bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustainable Development of Construction Industry in China
Authors: Ju Zhimin , Solopova Natalia A.
Published: September 2024

The research aims to determine the direction of sustainable development of the construction industry in China and ensure its regular and stable development. A series of data comparisons and methods of the comprehensive analysis showed that the construction industry in China, on the one hand, is a major industry with a huge scale and a significant position on the international market. On the other hand, it is also an industry with low investment in technology, high energy consumption, relatively backward engineering technology, and management. Besides, management and operation methods are relatively traditional and associated with challenges of industry development. The comparison with advanced manufacturing industries and foreign developed countries clarified the shortcomings of China’s construction industry and set the directions for future development. These include (1) active development of green building, (2) promotion of the industrialization process, (3) improvement of the technology application level, and (4) timely improvements of the relevant regulations. China also needs to adjust the industrial form of the construction industry and increase the internationalization level. Based on the methods of data description research and literature review, we identified the conditions for sustainable development of the construction industry and proved the importance of using Integrated Project Delivery [IPD] and BIM (Building Information Modeling) technology in the development of the Chinese construction industry. The research allowed us to understand the important role of technology and organization management in developing the construction industry. When we continue to learn lessons from advanced science and technology, smart organization, and management and implement them in the construction industry, only then it will develop sustainably.
Smart Screen Design in Public Spaces: A Case Analysis of Xiushui Square Park in Chun’an County
Authors: Fang Weihao , Tan Ruiguang
Published: September 2024

This paper explores the importance of outdoor smart screens in smart city development, using Xiushui Square Park in Chun’an, Zhejiang, as a case. It critiques current smart screens’ site selection, exterior design, and interface, and suggests improvements. Based on field research, the study proposes a site selection strategy considering pedestrian flow, climate, and regulations. It highlights designs that integrate local culture and interfaces to serve all ages. The findings suggest these strategies can improve smart screens’ practicality and service quality, promoting smart city sustainability. The paper aims to provide references for researchers and practitioners in smart city public space design.
Paradigm Shift for Green Space Planning in Tourism Towns: The Design of Interactive Sculpture
Authors: Yao Yitong
Published: September 2024

The planning of green spaces in tourism small towns emerges as a critical pathway to promote positive experiences of tourists and residents. This study proposes empirical research to explore the unique characteristics and methodologies of green space planning within such contexts, recognizing the importance of the design of interactive sculptures. The paper introduces a conceptual framework for urban tourism research that integrates a spatial scale with various thematic areas, suggesting a holistic ecological planning approach. This approach advocates for the coordinated development between human and natural systems to optimize overall benefits. Interactive sculptures enhance biodiversity conservation and ecological sustainability in tourism towns by raising environmental awareness, promoting sustainable practices, providing wildlife habitats, and boosting ecotourism. They integrate art with nature to celebrate local ecosystems and foster community involvement in conservation efforts.
Substaminale development in agricultural investments and the food security system
Authors: Pruntseva Gelena , Danylyshyn Bohdan , Popadynets Nazariy , Kopylyuk Oksana , Kotsan Igor
Published: September 2024

Agricultural investments play a crucial role in boosting productivity, reducing poverty, and enhancing food security. By increasing food availability and stabilizing prices, these investments make essential food more accessible to low-income groups. They also foster rural development through job creation and infrastructure growth, contributing to poverty reduction and consistent food consumption. In the face of challenges like climate change, shrinking land availability, declining fertility, and water scarcity, agricultural investments are vital for sustaining and increasing production. As global population growth heightens food demand, effective investment becomes even more critical to prevent famine. However, expanding agricultural land is limited, so future agricultural growth will rely on productivity improvements driven by investments. It is imperative for governments to create a conducive environment to attract such investments while ensuring that they are allocated efficiently. Mismanagement or ineffective use of investments can lead to negative social and environmental impacts. Therefore, continuous monitoring and analysis of agricultural investments are essential to maximize their effectiveness in ensuring food security.
Improvement of mechanical and operational steel characteristics by strengthening the surface
Authors: Filonenko Nataliia , Bartashevska Liudmyla , Haldina Oleksandra
Published: September 2024

The growing demands in the mining industry require steel products capable of withstanding heavy loads. To achieve enhanced mechanical, service, and operational properties in steel, common methods include adjusting carbon content, optimizing primary element concentrations, and applying expensive microalloying and heat treatments. For metal products operating under high vibration or as contact pairs, surface layer strengthening is essential. This study investigates the relationship between the composition of the saturating medium, the degree of cold plastic deformation, and the effects of saturation regimes on the structure, mechanical, and service properties of low-carbon steel. Samples were analyzed after annealing and cold plastic deformation using metallographic analysis, mechanical and tribological testing, X-ray diffraction, and chemical and X-ray spectral analysis. The results indicate that cold plastic deformation enhances the diffusion mobility of boron and carbon. To produce effective boron-cemented surface layers, a saturating mixture with up to 4.5% boron carbide is recommended. These boron-cemented layers, containing phases such as Fe2B, Fe3(CB), and Fe23(CB)6, exhibit strong adhesion to the matrix and superior mechanical and tribological properties. The boron-bearing phases are partially located along grain boundaries and within grains. This method allows for boron-cemented layers up to 2.0 – 2.3 mm deep, nearly double the depth achieved by traditional cementation methods, offering significant potential for strengthening steel products in the mining industry.
Coal mine methane utilization as a component of the complex mining concept in the context of conversion into thermal and electrical energy
Authors: Bondarenko Volodymyr , Salieiev Іldar , Kovalevska Іryna , Vivcharenko Іvan , Buriak Serhii , Pererva Andrii
Published: September 2024

