bluuebunny/crossref_metadata_2025 huggingface dataset:
Solvation entropy, enthalpy and free energy prediction using a multi-task deep learning functional in 1D-RISM
Authors: Fowles Daniel J. , Palmer David S.
Published: February 2023

A deep learning functional for the 1D Reference Interaction Site Model (1D RISM) enables accurate predictions of solvation entropy, enthalpy and free energy.
Sequence-dependent fusion dynamics and physical properties of DNA droplets
Authors: Sato Yusuke , Takinoue Masahiro
Published: February 2023

Physical properties of DNA droplets formed by liquid–liquid phase separation of DNA nanostructures were investigated at a phase transition temperature. The surface tension was strongly influenced by the design of sticky ends.
Tuning the emission and lighting the circularly polarized luminescence of polyfluorene by incorporating a non-emissive polycarbene
Authors: Wang Chao , Zhou Li , Zhu Yuan-Yuan , Liu Na , Wu Zong-Quan
Published: February 2023

Polyfluorenes carrying a Ni(ii)-terminal were first prepared via Ni(ii)-catalyzed quasi-living Kumada catalyst-transfer polymerization, and poly(fluorene)-b-polycarbene copolymers with high optical activity and CPL were obtained in one pot.
FinO/ProQ-family proteins: an evolutionary perspective
Authors: Liao Zhen , Smirnov Alexandre
Published: February 2023

RNA-binding proteins are key actors of post-transcriptional networks. Almost exclusively studied in the light of their interactions with RNA ligands and the associated functional events, they are still poorly understood as evolutionary units. In this review, we discuss the FinO/ProQ family of bacterial RNA chaperones, how they evolve and spread across bacterial populations and what properties and opportunities they provide to their host cells. We reflect on major conserved and divergent themes within the family, trying to understand how the same ancestral RNA-binding fold, augmented with additional structural elements, could yield either highly specialised proteins or, on the contrary, globally acting regulatory hubs with a pervasive impact on gene expression. We also consider dominant convergent evolutionary trends that shaped their RNA chaperone activity and recurrently implicated the FinO/ProQ-like proteins in bacterial DNA metabolism, translation and virulence. Finally, we offer a new perspective in which FinO/ProQ-family regulators emerge as active evolutionary players with both negative and positive roles, significantly impacting the evolutionary modes and trajectories of their bacterial hosts.
Describing the Spoken Language Skills of Typically Developing Afrikaans-Speaking Children Using Language Sample Analysis: A Pilot Study
Authors: Liebenberg Petria , van der Linde Jeannie , Schimper Isabella , de Wet Febe , Graham Marien , Bornman Juan
Published: February 2023

Purpose:

Language sample analysis is widely regarded as the gold standard of language assessment. However, the uncertainty regarding the optimal length of sample and the limited availability of developmental language data for nonmainstream languages such as Afrikaans complicate reliable use of the method. The study aimed to provide guidelines on representative length of sample and concurrently provide a preliminary description of the spoken language skills of Afrikaans-speaking children.

Method:

The study involved 30 typically developing Afrikaans-speaking children aged between 3;6 and 9;6 (years;months). A descriptive research design was used to transcribe and analyze 1-hr interactions collected in natural environments of participants who were recruited using referral sampling. Video and audio recordings of the samples were transcribed using adapted Sampling Utterances and Grammatical Analysis Revised analysis procedures.

Results:

Results indicated that mean length of utterance in words per minute, number of different words per minute, and total number of words per minute stabilized at 30 min and no significant differences were found between 30 min and longer time segments. Morphology results concur with existing developmental findings in Afrikaans. Lexical diversity results correlated with the findings of the lexical specificity and accuracy in the Prutting and Kirchner Pragmatic Protocol (Prutting & Kirchner, 1987). The developmental trajectories for pragmatic and phonological development were consistent with existing guidelines.

Conclusions:

The study concluded that a 30-min interaction segment provides a representative language sample for Afrikaans-speaking children who are between 3;6 and 9;6. It provides promising preliminary developmental data and clinical guidelines, confirming the potential of language sample analysis (LSA) as a reliable component of language assessment in Afrikaans.
The Influence of Language Background on Dichotic Listening in Primary School Children
Authors: Brännström K. Jonas , Rudner Mary , Carlie Johanna , Andersson Ketty , Johansson Roger , Gulz Agneta , Sahlén Birgitta
Published: February 2023

Purpose:

Dichotic speech tests are commonly used in audiological assessments of children with suspected listening difficulties, which may have a range of origins. In Sweden, today, one in four primary schoolchildren has a foreign background, which means that a large proportion of children will be assessed through the medium of a language that they speak at school, but it is not the language they regularly speak at home. This study examines dichotic listening ability among children attending primary schools in two cities in southern Sweden with a high proportion of recent immigrants.

Method:

In this study, 82 Swedish second and third graders aged 7–9 years with varying Swedish language exposure performed a dichotic listening task, under free recall and directed conditions. They also performed backward digit span as a measure of working memory and crosslinguistic nonword repetition, which is central for language learning.

