bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling the Interaction Between Inclusions and Nanocracks in Flexoelectric Solids
Authors: Xu Mengkang , Tian Xinpeng , Deng Qian , Li Qun
Published: June 2023

Natural defects such as nano inclusions and nanocracks are inevitable in dielectric materials. When materials are subjected to mechanical loading, the strain gradient around crack tips and inclusions would become large and induce significant flexoelectric fields. In contrast to classical crack–inclusion problems, the interactions between these flexoelectric fields may locally change the electromechanical behaviors of materials and result in some interesting phenomena. To better understand the crack–inclusion interactions in flexoelectric solids, in this work, we use a collocation mixed finite element method to model and analyze the flexoelectric fields around the crack tip and inclusion. On the basis of the J-integral, we analyze how the flexoelectric effect affect the interaction energy between nanocracks and nearby nano inclusions. This work proposes a new coupling mechanism in crack–inclusion problems and may inspire future experiments in flexoelectric solids.
Simultaneous Optimization of Part and Parting Surface for Hybrid Casting and Additive Manufacturing
Authors: Wang Shu , Zheng Xueqin , Wang Cunfu , Luo Huageng , Jing Shikai
Published: June 2023

This paper presents formulations for hybrid casting and additive manufacturing (AM) in the density-based topology optimization. A location-based Heaviside function is introduced to represent the parting surface. The optimized part on two sides of the parting surface can be fabricated with casting, additive manufacturing, or both. Through the location-based Heaviside function and density gradient, two global constraints are formulated to remove undercuts and overhangs for casting and AM, respectively, inside the design domain. Since density gradient vanishes on the design domain boundary, two extra density-based global constraints are developed to control the overhangs and undercuts outside the design domain. Due to the smoothed parameterization of the parting surface, we are able to optimize the part and partition surface (including location and parting direction) simultaneously for hybrid casting and additive manufacturing. The proposed formulations for hybrid manufacturing processes are validated through 2D and 3D numerical examples. The proposed approach further enlarges the design space with manufacturing constraints, and has the potential to be used in the design for hybrid and multi-component manufacturing.
Concurrent Build Direction, Part Segmentation, and Topology Optimization for Additive Manufacturing Using Neural Networks
Authors: Chen Hongrui , Joglekar Aditya , Whitefoot Kate S. , Burak Kara Levent
Published: June 2023

Without an explicit formulation to minimize support structures, topology optimization may create complex shapes that require an intensive use of support material when additively manufactured. We propose a neural network-based approach to topology optimization that aims to reduce the use of support structures in additive manufacturing. Our approach uses a network architecture that allows the simultaneous determination of an optimized: (1) part segmentation, (2) the topology of each part, and (3) the build direction of each part that collectively minimize the amount of support structure. Through training, the network learns a material density and segment classification in the continuous 3D space. Given a problem domain with prescribed load and displacement boundary conditions, the neural network takes as input 3D coordinates of the voxelized domain as training samples and outputs a continuous density field. Since the neural network for topology optimization learns the density distribution field, analytical solutions to the density gradient can be obtained from the input–output relationship of the neural network. We demonstrate our approach on several compliance minimization problems with volume fraction constraints, where support volume minimization is added as an additional criterion to the objective function. We show that simultaneous optimization of part segmentation along with the topology and print angle optimization further reduces the support structure, compared to a combined print angle and topology optimization without segmentation.
A Single-Fidelity Surrogate Modeling Method Based on Nonlinearity Integrated Multi-Fidelity Surrogate
Authors: Li Kunpeng , He Xiwang , Lv Liye , Zhu Jiaxiang , Hao Guangbo , Li Haiyang , Song Xueguan
Published: June 2023

Surrogate model provides a promising way to reasonably approximate complex underlying relationships between system parameters. However, the expensive modeling cost, especially in large problem sizes, hinders its applications in practical problems. To overcome this issue, with the advantages of the multi-fidelity surrogate (MFS) model, this paper proposes a single-fidelity surrogate model with a hierarchical structure, named nonlinearity integrated correlation mapping surrogate (NI-CMS) model. The NI-CMS model first establishes the low-fidelity model to capture the underlying landscape of the true function, and then, based on the idea of MFS model, the established low-fidelity model is corrected by minimizing the mean square error to ensure prediction accuracy. Especially, a novel MFS model (named NI-MFS), is constructed to enhance the stability of the proposed NI-CMS model. More specifically, a nonlinear scaling term, which assumes the linear combination of the projected low-fidelity predictions in a high-dimensional space can reach the high-fidelity level, is introduced to assist the traditional scaling term. The performances of the proposed model are evaluated through a series of numerical test functions. In addition, a surrogate-based digital twin of an XY compliant parallel manipulator is used to validate the practical performance of the proposed model. The results show that compared with the existing models, the NI-CMS model provides a higher performance under the condition of a small sample set, illustrating the promising potential of this surrogate modeling technique.
A Unified Inverse Design and Optimization Workflow for the Miura-oRing Metastructure
Authors: Chen Yao , Shi Jiayao , He Ruoqi , Lu Chenhao , Shi Pan , Feng Jian , Sareh Pooya
Published: June 2023