The paper deals with multi-component complex mining of mineral raw materials in the context of sustainable development and its important component – coal mine methane utilization and its conversion into thermal and electrical energy. The conducted analysis of scientific and practical experience has shown the multi-parameter nature of this process and the influence of a large number of factors. The mining-geological conditions of the Western Donbas (Ukraine) are substantiated as the research object, which makes it possible to limit the variation of geomechanical factors, as well as to develop basic provisions and general principles for reasoning predictive assessments of outgassing during complete mining of coal reserves. The dependence of gas volume on specific gas content of lithotypes and the volume of their destruction related to the coal-bearing stratum shear mechanisms at different options of complete mining of the Western Donbas coal reserves, is presented. The patterns of influence of the main geomechanical factors on the propagation of disturbed rock zones are substantiated.
Density functional theory calculations applied to olivine-like NaMnPO4 with transition metal substitutions for energy storage applications
Authors: Hariti Nora , Assila Abdelmajid , Rkhis Mourad , Laasri Said , Belhora Fouad , El Idrissi Mohammed , Hlil El kébir , Laghzizil Abdelaziz
Published: September 2024

In this study, Density Functional Theory (DFT) calculations are applied to evaluate the structural and thermodynamic properties of MPO4 and NaMPO4 as cathode materials for sodium-ion batteries (SIBs). Using the modified Perdew-Burke-Ernzerhof (PBE) method and the projector augmented wave (PAW) method, the effect of metal substitution in MPO4 and NaMPO4 lattices (M = Mn, Fe, Co, Ni,), as well as Fe-Ni substituted NaMnPO4 was examined for its structural and electrochemical characteristics. As NaMnPO4 has less ionic and electronic conductor, the partial substitution of Mn by simultaneous Ni and Fe gives good physicochemical properties useful for good cathode materials in SIBs. For NaMn0.5Ni0.25Fe0.25PO4, its optimal values of gravimetric capacity (154 mAh.g−1), bandgap energy (0.45 eV) and intercalation potential (3.54 V) appeared very interesting to be an attractive cathode material for SIBs. Na+ diffusion required less energy in NaFePO4, NaMnPO4, and Fe-Ni co-doped NaMnPO4 systems, promoting a rapid recharge rate and good ionic conductivity thanks to the desodiation process in creating a mixed oxidation state particularly for Fe and Mn atoms.
Nuklearmedizinische Funktionsdiagnostik in der Kardiologie
Authors: Diekmann Johanna , Bengel Frank M
Published: September 2024

Herz-Kreislauf-Erkrankungen sind die häufigste Todesursache in Deutschland. In Kombination ermöglichen klinische Kriterien und geeignete Bildgebungsverfahren eine präzise Diagnosefindung und führen zur Einleitung einer passenden Therapie. Nuklearmedizinische bildgebende Verfahren sind Funktionsuntersuchungen, die biologische Prozesse sichtbar machen. Dieser Beitrag bietet eine Übersicht aktueller nuklearmedizinischer Bildgebungsmethoden für kardiale Fragestellungen.
S2k Leitlinie akute infektiöse Gastroenteritis im Säuglings-, Kindes- und Jugendalter – Update 2024
Authors: Posovszky Carsten , Buderus Stephan , Huebner Johannes , Adam Rüdiger , Papan Cihan , Gruber Bernd , Schmid Florian , Krohn Kathrin , Wintermeyer Philip , Schwenke Reto , Laffolie Jande , Both Ulrichvon , Epple Hans-Jörg , Reuken Philipp A. , Kipfmüller Florian , Schneider Anna-Maria , Fruth Angelika , Simon Sandra , Schmitt Anne , Hauer Almuthe Christina
Published: September 2024

Das Ziel der interdisziplinären S2k-Leitlinie „Akute infektiöse Gastroenteritis im Säuglings-, Kindes- und Jugendalter“ ist es, den aktuellen Kenntnisstand zu klinischem Bild, Diagnostik, Therapie, Prävention und Hygiene der akuten infektiösen Gastroenteritis, einschließlich der nosokomialen gastrointestinalen Infektionen, bei Säuglingen, Kindern und Jugendlichen auf Basis der wissenschaftlichen Evidenz zusammenzufassen, im Expertenkonsens zu bewerten und daraus praxisrelevante Empfehlungen abzuleiten. Die Leitlinie liefert einen Handlungskorridor für häufige Entscheidungen. Sie dient zudem der evidenzbasierten Fort- und Weiterbildung und soll damit eine Verbesserung der medizinischen Versorgung von Kindern mit akuter Gastroenteritis erreichen. Insbesondere sollen durch die Leitlinie unnötige stationäre Aufnahmen von Kindern mit AGE vermieden und präventive Maßnahmen zur Infektionsvermeidung und -ausbreitung ergriffen werden.
Implantation einer inversen Schulterendoprothese unter Verwendung der Navigation
Authors: Rolf Olaf , Blana Andreas , Hagedorn Philipp
Published: September 2024

