bluuebunny/crossref_metadata_2025 huggingface dataset:
Active distribution network dynamic partitioning method based on the Voltage/Var sensitivity using branch cutting and binary particle swarm optimisation
Authors: Ji Yuqi , Chen Xuehan , He Ping , Liu Xiaomei , Li Congshan , Tao Yukun , Fan Jiale
Published: August 2024

To optimally harness the adjustable capabilities of reactive power sources for voltage control, a dynamic partitioning method that uses reactive power flow tracking for branch cutting through Binary Particle Swarm Optimisation (BPSO) is proposed for Active Distribution Networks (ADNs). Initially, the limitations of existing Voltage/Var Sensitivity (VVS) calculation methods are analysed, leading to the proposition of a novel VVS calculation method capable of capturing variations in source‐load timing characteristics. Subsequently, the fuzzification of the VVS matrix between nodes is used to derive the membership degree matrix. Next, based on the membership relationship between reactive power source nodes, these nodes are pre‐partitioned, and the number of leading nodes and zones alongside are preliminarily determined. Then, the range of the branch to be cut is established, guided by the reactive power flow direction of the branch. Employing the zonal comprehensive coupling degree as the objective function of the BPSO facilitates the identification of optimal branch cutting points, thereby determining the partitioning outcome. Finally, a reactive power reserve check is executed to rectify any non‐compliant zones. In this study, numerical simulations are conducted using the enhanced IEEE 33‐node power system to demonstrate the efficacy of the proposed method.
Preparation, characterisation and enhanced fungistatic properties of silicone rubber with different concentrations of CMIT/MIT
Authors: Yang Shifang , Zhang Zexuan , Hou Qianpeng , Liu Yunpeng , Gong Chi
Published: August 2024

The authors explore the limitations of silicone rubber (SR) in tropical environments due to its lack of antimicrobial activity. The use of a 2‐methylisothiazol‐3(2H)‐one compound with 5‐chloro‐2‐methylisothiazol‐3(2H)‐one is proposed as an efficient and environmentally friendly antimicrobial agent to enhance the fungistatic properties of SR. The fungicide added specimen was obtained by directly adding a quantitative amount of isothiazolinone to the polymer system. Through an in‐depth analysis of the material properties of MCMSR, the form in which 2‐methyl‐4‐isothiazolin‐3‐one/5‐chloro‐2‐methyl‐4‐isothiazolin‐3‐one (MIT/CMIT) exists in the molecular structure of the SR crosslink system was carefully explored. The accelerated hydrolysis process of polysiloxane, which caused fungi secretion, was proven to be suppressed due to the effects of MIT/CMIT. The antimicrobial mechanism of isothiazolinone in preventing microbial growth was interpreted as the apoptosis and necrosis procedures of Aspergillus niger cells, which were verified by flow cytometry results. By choosing the appropriate concentration of isothiazolinone, the original properties of the SR were successfully maintained while effectively preventing the aggregation of isothiazolinone. This opens up a new research direction and application prospect for the antimicrobial modification of SR.
Robust parameter identification based on nature‐inspired optimization for accurate photovoltaic modelling under different operating conditions
Authors: He Zengxiang , Hu Yihua , Zhang Kanjian , Wei Haikun , Alkahtani Mohammed
Published: August 2024

Accurate parameter identification plays a crucial role in realizing precise modelling, design optimization, condition monitoring, and fault diagnosis of photovoltaic systems. However, due to the nonlinear, multivariate, and multistate characteristics of PV models, it is difficult to identify perfect model parameters using traditional analytical and numerical methods. Besides, some existing methods may stick in local optimum and have slow convergence speed. To address these challenges, this paper proposes an enhanced nature‐inspired OLARO algorithm for PV parameter identification under different conditions. OLARO is improved from ARO incorporating existing opposition‐based learning, Lévy flight and roulette fitness‐distance balance to improve global search capability and avoid local optima. Firstly, a novel data smoothing measure is taken to reduce the noises of I–V curves. Then, OLARO is compared with several common algorithms on different solar cells and PV modules using robustness analysis and statistical tests. The results indicate that OLARO has better ability than others to extract parameters from PV models such as single diode, double diode, and PV module models. Moreover, the convergence performance of OLARO is more excellent than the other algorithms. Additionally, the I–V curves of two PV modules under different irradiance and temperature conditions are applied to verify the robustness of the proposed parameter extraction algorithm. Besides, OLARO is successfully applied to two real operating PV modules, and it is compared with two recent well‐known methods improved by FDB. Finally, sensitivity analysis, stability analysis, and discussion of practical challenges are provided.
Efficient water delivery: The use of nanomaterial-enabled drip irrigation
Authors: Charykulyyeva Nasiba
Published: August 2024

