E. , Di Mascolo L. , Ikeda R. , Jin S. , Toft S.
Published: September 2023

Context.Spatially resolved studies of the kinematics of galaxies provide crucial insights into their assembly and evolution, enabling one to infer the properties of the dark matter halos, derive the impact of feedback on the interstellar medium (ISM), as well as measure and characterize the outflow motions. To date, most of the kinematic studies atz = 0.5 − 3.5 have been obtained using emission lines tracing the warm, ionized gas (e.g., Hα, [OII], and [OIII]). However, whether these provide an exhaustive or only a partial view of the dynamics of galaxies and of the properties of the ISM is still debated. Complementary insights into the cold gas kinematics are therefore needed.

Aims.We present the Archival Large Program to Advance Kinematic Analysis (ALPAKA), a project aimed at gathering high-resolution observations of CO and [CI] emission lines of star-forming galaxies atz = 0.5 − 3.5 from the Atacama Large Millimeter Array (ALMA) public archive. With ≈147 h of total integration time, ALPAKA assembles ∼0.25″ observations for 28 star-forming galaxies, which is the largest sample with spatially resolved cold gas kinematics as traced by either CO or [CI] atz ≳ 0.5, spanning 7 Gyr of cosmic history. A large fraction of ALPAKA galaxies (19 out of 28) lie in overdense regions (clusters, groups, and protoclusters).

Methods.By combining multiwavelength ground- and space-based ancillary data, we derived the stellar masses (M⋆) and star-formation rates (SFRs) for the ALPAKA targets. We exploited the ALMA data to infer the dynamical state of the ALPAKA galaxies and derive their rotation curves and velocity dispersion profiles using3DBAROLO.

Results.ALPAKA probes the massive (M⋆ ≳ 1010 M⊙), actively star-forming (SFR ≈ 10 − 3000 M⊙yr−1) part of the population of galaxies atz ∼ 0.5 − 3.5. Based on our kinematic classification, we find that 19 out of 28 ALPAKA galaxies are rotating disks, two are interacting systems, while for the remaining seven sources the classification is uncertain. The disks have velocity dispersion values that are typically larger in the innermost regions than in the outskirts, with a median value for the entire disk sample of 35−9+11km s−1. Despite the bias of our sample toward galaxies hosting very energetic mechanisms, the ALPAKA disks have high ratios of ordered-to-random motion (V/σ) with a median value of 9−2+7.
Probing magnetic fields in the circumgalactic medium using polarization data from MIGHTEE
Authors: Böckmann K. , Brüggen M. , Heesen V. , Basu A. , O’Sullivan S. P. , Heywood I. , Jarvis M. , Scaife A. , Stil J. , Taylor R. , Adams N. J. , Bowler R. A. A. , Tudorache M. N.
Published: September 2023

Context.The properties and evolution of magnetic fields surrounding galaxies are observationally largely unconstrained. The detection and study of these magnetic fields is important to understand galaxy evolution since magnetic fields are tracers for dynamical processes in the circumgalactic medium (CGM) and can have a significant impact on the evolution of the CGM.

Aims.The Faraday rotation measure (RM) of the polarized light of background radio sources passing through the magnetized CGM of intervening galaxies can be used as a tracer for the strength and extent of magnetic fields around galaxies.

Methods.We used rotation measures observed by the MIGHTEE-POL (MeerKAT International GHz Tiered Extragalactic Exploration polarization) survey by MeerKAT in the XMM-LSS and COSMOS fields to investigate the RM around foreground star-forming galaxies. We used spectroscopic catalogs of star-forming and blue cloud galaxies to measure the RM of MIGHTEE-POL sources as a function of the impact parameter from the intervening galaxy. In addition, we examined the dependence of the RM on redshift. We then repeated this procedure using a deeper galaxy catalog with photometric redshifts.