Die Implantation einer inversen Schulterendoprothese (TEP) stellt eine bewährte Methode zur Schmerzlinderung und Schulterfunktionsverbesserung dar. Die Ergebnisse variieren je nach Patientenalter, Krankheitsgrad und Erfahrung des Operateurs. Indikationen für eine inverse TEP sind vielfältig, von der Defektarthropathie bis hin zu Frakturen. Aktuelle Studien zeigen verbesserte Überlebensraten und reduzierte Komplikationen nach primärer Implantation. Die präoperative Planung mittels 3-D-CT oder MRT gilt als Goldstandard. Patientenspezifische Instrumente (PSI) wurden eingeführt, sind jedoch mit Kosten und Wartezeit verbunden. Die Navigation mit „Augmented Reality“ (AR) bietet eine effizientere Alternative. Die intraoperative Übertragung der Planung auf den Patienten erfolgt über AR-Brillen und ermöglicht Echtzeitinformationen, wodurch der Chirurg den Blick vom Situs nicht abwenden muss. Dies optimiert den Workflow und bietet potenziell präzisere Implantationsresultate.
Zusammenfassend bietet die Kombination von 3-D-Planung, Navigation und AR eine vielversprechende Methode für präzise und effiziente Implantationen von inversen Schulterendoprothesen. Allerdings steht der Nachweis verbesserter Standzeiten und Funktionsscores noch aus.
Allgemeine Abschätzung des kardiovaskulären Risikos
Authors: Gielen Stephan , Bagdoniene Irma , Wienbergen Harm
Published: September 2024

Validierte Scores zur Bestimmung des kardiovaskulären Risikos erlauben es, die Individuen zu identifizieren, die von präventiven Interventionen am meisten profitieren. Daneben verdeutlichen sie auf individueller Basis die Folgen ungesunden Lebensstils und die Risikoreduktion durch zielgerichtete Anpassung (z.B. LDL-C-Reduktion). Scores sind damit ein wichtiges Instrument zur Motivation von Patienten, ihr Risikoprofil zu verbessern.
Optimierung von Prozessen auf einer
Schwerbrandverletztenintensivstation durch Etablierung eines digitalen
Managementsystems
Authors: Schmidt Sonja Verena , Drysch Marius , Steubing Yonca , Wallner Christoph , Lehnhardt Marcus , Schoeffski Oliver , Reinkemeier Felix
Published: September 2024

Hintergrund Die Behandlung Schwerbrandverletzter ist anspruchsvoll und
erfordert spezialisierte Zentren, die eine adäquate Therapie über einen Zeitraum
von bis zu mehreren Monaten gewährleisten können. Die Etablierung von digitalen
Managementsystemen auf Intensivstationen markiert einen immensen Fortschritt in
der modernen Gesundheitsversorgung. Die Einführung eines solchen Systems auf
einer spezialisierten Intensivstation für Schwerbrandverletzte bietet diverse
Möglichkeiten zur Optimierung, aber auch mögliche Hindernisse. Diese Studie soll
einen Überblick über die Wahrnehmung der Veränderungen aus Sicht der
Mitarbeitenden geben und die Einführung digitaler Systeme im
intensivmedizinischen Bereich diskutieren.

Methode Nach der Stichprobenauswahl mittels selektiven Samplings wurden
die Auswirkungen eines digitalen Managementsystems in verschiedenen Kategorien
betrachtet. Die Daten, die durch einen Fragebogen und kurze Interviews gesammelt
wurden, wurden hinsichtlich der Durchschnittswerte in jeder Kategorie
ausgewertet, wobei die Interpretationen Merkmale wie Berufsgruppe und
Berufserfahrung berücksichtigen.

Ergebnisse Insgesamt wird das digitale Managementsystem sowohl ärztlicher-
als auch pflegerischerseits als geeignet für die Arbeit auf der
Schwerbrandverletztenintensivstation eingeschätzt, wobei besonders die stetige
Vitalparametererfassung und die Reduktion der Fehlerquote bei
Medikamentenverabreichungen positiv hervorgehoben werden. Negativ werden jedoch
die Erfassung von Verbrennungswunden und die spezialisierte Dokumentation von
Verbrennungspatientinnen und -patienten angemerkt.

Schlussfolgerung Neben verschiedenen Faktoren, die hinsichtlich der
Nutzbarkeit des Programms eine Rolle spielen, wie die Berufserfahrung, die Größe
des Teams oder des zu behandelnden Patientenklientels, werden zwar einzelne
verbesserungsfähige Aspekte herausgearbeitet, zusammenfassend lässt sich jedoch
sagen, dass der Konsens hinsichtlich der Einführung eines solchen Systems auf
der Intensivstation positiv und zustimmend war. Als Fazit kann zudem jedoch
festgehalten werden, dass das System für eine allgemeine chirurgische
Intensivstation deutlich effektiver beschrieben wird als für eine spezialisierte
Intensivstation, wie für Schwerbrandverletzte.
Compartment Syndrome in Association with Tibial Plateau Fracture: Standardized Protocols Ensure Optimal Outcomes
Authors: Schwartz Luke , Parola Rown , Ganta Abhishek , Konda Sanjit , Rivero Steven , Egol Kenneth A.
Published: September 2024