Origami structures are often attractive for a broad range of applications in engineering, design, and robotics because of their useful characteristics such as reconfigurable geometry, tunable stiffness, and energy absorption capacity. Although a range of algorithms and software is available for origami design and folding analysis, they are generally isolated from other computational tools. To contribute to filling this research gap, we propose a unified parametric origami design workflow based on grasshopper combined with a multi-objective optimization process. To this end, first, a parametric model for a ring-shaped fourfold origami structure, called the Miura-oRing metastructure, is developed based on appropriate geometric parameters. Its nonlinear folding process is then simulated according to geometric compatibility conditions and given constraints. Simultaneously, modal analysis is iteratively performed, using SAP2000 through C# scripts, to obtain relationships for the structural configuration, mass, and stiffness of the origami structure. Finally, an inverse design process based on a fitting cylindrical annulus is carried out using Octopus, considering the spatial fit, mass, and stiffness of the Miura-oRing. A comparison is made between the obtained results and those of the origami simulator and the physical models to validate the performance of the proposed method. After balancing the three objectives of inverse design, a recommended range of parameters is prescribed for the Miura-oRing for a given set of dimensions. This study provides a workflow that integrates geometry, kinematics, and structural performance, enabling the design of origami structures with desirable geometric, kinematic, and structural characteristics.
Design, Dimensional Synthesis and Evaluation of a Novel Two-Degrees-of-Freedom Spherical Remote Center of Motion Mechanism for Minimally Invasive Surgery
Authors: Li Jianmin , Wang Jiatong , Zhao Jianchang , Wei Guowu
Published: June 2023

With the development of minimally invasive surgery (MIS) technology, higher requirements are put forward for the performance of remote center of motion (RCM) manipulator. This paper presents the conceptual design of a novel two-degrees-of-freedom (2-DOF) spherical RCM mechanism, whose axes of all revote joints share the same RCM. Compared with the existing design, the proposed mechanism indicates a compact design and high structure stability, and the same scissor-like linkage makes it easy to realize modular design. It also has the advantages of singularity-free and motion decoupling in its workspace, which simplifies the implementation and control of the manipulator. In addition, compared with the traditional spherical scissor linkage mechanism, the proposed mechanism adds a rotation constraint on the output shaft to provide better operating performance. In this paper, the kinematics and singularities of different cases are deduced and compared, and the kinematic model of the best case is established. According to the workspace and constraints in MIS, the optimal structural parameters of the mechanism are determined by dimensional synthesis with the goal of optimal global operation performance. Furthermore, a prototype is assembled to verify the performance of the proposed mechanism. The experimental results show that the two-degrees-of-freedom prototype can provide a reliable RCM point. The compact design makes the manipulator have potential application prospects in MIS.
Multidisciplinary Design of an Electrically Powered High-Lift System
Authors: Maroldt Niklas , Lohse Stefanie , Kalla Matthias , Ponick Bernd , Seume Joerg R.
Published: June 2023

To date, design processes for electrically powered compressor are mainly based on separate processes for each individual component. Whereas the blading is often designed by an integrated aerodynamic and mechanical design optimization, additional components such as the electrical machine are usually not included. These approaches neglect the interactions of the individual components, which can influence the system performance. This paper demonstrates a multidisciplinary design approach, combining an optimization approach for a compressor stage and an electrical machine. The automated optimization process is based on an evolutionary algorithm, evaluating each individual of a population in terms of aerodynamic performance, structural integrity and performance of the electrical machine. This approach is applied to the design of a mixed-flow compressor for active high-lift applications in aircraft. The results suggest that the overall system efficiency is mainly influenced by the compressor stage, whereas the system mass is dominated by the electrical components which highlights the need to combine both optimization approaches. Key design parameters of high power-density electrical-machine designs are identified. A comparison between a previous compressor-only optimization and a new design based on the new multidisciplinary optimization confirms the improvements the latter optimization approach yields.
A Novel Free-Standing Riser Concept for Deepwater Developments
Authors: Bomfimsilva Carlos Terencio Pires , Netto Theodoro Antoun
Published: June 2023

Free-standing hybrid risers (FSHR) are well established in deepwater field developments in the oil and gas industry. The major advantages foreseen for the FSHR are the possibility of safely anticipating production and requiring significantly reduced payloads at the floating production unit. This work addresses the feasibility of a novel proposed optimized concept, the free-standing integrated riser (FSIR), where the pipeline is integrated into the riser by means of a transition section, which is kept in place by a multiple line mooring system, developed to keep the functionality and integrity of the entire riser along its lifetime. The work provides the findings from numerical analysis simulated in orcaflex, a finite element simulation software dedicated to global analysis of risers, considering the design criteria provided in API 2RD Standard. As part of the FSIR evaluation, screening static analysis was performed to identify the most promising configurations for the multiple line mooring system, followed by a series of dynamic analyses to evaluate the behavior of the riser in extreme conditions. In addition, several investigations were performed to assess the functionality and the robustness of the system, including parametric studies to check for installation and dimensional tolerances, assessment of fatigue damage, and checking the impact of pipe size on the design. The results show that the proposed novel FSIR concept can provide a practical and economical solution for deepwater projects.
A subterranean new genus and species of Eutrombidiinae (Trombidiformes: Microtrombidiidae) from Turkey
Authors: Sevsay Sevgi , Elverici Mert
Published: June 2023

