bluuebunny/crossref_metadata_2025 huggingface dataset:
Metrological evaluation of an AI-based vision computing model for crack detection on masonry structures
Authors: Salerno Giovanni , Calcagni Maria Teresa , Martarelli Milena , Revel Gian Marco
Published: September 2024

Ensuring the structural integrity of buildings is essential for their longevity and safety. Traditional methods of surface monitoring, crucial for detecting potential damages that could lead to structural failures, are often labour-intensive, subjective, and challenging to document comprehensively. This paper proposes an innovative, automated approach to address these challenges by leveraging advanced computer vision and artificial intelligence. The method focuses on the detection of cracks in masonry building elements, a common but critical indicator of building surface wear. Utilizing a robust AI model trained on a diverse dataset of real crack images, the crack area is identified, and the system is able to accurately determine crack dimensions, encompassing both width and length, by analysing the contour of this area. An analysis was carried out on synthetically generated images to determine which parameters most significantly affect the detection capabilities of the AI model, and validation of real crack images was performed. Our approach redefines building monitoring by combining the precision of machine learning and vision systems techniques with the strategic insights provided by a comprehensive platform, setting a new standard for structural health management in the construction industry.
Tensile failure mechanisms of historic fibrous plaster ceiling wads: Experiments at the UK Diamond Light Source
Authors: Zuo Jiaxu , Akcicek Kutsi , Nauriyal Shivansh , Dams Barrie , Michalik Stefan , Zillhardt Thomas , Ansell Martin , Ball Richard , Burca Genoveva , Sheil Brian , Marrow James , Acikgoz Sinan
Published: September 2024

Fibrous plaster (FP) ceilings, prevalent in late 19th- and early 20th-century UK theatres, are suspended using ‘wads’. Wads are hangers made of Plaster of Paris, reinforced with twisted woven jute fabric. Several recent collapses in historic fibrous plaster ceilings have been attributed to tensile failures in wads. To understand the failure mechanisms involved, tensile tests were performed on laboratory-produced wad-like samples at the I12 beamline of the UK Diamond Light Source. The tested samples were designed with a dog bone shape and mounted with clevis-grips at each end, to ensure controlled failures along the gauge length. The beamline offered the opportunity to conduct simultaneous synchrotron X-ray computed tomography (sCT) and diffraction measurements during loading, enabling the monitoring of internal crack formation and strain propagation at the microstructural scale. Simultaneously, acoustic emission (AE) and digital image correlation (DIC) measurements were conducted. Preliminary results from these datasets are discussed in this paper. The datasets will provide useful information to validate the ongoing development of algorithms which can categorise the internal failure mechanisms and damage state of wads using only AE signals.
Conceptual design of a modular Expanded Polystyrene (EPS) formwork for sustainable prefabricated concrete slab
Authors: Martinelli Alessandra , Scioti Albina , Fatiguso Fabio , Fiorito Francesco
Published: September 2024

European policymakers emphasize the critical need for a substantial renovation of the current European building stock, stressing the imperative to sustainably integrate energy and structural design. Consistent with the European objectives, industrialized construction and precast/offsite methods offer potential advantages in terms of time, cost, and quality for building renovation; along with the possibility of utilizing secondary raw materials, they enhance the energy performance of building products and advocate for environmentally sustainable solutions. This study presents the initial stage in designing a prefabricated concrete floor system, thermally and structurally high-performing, to be integrated into new and existing buildings. Specifically, the study outlines the design development of a modular element made with expanded polystyrene (EPS) for the construction of insulated floor systems with EPS lost-formwork (ICF - Insulated Concrete Form). This element ensures high and continuous thermal insulation without contributing to the structural resistance of the finished floor system. The process of designing, optimizing, and testing various design iterations is described. Materials and finished product requirements were identified, and numerical analyses and experimental tests were conducted. The main step involved the formwork mould, focusing on the shaping of joints, and evaluating the performance from a mechanical and thermal perspective. Field tests were also conducted, first on virgin EPS formwork and subsequently on a formwork containing a percentage of recycled EPS.
Influence of type of mortar and unit in the flexural strength parallel to the bed-joints of brick-mortar assemblages
Authors: Briceño Carolina , Azenha Miguel , Vasconcelos Graça , Lourenço Paulo B.
Published: September 2024

According to EN 1996 Part 1-1, the flexural strength of masonry could be estimated based on information related mainly to the compressive strength of the mortar and the type of material of the unit. However, it is necessary to consider the impact of the interaction between components due to their physical characteristics, such as water absorption of the units and water retentivity of the mortar that may affect the bond between masonry components. Therefore, this paper evaluates the influence of the use of different types of mortar and units on the flexural strength parallel to the joints of masonry. For this, two types of mortar were considered: 1:1:6, and 1:0:5 (Cement: Lime: Sand), by volume. Regarding the units, two types of clay bricks of different geometric configuration (solid and frogged) were chosen. Thus, four combinations of units and mortar types were considered for the construction of the masonry wallets according to the guidelines indicated in EN1052-2. Flexural strength parallel to the bed-joints was tested according to EN1052-2, and compressive strengths of mortar specimens were controlled in accordance with EN1015-11 for the age of 90 days. In addition, characteristics of the units and water retentivity of mortars were also evaluated. The results showed that the compressive strength of the mortar is a significant factor if the failure occurs at the mortar bed-joint and not at the interface between components.
Modular construction as a promising alternative for the construction of affordable and quality housing
Authors: Antunes Duarte R.P.B. , Lúcio Válter J.G. , Pinho Fernando F.S.
Published: September 2024