The purpose of this study was to report on the treatment, results, and longer-term outcomes of patients who sustained a tibial plateau fracture with an associated leg compartment syndrome (CS). A total of 766 patients who sustained 766 tibial plateau fractures met inclusion criteria. Fourteen patients (1.8%) were diagnosed with CS in association with a tibial plateau fracture during their initial hospitalization, 13 at the time of presentation and 1 delayed. The treatment protocol consisted of initial external fixation and fasciotomy, followed by irrigation and debridement, and eventual closure. Fasciotomy cases included 2/14 (14.3%) single incision approaches and 12/14 (85.7%) dual incision approaches. Operative treatment of the tibial plateau fracture was performed at the time of final closure or once soft tissues were permitted. One case of CS that developed following definitive fixation was treated with fasciotomy and delayed primary closure after initial stabilization. Ten (71.4%) were available at 1-year follow-up. We compared these 10 cases to the patients with operative tibial plateau fractures without CS to assess for surgical, radiographic, clinical, and functional outcomes. We used a propensity match based on age, body mass index, sex, Charleson comorbidity index, and fracture type to reduce the presence of confounding biases. Standard statistical methods were employed. Those in the CS cohort were younger males (p < 0.05). At latest follow-up, function did not differ between those in the CS group compared with the non-CS cohort (p > 0.05). Clinically, knee flexion (130.7 vs. 126; p = 0.548), residual depression (0.5 vs. 0.2; p = 0.365), knee alignment (87.7 vs. 88.3; p = 0.470), and visual analog scale pain scores (3.0 vs. 2.4; p = 0.763) did not differ between the cohorts. Although infection was higher in the CS cohort, the overall complication rates did not differ between the CS patients and non-CS cohort (p > 0.05). Early identification and standardized treatment protocols for the management of CS that develops in association with a tibial plateau fracture lead to outcome scores that were not significantly different from patients who did not develop CS.
Unleashing the potential: a quest to understand and examine the factors enriching research and innovation productivities of South Asian universities
Authors: Javed Saima , Rong Yu , Zafeer Hafiz Muhammad Ihsan , Maqbool Samra , Abbasi Babar Nawaz
Published: September 2024

South Asian universities play a crucial role in driving economic development through research and innovation. However, these institutions often face challenges that hinder their productivity in these areas. To address these challenges, this study aims to understand and examine the factors enhancing research and innovation productivity in universities across South Asian countries, specifically Bangladesh, India, Nepal, Pakistan, and Sri Lanka. Using panel data from 2009 to 2021, the study employs the newly developed dynamic common correlated effects (DCCE) approach by Chudik and Pesaran (2015a). The results revealed that the factors found to be enriching research productivity, though the impact is negligible, are patent rights, funding for tertiary education, information technology, and publications. However, tertiary school enrollment is not a significant factor. On the other hand, for innovation productivity, the influencing factors with a negligible impact are patent rights, funding for tertiary education, and information technology. In this case, neither tertiary school enrollment nor publications play a significant role. Furthermore, the research productivity of the universities in South Asian countries is negligibly stimulating the countries’ GDP per capita, while the innovation productivity of the universities is not. Moreover, examining these relations using models such as mean group (MG), pooled mean group (PMG), and augmented mean group (AMG) can produce misleading results due to cross-sectional dependence among the units. Nonetheless, PMG outperformed AMG, followed by MG. Policy recommendations were suggested based on the findings.
An automatic variable laser power attenuator for continuous-wave quantum cascade lasers in cryogenic ion vibrational predissociation spectroscopy
Authors: Gorbachev Vladimir , Miloglyadova Larisa , Chen Peter
Published: September 2024

Cryogenic ion vibrational predissociation (CIVP) spectroscopy is an established and valuable technique for molecular elucidation in the gas phase. CIVP relies on tunable lasers, wherein among typical laser schemes, the application of mid-infrared continuous-wave quantum cascade laser (cw-QCL) is the most robust and elegant solution, as we have recently demonstrated. However, potential challenges arise from an inhomogeneous character across laser power tuning curves. A large laser power output could have undesired consequences, such as multiphoton absorption or saturation effects. Significant variations in laser power tuning curves could potentially alter the shape of the investigated band, particularly for diffuse bands. In this study, we have developed and introduced an automatic variable laser power attenuator designed to keep the laser power output uniform at a user-defined value across the entire available spectral range. We demonstrated the application of this attenuator in obtaining CIVP spectra of a model compound with a diffuse N–H–N band. This approach enhances the reliability of measuring diffuse bands and overall applicability of cw-QCL.
Stückelberg-modified massive Abelian 3-form theory: Constraint analysis, conserved charges and BRST algebra
Authors: Rao A. K. , Malik R. P.
Published: September 2024