A new genus and species of the Microtrombidiidae, Troglotrombidium dolichopodum n. gen. et n. sp. is described based on ectoparasitic larvae collected from two Dolichopoda lycia (Galvagni 2006) (Orthoptera: Rhaphidophoridae) specimens from a cave in Western Taurus Mountains, Turkey. The new genus can be distinguished from other genera by the absence of eyes, highly modified claws of tarsi III, sensillary setae structure of the anterior dorsal scutum, and the number of adoral setae. The new species is a typical troglobite, and this interspecific interaction is a well-documented case for the little-known host-parasite relationships from subterranean ecosystems.
Understanding the unique optical and vibrational signatures of sequential infiltration synthesis derived indium oxyhydroxide clusters for CO2 absorption
Authors: Kunene Thabiso , Martinson Alex B. F.
Published: June 2023

Sequential infiltration synthesis (SIS) is a vapor phase synthesis technique with potential to exert precise control over metal oxyhydroxide incorporation into polymer scaffolds. We observe strong size-dependent properties of InOx(OH)y few-atom clusters deposited with variable SIS cycle numbers within a polymethylmethacrylate (PMMA) matrix. Infrared spectroscopy and ultraviolet-visible absorption spectroscopy reveal that the metal atom coordination and optical properties of the clusters depend on the number of SIS cycles performed as well as the choice of processing parameters. The incorporation of indium oxyhydroxide in PMMA via SIS presents an opportunity to improve the CO2 absorption capacity and gas selectivity of inexpensive polymers.
Long and flexible atmospheric pressure plasma jet probes for operation in humid environments
Authors: Kim Jae Young , Bae Gyu Tae , Lee Ye Rin , Jang Sebinn , Jung Eun Young , Tae Heung-Sik
Published: June 2023

Herein, we describe a new flexible atmospheric pressure plasma jet device composed of hollow-core optical fibers and introduce two potential applications of the device: endoscopic plasma treatment and decomposition of aqueous phosphorus compounds. The proposed device is 1.6 m long and highly flexible, has a small probe size of several hundred micrometers, and spatially separates the plasma jet from the electrical input, making it very suitable for treatment through the biopsy channel of a conventional endoscope. Because the wire electrode of the fabricated atmospheric pressure plasma jet device is thoroughly isolated inside the hollow of the optical fiber, the device produces a plasma column in an identical discharge state regardless of external environmental conditions. As a result, the device can operate safely and steadily in highly humid environments, such as underwater, which can be utilized to decompose phosphorus compounds in fresh water.
Nonequilibrium thermodynamics modeling of the rheological response of cement pastes
Authors: Ioannou Amalia K. , Stephanou Pavlos S.
Published: June 2023

Undoubtedly, cement is one of the most important materials in the construction industry. For its effective use, it is particularly important to fully comprehend the rheological behavior of cement paste. When cement is mixed with water, a suspension is initially formed and the rate of hydrolysis reactions accelerates leading to the formation of a new irreversible structure, i.e., the cement paste gradually solidifies. At the same time, the viscosity of the paste initially decreases with time, while at long times it gradually increases due to the formation of the irreversible structure. We herein introduce a continuum model for predicting the rheological behavior of cement pastes. The model is developed using nonequilibrium thermodynamics, in particular, the Generalized Brackets formalism, to guarantee model admissibility with thermodynamic laws. To this end, we consider two scalar structural variables: a reversible, λrev, characterizing the reversible structure, and an irreversible one, λirr, characterizing the irreversible structure resulting from the hydrolysis reactions. Also, we consider a tensorial structural variable, the conformation tensor c, to characterize the deformation of the cement particles. The predictions of the new model compare reasonably well with available experimental data, especially at large times, and further highlight the capacity of the new model to address the thixotropic behavior of cement pastes. It is expected that the use of this model in concrete rheology simulators will allow for the in silico testing and tailor-designing of concrete to meet specific processing needs.
Automated time-lapse data segmentation reveals in vivo cell state dynamics
Authors: Genuth Miriam A. , Kojima Yasuhiro , Jülich Dörthe , Kiryu Hisanori , Holley Scott A.
Published: June 2023

Embryonic development proceeds as a series of orderly cell state transitions built upon noisy molecular processes. We defined gene expression and cell motion states using single-cell RNA sequencing data and in vivo time-lapse cell tracking data of the zebrafish tailbud. We performed a parallel identification of these states using dimensional reduction methods and a change point detection algorithm. Both types of cell states were quantitatively mapped onto embryos, and we used the cell motion states to study the dynamics of biological state transitions over time. The time average pattern of cell motion states is reproducible among embryos. However, individual embryos exhibit transient deviations from the time average forming left-right asymmetries in collective cell motion. Thus, the reproducible pattern of cell states and bilateral symmetry arise from temporal averaging. In addition, collective cell behavior can be a source of asymmetry rather than a buffer against noisy individual cell behavior.
Immune engineered extracellular vesicles to modulate T cell activation in the context of type 1 diabetes
Authors: Becker Matthew W. , Peters Leeana D. , Myint Thinzar , Smurlick Dylan , Powell Andrece , Brusko Todd M. , Phelps Edward A.
Published: June 2023