Results:

We found no effect of Swedish language exposure on dichotic listening performance. Right ear was not significantly better than the left ear in either free or directed recall indicating no right ear advantage. Dichotic listening performance was significantly better in free recall compared with directed recall. Dichotic listening was related to working memory capacity. After controlling for working memory capacity, nonword repetition showed a significant positive association with dichotic listening under free recall but not directed recall.

Conclusions:

Test language exposure and knowledge do not seem to influence primary school children's performance on a dichotic digit task. Performance was related to working memory capacity and the complex skill of perceiving, coding, and producing novel words in a nonword repetition task. In clinical practice, both tests of working memory capacity and crosslinguistic nonword repetition may inform the interpretation of dichotic listening results in children with diverse language backgrounds.
Picosecond pulses with 40 W peak power from a passively mode‐locked tapered quantum well laser
Authors: Wohlfeil Shulin , Christopher Heike , Fricke Jörg , Wenzel Hans , Knigge Andrea , Tränkle Günther
Published: February 2023

In this letter, the authors present a monolithic edge emitting diode laser intended as a potential key component for the generation of terahertz radiation in a compact time‐domain spectroscopy system. The 6 mm long multi‐section InGaAsP double quantum well (DQW) laser, featured with a 3.6 mm long tapered (TP) gain section, operates at a wavelength of ∼832 nm and generates pulses at a fundamental repetition rate of ∼6.3 GHz in passive mode‐locking operation. Pulses with 2.6 ps width and 40 W peak power are measured. The generated pulses are not bandwidth‐limited and should be compressible for further applications.
Identification of vulnerable nodes in power grids based on graph deep learning algorithm
Authors: Gu Xueping , Liu Tong , Li Shaoyan , Yang Xiaodong , Cao Xin
Published: February 2023

Comprehensive and timely identification of vulnerable nodes is of great significance to ensure the security of the power system. With the development of power grids, traditional identification methods for vulnerable nodes with high operational risks can no longer meet the actual operation needs in terms of model accuracy, and it is prone to ignore some critical nodes. In view of this, a method based on graph deep learning is proposed for grid vulnerable nodes identification to realize fast and accurate identification of vulnerable nodes. Firstly, the GraphSAGE algorithm is used to aggregate the operation states of each node and its neighbours. The node attribute information and topology information are mapped to the output layer at the same time to form a comprehensive representation of the node state through non‐linear transformation. Then according to the similarity between the states, the improved K‐means algorithm is used to cluster the nodes so as to realize the identification of vulnerable nodes. The distances between the nodes and the vulnerability centre are calculated to rank the node vulnerabilities. Finally, the effectiveness and feasibility of the proposed method are verified by the simulation results of the IEEE 30‐bus system and a practical power system.
Systematic protective scheme for mega‐city power systems against stray currents caused by metro systems
Authors: Guo Yujun , Du Qing , Liu Yijie , Yang Feng , Chen Lu , Zhang Xueqin , Xiao Song , Li Chunmao , Wu Guangning
Published: February 2023

In modern megacities, stray currents from metro systems intrude into multiple transformers' neutral points becoming a potential threat to the high‐capacity transformers. Neutral current anomalies are exacerbated in unprotected substations when we instal guards at single stations. This paper presents a system protection strategy for multiple substations affected by stray currents in modern megacities. The model, taking Shanghai as an example, includes the spatial distribution information of the urban electrical energy transmission structure, the power system, and the metro system. A Particle swarm algorithm is used to calculate the resistance values of the devices for each station. Further stability tests are performed to select the optimal protection solution. The results show that when protection is considered as a system, the protection runs well and the neutral current level remains below the unprotected level when the protection fails at a single station or multiple stations.
Adopting metaverse‐related mixed reality technologies to tackle urban development challenges: An empirical study of an Australian municipal government
Authors: An Aaron
Published: February 2023

Fast‐growing urban areas bring challenges to government authorities. The urban planning system in Australia is still very analogue with paper‐based systems as standard practice. Two‐dimensional document‐based blueprints and Geographic Information System (GIS) maps do not always give stakeholders and investors the necessary insights. By exploring Mixed Reality (MR) application at the municipal government level, this research explains how metaverse‐related immersive technologies can assist the government in better engaging with stakeholders and potential partners to improve their understanding of the urban environment and showcase future city developments to foster new opportunities and contribute to the development of the real living world.
The kinematics of the magnetized protostellar core IRAS15398-3359
Authors: Tabatabaei Farideh S. , Redaelli Elena , Caselli Paola , Alves Felipe O.
Published: February 2023

Context. Observations of protostellar envelopes are essential in order to understand better the process of gravitational collapse toward star and planet formation. From a theoretical perspective, magnetic fields are considered an important factor during the early stages of star formation, especially during the main accretion phase.

Aims. Our aim is to study the relation between kinematics and magnetic fields at a very early stage of the star formation process by using data from the Atacama Pathfinder EXperiment (APEX) single-dish antenna with an angular resolution of 28".