This study seeks to explore the fundamental characteristics of modular construction, which covers the details of design and construction processes, from production through to assembly. Its objective is to evaluate essential parameters, such as project timelines and costs, associated with this construction method, in comparison with traditional construction systems. This analysis is prompted by labour shortages and the lack of affordable housing in Portugal. Modular construction prioritises the adoption of prefabricated construction systems, with potential benefits including cost and time savings, contributing to the provision of quality, economically viable, and accessible housing. This study provides valuable insights to tackle housing challenges in the Portuguese context, highlighting modular construction as a promising and sustainable alternative within the engineering domain.
The Church of San Giovanni Evangelista in Castelseprio – multi-disciplinary strategies for the characterization of the masonry structures
Authors: Valluzzi Maria Rosa , Secco Michele , Sbrogiò Luca , Razzante Valeria , Chavarria Arnau Alexandra
Published: September 2024

The remains of the archaeological site of Castelseprio (Varese province, Italy) are listed under the UNESCO World Heritage as proof of one of the seven settlements of the Lombards in Italy. Freestanding elements belonging to the apse and the lateral walls of the church of San Giovanni Evangelista are still preserved nowadays, reaching heights around 5 and 10 m, respectively. The condition of these walls, both in terms of slenderness and incompleteness, constitutes a possible vulnerability under horizontal actions that would need to be assessed for conservation. In particular, the presence of multi-leaf and/or low-compact sections could limit the structural capacity of the walls and contribute to brittle collapses, even under low forces. According to the analyses of mortars carried out in the excavation site, the specific characteristics of the local geo-resources (clay-rich sediments traditionally called “Ferretto” deposits) directly influenced the incidence of pozzolanic binding processes, allowing the formation of two different aluminosilicate-based reaction products based on a standard calcic system (C-A-S-H) and on a magnesian one (M-A-S-H). This peculiar reuse of local lateritic soils, with a high concentration in the bedding mortars of the foundational structures, increased not only the general durability of the masonry but also the mechanical properties of the first architectural complex of San Giovanni. Based on the types of mortar identified, various configurations of wall sections were assumed (monolithic and multi-layered) and their mechanical behaviour through kinematic analyses was compared, to evaluate the relevant limits of the seismic capacity of the walls.
The impact of lime as a replacement of cement-based mortar, on the water absorption and rain penetration of masonry
Authors: Vanderschelden Bruno , Van den Bossche Ruben , Van Den Bossche Nathan , Cnudde Veerle , De Kock Tim
Published: September 2024

Since the 1970s, the rise of cement-based mortars has overtaken the traditional lime mortar in construction. This marks a drastic change from circular traditions of reusing ceramic facade materials to a linear economy with an increased difficulty in the reuse of bricks. Lime mortar joints make the recovery of bricks manageable, while cracks can easily occur during dismantling of cement-based masonry. This has prompted a resurgence in the use of lime mortar especially in historical restoration and renovation. It also presents lower CO2 emissions compared to cement mortar, which is a crucial aspect in an industry responsible for 37% of global CO2 emissions. Lime has the ability to capture up to 90% of its production CO2 through carbonation further emphasizes its environmental advantages. This study investigates the hygrothermal behaviour of a hybrid construction with load-bearing masonry, and an interior lime-hemp insulation. Typically, lime mortar exhibits higher moisture transport and storage characteristics, enhancing masonry waterproofing compared to cement mortar. Eighteen setups are subjected to rain-tightness tests in order to monitor potential water infiltration. During these tests, visual evaluations, weight, and moisture measurements are conducted to monitor moisture absorption and rain infiltration to assess the performance of lime mortar versus cement-mortar. This research contributes to sustainable building practices by promoting the advantages of lime mortar in enhancing material reuse, reducing CO2 emissions, and improving the hygrothermal performance.
HBIM for the structural assessment and repair of historic masonry buildings
Authors: Saisi Antonella , Adami Andrea , Borlenghi Paolo , Treccani Daniele , Gentile Carmelo
Published: September 2024

The research implements a procedure based on (H)BIM (Historic Building Information Modelling) operational practices for the structural assessment of heritage slender structures. The application of HBIM creates a digital model integrated with all the information for the structural modelling and for the intervention design. The activity starts from detailed on site surveys, inspections, documentary research, geomatics surveys, dynamic testing aimed to the development and calibration of a FE model. The proposed methodology is applied to the Arengario, the 13th-century Town Hall of Monza, representing the main symbol of the city.
Hypothermie, hyperthermie et syndrome fébrile chez le lapin
Authors: Will Cédric
Published: September 2024