For the Stückelberg-modified massive Abelian 3-form theory in any arbitrary D-dimension of spacetime, we show that its classical gauge symmetry transformations are generated by the first-class constraints. We establish that the Noether conserved charge (corresponding to the local gauge symmetry transformations) is same as the standard form of the generator for the underlying local gauge symmetry transformations (expressed in terms of the first-class constraints). We promote these classical local, continuous and infinitesimal gauge symmetry transformations to their quantum counterparts Becchi–Rouet–Stora–Tyutin (BRST) and anti-BRST symmetry transformations which are respected by the coupled (but equivalent) Lagrangian densities. We derive the conserved (anti-)BRST charges by exploiting the theoretical potential of Noether’s theorem. However, these charges turn out to be non-nilpotent. Some of the highlights of our present investigation are (i) the derivation of the off-shell nilpotent versions of the (anti-)BRST charges from the standard non-nilpotent Noether conserved (anti-)BRST charges, (ii) the appearance of the operator forms of the first-class constraints at the quantum level through the physicality criteria with respect to the nilpotent versions of the (anti-)BRST charges, and (iii) the deduction of the Curci–Ferrari-type restrictions from the straightforward equality of the coupled (anti-)BRST invariant Lagrangian densities as well as from the requirement of the absolute anticommutativity of the off-shell nilpotent versions of the conserved (anti-)BRST charges.
Theory of phase-space hydrodynamics of electron and ion holes in collisionless plasmas
Authors: Lobo Allen , Sayal Vinod Kumar
Published: September 2024

Phase-space holes are well-known Bernstein–Greene–Kruskal (B.G.K.) modes and are formed by particle-trapping in solitary potential waveforms. They exhibit orbital particle trajectories in the phase-space, due to which they are also referred to as phase-space vortices. In this article, we develop the theory of phase-space hydrodynamics for electron and ion phase-space in collisionless plasmas. The analogy between ordinary two-dimensional fluids and 1D−1V phase-space has been explored by introducing a momentum equation and a phase-space vorticity field, which enable the fluid-like analyses of the plasma phase-space. The developed kinetic-hydrodynamic equations are then employed to address the vortical nature of phase-space holes by exploring their fluid-analogous vortex-like characteristics, an identification technique of phase-space vortices, an exact derivation of the Schamel-df equations, and a measurable definition of the particle-trapping β parameter. This article introduces a new technique to the study of phase-space holes which focuses on the fluid-analogous vortical nature of the phase-space holes and prevents the need for an initial assumption of the trapped and free particle phase-space densities, thus presenting itself as a precursor to the Schamel-pseudopotential method.
A novel testing method for ultra-low-frequency vibration signal based on passive radio frequency tag sensing
Authors: Lou Litai , Yang Jianhua , Ma Kaixuan , Gong Tao , Wang Zhongqiu , Li Baofeng
Published: September 2024

Ultra-low-frequency vibration is prevalent in many critical research fields. Nevertheless, for ultra-low-frequency vibration signals below 1 Hz, there is currently a lack of a cost-effective and efficient measurement method. A new ultra-low-frequency vibration signal testing method based on the passive radio frequency tag phase is proposed using the Radio Frequency Identification (RFID) sensing method. By employing vibration detection on ultra-low-frequency vibration signals, the effectiveness of the proposed approach across different frequencies is validated while thoroughly considering factors such as measurement range, precision, distance, and occlusion effects. The results indicate that this method can accurately measure ultra-low frequency vibration signals as low as 0.01 Hz, with an average relative error of only less than 1.5% for all measurement results, and the error decreases with increasing detection frequency. For the measurement of a 1 Hz vibration signal, the average relative error is less than 1%. In addition, the measurement accuracy remains unaffected by distance or occlusion. Sensitivity and stability tests are also conducted. Continuous monitoring for 8 hours demonstrates the excellent measurement stability of the proposed method. Finally, a performance comparison has been made with laser displacement sensors commonly used in non-contact ultra-low-frequency measurement methods. The results show that the RFID sensing method can detect lower vibration frequencies and has a larger amplitude measurement range and better environmental adaptability. Overall, for ultra-low-frequency vibration, this method offers advantages such as high precision, passive non-contact operation, non-line-of-sight path monitoring, affordability, and convenience. These attributes render it suitable for extensive application in various engineering scenarios requiring ultra-low-frequency vibration testing.
Atomistic simulation on the deposition behavior of cold spray
Authors: Feng Jianrui , An Erfeng , Zhao Wensen
Published: September 2024

Cold spray is an effective method for surface coating, which has been applied in various engineering areas. However, it is difficult to directly observe the dynamic deformation process in experiments. This paper applies the molecular dynamics simulation to model the deposition of a monocrystalline Cu particle onto a Cu substrate and, subsequently, carries out a systematic study on the deposition mechanism and microstructure evolution. The results indicate that the deposition process consists of an impact stage and a relaxation stage. It is mainly the high speed collision and the friction following the collision that lead to particle deposition, which, under different circumstances, can be defined as surface deposition or penetration deposition. Two methods, namely, drastic shear deformation and cooling in the relaxation stage, can help form nanocrystallines. Jetting and melting are not the necessary factors for the deposition of nano-sized particles. The formation of dislocation lines is influenced by impact velocities. At lower impact velocities, the dislocation lines are mainly distributed near the contact surface. However, when the impact velocity is higher, dislocation lines are almost uniformly distributed in the particle.
Optical atompilz: Propagation-invariant strongly longitudinally polarized toroidal pulses
Authors: Wang Ren , Yang Ding-Tao , Xin Tao , Shi Shuai , Wang Bing-Zhong , Shen Yijie
Published: September 2024