Extracellular vesicles (EVs) can affect immune responses through antigen presentation and costimulation or coinhibition. We generated designer EVs to modulate T cells in the context of type 1 diabetes, a T cell–mediated autoimmune disease, by engineering a lymphoblast cell line, K562, to express HLA-A*02 (HLA-A2) alongside costimulatory CD80 and/or coinhibitory programmed death ligand 1 (PD-L1). EVs presenting HLA-A2 and CD80 activated CD8
+
T cells in a dose, antigen, and HLA-specific manner. Adding PD-L1 to these EVs produced an immunoregulatory response, reducing CD8
+
T cell activation and cytotoxicity in vitro. EVs alone could not stimulate T cells without antigen-presenting cells. EVs lacking CD80 were ineffective at modulating CD8
+
T cell activation, suggesting that both peptide-HLA complex and costimulation are required for EV-mediated immune modulation. These results provide mechanistic insight into the rational design of EVs as a cell-free approach to immunotherapy that can be tailored to promote inflammatory or tolerogenic immune responses.
Cobalt mineralogy at the Iron Creek deposit, Idaho cobalt belt, USA: Implications for domestic critical mineral production
Authors: Holley E.A. , Zaronikola N. , Trouba J. , Pfaff K. , Thompson J. , Spiller E. , Anderson C. , Eggert R.
Published: June 2023

Current U.S. policies aim to establish domestic supply chains of critical minerals for the energy transition. The Iron Creek deposit in the Idaho cobalt belt (ICB) is one of the most promising cobalt (Co) targets. Our case study illustrates the importance of mineralogy in strategic evaluations of critical mineral potential. Most of the Co at Iron Creek occurs as Fe substitution in pyrite, with lattice-bound and inclusion-hosted Ag, As, Bi, Ni, Pb, Se, Te ± trace Au and Sb. Cobalt also occurs in minor cattierite-vaesite. The Co minerals are intergrown with Co-poor chalcopyrite hosting Cu ± minor In and Zn. Worldwide, most Co is recovered from deposits mineralogically distinct from the ICB, and the United States currently lacks infrastructure to recover this Co and its associated metals. ICB ore minerals could be processed by autoclave, roaster, smelter, bioleach, or heap leach. Recovery of the Ag, As, Au, Bi, In, Pb, Se, Te, and Zn would be costly by autoclave, and construction of a custom smelter for ICB ores is likely uneconomic, so these elements would become waste irrespective of criticality. The Co-Fe and Co-As sulfide minerals are most suitable for Co and Ni recovery by a hydrometallurgical autoclave process, with potential pretreatment of cobaltiferous pyrite/arsenopyrite in an inert-atmosphere roaster, in new domestic or anticipated international facilities. The ICB is the second largest known Co resource in the United States. Consideration of ore mineralogy in the ICB is essential in strategies for domestic production.
Subclinical congestion assessed by lung ultrasound in ST segment elevation myocardial infarction
Authors: Carreras-Mora José , Simón-Ramón Clara , Vidal-Burdeus María , Rodríguez-Sotelo Laura , Sionis Alessandro , Giralt-Borrell Teresa , Izquierdo-Marquisá Andrea , Rodríguez-González Clara , Farré Núria , Cainzos-Achirica Miguel , Tizón-Marcos Helena , Garcia-Picart Joan , Milà-Pascual Laia , Vaquerizo Beatriz , Rivas-Lasarte Mercedes , Ribas-Barquet Núria
Published: June 2023

Objective

We evaluated the prognostic value of subclinical congestion assessed by lung ultrasound (LUS) in patients admitted for ST segment elevation myocardial infarction (STEMI).

Methods

This was a multicentre study that prospectively enrolled 312 patients admitted for STEMI without signs of heart failure (HF) at admission. LUS was performed during the first 24 hours after revascularisation and classified patients as having either wet lung (three or more B-lines in at least one lung field) or dry lung. The primary endpoint was a composite of acute HF, cardiogenic shock or death during hospitalisation. The secondary endpoint was a composite of readmission for HF or new acute coronary syndrome or death during 30-day follow-up. Zwolle score was calculated in all patients to assess predictive improvement by adding the result of the LUS to this score.

Results

14 patients (31.1%) in the wet lung group presented the primary endpoint vs 7 (2.6%) in the dry lung group (adjusted RR 6.0, 95% CI 2.3 to 16.2, p=0.007). The secondary endpoint occurred in five patients (11.6%) in the wet lung group and in three (1.2%) in the dry lung group (adjusted HR 5.4, 95% CI 1.0 to 28.7, p=0.049). Addition of LUS improved the ability of the Zwolle score to predict the follow-up composite endpoint (net reclassification improvement 0.99). LUS showed a very high negative predictive value in predicting in-hospital and follow-up endpoints (97.4% and 98.9%, respectively).