L’hypothermie (température corporelle basse) et l’hyperthermie (température corporelle élevée) sont observées chez le lapin de compagnie lors de dysfonctionnements de la thermorégulation. Les mécanismes permettant l’homéothermie sont nombreux et complexes. La température rectale normale des lapins se situe entre 38,5 °C et 40 °C [1]. L’hypothermie peut être primaire ou secondaire à de nombreuses maladies. La cause doit être identifiée rapidement et les mesures de réchauffement ou de refroidissement doivent s’effectuer progressivement et sous le contrôle permanent de nombreux paramètres cliniques et biologiques. L’hyperthermie est moins fréquente chez le lapin que l’hypothermie, car les infections bactériennes ne sont que rarement associées à de la fièvre chez le lapin.
Chemotherapy for the treatment of alveolar echinococcosis: Where are we?
Authors: Autier Brice , Robert-Gangneux Florence , Dion Sarah
Published: September 2024

Alveolar echinococcosis (AE) is a severe liver disease due to infection with the Echinococcus multilocularis larval stage, called the metacestode. Management of AE is based on benzimidazole chemotherapy (albendazole or mebendazole), associated with surgery when possible. Benzimidazoles are the only compounds recommended for the treatment of AE; however, these are parasitostatic, which means that the parasite can resume growth when treatment is interrupted. Also, benzimidazoles can cause liver dysfunction which may prevent their use. Numerous drugs have been reported to have in vitro activity against E. multilocularis, but few had satisfactory in vivo activity, and none were clearly more effective than benzimidazoles. These drugs belong to various therapeutic categories including anti-infective agents (e.g. amphotericin B, mefloquine, pentamidine derivatives), anti-neoplastic compounds (e.g. imatinib, nilotinib, bortezomib), plant-extracted compounds (e.g. thymol, crocin, carvacrol) and others (e.g. metformin, verapamil, thiaclopride). These treatments are generally of limited interest due to their toxicity, their unfavorable pharmacokinetics, or the scarcity of studies involving humans. Apart from benzimidazoles, only amphotericin B, mefloquine and nitazoxanide have been reported to be used for human AE treatment, with unsatisfactory results. Few studies have aimed at developing innovative strategies for AE drug therapy, such as vectorization of drugs using nanoparticles. Altogether, this review emphasizes the urgent need for new therapeutic strategies in AE management, for which there is currently no curative chemotherapy.
Der assistierte Suizid in der Schweiz, ein Modell in der internationalen Diskussion zum Thema „Assisted dying“
Authors: Güth Uwe , Jox Ralf J. , Abawi Karim , Weitkunat Rolf , Schneeberger Andres R.
Published: September 2024

Im Beobachtungszeitraum zwischen 1999 und 2022 hat das Schweizerische Bundesamt für Statistik 14 170 assistierte Suizide dokumentiert. In diesem 24-Jahres-Zeitraum haben die jährlichen Fallzahlen markant zugenommen: Während im Jahr 1999 lediglich 63 Fälle verzeichnet wurden, betrug die Anzahl der Fälle im Jahr 2022 nahezu 1600; dies entspricht 2,1 % aller Todesfälle in der Schweiz. Die häufigste, den assistierten Suiziden zugrunde liegende Erkrankungsgruppe bildeten mit 40 % der Fälle Krebserkrankungen. Die mehrheitlich von Frauen gewählte Sterbehilfe (über die Zeit unverändert 58 % der Fälle) ist vor allem ein Altersphänomen: Im Jahr 2022 betrug das mediane Alter derjenigen, die sich für den assistierten Suizid entschieden haben, 81 Jahre; bei der Gruppe derjenigen, die den assistierten Suizid wegen einer Krebserkrankung gewählt haben, betrug das mediane Alter zuletzt 77 Jahre, bei den nicht krebsbedingten Sterbehilfefällen lag es bei 84 Jahren.
Entwicklung und Validierung eines Fragebogens zur Erfassung der
Zufriedenheit von Patienten mit digitaler Bewegungstherapie
Authors: Krell Jan , Wulff Hagen
Published: September 2024

Zielsetzung Die digitale Transformation hat Einfluss auf das
Gesundheitswesen. Für die Konzeption und Optimierung digitaler Bewegungstherapie
besitzt das Konstrukt der Patientenzufriedenheit und die Entwicklung eines
Messmodells hohe Relevanz.

Methodik Die Entwicklung des Fragebogens erfolgte durch ein mehrstufiges
Verfahren. Eine Hauptkomponentenanalyse mit Daten von 180 Befragten (♀=71, ♂=90,
k.A.=19) diente zur Analyse der Struktur des Fragebogens. Die interne Konsistenz
der Skalen wurde durch Cronbachs Alpha und die Trennschärfe der Items durch
Item-Skala-Korrelationen geprüft.

Ergebnisse Fünf Dimensionen wurden aus dem initialen Itempool extrahiert.
Die Kenngrößen der internen Konsistenz (α=0,74) und
Item-Skala-Korrelation r > 0,30 waren zufriedenstellend bis hoch.