Methods. We observed the two molecular lines C18O (2–1) and DCO+ (3–2) toward the Class 0 young stellar object IRAS15398-3359. We implemented a multi-component Gaussian fitting on the molecular data to study the kinematics. In addition, we used previous polarization observations on this source to predict the influence of the magnetic field on the core.

Results. The velocity gradient along the central object can be explained as an ongoing outflow motion. We report the flowing of material from the filament toward the central object, and the merging of two velocity components in the C18O (2–1) emission around the protostar position, probably due to the merging of filamentary clouds. Our analysis shows that the large-scale magnetic field line observed previously is preferentially aligned to the rotation axis of the core.
Estimating the longitudinal magnetic field in the chromosphere of quiet-Sun magnetic concentrations
Authors: Esteban Pozuelo S. , Asensio Ramos A. , de la Cruz Rodríguez J. , Trujillo Bueno J. , Martínez González M. J.
Published: February 2023

Context. Details of the magnetic field in the quiet-Sun chromosphere are key to our understanding of essential aspects of the solar atmosphere. However, the strength and orientation of this magnetic field have not been thoroughly studied at high spatial resolution.

Aims. We aim to determine the longitudinal magnetic field component (B∥) of quiet-Sun regions depending on their size.

Methods. We estimated B∥ by applying the weak-field approximation to high-spatial-resolution Ca II 854.2 nm data taken with the Swedish 1 m Solar Telescope. Specifically, we analyzed the estimates inferred for different spectral ranges using the data at the original cadence and temporally integrated signals.

Results. The longitudinal magnetic field in each considered plasma structure correlates with its size. Using a spectral range restricted to the line core leads to chromospheric longitudinal fields varying from ∼50 G at the edges to 150–500 G at the center of the structure. These values increase as the spectral range widens due to the photospheric contribution. However, the difference between this contribution and the chromospheric one is not uniform for all structures. Small and medium-sized concentrations show a steeper height gradient in B∥ compared to their chromospheric values, so estimates for wider ranges are less trustworthy. Signal addition does not alleviate this situation as the height gradients in B∥ are consistent with time. Finally, despite the amplified noise levels that deconvolving processes may cause, data restored with the destretching technique show similar results, though are affected by smearing.

Conclusions. We obtained B∥ estimates similar to those previously found, except for large concentrations and wide spectral ranges. In addition, we report a correlation between the height variation of B∥ compared to the chromospheric estimates and the concentration size. This correlation affects the difference between the photospheric and chromospheric magnetic flux values and the reliability of the estimates for wider spectral ranges.
Scattered polarized radiation of extrasolar circumplanetary rings
Authors: Lietzow M. , Wolf S.
Published: February 2023

Aims. We have investigated the impact of circumplanetary rings consisting of spherical micrometer-sized particles on the net scattered light polarization of extrasolar gas giants.

Methods. Using the three-dimensional Monte Carlo radiative transfer code POLARIS, we studied the impact of the macroscopic parameters that define the ring, such as its radius and inclination, and the chemical composition of the ring particles on the net scattered polarization. For the spherical ring particles, we applied the Mie scattering theory. We studied the flux and polarization of the scattered stellar radiation as a function of planetary phase angle and wavelength from the optical to the near-infrared.

Results. For the chosen grain size distribution, the dust particles in the ring show strong forward scattering at the considered wavelengths. Thus, the reflected flux of the planet dominates the total reflected and polarized flux at small phase angles. However, the scattered and polarized flux of the ring increase at large phase angles and exceeds the total reflected planetary flux. For large rings that contain silicate particles, the total reflected flux is dominated by the radiation scattered by the dust in the ring at all phase angles. As a result, the orientation of polarization is parallel to the scattering plane at small phase angles. In contrast, for a ring that contains water ice particles, the orientation of polarization is parallel to the scattering plane at large phase angles. Depending on the ring inclination and orientation, the total reflected and polarized flux show a specific distribution as well. Large particles show a strong polarization at large phase angles compared to smaller particles. For a Jupiter-like atmosphere that contains methane and aerosols, methane absorption features are missing in the spectrum of a ringed planet.

Conclusions. Scattering of the stellar radiation by dust in circumplanetary rings of extrasolar planets results in unique features in the phase-angle- and wavelength-dependent reflected and polarized net flux. Thus, exoplanet polarimetry provides the means to study not only the planetary atmosphere and surface, but also to identify the existence and constrain the properties of exoplanetary rings.
Toward a global quantum network
Authors: Pan Jian-Wei
Published: February 2023

About 90 years ago, Albert Einstein complained about the “spooky action at a distance” of quantum entanglement and questioned the completeness of quantum mechanics [1]. This year, the Nobel Prize is awarded to three pioneers that put Einstein’s curiosity under experimental tests based on Bell’s inequality [2]. The fundamentals of quantum mechanics are not of just theoretical or philosophical interest. Rather, worldwide efforts are harnessing these quantum weirdness to develop emerging technologies.
Entanglement, causality and quantum networks
Authors: Polino Emanuele , Sciarrino Fabio
Published: February 2023