Recent advancements in optical, terahertz, and microwave systems have unveiled non-transverse optical toroidal pulses characterized by skyrmionic topologies, fractal-like singularities, space-time nonseparability, and anapole-exciting ability. Despite this, the longitudinally polarized fields of canonical toroidal pulses notably lag behind their transverse counterparts in magnitude. Interestingly, although mushroom-cloud-like toroidal vortices with strong longitudinal fields are common in nature, they remain unexplored in the realm of electromagnetics. Here, we present strongly longitudinally polarized toroidal pulses (SLPTPs), which boast a longitudinal component amplitude exceeding that of the transverse component by over tenfold. This unique polarization property endows SLPTPs with robust propagation characteristics, showcasing nondiffracting behavior. The propagation-invariant strongly longitudinally polarized field holds promise for pioneering light–matter interactions, far-field superresolution microscopy, and high-capacity wireless communication utilizing three polarizations.
Characterizing polarization switching kinetics of ferroelectric Hf0.5Zr0.5O2 at cryogenic temperature
Authors: Xu Jiacheng , Shen Rongzong , Qian Haoji , Lin Gaobo , Gu Jiani , Rong Jian , Liu Huan , Ding Yian , Zhang Miaomiao , Liu Yan , Jin Chengji , Chen Jiajia , Han Genquan
Published: September 2024

We have characterized polarization switching kinetics of Hf0.5Zr0.5O2 (HZO) at cryogenic temperature (T) down to 100 K. By the nucleation-limited-switching model with Lorentzian distribution fittings, the dependences of the average switching time (log τ1) and switching time distribution (ω) on T are extracted. As T decreases from 300 to 100 K, log τ1 first rapidly decreases and then gradually stabilizes. Meanwhile, ω exhibits different trends under different external electric fields (Eext), decreasing under low Eext while increasing under high Eext, eventually stabilizing at non-zero constants. With the further decrease in T (<100 K), log τ1 and ω exhibited by HZO are almost unchanged, indicating the intrinsic properties of ferroelectric multiple domains, which are different from the prediction in previous literature studies that log τ1 and ω will linearly decrease as T decreases.
Enhancing superconductivity in CoSi2 films with laser annealing
Authors: Dumas P. , Gustavo F. , Opprecht M. , Freychet G. , Gergaud P. , Kerdilès S. , Guillemin S. , Lábár J. L. , Pécz B. , Lefloch F. , Nemouchi F.
Published: September 2024

Laser annealing was employed to trigger the solid-state reaction of a thin Co film (2.5 nm) with undoped Si. A metastable disilicide layer was obtained after one laser pulse close to the melt threshold. Its diffraction pattern, relaxed lattice parameter, and residual resisitivity are consistent with the formation of the defective CsCl structure. The CoSi2 phase was found after prolonging the thermal treatment with additional pulses or rapid thermal annealing. Because CoSi is skipped in the phase sequence, CoSi2 layers are more uniform in thickness, have an increased superconductivity and a reduced formation temperature. This approach is compatible with the SALICIDE process and can be used to form smooth contacts in superconducting or regular transistors.
Epitaxial growth of single unit-cell superconducting β-Bi2Pd
Authors: Lyu Yanfeng , Zhang Yasong , Wang Wen-Lin , Wang Yunhui , Song Can-Li , Ma Xu-Cun , Xue Qi-Kun
Published: September 2024

Bismuth-based binary alloy β-Bi2Pd has recently been suggested as a connate topological superconductor with immense promise for Majorana zero modes. However, the epitaxial thin films down to the ultimate level of single unit-cell have been challenging. Here, we employed the state-of-the-art molecular beam epitaxy to prepare single unit-cell superconducting β-Bi2Pd films with lateral dimensions of hundreds of nanometers. Utilizing in situ scanning tunneling microscopy/spectroscopy, we uncover evidence of anisotropic superconductivity whose spectra are well fit by anisotropic s-wave gap functions and demonstrate that the epitaxial growth of β-Bi2Pd films relies substantially on the substrate temperature, flux ratio, growth rate, and coverage. The high-quality epitaxial films provide a promising platform to investigate the topological superconductivity at the two-dimensional limit.
Near-infrared irradiation study of honey-mediated Au nanoparticles for photothermal therapy
Authors: Kan-Dapaah K. , Aidoo J. A. , Agyei-Tuffour B. , Mensah B. , Yaya A. , Abudu S. A. , Hatekah S. W. K.
Published: September 2024

Gold nanoparticles synthesized via honey-mediated chemical reduction have desirable features that make them ideal candidates for nanoparticle-assisted photothermal therapy (N-PTT). However, their photothermal properties have not been previously explored. In this study, after synthesis and characterization (structural and optical) of the HM-AuNPs, we investigated their photothermal conversion efficiency (η) and absorption cross section (σabs) in aqueous solution, cytotoxic effects in in vitro MDA-MB-468 breast cancer cell culture, and temperature profiles in agarose gel under 810 nm NIR irradiation. The results showed that ≈15 nm and primarily spherical HM-AuNPs had η values of up to 40% and an average σabs of 2.15±0.08×10−18 m2. Furthermore, cell viability was reduced to about 52% and the temperature profile in agarose gel had the typical radially increasing topology. Collectively, the findings show that HM-AuNPs can be used in N-PTT.
GdWN3 is a nitride perovskite
Authors: Smaha Rebecca  W. , Mangum John S. , Yadav Neha , Rom Christopher L. , Wieliczka Brian M. , Julien Baptiste , Treglia Andrew , Perkins Craig L. , Gorai Prashun , Bauers Sage R. , Zakutayev Andriy
Published: September 2024