Schlussfolgerung Der validierte Fragebogen ermöglicht erstmals die
Erfassung der Zufriedenheit mit digitaler Bewegungstherapie, um Maßnahmen zu
optimieren und die Beantwortung weiterführender Forschungsfragen mit
Implikationen für Theorie (Zufriedenheitsmodellierung) und Transfer
(Qualifikation).
A Comparative Analysis of ADRs under Obeticholic Acid and
Ursodeoxycholic Acid in Cholestatic Liver Diseases Using the FAERS
Database
Authors: Zhu Meng , Tao Linghui , Zhu Feiye , Zhang Yongsheng
Published: September 2024

Background The objective of this study was to compare the safety profiles
of OCA and UDCA for the treatment of PBC using the FDA Adverse Event Reporting
System database.

Methods We extracted reports for OCA from 2016 to 2023 and UDCA from 2004
to 2023. Demographic details, adverse events (AEs), and concomitant medications
were analyzed using descriptive statistics and signal detection methods.

Results The most common for OCA were pruritus (1345 cases, ROR 20.96) and
fatigue (528 cases, ROR 3.46). UDCA was more frequently associated with
hepatocellular carcinoma (22 cases, ROR 16.37) and type I hypersensitivity
reactions (11 cases, ROR 12.77). OCA was also linked to a higher frequency of
constipation (161 cases, ROR 3.92) and increased blood alkaline phosphatase
levels (145 cases, ROR 44.27).

Conclusion This study reveals distinct safety profiles for OCA and UDCA in
the treatment of PBC. OCA is associated with a higher frequency of pruritus,
fatigue, constipation, and increased blood alkaline phosphatase levels, while
UDCA is linked to hepatocellular carcinoma and type I hypersensitivity
reactions. These findings support personalized treatment approaches based on
individual patient characteristics.
Immunomodulatory Activity and Inhibitory Effects of Viscum album on Cancer Cells, Its Safety Profiles and Recent Nanotechnology Development
Authors: Yosri Nermeen , Kamal Nurkhalida , Mediani Ahmed , AbouZid Sameh , Swillam Ahmed , Swilam Mahmoud , Ayyat Ahmed M. , Jantan Ibrahim
Published: September 2024

Viscum album has been employed traditionally to treat various ailments including as add-on therapy for cancer treatment. V. album formulations have been employed as adjuvants in cancer treatment due to their immunomodulatory activities as well as to alleviate the side effects of conventional cancer therapies. The present review provides updated information from the past 10 years on the immunomodulatory activity and inhibitory effects of V. album on cancer cells, its safety profile, and recent nanotechnology development. V. album extracts and their bioactive phytochemicals, particularly lectins, viscotoxins, and polyphenols, have demonstrated immunomodulatory activity and inhibitory effects against various types of cancer, with low cytotoxicity and side effects, in experimental studies and demonstrated promising anticancer activity in clinical studies in cancer patients. V. album extracts have been shown to enhance immune function by
promoting cytokine secretion and inducing both innate and adaptive immune responses, which can help improve immune surveillance against cancer cells. The development of V. album nanoparticles has boosted their biological activities, including inhibitory activity on cancer cells, and could possibly reduce undesired side effects of the plant. Further prospective studies on the plant as a source of new medicinal agents for use as an adjuvant in the treatment of cancer must be performed to provide sufficient efficacy and safety data.
A Comprehensive Multifunctional Approach for Measuring Parkinson's Disease Severity
Authors: Rahimi Morteza , Al Masry Zeina , Templeton John Michael , Schneider Sandra , Poellabauer Christian
Published: September 2024

Objectives This research study aims to advance the staging of Parkinson's disease (PD) by incorporating machine learning to assess and include a broader multifunctional spectrum of neurocognitive symptoms in the staging schemes beyond motor-centric assessments. Specifically, we provide a novel framework to modernize and personalize PD staging more objectively by proposing a hybrid feature scoring approach.

Methods We recruited 37 individuals diagnosed with PD, each of whom completed a series of tablet-based neurocognitive tests assessing motor, memory, speech, executive functions, and tasks ranging in complexity from single to multifunctional. Then, the collected data were used to develop a hybrid feature scoring system to calculate a weighted vector for each function. We evaluated the current PD staging schemes and developed a new approach based on the features selected and extracted using random forest and principal component analysis.

Results Our findings indicate a substantial bias in current PD staging systems toward fine motor skills, that is, other neurological functions (memory, speech, executive function, etc.) do not map into current PD stages as well as fine motor skills do. The results demonstrate that a more accurate and personalized assessment of PD severity could be achieved by including a more exhaustive range of neurocognitive functions in the staging systems either by involving multiple functions in a unified staging score or by designing a function-specific staging system.