Conclusion

Early subclinical pulmonary congestion identified by LUS in patients with Killip I STEMI at hospital admission is associated with adverse outcomes during hospitalisation and 30-day follow-up.
Pulmonary emphysema subtypes defined by unsupervised machine learning on CT scans
Authors: Angelini Elsa D , Yang Jie , Balte Pallavi P , Hoffman Eric A , Manichaikul Ani W , Sun Yifei , Shen Wei , Austin John H M , Allen Norrina B , Bleecker Eugene R , Bowler Russell , Cho Michael H , Cooper Christopher S , Couper David , Dransfield Mark T , Garcia Christine Kim , Han MeiLan K , Hansel Nadia N , Hughes Emlyn , Jacobs David R , Kasela Silva , Kaufman Joel Daniel , Kim John Shinn , Lappalainen Tuuli , Lima Joao , Malinsky Daniel , Martinez Fernando J , Oelsner Elizabeth C , Ortega Victor E , Paine Robert , Post Wendy , Pottinger Tess D , Prince Martin R , Rich Stephen S , Silverman Edwin K , Smith Benjamin M , Swift Andrew J , Watson Karol E , Woodruff Prescott G , Laine Andrew F , Barr R Graham
Published: June 2023

Background

Treatment and preventative advances for chronic obstructive pulmonary disease (COPD) have been slow due, in part, to limited subphenotypes. We tested if unsupervised machine learning on CT images would discover CT emphysema subtypes with distinct characteristics, prognoses and genetic associations.

Methods

New CT emphysema subtypes were identified by unsupervised machine learning on only the texture and location of emphysematous regions on CT scans from 2853 participants in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS), a COPD case–control study, followed by data reduction. Subtypes were compared with symptoms and physiology among 2949 participants in the population-based Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study and with prognosis among 6658 MESA participants. Associations with genome-wide single-nucleotide-polymorphisms were examined.

Results

The algorithm discovered six reproducible (interlearner intraclass correlation coefficient, 0.91–1.00) CT emphysema subtypes. The most common subtype in SPIROMICS, the combined bronchitis-apical subtype, was associated with chronic bronchitis, accelerated lung function decline, hospitalisations, deaths, incident airflow limitation and a gene variant nearDRD1, which is implicated in mucin hypersecretion (p=1.1 ×10−8). The second, the diffuse subtype was associated with lower weight, respiratory hospitalisations and deaths, and incident airflow limitation. The third was associated with age only. The fourth and fifth visually resembled combined pulmonary fibrosis emphysema and had distinct symptoms, physiology, prognosis and genetic associations. The sixth visually resembled vanishing lung syndrome.

Conclusion

Large-scale unsupervised machine learning on CT scans defined six reproducible, familiar CT emphysema subtypes that suggest paths to specific diagnosis and personalised therapies in COPD and pre-COPD.
Problem-based learning applications in online environments
Authors: Kumaş Ahmet
Published: June 2023

Online learning environments have been used intensively during the COVID-19 pandemic and are frequently preferred alternative learning environments afterward. On the other hand, the lack of adequate learning applications for online environments negatively affects teaching. The main purpose of this research is to develop problem-based learning (PBL) activities for online learning environments within the scope of Physics course and to reveal the application processes. The study was carried out with 97 students in the fall semester of the 2020–2021 academic year. PBL applications were carried out in online learning environments with the interaction of online groups of 5–7 people through the Zoom program. A qualitative research approach and critical action research model were used in this research. The data were obtained with the help of rubric form, interview, peer assessment, peer group assessment, and documents and evaluated with content analysis and descriptive analysis. In the process of PBL activities in online learning environments, students took an active role as a part of their learning processes, interacted constantly with their peers, and demonstrated high-level success in their learning competencies by fulfilling their responsibilities. In online learning environments, there is a need for application examples where all students can demonstrate their process skills and student-centered assessment–evaluation applications that will determine the application outputs.
Ab initio study on the spectroscopic and radiative properties of lithium monocarbide
Authors: Zhou Mingxin , Sun Shan , Gao Yufeng , Zhu Zunlue
Published: June 2023

High-level electronic structure calculations were conducted for LiC molecule and compared to other theoretical results. The potential energy curves (PECs) for the 18 states originating from the first three dissociation channels of LiC molecule were calculated by the internally contracted multireference configuration interaction method. The spectral constants and vibrational energy levels are reported. The transition properties for the a2Π, b2Δ, c2Σ−, d2Σ+, and 22Π states are discussed. In addition, the spin-orbit coupling effects were taken into account in the electronic transition d2Σ+–a2Π. The b2Δ and c2Σ− states had radiative lifetimes of approximately 0.03–16.83 and 0.86–8.06 ms, respectively. The d2Σ+ and 22Π states had radiative lifetimes of approximately 1.94–64.83 and 0.31–16.59 µs, respectively. Between these transitions, the emissions from the d2Σ+–a2Π, 22Π–c2Σ−, 22Π–b2Δ, and 22Π–a2Π systems were strongest, while the emissions from the c2Σ−–a2Π, b2Δ–a2Π, and 22Π–d2Σ+ systems were weaker. The d2Σ+ 1/2 state had radiative lifetimes of approximately 3.75–29.81 µs. Among the spontaneous emissions of the transitions generated by the d2Σ+ 1/2 state, the emissions from the d2Σ+ 1/2–a2Π1/2 and d2Σ+ 1/2–a2Π3/2 systems were relatively strong and easily observed experimentally. The radiative lifetime variation law with the rotational quantum number for the d2Σ+ 1/2 state at rotational quantum number J ≤ 70 and vibrational quantum number ν ≤ 15 is also presented in this paper. In addition, almost all the strong emissions of the transitions were distributed in the infrared region. It is expected that the results of this study will serve as a helpful reference for future experimental and theoretical studies.
SN1987A neutrino burst: limits on flavor conversion
Authors: Dedin Neto Pedro , dos Santos Marcos V. , de Holanda Pedro Cunha , Kemp Ernesto
Published: June 2023