Water scarcity is a rising challenge in many regions around the world, including nations economically dependent upon agriculture. Interventions for efficient use of scarce water can include lining irrigation canals with artificial materials or the use of enclosed horizontal drainage systems. One key innovation widely deployed in arid regions is drip irrigation which allows targeting water delivery to irrigated cropland, minimizing unutilized and wasted agricultural runoff. However, conventional approaches to construct and operate drip irrigation systems face can encounter disruptions from hot temperatures, exposure of drip irrigation plastics to sediment buildup, high-salinity soils, heavy metals, and chemical fertilizer runoff. This paper describes how nanomaterial- enabled drip irrigation systems can overcome some limitations of conventional plastic drip irrigation systems, as well as (a) improve the efficient delivery of water, and (b) enrich soil quality in specific environments. To determine the influence of nanomaterials were used methods of ion chromatography, potentiometric, and electrochemical methods. As a result, an innovative injector was obtained containing sulfur nanoparticles. The chemical composition of this injector has a positive effect on the indicators of mineral components of water.
Responsible and sustainable consumption in the field of information services
Authors: Antoniuk Olena , Pavelko Olha , Koshchynets Marianna , Skakovska Svitlana , Zinkevych Oksana
Published: August 2024

The article is devoted to the issues of responsible and sustainable consumption using the example of business entities in information services. The basis for the research is information from the audit firms, particularly the companies of the «Big Four». The study was based on information from auditing companies, particularly the Big Four sustainability and transparency companies. It was found that audit firms provide sustainability services for their clients. At the same time, audit firms take into account the goals of sustainable development, in particular, Goal 13. The authors have classified audit services as are related to the field of sustainable development provided by audit firms. It was analyzed transparency reports and sustainable development reports, which made it possible to identify the factors influencing the formation of responsible consumption in companies in the information services field. Due attention was to the organization of the “green office”. Responsible consumption of energy, water, paper and CO2e emissions were analyzed using information from the 2018-2022 sustainability reports of the world-renowned auditing company Deloitte. This allowed the authors to obtain results regarding the specifics of the consumption of certain types of resources, taking into account the industry aspect - the provision of information and audit services.
Green innovation and environmental reputation: A bibliometric and research future avenue
Authors: Arsawan I Wayan Edi , Azizah Amiril , Lina Ni Putu Maha , Abdi I Nyoman , Kazancoglu Yigit , Koval Viktor
Published: August 2024

Environmental reputation received many attentions in light with worldwide efforts to preservation with a focus on enhancement of environmental strategy throughout green technology. This study mapped 69 peer-reviewed articles in the Scopus database from 2003 to 2024. The results demonstrate nine prominent clusters that are significant references for future researchers in identifying organizations’ pursuits of green innovation toward environmental reputation. The nine clusters are green innovation capability, sustainability, environmental legitimacy, environmental regulation, social capital, firm reputation, environmental governance, human resources, and impression management. The implications of the study are elaborated further.
Development of the human capital in the context of corporate personnel training digitalization
Authors: Neboha Tetiana , Zapsha Halyna , Kuznetsova Maryna , Golikova Olha , Striy Lyubov
Published: August 2024

The goal of the study is to identify the essence of the category “human capital” as a production modern dominant factor by the trends of the knowledge economy formation and the influence of the system of corporate professional staff’s training based on digital tools used on the strengthening of the formation and use human capital mechanisms in Ukraine. The authors have studied the human capital characteristic features, distinguishing it from other types of main capital. A SWOT analysis of Ukraine’s human capital development state was carried out, and its key determinants were formed. The conceptual system provisions of corporate professional training for personnel have been developed, including the principles of formation, digital tools and technologies of professional training, and current methods of training personnel. As a result of the study, the authors presented proposals of changes for implementation into the Tax Code of Ukraine and Concept for the development of digital competencies and use of advanced digitalization tools for enterprises to increase the efficiency and improve the efficiency of professional training for personnel based on the development of a daily initial digital environment.
Digitalization and management of crypto assets as a source of investment for “green” projects
Authors: Laktionova Olga , Ismailov Taner , Kalinin Oleksandr , Gonchar Viktoriya , Onofriichuk Oleh
Published: August 2024

Cryptocurrencies are digital assets that are used to store and protect savings. The study examined the cryptocurrency market and analyzed the development of investment. A methodology for researching the crypto-asset market is proposed. The main directions for forming a cryptocurrency portfolio (crypto portfolio) have been identified. Methods for forming an optimal “cryptocurrency portfolio” (hedging) have been studied, including risk assessment in the context of income from cryptocurrency and determining the relationship between profitability and volatility. Crypto assets with the “Proof-of-Work” principle (for example, Bitcoin) as a source of investment for environmental events are acceptable when attracting other financial instruments. The prerequisites for developing the cryptocurrency market as a source of investment in “green” projects have been determined.
Gerinnungsstörungen bei Leberzirrhose – Diagnostik und Management
Authors: Kasper Philipp , Tacke Frank , Michels Guido
Published: August 2024

Patienten mit Leberzirrhose weisen komplexe Veränderungen des hämostatischen Systems auf, die sowohl mit Blutungs- als auch mit thrombotischen Komplikationen einhergehen können und im Rahmen des klinischen Managements berücksichtigt werden sollten.

Während eine prophylaktische Korrektur abnormaler Gerinnungsparameter vermieden werden sollte, ist vor invasiven Prozeduren ein individualisiertes Vorgehen zu empfehlen, wobei sich spezifische Präventionsmaßnahmen zur Stabilisierung der Gerinnung am periprozeduralen Blutungsrisiko orientieren sollten.

Weiterhin gilt zu beachten, dass sich die hämostatischen Veränderungen in Abhängigkeit des Stadiums der Erkrankung unterscheiden. Während sich das hämostatische System bei kompensierter Zirrhose oftmals in einem Gleichgewicht befindet, kann das Auftreten einer akuten Dekompensation zu einer Destabilisierung dieses Zustands führen.