Quantum nonlocality, generated by strong correlations between entangled systems, defies the classical view of nature based on standard causal reasoning plus physical assumptions. The new frontier of the research on entanglement is to explore quantum correlations in complex networks, involving several parties and generating new striking quantum effects. We present recent advances on the realization of photonic quantum networks.
A new and general stochastic parallel machine ScheLoc problem with limited location capacity and customer credit risk
Authors: Liu Ming , Lin Tao , Chu Feng , Zheng Feifeng , Chu Chengbin
Published: February 2023

Scheduling-Location (ScheLoc) problem considering machine location and job scheduling simultaneously is a relatively new and hot topic. The existing works assume that only one machine can be placed at a location, which may not be suitable for some practical applications. Besides, the customer credit risk which largely impacts the manufacturer’s profit has not been addressed in the ScheLoc problem. Therefore, in this work, we study a new and general stochastic parallel machine ScheLoc problem with limited location capacity and customer credit risk. The problem consists of determining the machine-to-location assignment, job acceptance, job-to-machine assignment, and scheduling of accepted jobs on each machine. The objective is to maximize the worst-case probability of manufacturer’s profit being greater than or equal to a given profit (referred to as the profit likelihood). For the problem, a distributionally robust chance-constrained (DRCC) programming model is proposed. Then, we develop two model-based approaches: (1) a sample average approximation (SAA) method; (2) a model-based constructive heuristic. Numerical results of 300 instances adapted from the literature show the average profit likelihood proposed by the constructive heuristic is 9.43% higher than that provided by the SAA, while the average computation time of the constructive heuristic is only 4.24% of that needed by the SAA.
Case Management für Personen mit Pflegebedarf und
gebrechliche ältere Personen
Authors: Herberg Stephan , Teuteberg Frank , Zerth Jürgen
Published: February 2023

Eine wachsende Fallschwere, höheres Lebensalter und teilweise nicht
vorhandene familiäre Betreuungsnetze führen dazu, dass die
Koordination von medizinisch-pflegerischen Leistungen und sozialen
Unterstützungsleistungen nicht in jedem Fall zu einer adäquaten
Versorgungssituation beitragen. Um Menschen soweit als möglich im
eigenen Lebens- und Betreuungsumfeld zu halten, ist ein adjustierter Care-Mix
zwischen Familienpflege und professioneller Pflege notwendig.

Die Betreuung eines vulnerablen Personenkreises durch professionelle wie
informelle Akteure bedarf allerdings einer professionellen Koordination. Das
Prinzip des Case Managements kann in fast idealtypischer Weise eingesetzt
werden, um professionelle und informelle Akteure in einen Care-Prozess zu
integrieren und sowohl medizinische Leistungen als auch Pflege- und
Betreuungsleistungen im dazu nötigen Setting auszubalancieren.

Eine stärke Koordination von Pflegeleistungen ist als Notwendigkeit
weithin anerkannt. In verschiedenen Projektansätzen werden
Ansätze wie Case Management, Pflegelosten, professionelle
Krankenhausnachbetreuung und Gemeindeschwesteransätze erprobt und
gelebt.

Die Auswertung internationaler Studien im Bereich des Case Managements zeigen
grundsätzlich eine proaktivere Herangehensweise an, mit der Empfehlung,
eine für ein zielführendes Case Management frühzeitigere
und spezifischere Fallauswahl vorzunehmen. Die klare Definition der
Einschlusskriterien, die Konzentration auf Patient*innen mit einer hohen
Wiederaufnahmewahrscheinlichkeit und ein intensives Case Management
können so zu effektiveren Versorgungsergebnissen und reduzierten
Inanspruchnahmen von Leistungen führen.

In diesem Beitrag soll die Frage diskutiert werden, ob die bestehenden Beratungs-
und Lotsenangebote gebündelt, fusioniert und zu einer Case
Management-Organisation weiterentwickelt werden können. Insbesondere,
falls sich die bestehenden Angebote überschneiden und vorhandene
Ressourcen nicht ausreichend koordiniert werden.

Es sollen insbesondere Organisationsstrukturen aufgezeigt werden, in denen Case
Management langfristig verortet werden könnte. Hier gilt es die
Bedeutung der eigenständigen pflegeinfrastrukturellen Rolle eines
erweiterten Case Managements zu verdeutlichen.
The Use of Montage Bone Putty in Assisting in the Maintenance of Reduction in Comminuted Distal Radius Fractures
Authors: Pien Irene J. , Jain Nirbhay S. , Benhaim Prosper , Yaghoubian Arezou , Azari Kodi K.
Published: February 2023

Background The distal radius fracture is the most common fracture in the United States. Achieving stable reduction and fixation of complex fracture patterns can be challenging. In order to help maintain reduction of comminuted fracture to simplify plating, the calcium phosphate-based bone putty Montage has been developed.

Questions/Purposes Does Montage assist in achieving stable reduction and fixation of complex distal radius fractures with an acceptable complication profile?