Results.For the spectroscopic star-forming sample, we find a redshift-corrected |RM| excess of 5.6 ± 2.3 rad m−2which corresponds to a 2.5σsignificance around galaxies with a median redshift ofz = 0.46 for impact parameters below 130 kpc only selecting the intervenor with the smallest impact parameter. Making use of a photometric galaxy catalog and taking into account all intervenors withMg < −13.6 mag, the signal disappears. We find no indication for a correlation between redshift and RM, nor do we find a connection between the total number of intervenors to the total |RM|.

Conclusions.We have presented tentative evidence that the CGM of star-forming galaxies is permeated by coherent magnetic fields within the virial radius. We conclude that mostly bright, star-forming galaxies with impact parameters less than 130 kpc significantly contribute to the RM of the background radio source.
Optical properties of metal-poor T dwarf candidates
Authors: Zhang J.-Y. , Lodieu N. , Martín E. L.
Published: September 2023

Context. Metal-poor brown dwarfs are poorly understood because they are extremely faint and rare. Only a few candidates have been identified as T-type subdwarfs in infrared surveys and their optical properties remain unconstrained.

Aims. We aim to improve the knowledge of the optical properties of T subdwarf candidates to break the degeneracy between metallicity and temperature and to investigate their atmospheric properties.

Methods. Deep z-band images of ten known T subdwarf candidates were collected with the 10.4-m Gran Telescopio Canarias. Low-resolution optical spectra for two of them were obtained with the same telescope. Photometric measurements of the z-band flux were performed for all the targets and they were combined with infrared photometry in J, H, K, W1, and W2 bands from the literature to obtain the colours. The spectra were compared with solar-metallicity T dwarf templates and with laboratory spectra.

Results. We found that the targets segregate into three distinct groups in the W1 − W2 versus z − W1 colour-colour diagram. Group I objects are mixed with solar-metallicity T dwarfs. Group III objects have W1 − W2 colours similar to T dwarfs but very red z − W1 colours. Group II objects lie between Group I and III. The two targets for which we obtained spectra are located in Group I and their spectroscopic properties resemble normal T dwarfs but with water features that are deeper and have a shape akin to pure water.

Conclusions. We conclude that the W1 − W2 versus z − W1 colour-colour diagram is excellent to break the metallicity-temperature degeneracy for objects cooler than L-type ones. A revision of the spectral classification of a T subdwarf might be needed in the future, according to the photometric and spectroscopic properties of WISE1810 and WISE0414 in Group III discussed in this work.
Control problem for quadratic parabolic differential equations with sparse sensor sets of finite volume or anisotropically decaying density
Authors: Dicke Alexander , Seelmann Albrecht , Veselić Ivan
Published: September 2023

We prove observability and null-controllability for quadratic parabolic differential equations. The sensor set is allowed to be sparse and have finite volume if the generator has trivial singular spaceS. In the case of generators with singular spaceS≠ {0} the sensor set is permitted to decay in directions determined byS. The proof is based on dissipation estimates for the quadratic differential operator with respect to spectral projections of partial harmonic oscillators and corresponding uncertainty relations.
A multi-stage stochastic programming approach for an inventory–routing problem considering life cycle
Authors: Paeizi Alireza , Makui Ahmad , Pishvaee Mir Saman
Published: September 2023

Food waste and proper methods to deal with it are one of the main challenges of supply chain network management. The majority of studies on how to use mathematical models in the supply chain have focused on goods that are at their peak of freshness as soon as they are produced and deteriorate over time. While some products experience an increase in value at the start of their life cycle, this value eventually reaches its maximum level, and after this point, these products experience a decline in value before being eliminated from the consumption cycle. The objective of this study is to develop a comprehensive inventory–routing model suitable for supply chain networks where products exhibit an increase and decrease in value over time. By considering the randomness and dynamic uncertainty of market demands and the fact that each period has effects on the next period, The proposed model employs a multi-stage stochastic programming (MSSP) approach. By doing so, the model ensures a balanced flow between different components of the network while considering nondeterministic demand under various scenarios that are shown in a tree of scenarios. The utilization of MSSP leads to more reliable solutions compared to deterministic models, making it possible for chain stores to make well-informed decisions in their inventory management and distribution strategies. Ultimately, this approach results in cost savings for chain stores handling such products. This research makes a significant contribution to the existing literature by demonstrating the effectiveness of the proposed model on actual data and highlighting the benefits of using stochastic programming in supply chain optimization.
Eplerenon zur Behandlung der chronisch rezidivierenden Chorioretinopathia centralis serosa
Authors: Herrmann Lisa-Marie , Matthé Egbert , Sandner Dirk , Wittig Dierk
Published: September 2023