Da konventionelle Gerinnungstests die komplexen Veränderungen des hämostatischen Systems bei Zirrhose nicht adäquat erfassen, können funktionelle Analysemethoden, wie viskoelastische Testverfahren oder Thrombingenerierungstests bei der Evaluation des Gerinnungsstatus hilfreich sein.

Die vorliegende Übersichtsarbeit beschreibt die zugrunde liegenden pathophysiologischen Veränderungen des hämostatischen Systems bei Leberzirrhose, liefert einen Überblick über geeignete Diagnostikmethoden und thematisiert Therapiemaßnahmen im Falle von Blutungs- und thrombotischen Komplikationen.
Interdisziplinäre Diagnostik und Therapie von malignen Mesotheliomen
Authors: van der Linde Lea I. S. , Hantzsch-Kuhn Birgit , Ellebrecht David , Stellmacher Florian , Welker Lutz
Published: August 2024

Das asbestbedingte maligne Mesotheliom (MM) gehört in Deutschland mit ca. 1000 Neuerkrankungen pro Jahr zu den häufigen berufsbedingten Krebserkrankungen. Die Diagnose eines MM ist, sofern die entsprechenden diagnostischen Kriterien erfüllt sind, sowohl aus histologischem als auch aus zytologischem Probenmaterial mit hoher Spezifität möglich. Allerdings werden viele MM zyto-/histologisch erst in fortgeschrittenen Stadien entdeckt. Klinisch/radiologische Aspekte ergänzen die Diagnostik und ermöglichen eine interdisziplinäre Beurteilung des Tumorstadiums und individuelle Entscheidungen über die bestmöglichen Therapieoptionen für jeden einzelnen Patienten. Diagnostisch hat die videoassistierte Thorakoskopie (VATS) den höchsten Stellenwert. Die Therapieplanung orientiert sich am vorliegenden MM-Subtyp, der Tumorausbreitung und Stadium sowie dem klinischen Zustand des Patienten. Die Prognose des MM ist im Allgemeinen sehr ungünstig. Dementsprechend zielt die Standardtherapie auf eine makroskopische radikale Tumorresektion im Sinne einer Zytoreduktion im Rahmen eines geeigneten multimodalen Therapiekonzepts (Chemotherapie, Strahlentherapie, Psychoonkologie). Ziel palliativer Maßnahmen sollte v.a. die Symptomkontrolle sein. Insgesamt ist die interdisziplinäre Diagnostik und Therapie des MM entscheidend für die bestmögliche Versorgung der MM-Kranken.
Management of Proximal (A1 Segment) Anterior Cerebral Artery Aneurysms: A Literature Review
Authors: Kumar Ashutosh , Ahamed Waseem , Bhaisora Kamlesh S. , Sardhara Jayesh C. , Raiyyani Vandan , Srivastava Arun , Mehrotra Anant , Behari Sanjay
Published: August 2024

Proximal or A1 segment anterior cerebral artery (ACA) aneurysms are rare aneurysms. They have certain unique properties when compared to all other intracranial aneurysms. They are smaller and prone to an early rupture. Thus, they need an aggressive intervention even when they are less than 7 mm in size. The technical difficulties that arise in their management are based on their location along the length and circumference of the ACA. Accordingly, they have been variously classified in literature. Their intimate relationship to the medial lenticulostriate perforators and the recurrent artery of Heubner is the prime factor in determining the surgical or endovascular strategy and outcome. These aneurysms are commonly associated with vascular anomalies, needing a thorough interpretation of preoperative angiograms. Though there are many series reporting the clinical features and management outcome of proximal ACA aneurysms, all are limited by a small sample size due to the rarity of the pathology. In this article, the pertinent literature related to the surgical nuances associated with dealing with A1 segment aneurysms is reviewed. The clinical presentation, associated anatomical characteristics, microsurgical management, role of endovascular therapy, and outcome are discussed.
Sustaining Joy in Serious Neurologic Illnesses
Authors: Seshadri Sandhya , Hauser Joshua , Kluger Benzi M.
Published: August 2024

The goals of medicine tend to be framed around addressing suffering, pathology, and functional deficits. While this is a natural orientation when dealing with serious illness, it is also incomplete and neglects significant opportunities to improve the quality of life of patients, families, and clinicians. The “total enjoyment of life” is a multidimensional framework that can serve as a positive counterbalance to the “total pain of illness.” It allows clinicians, researchers, policymakers, and other stakeholders to take a systematic and comprehensive approach to the active promotion of well-being. The five opportunities for enhancing well-being in this framework are meaning, social connections, happiness/contentment, spiritual transcendence, and pleasure. Applying these concepts in clinical settings, patients, families, and clinicians can together find opportunities to increase the total enjoyment of life in the face of incurable and intractable illnesses. For family care partners, these concepts can be applied to improve self-care, enhance relationships, and develop more creative approaches to supporting a loved one living with illness. Clinicians working with these concepts may find their clinical work more satisfying and impactful and can also apply these concepts to their own lives to increase wellness. In clinical research, this framework can be applied to improve intervention effectiveness and relevance of outcome measures. Lastly, these concepts have the potential to impact public health approaches that focus on well-being and flourishing as the goal and metric of a healthy society.
Mode transitions in a magnetically shielded Hall thruster. II. Stability criterion
Authors: Jorns Benjamin A. , Byrne Matthew , Roberts Parker , Su Leanne , Dale Ethan , Hofer Richard R.
Published: August 2024