Conclusion The proposed hybrid feature score approach provides a comprehensive understanding of PD by highlighting the need for a staging system that covers various neurocognitive functions. This approach could potentially lead to more effective, objective, and personalized treatment strategies. Further, this proposed methodology could be adapted to other neurodegenerative conditions such as Alzheimer's disease or amyotrophic lateral sclerosis.
Effectiveness and safety of a new clip for delivery using a duodenoscope for bleeding after endoscopic sphincterotomy
Authors: Yamaguchi Atsushi , Kamada Hiroki , Semba Shigeaki , Kato Naohiro , Okuda Yasuhiro , Teraoka Yuji , Mizumoto Takeshi , Tamaru Yuzuru , Hatakeyama Tsuyoshi , Kouno Hirotaka , Yoshida Shigeto
Published: September 2024

Background and study aims Hemostasis for post-endoscopic sphincterotomy (post-EST) bleeding involves no standard strategy. New clips designed for delivery using the duodenoscope (SureClip, Micro-Tech, Nanjing, China) have been utilized for gastrointestinal bleeding hemostasis and bleeding prevention after polypectomy and papillectomy. We retrospectively analyzed the effectiveness and safety of SureClip for post-EST bleeding.

Patients and methods Of 608 patients with endoscopic sphincterotomy (EST), 41 cases (6.7%) experienced post-EST bleeding from 2019 to 2023. Of these patients, 24 underwent hemostasis by SureClip, and the success rate of complete hemostasis and complication by hemostasis by SureClip was analyzed.

Results In 12 and 12 patients with urgent and delayed bleeding, 11 (91.7%) and 11 (91.7%) had successful hemostasis, respectively. In addition, missed patients achieved complete hemostasis with additional transcatheter arterial embolization and balloon compression, respectively. No complications were observed, including perforation, pancreatitis, and clipping bile duct and pancreatic duct by mistake.

Conclusions Hemostasis with SureClip is safe, effective, and not expensive for post-EST bleeding. It could be the first choice for hemostasis in patients with post-EST bleeding refractory to balloon compression.
The impact of NOCs in Chinese foreign policy: the cases of Angola and Sudan
Authors: Behrndt-Eriksen T. Kasandra
Published: September 2024

Chinese companies have invested substantially in countries abroad in recent years, including countries in Africa. This article investigates the activities of Chinese energy companies in Africa, looking at the cases of Angola and Sudan. It develops a theoretical framework that can examine the role of non-state actors in foreign policy. The article presents evidence that non-state actors play a role for Chinese foreign policy and sometimes go against the policy line from Beijing. Theoretically, it illuminates the increasing role played by national oil companies (NOCs) in foreign policy and contributes with explicitation of the role played by NOCs for the foreign policy of the state. The article also contributes with insights regarding the importance of concerns with domestic stability (weiwen) to Chinese foreign policy and how this motive relates to the Chinese NOC activities in a number of countries.
When in-memory computing meets spiking neural networks—A perspective on device-circuit-system-and-algorithm co-design
Authors: Moitra Abhishek , Bhattacharjee Abhiroop , Li Yuhang , Kim Youngeun , Panda Priyadarshini
Published: September 2024

This review explores the intersection of bio-plausible artificial intelligence in the form of spiking neural networks (SNNs) with the analog in-memory computing (IMC) domain, highlighting their collective potential for low-power edge computing environments. Through detailed investigation at the device, circuit, and system levels, we highlight the pivotal synergies between SNNs and IMC architectures. Additionally, we emphasize the critical need for comprehensive system-level analyses, considering the inter-dependencies among algorithms, devices, circuit, and system parameters, crucial for optimal performance. An in-depth analysis leads to the identification of key system-level bottlenecks arising from device limitations, which can be addressed using SNN-specific algorithm–hardware co-design techniques. This review underscores the imperative for holistic device to system design-space co-exploration, highlighting the critical aspects of hardware and algorithm research endeavors for low-power neuromorphic solutions.
Temperature-dependent generalized ellipsometry of the metal–insulator phase transition in low-symmetry charge-transfer salts
Authors: Tiwari Achyut , Gompf Bruno , Dressel Martin
Published: September 2024

Determining the optical and electronic properties of strongly anisotropic materials with symmetries below orthorhombic remains challenging; generalized ellipsometry is a powerful technique in this regard. Here, we employ Mueller matrix spectroscopic and temperature-dependent ellipsometry to determine the frequency dependence of six components of the dielectric-function tensor of the two-dimensional charge-transfer salt α-(BEDT-TTF)2I3 across its metal–insulator transition. Our results offer valuable insights into temperature-dependent changes of the components of the spectroscopic dielectric-function tensor across the metal–insulator transition. This advanced method allows extension to other electronic transitions.
Quantum subspace expansion in the presence of hardware noise
Authors: Getelina João C. , Sharma Prachi , Iadecola Thomas , Orth Peter P. , Yao Yong-Xin
Published: September 2024

Finding ground state energies on current quantum processing units (QPUs) using algorithms such as the variational quantum eigensolver (VQE) continues to pose challenges. Hardware noise severely affects both the expressivity and trainability of parameterized quantum circuits, limiting them to shallow depths in practice. Here, we demonstrate that both issues can be addressed by synergistically integrating VQE with a quantum subspace expansion, allowing for an optimal balance between quantum and classical computing capabilities and costs. We perform a systematic benchmark analysis of the iterative quantum-assisted eigensolver in the presence of hardware noise. We determine ground state energies of 1D and 2D mixed-field Ising spin models on noisy simulators and the IBM QPUs ibmq_quito (5 qubits) and ibmq_guadalupe (16 qubits). To maximize accuracy, we propose a suitable criterion to select the subspace basis vectors according to the trace of the noisy overlap matrix. Finally, we show how to systematically approach the exact solution by performing controlled quantum error mitigation based on probabilistic error reduction on the noisy backend fake_guadalupe.
Extended transfer matrix method for electron transmission in anisotropic 2D materials: Interplay of strain and (a)periodicity of potentials
Authors: Díaz-Bautista Erik , Betancur-Ocampo Yonatan , Raya Alfredo
Published: September 2024