In this paper, we revisit the SN1987A neutrino data to see its constraints on flavor conversion. We are motivated by the fact that most works that analyze this data consider a specific conversion mechanism, such as the MSW (Mikheyev–Smirnov–Wolfenstein) effect, although flavor conversion is still an open question in supernovae due to the presence of neutrino–neutrino interactions. In our analysis, instead of considering a specific conversion mechanism, we let the electron antineutrino survival probability $$P_{{\overline{e}}{\overline{e}}}$$

P

e
¯

e
¯

be a free parameter. We fit the data from Kamiokande-II, Baksan, and IMB detected spectrum with two classes of models: time-integrated and time-dependent. For the time-integrated model, it is not possible to put limits above $$1\sigma $$

1
σ

(68% confidence level) on the survival probability. The same happens for the time-dependent model when cooling is the only mechanism of antineutrino emission. However, for models considering an accretion phase, $$P_{{\overline{e}}{\overline{e}}}\sim 0$$

P

e
¯

e
¯

∼
0

is strongly rejected, showing a preference for the existence of an accretion component in the detected antineutrino flux, and a preference for normal mass ordering when only the MSW is present.
Detection of baby food sterilized with ionizing radiation using thermoluminescence
Authors: Kazakis N. A. , Betsou Ch.
Published: June 2023

Food sterilization with ionizing radiation is a well-established technology, which is constantly extending to several products due to its numerous advantages. However, radiosterilization is prohibited to several food categories, such as baby food products since it could cause nutrient degradation of such foods with significant effects on the infants’ health. As a result, any governmental agency responsible for the detection of irradiated products should first focus on products consumed by babies/children. To this respect, the present work explores whether TL can be employed as a method for post-sterilization dosimetry on baby food, by studying the properties of their glass containers since they would be equally and jointly exposed to the ionizing radiation during the sterilization process. Two different reputable brands, i.e., Hipp® and Nestle®, are used for this purpose. Both glass containers exhibit a linear TL dose response for doses up to 3 kGy, while no sensitization of the main peaks is observed. Though their behavior is not very stable with time (strong fading) yet fading correction is possible. Dose recovery tests were successfully conducted, calculating the administered dose with high accuracy. A computerized curve deconvolution analysis (CCDA) was also performed revealing that all glow curves can be fitted with one peak of continuous trap distribution and three discrete-energy peaks, which also demonstrate a linear dose response over the range 50–3000 Gy. Thus, findings are very promising towards the post-sterilization dosimetry of baby food through their glass containers.
CR-39 detector-based Radon dosimetry system calibration in the self-decay mode
Authors: Lüley J. , Filova V. , Blahušiak P. , Vrban B. , Čerba Š. , Bonková I. , Nečas V.
Published: June 2023

This paper describes cooperation of the Slovak University of Technology in Bratislava (STU) and the Slovak Institute of Metrology (SMU) in the verification of the calibration factors for the solid-state nuclear track detector utilized for radon dosimetry and establishing traceability for the STU laboratory. The SMU operates the Air Radon Standard which consists of a radon chamber and calibrated radon atmosphere monitoring system. A specification of the radon chamber is that the radon concentration changes during the exposure time. The radon atmosphere is created by the insertion of a specified amount of radon gas into the chamber, which subsequently decays over time. The STU laboratory is equipped with the TASLImage™ system for radon dosimetry with corresponding TASTRAK CR-39 type detectors and diffusion chambers. These chambers allow radon to diffuse inside and prevent dust and radon progeny to enter the container. Each diffusion container is characterized by its own diffusion rate, which should be considered in the metrology calibration approach, especially when the radon chamber is operated in the decay mode. Therefore, several measurements were carried out to determine the optimal condition for conversion factor verification. The experiments were conducted for low radon concentrations, but still in the range that the radon chamber can reliably provide (100 Bq m−3 to 100 kBq m−3) and in combination with several times of exposure. Based on the achieved results the default calibration factor was verified, and an optimal calibration approach was proposed. To improve the capability of the radon measurement, a custom diffusion container design was proposed. The design incorporates compact dimensions with an aerosol filter at the entrance to the container. This allows to increase in an entry hole and thus increases the diffusion rate. Subsequently, the homogeneity of the radon atmosphere in the chamber was tested.
FEDIS: A set of algorithms for defect identification
Authors: Wang Yu , Zhang Chuanguo , Li Jiahui , Wei Liuming , Zeng Zhi
Published: June 2023

The aim of this paper is to develop a set of algorithms for defect identification in any crystal system based on structural data from molecular dynamics simulations. The set, named FEDIS, consists of two algorithms: the extended centrosymmetric parameter (E-CSP) method and the fast neighbor distance analysis (F-NDA) method. The E-CSP extends the Central Symmetric Parameter (CSP) method for centrally symmetric materials by introducing a compensation term for asymmetric crystal that adapts to all crystal systems. The F-NDA modifies the Nearest Neighbor Analysis (NDA) method by replacing vector computation with scalar computation. The developed algorithms are validated through several cases that demonstrate their effectiveness and efficiency in detecting various types of defects. The algorithms are implemented in C++ and integrated into 3D interactive interface software that can be downloaded on GitHub.
Robotic Grasp Pose Detection Method Based on Multiscale Features
Authors: Wang Zheng , Leng Longlong , Zhou Xianming , Zhao Yanwei
Published: June 2023