A stability criterion is derived for mode transitions in the discharge current oscillations of a magnetically shielded Hall thruster. The two-equation model evaluated in Paper I for these large-amplitude (>100% background), low-frequency (<25 kHz) current oscillations is generalized and then validated with measurements from a 9 kW class test article. It is shown that the model can re-create quantitatively trends in both oscillation amplitude and frequency with discharge voltage and current. The validated model is non-dimensionalized and applied to derive an analytical stability criterion for the onset of large-amplitude oscillations. The resulting expression depends on several properties, including discharge current, discharge voltage, neutral transit time in the channel, length of the acceleration zone, magnetic field strength, and channel area. The criterion is leveraged to inform two mitigation strategies—changing magnetic field strength and controlling anode temperature— for adjusting the stability margin of the thruster. The criterion is also employed to motivate a physical explanation for why mode transitions occur and, in turn, why the stability margin differs between shielded and unshielded thrusters.
Nonlinear torsion-dominated deterioration behavior of wind generator output cable under electrothermal aging
Authors: Li Shuaibing , Lu Baopeng , Cui Yi , Kang Yongqiang , Dong Haiying
Published: August 2024

Wind turbine generator output cables are subjected to alternating torsional loads during long-term operation, combined with electrothermal stress, which may lead to insulation failure and other serious issues. Currently, the electrothermal aging mechanism under torsional stress is not fully understood. This study explores the synergistic degradation mechanism of electrothermal aging and nonlinear torsion by constructing a multi-stress aging test platform in the laboratory environment. This study involved accelerated aging tests with thermal, electrothermal, and electrothermal–torsional alternating stresses. The aged cable samples were analyzed for their physical and chemical properties using differential scanning calorimetry and Fourier transform infrared spectroscopy, while dielectric spectroscopy and mechanical tests were employed to evaluate their dielectric and mechanical performance. The results indicate that torsional stress induces physical changes at the molecular level in the ethylene–propylene rubber (EPR), leading to reduced strength, hardening, and increased brittleness, resulting in decreased mechanical strength. In addition, torsional stress promotes oxidation reactions and chain scission processes in the insulation layer, reducing crystallinity and causing a decline in mechanical performance. Increased oxidation and chain scission reactions result in an increase in polar groups, leading to an increase in the dielectric loss factor of the EPR. The findings of this study provide valuable insights for the design, manufacturing, and operational monitoring of wind turbine generator output cables.
Influence of molecular parameters on the representativeness of interfacial properties of simple fluids
Authors: Nicolás-Apolinar B. , Ibarra-Tandi B. , López-Lemus J. , Luis-Jiménez D. P.
Published: August 2024

New parameterizations for the Lennard-Jones 12/6 potential capable of reproducing the vapor pressure and surface tension with sufficient precision, but not the liquid–vapor equilibrium densities for the case of simple fluids that include Ar, Kr, Xe, Ne, and CH4 are presented in this work. These results are compared with those derived from the family of Mie(n, 6) potentials, which adequately reproduce the coexistence curve and the vapor pressure, leaving aside the surface tension. In addition, a detailed analysis is presented on different parameterizations and methodologies, which have been developed in recent decades to estimate the interfacial properties of interest here for simple fluids, such as argon, which is a molecule that is, in principle, “simple” to study but that clearly reveals the enormous discrepancy between the results reported in the literature throughout these years. These facts undoubtedly reveal one of the fundamental problems in the context of molecular thermodynamics of fluids: reproducing different thermodynamic properties with sufficient precision from a single set of free parameters for some interaction potential. In order to show the scope of the parameterizations presented for the Lennard-Jones model, they were successfully applied to the case of binary mixtures, which included Ar–Kr, Ar–CH4, and Xe–Kr. Finally, and with the aim of showing a possible solution to the problem posed in this research, results of the same interfacial properties above mentioned for argon and methane were presented in this work by using a set of molecular interactions, called ANC2s, whose flexibility allowed to reproduce the experimental evidence with just one parameterization. The results reported in this work were generated using molecular dynamics simulations.
Design of 1.1T/300 mm Bitter-type magnet for gyro-traveling-wave tube with power consumption optimization theory
Authors: Dai Xinge , Yao Yelei , Feng Chengzhen , Liu Guo , Jiang Wei , Tang Zeping , Wu Xu , Wang Jianxun , Luo Yong
Published: August 2024

To improve the portability of magnets in gyrotron devices, we designed a compact Bitter-type magnet with power consumption optimization theory. This magnet operates at room temperature in a small volume. The theory revises existing electromagnetic theory for non-uniform structural Bitter-type magnets and achieves the lowest energy consumption through iterative optimization. To extend the magnetic field homogeneity region, the ferromagnetic material armature is applied to the Bitter-type system without additional power consumption. Unlike previous manual designs, the proposed Bitter-type magnets can obtain optimal parameters with a significant reduction in computing time. Through the introduction of correction factors, we improve accuracy through multiple verifications of simulations and experiments. On this basis, a room-temperature Bitter-type magnet system for Ka-band fundamental mode gyrotron amplifiers is designed. Its maximum magnetic field strength is 1.1 T, and the length of the homogeneity region is 300 mm. Through optimization, its energy consumption is only 27.5 kW.
Observation of wind and thermodynamic structure within an urban boundary layer
Authors: He J. Y. , Chan P. W. , Liu Z. F. , Fung J. C. H. , Li Q. S.
Published: August 2024