Patient and Methods We retrospectively analyzed all patients who were treated intraoperatively with Montage bone putty along with volar plate fixation at a large-volume urban county hospital. Preoperative, intraoperative, and postoperative measurements of radiographic features were recorded at 2 and 6 months, as were any complications. Statistical analysis was then performed on these values.

Results Preoperative and postoperative radiographs demonstrated significant improvement in standard distal radius fracture measurements, reflecting adequate reduction with the use of Montage intraoperatively. Critically, radiographs demonstrated maintenance of reduction compared to intraoperative fluoroscopy images at 2 months, showing short-term stability of the use of Montage in these fracture patterns as well as long-term stability at 6 months in a subset of patients. There were no major complications in this study.

Conclusion In this study, we demonstrate the utility of Montage bone putty for complex distal radius fractures with short-term follow-up and limited long-term follow-up. This initial study underlines its efficacy in maintaining reduction without major complications.

Level of Evidence IV, Therapeutic
Additive engineering enables efficient, stable perovskite solar cells
Authors: Piccone Ashley
Published: February 2023

Perovskite films with additives have bigger grains and better crystallinity, decreasing the density of defects.
An efficiency-driven, correlation-based feature elimination strategy for small datasets
Authors: Rickert Carolin A. , Henkel Manuel , Lieleg Oliver
Published: February 2023

With big datasets and highly efficient algorithms becoming increasingly available for many problem sets, rapid advancements and recent breakthroughs achieved in the field of machine learning encourage more and more scientific fields to make use of such a computational data analysis. Still, for many research problems, the amount of data available for training a machine learning (ML) model is very limited. An important strategy to combat the problems arising from data sparsity is feature elimination—a method that aims at reducing the dimensionality of an input feature space. Most such strategies exclusively focus on analyzing pairwise correlations, or they eliminate features based on their relation to a selected output label or by optimizing performance measures of a certain ML model. However, those strategies do not necessarily remove redundant information from datasets and cannot be applied to certain situations, e.g., to unsupervised learning models. Neither of these limitations applies to the network-based, correlation-driven redundancy elimination (NETCORE) algorithm introduced here, where the size of a feature vector is reduced by considering both redundancy and elimination efficiency. The NETCORE algorithm is model-independent, does not require an output label, and is applicable to all kinds of correlation topographies within a dataset. Thus, this algorithm has the potential to be a highly beneficial preprocessing tool for various machine learning pipelines.
Lipschitz continuity under toric equivalence for asynchronous Boolean networks
Authors: Chen Ricky X. F. , McNitt Joseph A. , Mortveit Henning S. , Pederson Ryan D. , Reidys Christian M.
Published: February 2023

Mathematical models rooted in network representations are becoming increasingly more common for capturing a broad range of phenomena. Boolean networks (BNs) represent a mathematical abstraction suited for establishing general theory applicable to such systems. A key thread in BN research is developing theory that connects the structure of the network and the local rules to phase space properties or so-called structure-to-function theory. While most theory for BNs has been developed for the synchronous case, the focus of this work is on asynchronously updated BNs (ABNs) which are natural to consider from the point of view of applications to real systems where perfect synchrony is uncommon. A central question in this regard is sensitivity of dynamics of ABNs with respect to perturbations to the asynchronous update scheme. Macauley & Mortveit [Nonlinearity 22, 421–436 (2009)] showed that the periodic orbits are structurally invariant under toric equivalence of the update sequences. In this paper and under the same equivalence of the update scheme, the authors (i) extend that result to the entire phase space, (ii) establish a Lipschitz continuity result for sequences of maximal transient paths, and (iii) establish that within a toric equivalence class the maximal transient length may at most take on two distinct values. In addition, the proofs offer insight into the general asynchronous phase space of Boolean networks.
Influence of boron implantation induced defects on solar cells: Modeling the process defects
Authors: Masilamani Sangaravadivel , Ammapet Vijayan Ramachandran , Varadharajaperumal Muthubalan
Published: February 2023

The effect of process-induced defects on the photo-generated charge-carrier lifetime and solar cell performance is critical, which will help optimize the process recipe. In this work, we attempt to quantify the effects of process-induced defects during boron implantation on the n-type silicon wafer in different annealing ambiences. We have evaluated the role of defects that can be formed during oxygen and inert ambience annealing on n-type bifacial passivated emitter rear totally diffused solar cells using a recombination current prefactor (J0). The numerically calculated J0 is calibrated with the reported experimental J0 values using two different methods: (i) Shockley–Read–Hall lifetime and (ii) effective trap-density method. In the latter method, we used the simulated defect density profiles. Both methods capture the process-induced degradation. We observed that the process-induced defects could deteriorate by almost 1% absolute efficiency for the considered annealing conditions. We found that dislocation loops alone cause an ignorable effect on terminal characteristics, but other process-induced mechanisms could dominantly degrade the cell's performance. To further support, we show that independent defects (apart from coupled defects) other than dislocation loops could explain the experimentally reported boron-implanted diodes’ J–V curves under reverse bias conditions.
A comparative study to determine the photovoltaic annual energy generation in the Brazilian Northeast
Authors: Alencar M. R. B. , Souza B. A.
Published: February 2023