Hintergrund Die Chorioretinopathia centralis serosa (CCS) ist eine häufige Erkrankung, die durch Dekompensation des retinalen Pigmentepithels zum Verlust der Ionen-/Flüssigkeitshomöostase der Retina und damit zur Ansammlung von Flüssigkeit mit Abhebung der neurosensorischen Retina und/oder des retinalen Pigmentepithels führt. Wir untersuchten die Auswirkung von Eplerenon, einem Hemmer des Mineralokortikoid-Rezeptors, auf die chronisch rezidivierende CCS (cr-CCS).

Methoden Es erfolgte die retrospektive Auswertung der Daten von 17 Augen (12 Patienten) aus den Jahren 2014 – 2021 mit cr-CCS, bei denen andere Methoden nicht wirksam, nicht anwendbar oder nicht gewünscht wurden. Dauer der CCS war mindestens 12 Monate mit mindestens einem Rezidiv. Jeder Patient erhielt 25 mg (1. Woche) bzw. 50 mg (ab der 2. Woche) für mindestens 3 Monate. Es wurde jeweils der bestkorrigierte Visus und die zentrale und periphere Netzhautdicke mittels SD-OCT gemessen. Nebenwirkungen wurden von den Patienten als „keine“, „mild“ (bemerkbar, aber nicht störend), „tolerabel“ (störend, aber bei guter Wirkung akzeptabel) und „nicht tolerabel“ (dann Therapieabbruch) eingeschätzt.

Ergebnisse Es kam zu keiner signifikanten Reduktion der zentralen oder peripheren Netzhautdicke. Eine komplette Reduktion der subretinalen Flüssigkeit wurde bei 5 von 17 Augen erreicht (29,4%). Bei 12 Augen konnte kein Effekt von Eplerenon nachgewiesen werden, sodass andere Maßnahmen erforderlich wurden. Die Visusänderung war hauptsächlich von der Dauer der CCS und dem Grad der Photorezeptorschädigung abhängig. Nebenwirkungen gaben 11 Patienten als „keine“ und 1 Patient als „mild“ an (arterielle Hypotonie). Andere Nebenwirkungen wurden nicht beobachtet.

Schlussfolgerung Die Ansprechraten der Therapie mit Eplerenon waren relativ niedrig, es ließ sich kein signifikanter Effekt nachweisen. Eplerenon sollte nicht (mehr) routinemäßig in der Therapie der cr-CCS eingesetzt werden.
Die Resektion solitärer Lungenmetastasen des Urothelkarzinom kann das Überleben bei selektionierten Patienten verlängern
Authors: Ehle Benjamin , Hassan Mohamed , Le Uyen-Thao , Passlick Bernward , Grapatsas Konstantinos
Published: September 2023