Understanding the fluid dynamics and thermodynamics in the urban atmospheric boundary layer (ABL) is of great practical importance. Based on one-year observations from two advanced remote sensing instruments, namely, the wind lidar and the microwave radiometer, this study investigates the urban ABL structure in a densely built downtown area of Hong Kong. Atmospheric stability, ABL height, wind shear, and wind veer are statistically analyzed. The interconnections among wind speed profiles, wind direction profiles, ABL stability, and ABL height are comprehensively examined. Some features of the wind and thermodynamic structure are observed, such as the prevalence of unstable conditions in the urban ABL and the increase in wind shear and veer with ABL stability. The research outcomes are expected to contribute to the understanding of urban meteorology and offer scientific insights into the influences of urban terrain on the ABL and the vertical and temporal structure of wind and thermodynamic properties in the urban ABL.
Dynamics of side chains in poly(quinoxaline-2,3-diyl)s studied via quasielastic neutron scattering
Authors: Inoue R. , Nagata Y. , Tominaga T. , Sato S. , Kawakita Y. , Yamawaki T. , Morishima K. , Suginome M. , Sugiyama M.
Published: August 2024

The side chain dynamics of poly(quinoxaline-2,3-diyl)s (PQXs) are expected to influence their conformation. To investigate these dynamics experimentally, quasielastic neutron scattering (QENS) was performed for PQXs in deuterated tetrahydrofuran (THF-d8) and deuterated 1,1,2-trichloroethane/THF (1,1,2-TCE-d3/THF-d8), in which they formed right-handed and left-handed helical structures, respectively. The mean-square displacement of the PQX side chains in 1,1,2-TCE-d3/THF-d8 was lower than that in THF-d8. Furthermore, QENS complementary studies and molecular dynamics simulations unraveled a coupling between the main-chain and side chain dynamics of PQXs, suggesting the possibility of controlling the main-chain helical chirality through the dynamics of chiral side chains. These insights present a novel strategy for the design of synthetic helical macromolecules with precise chirality control.
A modular, composite framework for the utilization of reduced-scaling Coulomb and exchange construction algorithms: Design and implementation
Authors: Poole David , Williams-Young David B. , Jiang Andy , Glick Zachary L. , Sherrill C. David
Published: August 2024

Multiple algorithms exist for calculating Coulomb (J) or exchange (K) contributions to Fock-like matrices, and it is beneficial to develop a framework that allows the seamless integration and combination of different J and K construction algorithms. In Psi4, we have implemented the “CompositeJK” formalism for this purpose. CompositeJK allows for the combination of any J and K construction algorithms for any quantum chemistry method formulated in terms of J-like or K-like matrices (including, but not limited to, Hartree–Fock and density functional theory) in a highly modular and intuitive fashion, which is simple to utilize for both developers and users. Using the CompositeJK framework, Psi4 was interfaced to the sn-LinK implementation in the GauXC library, adding the first instance of noncommercial graphics processing unit (GPU) support for the construction of Fock matrix elements to Psi4. On systems with hundreds of atoms, the interface to the CPU sn-LinK implementation displays a higher performance than all the alternative JK construction methods available in Psi4, with up to x2.8 speedups compared to existing Psi4JK implementations. The GPU sn-LinK implementation, harnessing the power of GPUs, improves the observed performance gains to up to x7.0.
Study on micro-vibration mechanism and flow characteristics of aerostatic bearings based on proper orthogonal decomposition
Authors: Cheng Cheng , Zhao Ming , Zhao Zhihui , Liu Zhengxian , Hou Weijie , Yan Lijia , Li Zhanxin , Chen Sheng , Xu Lianchao
Published: August 2024

The unsteady flow field in the aerostatic bearing always induces micro-vibrations, which are severely detrimental to the stability and precision of the bearing. Extensive research has been conducted on the mechanism of micro-vibration, but a consensus has not yet been reached. To this end, the large eddy simulation (LES) and proper orthogonal decomposition methods were employed to analyze the flow field of an annular aerostatic bearing in this paper. A mechanism for inducing micro-vibration and the identification of a novel flow behavior were ultimately revealed. First, the accuracy of our LES method has been validated through quantitative comparison with experimental data. Then, the mode decomposition has been conducted to analyze the flow field under various gas supply pressures. The results demonstrate that when the supply pressure Ps = 0.4 MPa, the micro-vibration is dominated by a pair of adjacent large-scale vortices with low frequencies in the recess. However, when Ps = 0.5 and 0.6 MPa, the convection and shearing processes near the orifice outlet and the rectangular recess inlet become intense, resulting in the displacement of large-scale vortices. Eventually, the small-scale high-frequency pressure fluctuation structures have been also observed, which are closely related to the convection process within recess. With the increase in gas supply pressure, the high-frequency pressure fluctuations at the circular recess outlet gradually diminish, while those at the orifice outlet emerge and gradually enlarge. Meanwhile, the mode dominant frequency is transferred from around 200 kHz to around 1000 kHz. The energy fraction of the high-frequency pressure fluctuations is also greatly increased.
A new method for image analysis of antibubble rupture
Authors: An Ji , Wu Guohao , Gong Jianing , Chen Bao , Wang Wei , Qiao Jipan , Zhang Yanfei
Published: August 2024