We extend the conventional transfer matrix method to include anisotropic features for electron transmission in two-dimensional materials, such as breaking reflection law in pseudo-spin phases and wave vectors, which are not usually considered appropriately in the literature. This method allows us to study transmission properties of anisotropic and stratified electrostatic potential media from a wide range of tunable parameters, which include strain tensor and gating. We apply the extended matrix method to obtain the electron transmission, conductance, and Fano factor for the interplay of a uniaxially strained graphene sheet with external one-dimensional aperiodic potentials. Our results suggest the possibility of visualizing this interplay from conductance measurements.
Stochastic Schrödinger equation for hot-carrier dynamics in plasmonic systems
Authors: Dall’Osto Giulia , Vanzan Mirko , Corni Stefano , Marsili Margherita , Coccia Emanuele
Published: September 2024

We present a multiscale method coupling the theory of open quantum systems with real-time ab initio treatment of electronic structure to study hot-carrier dynamics in photoexcited plasmonic systems. We combine the Markovian Stochastic Schrödinger equation with an ab initio GW coupled to the Bethe–Salpeter (BSE) equation description of the electronic degrees of freedom, interacting with a metallic nanoparticle modeled classically according to the polarizable continuum model. We apply this methodology to study the effect of relaxation (T1) and pure dephasing (T2) times on the hot-carrier dynamics in a system composed of a quantum portion described at GW/BSE level, i.e., a CHO fragment adsorbed on a vertex of a rhodium nanocube, and of the rest of the nanocube, treated classically, when irradiated with a 2.7 eV light pulse, inspired by the experimental results on plasmon-driven CO2 photoreduction. A net hole injection from rhodium to CHO is observed, with and without the classical portion of the nanocube. The nanocube effect is to enhance the generated charge population by two orders of magnitude. The nonradiative decay, via a relaxation time T1 based on the energy-gap law, produces a rapid decrease of the charge population. Results with T2 only show that a charge injection retarded with respect to the pulse, which is present in the coherent dynamics, disappears when coherence is erased.
Improving the energy harvesting performance of clamped flexible plates using vortex shedding behind bluff bodies: A computational study
Authors: Wang Xinyu , Guo Xu , Mei Yue , Kadapa Chennakesava
Published: September 2024

This study assesses flow-induced vibrations of clamped flexible plates with the objective of improving their energy harvesting performance. Toward this, a rectangular bluff body is placed between the two clamped flexible plates to harness the vortices generated behind the bluff body. The strain energy of the plate is used as a measure of energy harvesting performance. Computational studies are performed for different parameters of interest, such as dimensions and material properties of the plate and dimensions and locations of the bluff body. The effects of these stated parameters on flow-induced vibration response and vortical structures are investigated, and the optimal values for the location and geometry of the bluff body, as well as the aspect ratio and Young's modulus of the plate for energy harvesting performance, are determined. The results show that vortex shedding from the bluff body strongly influences the dynamic behavior and energy output of the flexible structures inside the wake region of the bluff body at different locations. Additionally, the aspect ratio and its effect on vorticity and energy harvesting are discussed in detail, along with the average displacement and average lift force experienced by the plates. The outcomes of this work offer significant insights into optimizing the design of clamped flexible plates for optimal energy generation by cleverly exploiting the vortex shedding behind fixed bluff bodies.
Spectral packing decomposition of CMV matrices through power-law subordinacy
Authors: Peng Yaxin , Guo Shuzheng
Published: September 2024

This note gives a classification for the spectral measures of CMV matrices, which are special unitary five-diagonal matrices related to orthogonal polynomials on the unit circle, with respect to packing measures.
Melt strain hardening of polymeric systems increasing with decreasing elongational rate: Experimental results and discussion of models
Authors: Münstedt H.
Published: September 2024

Melt strain hardening is a special feature of polymer materials and polymeric systems relevant for applications and fundamental insights into rheological properties. Strain hardening is dependent on the molecular structure of materials and deformation parameters. This paper deals with literature results of materials exhibiting strain hardening increasing with decreasing elongational rate opposite to most of common polymers. Such a behavior is found for ionomers and polymers with hydrogen bonding, and electrostatic molecular interactions are discussed as the physical origin. Furthermore, layered composites of non-strain hardening polymers are presented that can be rendered strain hardening by introducing compatibilizers or increasing the effect of interfacial tension between two layers by using multilayer arrangements. The strain hardening behavior of polypropylene/high density polyethylene blends of various compositions is discussed. Measurements on ethylene/α-olefin copolymers showing strain hardening significantly increasing with decreasing rate in contrast to linear ethylene homopolymers are described, and it is hypothesized that this behavior is due to a heterogeneous molecular structure with large differences of molar masses of the components.
Establishing universality in entropy change and critical behavior for magnetocaloric effect in Si-substituted Mn50Ni40Sn10 inverse Heusler alloy
Authors: Biswal Sambit Kumar , Panda Shantanu Kumar , Mallick Jyotirekha , Rout Sushree Nibedita , Dev Amar , Kar Manoranjan
Published: September 2024