Die aktuelle Datenlage der pulmonalen Metastasektomie des Urothelkarzinoms ist stark begrenzt. In unserer aktuellen Studie haben wir basierend auf unserer 20-jährigen Zentrumserfahrung das
Langzeitergebnis nach Lungenmetastasektomie bei Urothelkarzinom sowie die Faktoren, die ein Langzeitüberleben beeinflussen, untersucht. Bei insgesamt 18 Patienten (4 Frauen und 14 Männer) wurde
eine Lungenmetastasektomie bei Urothelkarzinom in den Jahren von 2000 bis 2020 in kurativer Intention durchgeführt. Klinische, demografische und chirurgische Daten wurden retrospektiv
analysiert. Das krankheitsfreie Intervall zwischen Behandlung des Primarius und Lungenmetastasektomie umfasste 1 bis 48 Monate. Die Überlebensanalyse wurde nach der Kaplan-Meier-Methode und dem
Log-Rank-Test durchgeführt. Das kumulative 3- und 5-Jahres-Überleben betrug 84,7% und 52,9%. Die Resektion einer solitären Lungenmetastase war ein unabhängiger positiver Prädiktor für ein
längerfristiges Überleben (p = 0,04). Die pulmonale Metastasektomie bei Urothelkarzinom ist mit einem günstigeren Langzeitergebnis verbunden und singuläre Metastasen mit einem verlängerten
Langzeitüberleben. Die operative Resektion solitärer Lungenmetastasen und die Metastasektomie bei Rezidivmetastase des Urothelkarzinoms ist eine praktikable Therapie bei selektierten
Patienten.
Vocal Cord Paralysis after Repair of Esophageal Atresia
Authors: Koivusalo A.I. , Suominen J.S. , Nokso-Koivisto J. , Pakarinen M.P.
Published: September 2023

Objective Etiology of vocal cord paralysis (VCP) and laryngeal dysfunction may be congenital or surgical trauma of recurrent and superior laryngeal nerves. We assessed the incidence, risk factors, and morbidity of VCP after repair of esophageal atresia (EA).

Methods Medical records of 201 EA patients from 2000 to 2022 were reviewed for this retrospective study. Postrepair vocal cord examination (VCE) included awake nasolaryngeal fiberoscopy by otolaryngologist or laryngoscopy under spontaneous breathing anesthesia. Before 2017, postoperative VCE was performed in symptomatic patients only and routinely after 2017.

Main Results Overall, VCE was performed on 79 (38%) patients (52 asymptomatic), whereas 122 asymptomatic patients underwent no VCE. VCP was diagnosed in 32 of 79 patients (right 12, left 10, and bilateral 10; symptomatic 25 and asymptomatic unilateral 7) corresponding with extrapolated overall VCP incidence of 16 to 24% among 201 patients including asymptomatic ones. Ten patients (bilateral VCP 8 and left VCP 2) required tracheostomy. Of 10 patients with bilateral VCP, three underwent laryngotracheal expansion surgery (left VC lateralization in one and laryngoplasty in two with acquired subglottic stenosis), three remained tracheostomy dependent, three were off tracheostomy, and one died of complications after redo esophageal reconstruction. All patients with unilateral VCP managed without tracheostomy. Cervical dissection or ostomy formation was a major risk factor of VCP.

Conclusion Repair of EA is associated with a considerable risk of VCP and associated morbidity. Cervical EA surgery significantly increased the risk of VCP. Bilateral VCP may eventually require laryngotracheal expansion surgery.
Role of nanoscale compositional inhomogeneities in limiting the open circuit voltage in Cu(In,Ga)S2 solar cells
Authors: Peedle Sean , Adeleye Damilola , Shukla Sudhanshu , Siebentritt Susanne , Oliver Rachel , Kusch Gunnar
Published: September 2023