The antibubble is a special spherical structure formed in a liquid, which consists of a layer of gas film and a droplet. In order to study the mechanism of antibubble rupture, the difference between artificial puncturing and free bursting was compared. The initial position and velocity of the free rupture of the antibubble are studied by using two-dimensional image analysis. The equations of the broken circle are derived from the space geometry. The two-dimensional image of antibubble burst was taken by experiment. The data were processed to establish the equation. The position of the initial burst of the antibubble was solved. The contraction velocity of the antibubble film was compared under different states.
Experimental molecular structures in the gas phase at the upper size limit: The case of Si6Tip6
Authors: Vishnevskiy Yury V. , Heider Yannic , Scheschkewitz David
Published: August 2024

Currently, the largest (ramax = 19.9 Å) and by far the most complicated (234 atoms, C1 symmetry, 696 independent geometrical parameters, and 27 261 interatomic terms) experimental molecular structure of a cage-type Si6Tip6 (Tip = 2,4,6-iPr3C6H2) isomer has been investigated in the gas phase by the electron diffraction method (Tav = 645 K) supplemented with theoretical simulations. A detailed analysis of the current possibilities for experimentally investigating large molecular structures is performed. A series of density functional theory approximations and the role of dispersion interactions have been benchmarked using the obtained data. Based on the refined geometry of Si6Tip6, various quantum-chemical methods have been applied for the investigation of the electronic structure of its Si6 core. In particular, natural bond orbital, quantum theory of atoms in molecules, interacting quantum atoms, fractional occupation number weighted density, and complete active space self-consistent field (CASSCF) methods were utilized. The diradical character of the molecule has been assessed by the UHF and CASSCF approximations. The problem of bonding between the hemispheroidal silicon atoms has been investigated.
Sheep performance and forage quality in grass-legume pastures with different canopy heights
Authors: Batista Ana Carolina Lopes , Barbosa Cristina Maria Pacheco , Penteado Lucas Ferreira , Ongaro Ana Flavia Bastos , Costa Ricardo Lopes Dias da , Simili Flavia Fernanda , Ribeiro Enilson Geraldo , Mattos Waldssimiler Teixeira de , Gerdes Luciana , Gimenes Flavia Maria de Andrade
Published: August 2024

Context Canopy height is an important grazing management tool in grass and multispecies pastures. Aim To evaluate the effect of different canopy heights on the nutritional value of forage and animal productivity in pastures formed by Aruana guineagrass (Megathyrsus maximus cv. Aruana) combined legumes [Macrotyloma (Macrotyloma axillare), Calopo (Calopogonium mucunoides) and Stylo (Stylosanthes macrocephala + Stylosanthes caweedstata)] managed under continuous stocking with sheep. Methods The treatments consisted of four forage canopy heights (15, 30, 45 and 60 cm) in a randomised block design with four replicates, totalling 16 experimental units (paddocks). The following parameters were assessed: total herbage mass, proportion of botanical and morphological components in samples obtained by grazing simulation, nutritional value and digestibility of forage, animal performance, stocking rate, and animal productivity. Key results Herbage mass was higher in taller pastures (45–60 cm; P < 0.0001). The proportion of legumes in herbage mass increased throughout the experimental period (P < 0.0001), and the highest proportion of legumes in the grazing simulation was observed in autumn (P < 0.0001). Pastures measuring 15 cm had a higher crude protein content (P < 0.0001), but the average daily weight gain was higher (P = 0.0404) in pastures maintained at 30 and 45 cm (100.3 and 87.4 ± 11.44 g/animal day−1, respectively). Stocking rate (P < 0.0001) and animal productivity (P = 0.0267) were lower in 60-cm pastures. Conclusion Multispecies pastures of Aruana guineagrass combined with Macrotyloma, Calopo and Stylo forage legumes should be managed at 15–45 cm under continuous stocking. Implications This study provides an option for combining forage species in intercropped tropical pastures, and indicates a range of pasture heights that will ensure animal productivity and pasture sustainability.
Including magnesium sulfate in the diet of twin-bearing ewes in the last week of gestation improves the adaptation of lambs to extrauterine life
Authors: Minteguiaga M. A. , López Mazz C. , Fierro S. , Banchero G.
Published: August 2024