Magnetic refrigeration working based on the magnetocaloric effect can be the perfect replacement of the conventional gas compression-based refrigeration technology and reduces its harmful effects on the environment. The boundary between a first-order and a second-order phase transition would be where the perfect magnetocaloric material would be found. Therefore, establishing the sequence of phase transitions clearly is essential for the characterization of other phase change materials and for applied magnetocaloric research. A quantitative fingerprint of second-order thermomagnetic phase transitions is reported here in Si-substituted high content Mn-based inverse Heusler alloy systems, which are found to be crystallized in cubic structures. The second-order nature of the phase transition has been confirmed from the Arrott plot analysis and a correlation between magnetocaloric effect and local exponent is established. Using the Arrott plot, the critical exponents are evaluated employing different techniques such as modified Arrott plot, Kouvel–Fisher method, and critical isotherm. Their values are found to be in great agreement with each other and follow the mean-field model signifying the presence of long-range ordering in the materials. The high value of isothermal magnetic entropy change and the reversibility justifies the suitability of the reported materials in the practical application as magnetic refrigerants.
Unraveling nano-scale effects of topotactic reduction in LaNiO2 crystals
Authors: Wu Yu-Mi , Puphal Pascal , Isobe Masahiko , Keimer Bernhard , Hepting Matthias , Suyolcu Y. Eren , van Aken Peter A.
Published: September 2024

Infinite-layer nickelates stand as a promising frontier in the exploration of unconventional superconductivity. Their synthesis through topotactic oxygen reduction from the parent perovskite phase remains a complex and elusive process. This study delves into the nano-scale effects of the topotactic lattice transformation within LaNiO2 crystals. Leveraging high-resolution scanning transmission electron microscopy and spectroscopy, our investigations uncover a panorama of structural alterations, including grain boundaries and coherent twin boundaries, triggered by reduction-induced transformations. In addition, our analyses unveil the formation of an oxygen-rich disordered transition phase encircling impurities and pervading crystalline domains and the internal strain is accommodated by grain boundary formation. By unraveling these nano-scale effects, our findings provide insights into the microscopic intricacies of the topotactic reduction process elucidating the transition from the perovskite to the infinite-layer phase within nickelate bulk crystals.
Feedback directions governing self-sustained thermoacoustic instability in rocket engine combustors
Authors: De Somnath , Kasthuri Praveen , Harvazinski Matthew E. , Gejji Rohan , Anderson William , Sujith R. I.
Published: September 2024

The occurrence of high-frequency (>1000 Hz) thermoacoustic instability (TAI) sustained by mutual feedback among the acoustic field, heat release rate oscillations, and hydrodynamic oscillations poses severe challenges to the operation and structural integrity of rocket engines. Hence, quantifying the differing levels of feedback between these variables can help uncover the underlying mechanisms behind such high-frequency TAI, enabling redesign of combustors to mitigate TAI. However, so far, no concrete method exists to decipher the varying levels of mutual feedback during high-frequency TAI. In the present study, we holistically investigate the mutual influence based on the spatiotemporal directionality among acoustic pressure, heat release rate, and hydrodynamic and thermal oscillations during TAI of a single-element rocket engine combustor. Using symbolic transfer entropy, we identify the spatiotemporal direction of feedback interactions between those primary variables when acoustic waves significantly emerge during TAI. We unveil the influence of vorticity dynamics at the fuel collar (or the propellant splitter plate) as the primary stimulant over the heat release rate fluctuations to rapidly amplify the amplitude of the acoustic field. Furthermore, depending on the quantification of the degree of the mutual information (i.e., the net direction of information), we identify the switches in dominating the thermoacoustic driving between the variables during TAI, each representing a distinct mechanism of a thermoacoustic state. Additionally, from this quantification, we analyze the relative dominance of the variables and rank-order the mutual feedback according to their impact on driving TAI.
Fragment quantum embedding using the Householder transformation: A multi-state extension based on ensembles
Authors: Cernatic Filip , Fromager Emmanuel , Yalouz Saad
Published: September 2024