As Si-based solar cell technologies approach their theoretical efficiency limits, alternative photovoltaic systems, such as tandem solar cells, are gathering increased attention due to their potential to reach higher efficiencies by better use of the solar spectrum. Cu(In,Ga)S2 (CIGS) is a promising material for the top cell due to its large, tunable bandgap energy (Eg), stability, and already established high efficiencies. However, the deficit in open circuit voltage is still large; therefore, an improved understanding of the efficiency losses is required. Scanning electron microscopy cathodoluminescence was used to study the role of the polycrystalline nature for radiative recombination in CIGS samples of varying Cu-content. Considerable differences between neighboring grains were observed in the emission energy and the emission intensity, with significant drops in emission energy at the grain boundaries. Lateral homogeneity in the near band edge (NBE) energy was found to reduce for samples with Cu-poor compositions, with its standard deviation halving (σNBE ∼ 20 meV) compared to the more stoichiometric films (σNBE ∼ 50 meV), which corresponds to an open circuit voltage loss contribution that is nearly an order of magnitude lower. Such inhomogeneities can be attributed mainly to local variations of the Ga concentration. Hence, the differences between the samples could be explained by the different deposition times at elevated temperature allowing for different extents of homogeneity. Thus, Cu-poor films are not only favorable because of lower concentrations of deep defects but also because of reduced bandgap variations.
Preliminary results of the 105 GHz collective Thomson scattering system on HL-2A
Authors: Deng W. C. , Shi Z. B. , Shi P. W. , Yang Z. C. , Chen W. , Huang M. , Zhang F. , Yu X. , Jiang M. , Wen J. , Liang A. S. , Shen Y. Q. , Zhou Y. , Tong R. H. , Zhong W. L.
Published: September 2023

A 105 GHz collective Thomson scattering (CTS) diagnostic has been successfully developed for fast-ion measurements on the HL-2A tokamak, and it has been deployed during an experimental campaign. Enhanced signals exhibiting synchronous modulation characteristics have been observed across all CTS channels upon the launch of a modulated probe wave. Results show that the intensity of the CTS signal increases with Neutral Beam Injection (NBI) power and is proportional to neutron count, indicating that the scattering signal contains a contribution from fast ions. Compared with the signal without NBI, the enhanced scattering spectrum due to NBI is slightly wider than the predicted fast ion range. Such broadening might be attributed to the heating effects of the gyrotron.
Monotone complexity measures of multidimensional quantum systems with central potentials
Authors: Dehesa Jesús S.
Published: September 2023

In this work, we explore the (inequality-type) properties of the monotone complexity-like measures of the internal complexity (disorder) of multidimensional non-relativistic electron systems subject to a central potential. Each measure quantifies the combined balance of two spreading facets of the electron density of the system. We show that the hyperspherical symmetry (i.e., the multidimensional spherical symmetry) of the potential allows Cramér–Rao, Fisher–Shannon, and Lopez-Ruiz, Mancini, Calbet–Rényi complexity measures to be expressed in terms of the space dimensionality and the hyperangular quantum numbers of the electron state. Upper bounds, mutual complexity relationships, and complexity-based uncertainty relations of position–momentum type are also found by means of the electronic hyperangular quantum numbers and, at times, the Heisenberg–Kennard relation. We use a methodology that includes a variational approach with a covariance matrix constraint and some algebraic linearization techniques of hyperspherical harmonics and Gegenbauer orthogonal polynomials.
Correlation between crystallite size, resistance to oxidation, and phase transformation of germanium-doped Fe3O4 nanocrystalline thin films by using a sputtering target of α-Fe2O3
Authors: Abe Seishi
Published: September 2023

We investigated the correlation between the crystallite size, resistance to oxidation, and phase transition of Ge-doped Fe3O4 nanocrystalline thin films. We prepared thin films on water-cooled glass substrates by radiofrequency sputtering with Ge-tipped α-Fe2O3 ceramic disks as targets. The addition of Ge caused a reductive phase transition from α-Fe2O3 with a corundum structure to Ge-doped Fe3O4 with an inverse spinel structure, resulting in a crystallite size of <10 nm. We annealed three samples with average sizes of 5, 8, and 10 nm by changing Ge addition concentrations at 673 K in air for up to 323 days until reaching near-thermal equilibrium. All samples maintained their magnetization at almost a constant value over long-term heat treatment. The results of Raman spectroscopy and optical transmittance spectroscopy suggest that there was a phase transition to Ge-doped γ-Fe2O3 at 5 nm, Ge-doped Fe3−δO4 with iron vacancies δ at 8 nm, and Ge-doped Fe3O4 at 10 nm. In other words, we retained Fe3O4 down to a relatively small crystallite size of 10 nm because of the improved oxidation resistance imparted by Ge doping.
Coherence effects on the interference colors of soap films
Authors: Lalli Navraj S. , Giusti Andrea
Published: September 2023