Context Most deaths of lambs in the first days of life are due to failure to adapt to extrauterine life. Aims This study aimed to test the hypothesis that adding magnesium sulfate (MgSO4) to the diet of twin-bearing ewes in the last week of gestation improves the adaptation to the extrauterine life of the lambs. Methods Eighty-three multiparous Finnish × Polwarth ewes carrying twins in the last week of gestation were MgSO4 supplemented (n = 40) or allocated to control (n = 43). We recorded the durations of gestation, expulsion and lambing, interlambing interval, and birthweights, meconium score, lamb rectal temperature (at birth and 3 h after birth), whether assistance was needed (yes or no) and time from lamb expulsion to stand and to suck (n = 148). A jugular blood sample of the lambs was analysed for acidity, partial pressures of CO2 and oxygen; active and standard HCO3, blood base excess (BE b) and extracellular fluid base excess (BE ecf), saturated oxygen, and total CO2 concentration. Glucose was analysed with a portable device. Key results Gestation was longer in supplemented ewes (147.7 ± 2.0 vs control: 146.7 ± 1.7 days, P < 0.05). Birthweight and litter birthweight of lambs were higher when ewes were supplemented (3.74 ± 0.6 and 7.47 ± 0.9 kg vs control: 3.51 ± 0.5 and 7.02 ± 0.9 kg, P < 0.05). The need for assistance, meconium score, durations of expulsion and lambing, and time to stand and to suck were not different between treatments (P > 0.05). The interlambing interval was shorter in the supplemented ewes (6.7 ± 2.7 m vs control: 10.4 ± 2.6, P < 0.05). Lamb rectal temperature was not different between treatments 3 h after birth, but at birth was lower in lambs of supplemented ewes (P < 0.05). Treatments did not differ in blood acidity, CO2 partial pressure and total concentration, active and standard HCO3, both measures of base excess, nor blood glucose. Lambs of supplemented ewes had higher oxygen saturation and partial pressure (P < 0.05). Conclusions The MgSO4 supplementation improves the adaptation to extrauterine life in pen conditions. Implications It should be tested whether maternal supplementation with MgSO4 reduces the mortality of twin lambs.
Slurry infiltrated low-quality construction and demolition coarse aggregate waste in concrete – a sustainable construction
Authors: Vijayan Vishnu , Shukla Sanjay Kumar , K M Mini
Published: August 2024

Exponential growth in infrastructure projects, stimulated by emerging sophisticated technologies have been instrumental in the salutary proliferation of the construction sector, globally. An indubitable adversity of the rapid boom in the construction industry has been the rampant cumulative fallout of burgeoning waste during the demolition and construction phases of restoration. The current study explored the propriety of replacing natural coarse aggregate by low-quality recycled coarse aggregates (RCA) with varying proportions, along with silica fume (SF) and polypropylene (PP) fibers as admixtures, for the preparation of concrete. As the quality of RCA is determined by the history of its parent demolished structure, this investigation was preceded by assessment of the properties of RCA. A statistical approach using design of experiments, adopted to determine the coherent combinations of RCA and admixtures, yielded 16 combinations. Accordingly, concrete specimens were prepared with various quantities of RCA in place of natural coarse aggregate. Optimum proportions of the ingredients were inferred, based on the compressive strength attained by the concrete specimens. Further strength property evaluation was conducted, using these low-quality RCA treated with cement and silica fume slurry. Based on the strength results, 75% slurry infiltrated RCA, coupled with 10% SF and 0.5% PP, provided better strength in compression, tension and flexure. Scanning electron microscopy study, adopted for characterization of the micro-structural slurry-infiltrated RCA, shows the presence of strong interfacial transition zone in the treated RCA concrete. Thus, this study confirmed the efficacy of low-quality RCA as a promising material for structural construction, concurrent with a solution to various ecological disruptions precipitated by infrastructure construction and demolition wastes.
Simulation analysis of cryogenic mechanical properties of carbon fiber reinforced silicon-containing epoxy resin composite
Authors: Zhang Xiaohui , Li Jialiang
Published: August 2024

The use of carbon fiber-reinforced resin matrix composites instead of metals to manufacture cryogenic propellant tanks for spacecrafts is a development trend in the world aerospace industry. Cryogenic mechanical properties of the composites should be investigated in detail due to that the ultra-low temperature environment may cause micro cracks in the composites, leading to propellant leakage. In the present study, cryogenic tensile properties of a carbon fiber reinforced silicon-containing epoxy resin aomposite are investigated using experimental and numerical simulation methods. A silicon-containing epoxy resin with excellent cryogenic mechanical properties is developed by introducing a synthesized organic silicon polymer epoxidized polysiloxane and Nano-SiO2 into bisphenol F type epoxy resin. The tensile strength and modulus of the silicon-containing epoxy resin at −180 °C are 202.63 MPa and 7.81 GPa, which are 16.71% and 3.03% higher than those of bisphenol F type epoxy resin. The tensile strength of the silicon-containing epoxy resin at −180 °C is increased by 107.7% compared to that at room temperature, and the modulus at −180 °C is nearly twice that at room temperature. The carbon fiber reinforced silicon-containing epoxy resin composite is prepared by vacuum injection molding. The finite element model for the representative volume element of the composite unidirectional plate is established. The random sequence expansion method is used to randomly distribute the carbon fibers and simulate the thermal residual stress, the elastic performance, and the damage of the composite at cryogenic environments. Through comparison, it is found that the simulation results are in good agreement with the experimental results. The simulation reliability for cryogenic mechanical properties of carbon fiber reinforced resin matrix composites is verified. It is expected to provide a reference for the analysis and evaluation of cryogenic mechanical properties of composite tanks.
An end-to-end deep learning pipeline to derive blood input with partial volume corrections for automated parametric brain PET mapping
Authors: Chavan Rugved , Hyman Gabriel , Qureshi Zoraiz , Jayakumar Nivetha , Terrell William , Wardius Megan , Berr Stuart , Schiff David , Fountain Nathan , Eluvathingal Muttikkal Thomas , Quigg Mark , Zhang Miaomiao , K Kundu Bijoy
Published: August 2024