Renewable energy sources have been growing worldwide and solar energy is a significant part of such sources. An essential step in planning studies, including the problem of optimal location and sizing of photovoltaic (PV) generators, is estimating how much energy the panels will generate over time. For that, two aspects must be considered: the stochastic nature of the input variables and the way to calculate the generator's output power. A brief literature review identified 12 approaches to determine the PV output power. Therefore, this article compares such methods through actual meteorological data and generated energy over 1 year by a solar power plant located in a specific site in the Brazilian Northeast. An analysis is carried out on the influence of correlations between meteorological variables in estimating the generated energy. There is no comparative work in the literature on the analytical models for calculating the PV output power in conjunction with the correlation analysis. As expected, models that consider the influence of ambient temperature on output power performed better than those that do not. How the energy generated by the PV panel is estimated can influence the economic viability of a project since oversizing the PV system entails unnecessary additional costs. Monte Carlo simulations generate data samples used by the studied models for power output calculation. According to our findings, considering the correlation between meteorological variables reduces the error in estimating the generated energy by PV panels.
Characterization of a low-noise superconductor–insulator–superconductor-based microwave amplifier with local oscillator phase-adjusting architecture
Authors: Kojima T. , Masui S. , Shan W. , Uzawa Y.
Published: February 2023

This paper describes a low-noise microwave amplifier based on up- and down-frequency-conversion processes in quasiparticle superconductor–insulator–superconductor (SIS) tunnel junctions. The SIS amplifier was configured with two SIS frequency-converter modules and a cryogenic millimeter-wave isolator inserted between them. Moreover, a local oscillator (LO) using millimeter-wave attenuators and a phase shifter was considered. This setup allowed the control of individual LO power and differential phase in these SIS frequency converters to optimize the amplifier performance. The SIS amplifier showed noise temperatures as low as 11 K and a 6–8 dB gain from nearly DC to 5 GHz. The attained microwave performance is promising for obtaining large-format arrays, such as multibeam heterodyne receivers. Moreover, this two-frequency-converter concept based on SIS junctions might enable microwave applications, such as wideband non-reciprocal circuits in isolators, gyrators, and circulators, which are essential devices in the quantum computing and radio astronomy fields.
Temporal dissipative solitons in the Morris–Lecar model with time-delayed feedback
Authors: Stöhr M. , Wolfrum M.
Published: February 2023

We study the dynamics and bifurcations of temporal dissipative solitons in an excitable system under time-delayed feedback. As a prototypical model displaying different types of excitability, we use the Morris–Lecar model. In the limit of large delay, soliton like solutions of delay-differential equations can be treated as homoclinic solutions of an equation with an advanced argument. Based on this, we use concepts of classical homoclinic bifurcation theory to study different types of pulse solutions and to explain their dependence on the system parameters. In particular, we show how a homoclinic orbit flip of a single-pulse soliton leads to the destabilization of equidistant multi-pulse solutions and to the emergence of stable pulse packages. It turns out that this transition is induced by a heteroclinic orbit flip in the system without feedback, which is related to the excitability properties of the Morris–Lecar model.
Machine learning-aided Genetic algorithm in investigating the structure–property relationship of SmFe12-based structures
Authors: Nguyen Duong-Nguyen , Dam Hieu-Chi
Published: February 2023

We investigate the correlation between geometrical information, stability, and magnetization of SmFe12-based structures using machine learning-aided genetic algorithm structure generation and first-principle calculation. In parallel with structure generation inherited using the USPEX program, a pool of structures is created for every population using the sub-symmetry perturbation method. A framework using embedded orbital field matrix representation as structure fingerprint and Gaussian process as a predictor has been applied to ranking the most potential stability structures. As a result, the original structure SmFe12 with the well-known tetragonal I4/mmm symmetry is investigated with a parabolic dependence between formation energy and its magnetization by continuous distortions of the unit-cell lattice parameter and individual sites. Notably, a SmFe12 structure with I4/mmm symmetry is found with 7.5% increasing magnetization while keeping the similar formation energy with the most stable structures in this family. With SmFe11CoN family, structures with N interstitial position in the center of Sm and Fe octahedron show outperform all other structures in both ability of stabilization and remaining high magnetization of the original structure. Finally, further investigation using metric learning embedding space brings valuable insight into the correlation between geometrical arrangement, stability, and magnetization of this structure family.
Decrypting the mechanisms of wicking and evaporation heat transfer on micro-pillars during the pool boiling of water using high-resolution infrared thermometry
Authors: Wang Chi , Rahman Md Mahamudur , Bucci Matteo
Published: February 2023