Acquiring the thickness field of a soap film from interference colors requires an accurate relationship between color and film thickness. Throughout the literature, an interference relation derived using monochromatic waves is widely used to calculate the colors of soap films illuminated by light sources with significant frequency bandwidths by applying the relation at a number of discrete wavelengths in the source, which assumes that the interfering waves are perfectly coherent. However, since the coherence between waves is expected to decrease with increasing film thickness, it is poorly understood when interference relations derived using monochromatic waves can be applied. In this study, an interference relation incorporating the coherence between interfering waves is derived. The effects of coherence on the interference colors of soap films are then studied by comparing the colors computed using each of these two interference relations for light sources with different frequency bandwidths. As the frequency bandwidth of the light source increases, the difference in the colors computed using each interference relation increases, which implies that the accuracy of the method involving the monochromatic relation decreases with increasing frequency bandwidth of the source. The findings of this study will allow for more accurate measurements of the thickness of soap films from their interference colors.
Entropic stress of grafted polymer chains in shear flow
Authors: Mees Jan , O’Connor Thomas C. , Pastewka Lars
Published: September 2023

We analyze the shear response of grafted polymer chains in shear flow via coarse-grained molecular dynamics simulations with an explicit solvent. We find that the solvent flow penetrates into almost the whole brush for “mushroom”-type brushes but only a few bond distances for dense brushes. In all cases, the external stress on the wall equals the entropic stress associated with the distorted polymer conformations. We find that the external stress increases linearly with shear rate at low rates and sublinearly at high rates. The transition from linear to sublinear scaling occurs where chains react to flow by reorienting. Sublinear scaling with shear rate disappears if the shear rate is nondimensionalized with the effective relaxation time of chain subsegments located in the outer part of the brush that experiences flow.
Efficiency of charge transfer in changing the dissociation dynamics of OD+ transients formed after the photo-fragmentation of D2O
Authors: Iskandar W. , Rescigno T. N. , Orel A. E. , Severt T. , Larsen K. A. , Streeter Z. L. , Jochim B. , Griffin B. , Call D. , Davis V. , McCurdy C. W. , Lucchese R. R. , Williams J. B. , Ben-Itzhak I. , Slaughter D. S. , Weber Th.
Published: September 2023

We present an investigation of the relaxation dynamics of deuterated water molecules after direct photo-double ionization at 61 eV. We focus on the very rare D+ + O+ + D reaction channel in which the sequential fragmentation mechanisms were found to dominate the dynamics. Aided by theory, the state-selective formation and breakup of the transient OD+(a1Δ, b1Σ+) is traced, and the most likely dissociation path—OD+: a1Δ or b1Σ+ → A 3Π → X 3Σ− → B 3Σ−—involving a combination of spin–orbit and non-adiabatic charge transfer transitions is determined. The multi-step transition probability of this complex transition sequence in the intermediate fragment ion is directly evaluated as a function of the energy of the transient OD+ above its lowest dissociation limit from the measured ratio of the D+ + O+ + D and competing D+ + D+ + O sequential fragmentation channels, which are measured simultaneously. Our coupled-channel time-dependent dynamics calculations reproduce the general trends of these multi-state relative transition rates toward the three-body fragmentation channels.
Measuring carrier diffusion in MAPbI3 solar cells with photocurrent-detected transient grating spectroscopy
Authors: Ouyang Zhenyu , Gan Zijian , Yan Liang , You Wei , Moran Andrew M.
Published: September 2023