Nitride perovskites ABN3 are an emerging and highly underexplored class of materials that are of interest due to their intriguing calculated ferroelectric, optoelectronic, and other functional properties. Incorporating novel A-site cations is one strategy to tune and expand such properties; for example, Gd3+ is compelling due to its large magnetic moment, potentially leading to multiferroic behavior. However, the theoretically predicted ground state of GdWN3 was a non-perovskite monoclinic structure. Here, we experimentally show that GdWN3−y crystallizes in a perovskite structure. High-throughput combinatorial sputtering with activated nitrogen is employed to synthesize thin films of Gd2−xWxN3−yOy with oxygen content y < 0.05. Ex situ annealing crystallizes a polycrystalline perovskite phase in a narrow composition window near x = 1. LeBail fits of synchrotron grazing incidence wide angle x-ray scattering data are consistent with a perovskite ground-state structure. Refined density functional theory calculations that included antiferromagnetic configurations confirm that the ground-state structure of GdWN3 is a distorted Pnma perovskite with antiferromagnetic ordering, in contrast to prior predictions. Initial property measurements find that GdWN3−y is paramagnetic down to T = 2 K with antiferromagnetic correlations and that the absorption onset depends on cation stoichiometry. This work provides an important path toward both the rapid expansion of the emerging family of nitride perovskites and understanding their potential multiferroic properties.
Comparison of ultra-low lattice thermal conductivity of the full-Heusler compound Li2Rb(Cs)Bi after considering strong quartic anharmonicity
Authors: Guo Qian , Zhao Yinchang , Sun Yuming , Ni Jun , Dai Zhenhong
Published: September 2024

This paper conducts a detailed study on the thermal transport and thermoelectric properties of Li2Rb(Cs)Bi and analyzes the optical phonon frequency shift caused by considering anharmonicity. We mainly focus on studying the microscopic mechanism of the difference in lattice thermal conductivity (κL) of the two materials. By calculating the group velocity, scattering rate, scattering phase space and scattering sub-process, it is concluded that κL is mainly dominated by the acoustic branch. Due to its small group velocity and large scattering rate, Li2CsBi has a low κL, which is 0.60 W m−1K−1 at 300 K. Research results show that n-type Li2CsBi has a higher ZT value of about 2.1 at T = 900 K, while p-type Li2RbBi has a higher ZT value of about 1.5 at the same temperature. These results provide an important theoretical basis for the application of Li2Rb(Cs)Bi in the field of thermoelectric conversion.
Non-unique machine learning mapping in data-driven Reynolds-averaged turbulence models
Authors: Man Anthony , Jadidi Mohammad , Keshmiri Amir , Yin Hujun , Mahmoudi Yasser
Published: September 2024

Recent growing interest in using machine learning for turbulence modeling has led to many proposed data-driven turbulence models in the literature. However, most of these models have not been developed with overcoming non-unique mapping (NUM) in mind, which is a significant source of training and prediction error. Only NUM caused by one-dimensional channel flow data has been well studied in the literature, despite most data-driven models having been trained on two-dimensional flow data. The present work aims to be the first detailed investigation on NUM caused by two-dimensional flows. A method for quantifying NUM is proposed and demonstrated on data from a flow over periodic hills and an impinging jet. The former is a wall-bounded separated flow, and the latter is a shear flow containing stagnation and recirculation. This work confirms that data from two-dimensional flows can cause NUM in data-driven turbulence models with the commonly used invariant inputs. This finding was verified with both cases, which contain different flow phenomena, hence showing that NUM is not limited to specific flow physics. Furthermore, the proposed method revealed that regions containing low strain and rotation or near pure shear cause the majority of NUM in both cases—approximately 76% and 89% in the flow over periodic hills and impinging jet, respectively. These results led to viscosity ratio being selected as a supplementary input variable (SIV), demonstrating that SIVs can reduce NUM caused by data from two-dimensional flows and subsequently improve the accuracy of tensor-basis machine learning models for turbulence modeling.
Comprehensive analysis of normal shock wave propagation in turbulent non-ideal gas flows with analytical and neural network methods
Authors: Nilam VenkataKoteswararao , Suresh M Xavier , Dondu Harish Babu , Avula Benerji Babu
Published: September 2024

Shock wave propagation in gases through turbulent flow has wide-reaching implications for both theoretical research and practical applications, including aerospace engineering, propulsion systems, and industrial gas processes. The study of normal shock propagation in turbulent flow over non-ideal gas investigates the changes in pressure, density, and flow velocity across the shock wave. The Mach number is derived for the system and explored across various gas molecule quantities and turbulence intensities. This study analytically investigated the normal shock wave propagation in turbulent flow of adiabatic gases with modified Rankine–Hugoniot conditions. Artificial neural network (ANN) techniques are used to estimate the solutions for shock strength and Mach number training validation phases of back-propagated neural networks with the Levenberg–Marquardt algorithm. The results reveal that pressure ratio with density ratio increase for higher values of increase in the turbulence level as well as intermolecular forces. A reverse trend is observed in velocity coefficient after shock in the presence of adiabatic gas. The regression coefficient values obtained using the network model ranged from 0.999 99 to 1, indicating an almost perfect correlation. These findings demonstrate that the ANN can predict the Mach number with high accuracy.
Molecular insights into methane hydrate dissociation: Role of methane nanobubble formation
Authors: Moorjani Bhavesh , Adhikari Jhumpa , Hait Samik
Published: September 2024