Surfaces with micrometer-scale pillars have shown great potential in delaying the boiling crisis and enhancing the critical heat flux (CHF). However, physical mechanisms enabling this enhancement remain unclear. This knowledge gap is due to a lack of diagnostics that allow elucidating how micro-pillars affect thermal transport phenomena on the engineered surface. In this study, for the first time, we are able to measure time-dependent temperature and heat flux distributions on a boiling surface with engineered micro-pillars using infrared thermometry. Using these data, we reveal the presence of an intra-pillar liquid layer, created by the nucleation of bubbles and partially refilled by capillary effects. However, contrarily to conventional wisdom, the energy removed by the evaporation of this liquid cannot explain the observed CHF enhancement. Yet, predicting its dry out is the key to delaying the boiling crisis. We achieve this goal using simple analytic models and demonstrate that this process is driven by conduction effects in the boiling substrates and, importantly, in the intra-pillar liquid layer itself. Importantly, these effects also control the wicking flow rate and its penetration length. The boiling crisis occurs when, by coalescing, the size of the intra-pillar liquid layer becomes too large for the wicking flow to reach its innermost region. Our study reveals and quantifies unidentified physical aspects, key to the performance optimization of boiling surfaces for cooling applications.
A polarization converter array based on microcavity patterned hydrophobic layer induced twisted-radial liquid crystals
Authors: Li Senhao , Zhang Lyudi , Li Jing , Lu Hongbo , Xu Miao
Published: February 2023

We report a facile method to prepare an array of liquid-crystal polarization converters (LCPCA) based on hydrophobic microcavity arrays. The reactive ion etching (RIE) technique was chosen to treat the homeotropic polyimide (PI⊥) layers through a metal mask with a through-hole array. Under the selective RIE treatment, a hydrophobic–hydrophilic pattern is obtained due to the increase in surface energy in the etched area from ∼34.6 to ∼73.2 mN/m. The etched area forms a microcavity with a diameter of 520 μm, depth of ∼23 nm, and center distance of 690 μm, which is consistent with the dimensions of the metal mask. Since the walls of the microcavity retain hydrophobicity, the liquid-crystal (LC) molecules show a radial arrangement in the microcavity. Combining a substrate covered by a parallel rubbed homogeneous polyimide (PI∥) layer with the substrate covered by a microcavity-patterned PI⊥ layer can form a “sandwich” structure. The LC molecules in the microcavities are arranged in a twisted-radial texture, which can convert linearly polarized light to radially or azimuthally polarized light depending on the polarization direction of the incident light. The proposed method has the merits of simple steps, controllable size, and easy to fabricate large-area arrays. Our LCPCA has potential applications in tight focus, material processing, biological tissue analysis, particle capture, and optical data storage.
Quantum identity authentication protocol based on flexible quantum homomorphic encryption with qubit rotation
Authors: Chen Geng , Wang Yuqi , Jian Liya , Zhou Yi , Liu Shiming , Luo Jiawei , Yang Kun
Published: February 2023

Quantum identity authentication (QIA) ensures that entities of quantum communication will not be impersonated by attackers. As an auxiliary protocol, an ideal QIA protocol cannot take up too many quantum resources and needs to be embedded in the original protocol to enhance security. In this paper, we propose a flexible ternary quantum homomorphic encryption (QHE) protocol using qubit rotation and indicate that the QHE framework can be used to design QIA protocols. The ternary QIA protocol based on QHE can be embedded in the original protocol because both protocols use the same quantum resources. The proposed protocol uses different vouchers from previous protocols, allowing it to prevent various types of attacks and performs well in terms of communication efficiency. The QHE framework can benefit other quantum cryptographic fields.
Thermodynamic analysis of electro-optic coefficients of ferroelectrics
Authors: Shirokov V. B. , Timoshenko P. E. , Kalinchuk V. V.
Published: February 2023

The electro-optic coefficients of ferroelectric materials were obtained by Landau thermodynamic theory. It is proved that if the permittivity tensor is diagonal, then some ratios of the electro-optical coefficients are equal to the ratios of its diagonal components. The dependence of electro-optic coefficients on the external electric field for single-crystal barium titanate was studied and discussed. It is shown that electro-optic coefficients are rather high for barium titanate due to a non-linear response of dielectric susceptibility to electric field strength.
General weak segregation theory with an application to monodisperse semi-flexible diblock copolymers
Authors: Jager P. M. , Briels W. J. , Slot J. J. M.
Published: February 2023

A general theory has been developed for a polydisperse semi-flexible multi-block copolymer melt. Using the Bawendi–Freed approach to model semi-flexible chains, an expression for the Landau free energy is derived in the weak segregation regime, which includes density and orientation order-parameters. The orientation order-parameter is described in the smectic phase and in more complicated structures, such as the hexagonal phase. The Landau free energy contains contributions of two kinds of interactions. The first kind is the Flory–Huggins interaction, which describes the incompatibility of chemically different blocks and may induce microphase separation. The second kind is the Maier–Saupe interaction, which may induce nematic ordering. In the framework of the weak segregation limit, the Landau theory allows us to predict phase structures in the melt as a function of the composition, persistence length, and the strength of the Flory–Huggins and Maier–Saupe interaction. The general theory is applied to a simple system of monodisperse semi-flexible diblock copolymers. In several phase diagrams, a number of possible phase structures are predicted, such as the bcc, hexagonal, smectic-A, smectic-C, and nematic phase. The influence of the Maier–Saupe interaction on the microphase structure is thoroughly discussed.
Research on pressure fluctuation induced by tip leakage vortex of axial flow circulating pump under unpowered driven conditions
Authors: Jia XiaoQi , Lv Hao , Rao Kun , Zhang ShuaiKang , Zhu ZuChao
Published: February 2023