Conventional time-of-flight methods can be used to determine carrier mobilities for photovoltaic cells in which the transit time between electrodes is greater than the RC time constant of the device. To measure carrier drift on sub-ns timescales, we have recently developed a two-pulse time-of-flight technique capable of detecting drift velocities with 100-ps time resolution in perovskite materials. In this method, the rates of carrier transit across the active layer of a device are determined by varying the delay time between laser pulses and measuring the magnitude of the recombination-induced nonlinearity in the photocurrent. Here, we present a related experimental approach in which diffractive optic-based transient grating spectroscopy is combined with our two-pulse time-of-flight technique to simultaneously probe drift and diffusion in orthogonal directions within the active layer of a photovoltaic cell. Carrier density gratings are generated using two time-coincident pulse-pairs with passively stabilized phases. Relaxation of the grating amplitude associated with the first pulse-pair is detected by varying the delay and phase of the density grating corresponding to the second pulse-pair. The ability of the technique to reveal carrier diffusion is demonstrated with model calculations and experiments conducted using MAPbI3 photovoltaic cells.
Low lattice thermal conductivity of two-dimensional monolayers of BxN (x = 2, 3, and 5) induced by complex bonding networks: A comparative study with h-BN
Authors: Tang Zhunyun , Wang Xiaoxia , Li Jin , He Chaoyu , Chen Mingxing , Li Xinghua , Tang Chao , Ouyang Tao
Published: September 2023

It is well known that different bonding networks could bring a wide variety of physical properties to the materials although they hold analogous element and structure features. In this paper, we present a first-principles calculation about the lattice dynamics and phonon transport properties of two-dimensional (2D) boron-rich material BxN (x = 2, 3, and 5). The calculations show that besides the obvious differences in electrical properties compared to h-BN, the special bonding environment in these boron-rich materials also results in quite different phonon behaviors, where their thermal conductivity is at least one order of magnitude smaller than that of h-BN. By performing bonding and lattice dynamics analysis, we reveal that such dramatic reduction of conductivity is attributed to the synergistic effect of weak bond strength (low phonon group velocity) and complex bonding network (strong phonon scattering). Relative regular residual analysis further indicates that the four-phonon process is limited in BxN, and the three-phonon scattering is sufficient to describe their anharmonicity. Starting from the basic physical mechanism, the present study sheds light on the thermal transport properties of 2D boron-rich BxN compounds, which could provide useful insight for their widespread applications in thermal management.
Research on shape identification of vacuum leakage hole based on improved VMD
Authors: Qi Lei , Ou Xiaoyu , Tian Kexin , Cui Yuhao , Sun Jing , Sun Lichen , Xiao Qingsheng , Wang Lina
Published: September 2023

With the increasing number of space debris and extreme working environment, the space station faces the risk of cabin damage. Once the leakage occurs, it must be repaired in time. Identifying the shape of leaks can guide for astronauts to make plugging plans. The current research on leak identification methods is mostly aimed at circular leaks with different diameters, and there is little research on leak identification with different shapes. Therefore, it is of great significance to research leak shape identification methods. A method for identifying the shape categories of vacuum leaks based on improved variational mode decomposition and support vector machine is proposed in this paper: first, using the improved algorithm to determine the uniform number of modes K and adaptively optimize the quadratic penalty coefficient α. Then, apply the variational mode decomposition to the leakage signal and calculate each mode’s maximum frequency. Setting these frequencies as eigenvalues for training and testing the identification model is based on support vector machine. In the experiment, four shapes of the leaks were used: ellipse, rectangle, round, and square. The experiment proves that this proposed method has stable and high identification accuracy, and can realize the shapes categories identification for the leaks, which can provide an important basis for spacecraft in-orbit leakage maintenance.
CoFeSn, a possible contender for spintronics: A first-principles study
Authors: Dhawan Rakshanda , Chaudhary Vikrant , Vishwakarma Chandan Kumar , Zeeshan Mohd , Nautiyal Tashi , Brink Jeroen van den , Kandpal Hem C.
Published: September 2023