Understanding the underlying physics of natural gas hydrate dissociation is necessary for efficient CH4 extraction and in the exploration of potential additives in the chemical injection method. Silica being “sand” is already present inside the reservoir, making the silica nanoparticle a potential green additive. Here, molecular dynamics (MD) simulations have been performed to investigate the dissociation of the CH4 hydrate in the presence and absence of ∼1, ∼2, and ∼3 nm diameter hydrophilic silica nanoparticles at 100 bar and 310 K. We find that the formation of a CH4 nanobubble has a strong influence on the dissociation rate. After the initial hydrate dissociation, the rate of dissociation slows down till the formation of a CH4 nanobubble. We find the critical concentration and size limit to form the CH4 nanobubble to be ∼0.04 mole fraction of CH4 and ∼40 to 50 CH4 molecules, respectively. The solubility of CH4 and the chemical potential of H2O and CH4 are determined via Gibbs ensemble Monte Carlo simulations. The liquid phase chemical potential of both H2O and CH4 in the presence and absence of the nanoparticle is nearly the same, indicating that the effect of this additive will not be significant. While the formation of the hydration shell around the nanoparticle via hydrogen bonding confirms the strength of interactions between the water molecules and the nanoparticle in our MD simulations, the contact of the nanoparticle with the interface is infrequent, leading to no explicit effect of the nanoparticle on the dynamics of methane hydrate dissociation.
The high-Q THz stereo metasurface sensor based on double toroidal dipole with wide operating angle bandwidth
Authors: Chen Cong , Gao Peng , Dai Yaowei , Cui Hongzhong , Wang Xinyan , Liu Hai
Published: September 2024

A highly sensitive terahertz stereo metasurface sensor, characterized by a high quality factor (Q-factor) and based on dual toroidal dipole (TD) resonance, has been proposed. The optimal structural parameters are ascertained by comparing the pertinent parameters of the stereo and planar structures in relation to TD modal excitation. The effective excitation of the TD mode is demonstrated using the calculations of multipole scattered power, reflection spectra, surface currents, electric fields, and magnetic field distributions. It is crucial that the stereo metasurface exhibits simplicity and that the dual TD resonance can be readily excited through simple adjustments in the distance and height of the intermediate gap. It also demonstrates exceptionally high sensitivity and Q-factor, both of which are essential for sensing applications. Moreover, the proposed stereo terahertz metasurface sensor still shows excellent sensing performance in a wide range of incidence angles (±40°), which is of great significance for practical applications. In conclusion, this structure offers a novel design framework for high-performance terahertz sensors based on the TD mode.
A theoretical framework for robust implementation of in situ measurements of ocean currents and waves in dynamics of mooring systems
Authors: Torres-Herrera Ulises , Keramat Alireza , Duan Huan-Feng
Published: September 2024

We develop an approximated method to solve analytically the equations of motion that describe mooring line dynamics in a one-dimensional model. For the first time, we derive integral closed-form expressions to compute dynamic properties of mooring lines subject to ocean currents and waves of arbitrary time and spatial dependence, in terms of modified Bessel functions. This is done by decomposing the mooring line in three regions where different approximations and mathematical techniques of solution are carried out. Our analytical results provide a robust framework to simulate and analyze extreme realistic oceanic events when data from in situ ocean observation systems are available, regardless of the resolution or coarseness of subsurface measurements and even for long acquisition times. In order to prove the advantages of this approach, we have processed data from two stations in the National Data Buoy Center of the National Oceanic and Atmospheric Administration. From simulations with ocean currents data, we have gained insights into the coupling of the spatial modulation of ocean currents with the characteristic wavelengths of elastic lines. From simulations with ocean waves data, we have defined a scheme to analyze wave data and identify the contribution of each subset of frequency peaks to the net fluctuation of mooring line tension. This could be useful for classification of irregular waves based on their impact on mooring line tension. The development of better tools that integrate theoretical and experimental findings is necessary for the assessment of marine structures under the environmental conditions associated with climate change.
Circle packing on spherical caps
Authors: Amore Paolo
Published: September 2024

We have studied the packing of congruent disks on a spherical cap, for caps of different size and number of disks, N. This problem has been considered before only in the limit cases of circle packing inside a circle and on a sphere (Tammes problem), whereas all intermediate cases are unexplored. Finding the preferred packing configurations for a domain with both curvature and border could be useful in the description of physical and biological systems (for example, colloidal suspensions or the compound eye of an insect), with potential applications in engineering and architecture (e.g., geodesic domes). We have carried out an extensive search for the densest packing configurations of congruent disks on spherical caps of selected angular widths (θmax=π/6, π/4, π/2, 3π/4, and 5π/6) and for several values of N. The numerical results obtained in the present work have been used to establish (at least qualitatively) some general features for these configurations, in particular the behavior of the packing fraction as function of the number of disks and of the angular width of the cap, or the nature of the topological defects in these configurations (it was found that as the curvature increases, the overall topological charge on the border tends to become more negative). Finally, we have studied the packing configurations for N=19, 37, 61, and 91 (hexagonal numbers) for caps ranging from the flat disk to the whole sphere, to observe the evolution (and eventual disappearance) of the curved hexagonal packing configurations while increasing the curvature.