Axial flow circulating pumps (AFCPs) are large marine steam turbine units for large-sized ships. One peculiar operation condition for AFCPs is when a ship cruises beyond a certain speed, the energy of pump inflow can completely overcome the frictional resisting moment of the pump itself, thereby driving the impeller to rotate. Such a condition is also known as the unpowered driven condition (UDC). At this time, the fluid is in the artesian flow state. In this paper, pressure fluctuation and inner flow of the AFCP under UDCs and different inflow conditions are analyzed using delayed detached-eddy simulation turbulence model. It is found that the intensity of the tip leakage vortex (TLV) decreases from the leading edge to the trailing edge of the blade, and the amplitude of pressure pulsation caused by TLV also decreases. Due to the jet wake structure at the blade trailing edge, the amplitude of pressure fluctuation at the trailing edge of the blade increases by 7.8% under the optimal UDC. In addition, the compression–expansion term determines the strength of the core of TLV, thus affecting the amplitude of pressure fluctuation. The viscous dissipation effect of TLV can cause high-frequency components of pressure fluctuation.
Entrapment and mobilization dynamics during the flow of viscoelastic fluids in natural porous media: A micro-scale experimental investigation
Authors: Mohamed Abdelhalim I. A. , Khishvand Mahdi , Piri Mohammad
Published: February 2023

Capillary desaturation process was investigated as a function of wetting phase rheological signatures during the injection of Newtonian and non-Newtonian fluids. Two sets of two-phase imbibition flow experiments were conducted on a water-wet sandstone core sample using brine and viscoelastic polymer solutions. During the experiments, a high-resolution micro-computed tomography scanner was employed to directly map pore-level fluid occupancies within the pore space. The results of the experiments revealed that at a given capillary number, the viscoelastic polymer was more efficient than the brine in recovering the non-wetting oil phase. At low capillary numbers, this is attributed to the improved accessibility of the viscoelastic polymer solution to the entrance of pore elements, which suppressed snap-off events and allowed more piston-like and cooperative pore-body filling events to contribute to oil displacement. For intermediate capillary numbers, the onset of elastic turbulence caused substantial desaturation, while at high capillary numbers, the superimposed effects of higher viscous and elastic forces further improved the mobilization of the trapped oil ganglia by the viscoelastic polymer. In the waterflood, however, the mobilization of oil globules was the governing recovery mechanism, and the desaturation process commenced only when the capillary number reached a threshold value. These observations were corroborated with the pore-level fluid occupancy maps produced for the brine and viscoelastic polymer solutions during the experiments. Furthermore, at the intermediate and high capillary numbers, the force balance and pore-fluid occupancies suggested different flow regimes for the non-Newtonian viscoelastic polymer. These regions are categorized in this study as elastic-capillary- and viscoelastic-dominated flow regimes, different from viscous-capillary flow conditions that are dominant during the flow of Newtonian fluids. Moreover, we have identified novel previously unreported pore-scale displacement events that take place during the flow of viscoelastic fluids in a natural heterogeneous porous medium. These events, including coalescence, fragmentation, and re-entrapment of oil ganglia, occurred before the threshold of oil mobilization was reached under the elastic-capillary-dominated flow regime. In addition, we present evidence for lubrication effects at the pore level due to the elastic properties of the polymer solution. Furthermore, a comparison of capillary desaturation curves generated for the Newtonian brine and non-Newtonian viscoelastic polymer revealed that the desaturation process was more significant for the viscoelastic polymer than for the brine. Finally, the analysis of trapped oil clusters showed that the ganglion size distribution depends on both the capillary number and the rheological properties of fluids.
Efficiency of electron doping to monolayer hexagonal boron nitride by alkali metals
Authors: Ichinokura S. , Hemmi A. , Cun H. , Tanaka K. , Shimizu R. , Hitosugi T. , Greber T. , Hirahara T.
Published: February 2023

We investigated electron doping of monolayer hexagonal boron nitride (hBN) on metallic substrates by doping alkali metals (AMs). The valence band maximum (VBM) of hBN/Rh after doping with Li and Cs was directly observed using angle-resolved photoemission spectroscopy in a wide wavenumber space. The valence band shift resulting from doping confirms the vacuum level alignment model. Furthermore, when the same AM is used, the resultant binding energy of VBM was almost identical regardless of the substrate, even if it differs by ∼1 eV before doping, which we found by comparison with the literature. This independence from the substrate is explained by an extension of the vacuum level alignment model, wherein the VBM is determined by the work function of the AM when it intercalates to the interface as well as adsorbs on surfaces of hBN. It means that the doping of Cs, which has the lowest work function, gives the deepest binding energy at VBM. This is evaluated as 5.7 eV in our experiments.