A robotic grasp detection algorithm based on multiscale features is proposed for autonomous robotic grasping in an unstructured environment. The grasp detection model borrowed the YOLOv3 object detection algorithm and retained the original idea of multiscale detection to improve the perception ability of the grasp rectangle on different scales. Squeeze and excitation blocks were embedded into the Residual Networks (ResNet) structure of the original model, with deformable convolution (DC) introduced, so that the model attained stronger feature extraction ability to cope with more complex grasp detection tasks. Meanwhile, the prediction of the direction angle was transformed into a combination of classification and regression, achieving the prediction of the direction angle of the grabbing frame under different postures. The model was simulated on the Cornell grasp dataset. The results demonstrate that the algorithm in this study can effectively balance the accuracy and efficiency of detection and can migrate the prediction of the grasp rectangle to new objects. The results of online grasp experiments on a Baxter robot show that the average grasp success rate of 93% is achieved for 10 different objects, demonstrating the practical feasibility of the algorithm.
A DFT Study of Bridge-Driven Engineering of Non-Fullerene-Based Acceptors for Efficacious Organic Solar Cell Applications
Authors: Ayub Ali Raza , Yaqoob Umer , Rafiq Sidra , Arshad Salba , Dad Muhammad Umar , Li Hui
Published: June 2023

The structural, optical, electronic and photovoltaic properties of non-fullerene molecular entity were analyzed by using density functional theory method MPW1PW91/6-31G (d, p). The simulated results of all the modeled molecules proved them as more efficient molecules for practical use in organic solar cell. Their good solution process-ability and interface (new modeled molecules: PBDBT) success made high value fill factor and open circuit voltage. Comparatively, BDCl2F-DS was proved to be an outstanding material with open-circuit voltage (1.71[Formula: see text]eV) and fill factor (92.25%). Assumption of a similar value of short circuit current from the reference work PCE was estimated. By doing so, outstanding calculated PCE values (in the range of 27.36% to 33.76%) made newly modeled molecules an advancement in investigation of unfused non-fullerene acceptors.
3D Spiral Zinc Electrode for Rechargeable Aqueous Zinc-Air Battery
Authors: Zhang Pengfei , Wang Keliang , Zuo Yayu , Wei Manhui , Wang Hengwei , Chen Zhuo , Shang Nuo , Pei Pucheng
Published: June 2023

Zinc metal has emerged as seeded anode material in the field of high-efficiency aqueous metal-air battery system due to the advantages of abundant reserves, strong reversibility and high capacity. Unfortunately, the conventional zinc electrodes commonly adopt a flat structure, and the dendrite accumulation and corrosion during the cycle process lead to sub-optimal efficiency and performance. Herein, the zinc electrode is designed as a three-dimensional (3D) spiral structure to improve the utilization efficiency of zinc and the quality of the battery. Compared with the zinc plate, the 3D spiral zinc electrode can shorten the movement distance of the particles in space and the operation period in time, increase the specific surface area of the reaction, reduce the resistance of mass and charge transfer, and achieve the effect of optimizing the performance of the battery system. The results show that the aqueous zinc-air battery made of 3D spiral zinc electrode exhibits better charge-discharge characteristics, higher power density and narrower voltage windows. This study demonstrates a zinc anode with simple feasibility properties and a special structure, aiming to provide a new research direction and innovation strategy for the development of high-performance rechargeable zinc-air battery systems.
Math Anxiety and Financial Anxiety Predicting Individuals’ Financial Management Behavior
Authors: Xin Ziqiang , Xiao Huiwen , Lin Gege
Published: June 2023

Background. In managing finances, people need to process various financial texts containing math (e.g., amount of money and mathematical concepts) and financial information (e.g., funds and bonds). Such information could trigger anxiety related to math and finance; however, previous literature has rarely investigated the prediction role of contextual anxiety on financial management behavior. Therefore, the current study examined how math anxiety and financial anxiety are related to individuals’ financial management behavior assessed by self-report and objective observation, respectively. Methods. Study 1 investigated 186 employees with the math anxiety scale, financial anxiety scale, and financial management behavior scale to explore how math anxiety and financial anxiety predicted financial management behavior. Study 2 used a “choice/no choice” paradigm to observe how the high (

n
=
50

) and low (

n
=
53

) financial anxiety groups chose (or avoided) between a math task and a finance task (as a measurement of financial avoidance). Results. Study 1 showed that financial anxiety fully mediated the negative relationship between math anxiety and financial management behavior and the mediating effect size was −0.24,

95
%
CI
=

−
0.34

,

−

0.16

. And compared to math anxiety (

r
=
−
0.24

,

p
<
0.01

), financial anxiety (

r
=
−
0.45

,

p
<
0.01

) was a stronger negative predictor of financial management behavior. Study 2 revealed that, compared to people with low financial anxiety, those with high financial anxiety were 2.75 times more likely to choose financial avoidance. Conclusions. People’s financial management behavior can be predicted by financial anxiety and math anxiety (especially the former), and the two types of anxiety seem to derive more from an irrational self-perception rather than actual ability. So, reducing financial anxiety and math anxiety should come first to motivate people to manage finances.
On Generalizations of Projective QTAG-Modules
Authors: Sikander Fahad , Begam Firdhousi , Fatima Tanveer
Published: June 2023