Dynamic 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography (dFDG-PET) for human brain imaging has considerable clinical potential, yet its utilization remains limited. A key challenge in the quantitative analysis of dFDG-PET is characterizing a patient-specific blood input function, traditionally reliant on invasive arterial blood sampling. This research introduces a novel approach employing non-invasive deep learning model-based computations from the internal carotid arteries (ICA) with partial volume (PV) corrections, thereby eliminating the need for invasive arterial sampling. We present an end-to-end pipeline incorporating a 3D U-Net based ICA-net for ICA segmentation, alongside a Recurrent Neural Network (RNN) based MCIF-net for the derivation of a model-corrected blood input function (MCIF) with PV corrections. The developed 3D U-Net and RNN was trained and validated using a 5-fold cross-validation approach on 50 human brain FDG PET scans. The ICA-net achieved an average Dice score of 82.18% and an Intersection over Union of 68.54% across all tested scans. Furthermore, the MCIF-net exhibited a minimal root mean squared error of 0.0052. The application of this pipeline to ground truth data for dFDG-PET brain scans resulted in the precise localization of seizure onset regions, which contributed to a successful clinical outcome, with the patient achieving a seizure-free state after treatment. These results underscore the efficacy of the ICA-net and MCIF-net deep learning pipeline in learning the ICA structure’s distribution and automating MCIF computation with PV corrections. This advancement marks a significant leap in non-invasive neuroimaging.
Innovative 3D printing and molding process for secondary-skin-collimator fabrication
Authors: Sohn James J , Kim Haram , Stolen Ethan , Chidel Gibson , Jang Sung , Furutani Keith , Beltran Chris , Lu Bo
Published: August 2024

Purpose. Secondary skin collimation (SSC) is essential for shielding normal tissues near tumors during electron and orthovoltage radiation treatments. Traditional SSC fabrication methods, such as crafting in-house lead sheets, are labor-intensive and produce SSCs with low geometric accuracy. This study introduces a workflow that integrated 3D scanning and 3D printing technologies with an in-house mold process, enabling the production of patient-specific SSCs within six hours. Methods. An anthropomorphic head phantom was scanned with a handheld 3D scanner. The resulting scan data was imported into 3D modeling software for design. The completed model was exported to a 3D printer as a printable file. Subsequently, molten Cerrobend was poured into the mold and allowed to set, completing the SSC production. Geometric accuracy was assessed using CT images, and the shielding effectiveness was evaluated through film dosimetry. Results. The 3D printed mold achieved submillimeter accuracy (0.5 mm) and exhibited high conformity to the phantom surface. It successfully endured the weight and heat of the Cerrobend during pouring and curing. Dosimetric analysis conducted with radiochromic film demonstrated good agreement between the measured and expected attenuation values of the SSC slab, within ±3%. Conclusions. This study presents a proof of concept for novel mold room workflows that produce patient-specific SSCs within six hours, a significant improvement over the traditional SSC fabrication process, which takes 2–3 days. The submillimeter accuracy and versatility of 3D scanning and printing technologies afford greater design freedom and enhanced delivery accuracy for cases involving irregular geometries.
Numerical simulation in magnetic resonance imaging radiofrequency dosimetry
Authors: Subaar Christiana , Gyan Emmanuel , Dompreh Kwadwo A , Amoako Joseph K , Edusei George , Owusu Alfred
Published: August 2024

Magnetic Resonance Imaging (MRI) employs a radiofrequency electromagnetic field to create pictures on a computer. The prospective biological consequences of exposure to radiofrequency electromagnetic fields (RF EMFs) have not yet been demonstrated, and there is not enough evidence on biological hazards to offer a definite response concerning possible RF health dangers. Therefore, it is crucial to research the health concerns in reaction to RF EMFs, considering the entire exposure in terms of patients receiving MRI. Monitoring increases in temperature in-vivo throughout MRI scan is extremely invasive and has resulted in a rise in the utilization of computational methods to estimate distributions of temperatures. The purpose of this study is to estimate the absorbed power of the brain exposed to RF in patients undergoing brain MRI scan. A three-dimensional Penne’s bio-heat equation was modified to computationally analyze the temperature distributions and potential thermal effects within the brain during MRI scans in the 0.3 T to 1.5 T range (12.77 MHz to 63.87 MHz). The instantaneous temperature distributions of the in-vivo tissue in the brain temperatures measured at a time, t = 20.62 s is 0.2 °C and t = 30.92 s is 0.4 °C, while the highest temperatures recorded at 1.03 min and 2.06 min were 0.4 °C and 0.6 °C accordingly. From the temperature distributions of the in-vivo tissue in the brain temperatures measured, there is heat build-up in patients who are exposed to electromagnetic frequency ranges, and, consequently, temperature increases within patients are difficult to prevent. The study has, however, indicated that lengthier imaging duration appears to be related to increasing body temperature.
Deriving measurement collapse using zeta function regularisation and speculative measurement theory
Authors: Stander Mark
Published: August 2024

This paper shows how an application of zeta function regularisation to a physical model of quantum measurement yields a solution to the problem of wavefunction collapse. Realistic measurement dynamics based on a particle becoming non-isolated are introduced and, based on this, an outcome function is derived using the method of maximum entropy. It is shown how regularisation of an information theoretic quantity related to this outcome function leads to apparent collapse of the wavefunction. The physical principles and key assumptions that underlie this theory are discussed. Some possible experimental approaches are described.