Anomalous carrier transport in magnetic Heusler compounds has evolved as a lively field of research owing to their unusual band structure and broken time-reversal symmetry. They have attractive properties for spintronics due to their high Curie temperature (Tc), high spin polarization, and extravagant transport properties. Here, we scrutinize CoFeSn. Based on the inferences from structural stability, lattice dynamics, and magnetic analysis, we propose a cubic polymorph of hexagonal CoFeSn and explain why we must consider cubic CoFeSn. Through density-functional-theory calculations, we predict a robust 3D half-metallic ferromagnetic compound, CoFeSn (P4¯3m) with a Tc ∼ 693 K, calculated via the Heisenberg magnetic exchange interactions under mean-field approximation, and a magnetic moment of 3 μB. In addition, Wannier interpolation suggests anomalous Hall conductivity (AHC) and spin Hall conductivity (SHC) in cubic CoFeSn, the largest SHC at the Fermi level being ≈ 47 (h/2πe) S/cm. Our theoretical results show that spin–orbit interaction at the Fermi level brings on finite Berry flux that gives an intrinsic AHC ∼ 122 S/cm at room temperature. We note that adjusting the Fermi level can be a sensible way to achieve high values of AHC or SHC. Our findings pave the way for the realization of the quantum anomalous and spin Hall effect in half-Heusler compounds.
Effect of outer-cylinder rotation on the radially heated Taylor–Couette flow
Authors: Aghor Pratik , Atif Mohammad
Published: September 2023

A Taylor–Couette setup with radial heating is considered where a Boussinesq fluid is sheared in the annular region between two concentric, independently rotating cylinders maintained at different temperatures. Linear stability analysis is performed to determine the Taylor number for the onset of instability. Two radius ratios corresponding to wide and thin gaps with several rotation rate ratios are considered. The rotation of the outer cylinder is found to have a general stabilizing effect on the stability threshold as compared to pure inner-cylinder rotation, with a few exceptions. The radial heating sets up an axial flow which breaks the reflection symmetry of isothermal Taylor–Couette flow in the axial coordinate. This symmetry breaking separates linear stability thresholds, and we find the fastest growing modes with both positive and negative azimuthal numbers for different parameters. Another important finding of the current study is the discovery of unstable modes in the Rayleigh-stable regime. Furthermore, closed disconnected neutral curves (CDNCs) are observed for both wide and thin gaps which can separate from or merge into open neutral–stability curves. Alternatively, CDNCs can also morph into open neutral stability curves as the rotation rate ratio is changed. CDNCs are observed to be sensitive to changes in control parameters, and their appearance/disappearance is shown to induce discontinuous jumps in the critical Taylor number. For both wide and thin gaps, the fastest-growing modes found in the pure corotation case are shown to have their origins in the instability islands at smaller values of rotation rate ratios.
A scalable electronic analog of the Burridge–Knopoff model of earthquake faults
Authors: Perinelli Alessio , Iuppa Roberto , Ricci Leonardo
Published: September 2023

The Burridge–Knopoff model implements an earthquake fault as a mechanical block-spring chain. While numerical studies of the model are abundant, experimental investigations are limited to a two-blocks, analog electronic implementation that was proposed by drawing an analogy between mechanical and electrical quantities. Although elegant, this approach is not versatile, mostly because of its heavy reliance on inductors. Here, we propose an alternative, inductorless implementation of the same system. The experimental characterization of the proposed circuit shows very good agreement with theoretical predictions. Besides periodic oscillations, the circuit exhibits a chaotic regime: the corresponding markers of chaoticity, namely, the correlation dimension and the maximum Lyapunov exponent, were experimentally assessed to be consistent with those provided by numerical simulations. The improved versatility and scalability of the circuit is expected to allow for experimental implementations of the Burridge–Knopoff model with a large number of blocks. In addition, the circuit can be used as the basic element of scalable platforms to investigate the dynamics of networks of oscillators and related phenomena.