In this manuscript, we define the class of

ω

1

-weakly

α

-projective QTAG-modules for the infinite ordinal

α

and provide its systematic study for the finite ordinal. Furthermore, we generalize this class to

ω
.
2
+
n

-projective modules and obtain some characterizations. We also study the

ω

-totally weak

ω
.
2
+
n

-projective modules under the formation of

ω

1

-bijections.
Clarification of Phylogenetic Relationships among Chinese Nemacheilids with Tube-Shaped Anterior Nostrils, with a Description of a New Genus and Two New Species
Authors: Du Li-Na , Li Shu-Jing , Xu Fei , Luo Tao , Luo Fu-Guang , Yu Guo-Hua , Zhou Jiang
Published: June 2023

Nostril structures are important characteristics for generic diagnosis in Nemacheilidae and Cobitidae. Based on phylogenetic analysis, we found that 10 genera within Nemacheilidae (Eonemachilus, Guinemachilus, Lefua, Micronemacheilus, Oreonectes, Paranemachilus, Protonemacheilus, Traccatichthys, Troglonectes, and Yunnanilus) shared tube-shaped anterior nostrils and formed a monophyletic group. Morphologically, the location between the anterior and posterior nostrils was divided into three types: (i) separated, i.e., a distance greater than 1.5 times the diameter of the posterior nostril; (ii) adjacent, i.e., a distance shorter than the diameter of the posterior nostril; and (iii) closely set, i.e., posterior margin of the anterior nostril connected to the anterior margin of the posterior nostril. Thus, the 10 genera can be distinguished based on nostril features. Additionally, we describe one new genus, Guinemachilus gen. nov., and two new species, Guinemachilus pseudopulcherrimus sp. nov. and Paranemachilus chongzuo sp. nov.
Effect of Adding Thymus leptobotrys on Extra Virgin Olive Oil’s Quality and Physicochemical Parameters
Authors: Aboudia Aouatif , Zefzoufi Manal , Rafya Meriem , Zehhar Naïma , El Antari Abderraouf , Abbad Abdelaziz , Benkhalti Fatiha
Published: June 2023

The present study aimed to evaluate the changes in extra virgin olive oil (EVOO) after enrichment treatments with Thymus leptobotrys, a Moroccan endemic aromatic plant. The EVOO sample was supplemented with two materials obtained from the aerial parts of T. leptobotrys: powder (2.5 and 5%) or essential oil (100 and 200 ppm). The chemical composition analysis of T. leptobotrys extracts (essential oil and powder methanolic extract) allowed the determination of its phenolic profile. Quality parameters (acidity, peroxide value, and specific extinction coefficients), color, fatty acids composition, minor components (pigments and phenol), and Rancimat oxidative stability of the control and enriched oils were measured. Rosmarinic acid and thymusin were the main identified compounds in the powder; thymusin was identified for the first time in the essential oil where it was predominant. Generally, the enrichments did not downgrade the oil from its initial category (EVOO), according to quality indexes. Adding T. leptobotrys to EVOO, especially the essential oil, enriched its phenolic profile by allowing the migration of thymusin, a lipophile flavone, without affecting its quality parameters or color.
A Study of the Electronic Absorption and Emission Spectra of DBDMA Dye: Solvent Effect, Energy Transfer, and Fluorescence Quenching
Authors: Al-Hazmy Sadeq M. , Al-Harby Jameelah , Hassan Mohammed , Messaoudi Sabri , Alhagri Ibrahim A. , Alhakimi Ahmed N.
Published: June 2023

This study is aimed to shed light on the electronic absorption and emission spectra of DBDMA (2-(1-(difluoroboraneyl)-1,2-dihydroquinolin-2-yl)-2-(1-methylquinoxalin-2-ylidene) acetonitrile) in different solvents. Both types of spectra were obtained theoretically and produced experimentally in different solvents. The photostability of dye was tested, and its energy transfer behavior in the presence of oxygen and hydrated copper sulfate quenchers was investigated. We also gave a qualitative estimation of the effect of acidic media on the absorption and emission spectra. There is good compatibility between the calculated and measured values of many photophysical parameters. DBDMA has a low chemical quantum yield in solvents of different polarities, and the fluorescence quantum yield is high enough, which confirms, together with the low values of the excited state lifetime, its efficiency as laser emitting dye in the range of wavelength emission maxima. The rigidity of the DBDMA molecule is the main reason for the photochemical stability and the absence of a considerable shift as a result of the change in the polarity of the solvents. Geometries of ground and excited states were optimized using the density functional theory (DFT) and the time-dependent density functional theory (TD-DFT), respectively. Upon using the TD-DFT method, the UV-Vis absorption and emission spectra of the DBDMA molecule in different solvents were illustrated. A slight change is observed in the position of the maximum emission and absorption wavelength with the change of the solvent due to the rigidity of the compound. There was no apparent effect of quenching by oxygen. Besides, no intersystem crossing (ISC) was observed for the excited state of the DBDMA as a result of aeration of a solution with O2 for 20 min, which was an explanation of the stability of peak emission intensity of dye after exposure to oxygen gas. The energy transfer rate constant has been calculated as well.