In recent studies by Yalouz et al. [J. Chem. Phys. 157, 214112 (2022)] and Sekaran et al. [Phys. Rev. B 104, 035121 (2021) and Computation 10, 45 (2022)], density matrix embedding theory (DMET) has been reformulated through the use of the Householder transformation as a novel tool to embed a fragment within extended systems. The transformation was applied to a reference non-interacting one-electron reduced density matrix to construct fragments’ bath orbitals, which are crucial for subsequent ground state calculations. In the present work, we expand upon these previous developments and extend the utilization of the Householder transformation to the description of multiple electronic states, including ground and excited states. Based on an ensemble noninteracting density matrix, we demonstrate the feasibility of achieving exact fragment embedding through successive Householder transformations, resulting in a larger set of bath orbitals. We analytically prove that the number of additional bath orbitals scales directly with the number of fractionally occupied natural orbitals in the reference ensemble density matrix. A connection with the regular DMET bath construction is also made. Then, we illustrate the use of this ensemble embedding tool in single-shot DMET calculations to describe both ground and first excited states in a Hubbard lattice model and an ab initio hydrogen system. Finally, we discuss avenues for enhancing ensemble embedding through self-consistency and explore potential future directions.
Optimization and knowledge discovery of profiled end walls in a turbine stage at a low Reynolds number
Authors: Yuan Hang , Zhang Jianshe , Wu Yunfeng , Sheng Xiaoying , Lu Xingen , Zhang Yanfeng
Published: September 2024

To comprehensively explore flow control method of profiled end wall for turbine stage at low Reynolds numbers, a surrogate model optimization platform including non-uniform rational B-spline surface parameterization method, support vector regression, and improved chaos particle swarm optimization algorithm is integrated. Optimization designs have been carried out for stator profiled end walls, rotor profiled end wall, and combined end walls, respectively. The results indicate that under the constraint of the output power, the application of various profiled end wall design cases all can effectively improve the aerodynamic performance of the turbine stage. By organizing the flow field of downstream rotor, the profiled end wall of stator can significantly affect the stage efficiency. The flow control benefits of the profiled end wall of the rotor is from the obstruction of the cross migration of the pressure side leg of the horseshoe vortex. The application of profiled end wall on stator has the most practical engineering value. Self-organizing maps and Shapley methods are used to explore potential correlation information of aerodynamic parameters and summarize design experience. The sensitive design variables of profiled end walls are extracted. Based on the local controllability of NURBS surfaces, the regions that affect the stage efficiency are mainly concentrated in the middle of the stator passage, near the stator trailing edge and near the rotor leading edge. The regions with a significant impact on the output power of the turbine stage are near the trailing edge of the rotor and stator. The corresponding design rules of end walls modeling are summarized.
Quantifying spin-torque efficiency and magnetoresistance coefficient by microwave photoresistance in spin-torque ferromagnetic resonance
Authors: Zhan Xiang , Duan Haotian , Wang Wenqiang , Yan Chunjie , Chen Lina , Wang Haozhe , Li Zishuang , Liu Ronghua
Published: September 2024

During the spin-torque ferromagnetic resonance (ST-FMR) measurement, the magnetization precession driven by the microwave field yields the radio frequency (rf) oscillating magnetoresistance and its time-averaged change (photoresistance). Here, we find that the strength of photoresistance can be directly determined by using dc bias current Idc modulating the symmetric component VS of the ST-FMR voltage spectrum. By measuring the angular dependence of photoresistance, we can quantify the in-plane and out-of-plane precession angles of ST-FMR, the actual rf current distribution in the magnetic and non-magnetic sublayers, and the magnitude of spin-torque and various magnetoresistance coefficients. These experimentally obtained values and analysis methods can more accurately quantify the spin-torque efficiency of both in-plane and out-of-plane spin polarizations by self-consistent calculation of the precession angle without harsh assumptions. And, we further confirm this universal method in three spintronic systems: the prototypical Pt/Py bilayer with anisotropic magnetoresistance (AMR), Py/Cu/Co20Tb80 spin valve trilayer with AMR and giant magnetoresistance, and [Co/Ni]3/Co/Pt multilayer with AMR and anisotropic interface magnetoresistance. This method eliminates potential deviation in calculating spin-torque efficiency by previously reported line shape analyzation and linewidth modulation methods of the ST-FMR technique and significantly extends its application range in characterizing spintronic materials and nanodevices.
Comparative study of atomic models of plastic deformation mechanism in ductile inorganic semiconductors: A theoretical discussion
Authors: Luo Jun , Gao Zhiqiang , Zhang Jiawei , Shi Xun , Chen Lidong
Published: September 2024

Recently developed ductile inorganic semiconductors have opened a new avenue toward potential applications such as flexible electronics. Significant studies have been conducted based on different atomic models to understand the deformation mechanism using first-principle calculations; however, the comparative study on these atomic models remains unexplored. In this paper, taking Ag2S as an example, we simulated the slipping process using bulk, slab, and tilt-cell models. Systematic supercell tests were performed to investigate the convergence of the slip/cleavage energy based on the three atomic models. It was found that a reasonably large supercell is required to converge the slip/cleavage energy, and the ratio between minimum cleavage and maximum slip energy converges to a comparable value among different atomic models, where the tilt-cell and slab models show slightly higher energy ratio values compared with the bulk model. However, the comparison of different exchange-correlation functionals and van der Waals corrections indicates that the calculations of slip and cleavage energies are sensitive to the choice of calculation methods, highlighting the importance of using the same method for comparing slip and cleavage energies of different materials. This work provides insights into understanding different atomic models of ductility mechanisms in ductile inorganic semiconductors.