bluuebunny/crossref_metadata_2025 huggingface dataset:
Angular momentum transport via gravitational instability in the Elias 2–27 disc
Authors: Longarini C. , Lodato G. , Clarke C. J. , Speedie J. , Paneque-Carreño T. , Arrigoni E. , Curone P. , Toci C. , Hall C.
Published: May 2024

Gravitational instability is thought to be one of the main drivers of angular momentum transport in young protoplanetary discs. The disc around Elias 2−27 offers a unique example of gravitational instability at work. It is young and massive, displaying two prominent spiral arms in dust continuum emission and global non-axisymmetric kinematic signatures in molecular line data. In this work, we used archival ALMA observations of 13CO line emission to measure the efficiency of angular momentum transport in the Elias 2−27 system through the kinematic signatures generated by gravitational instability, known as “GI wiggles”. Assuming the angular momentum is transported by the observed spiral structure and leveraging previously-derived dynamical disc mass measurements, the amount of angular momentum transport we found corresponds to an α-viscosity of α = 0.038 ± 0.018. This value implies an accretion rate onto the central star of log10 Ṁ⋆ = −6.99 ± 0.17 M⊙ yr−1, which reproduces the one observed value of log10 Ṁ⋆,obs = −7.2 ± 0.5 M⊙ yr−1 very well. The excellent agreement we have found serves as further proof that gravitational instability is the main driver of angular momentum transport acting in this system.
ZTF J185259.31+124955.2: A new evolved disc-eclipsing binary system
Authors: Bernhard Klaus , Lloyd Christopher
Published: May 2024

Discs in long-period eclipsing binary systems are rare and can lead to extraordinary eclipsing events. ZTF J185259.31+124955.2 was identified as a candidate disc-eclipsing system through a continuing search programme of ZTF variables with a near-IR excess in the WISE data. Examination of the combined ZTF and ATLAS photometry shows seven eclipses since 2017 with depths of 0.m34 in all bands on a period of 289.57 ± 0.09 d. The eclipse width is ∼40 d but this and the profile evolve over time. Comparison with library spectra shows that the spectral energy distribution from the available photometry is consistent with an early K-type giant, and fitting black-body profiles suggests Teff ∼ 4000 K for the stellar component, with a cool component having Teff < 500 K. The reddening and distance, and hence the luminosity place the star within the giant branch. The most likely scenario is that the system is in a state of rapid evolution following Case B/C mass transfer into an extended disc around an unseen companion.
Waste to Energy-Effects of Complex Components of Organic Wastewater on Coal Water Slurry Stabilizers
Authors: Li Dedi , Feng Biao , Luo Yuanlin , Wu Yuechao , Xu Junyang , Zhao Jun
Published: May 2024

Coal water slurry is an advanced and efficient coal utilization technology, prepare coal water slurry by gasification wastewater can realize the recycling of wastewater and improve the combustion or gasification efficiency of the slurry. Stabilizer is an important component to ensure fluidity and stability in industrial applications of coal water slurry, and the complex substances in wastewater for coal water slurry preparation have a great influence on the stabilizer. Therefore, in this paper, the influence of the major substances in gasification wastewater on the stabilizer is studied. Results show that (a) Ammonia nitrogen substances have adverse effects on stabilizers, because the ionized NH4+ in the solution will bond with the polar groups on the stabilizer, which will affect the stabilizer to lose its effectiveness and reduce the stability of the slurry. (b) Small organic molecules have little effect on stabilizers, this is because the binding strength and quantity of stabilizer to water molecules is much larger than that of organic matters such as phenolic substances. (c) Highvalent metal ions have a greater impact on stabilizers, the metal ions easily form gels or precipitates with the stabilizer, causing it to lose its effectiveness, and also have an electrostatic effect with the carboxyl group on the side chain of the stabilizer, which makes the stabilizer easy to aggregate together and lose the steric hindrance effect, finally cause the stability of the slurry reduced. The conclusion of the influence of substances in wastewater on stabilizer can provide a technical reference for the selection of suitable wastewater and stabilizer to prepare coal water slurry, then promoting the efficient use of energy.
Research on the key technology of Turkish gas storage shaft
Authors: Wang Yaohui
Published: May 2024

The construction procedure of the gas storage well is complicated, and each technical index request is extremely high, does not allow any mistake. The well deviation is difficult to control. Because of the large dip angle of formation, it is difficult to ensure the wellbore quality by conventional anti-deviation measures, and the change of well deviation and azimuth can not be monitored at any time. So it's almost impossible for conventional anti-incline measures to satisfy the design. In the upper large hole section, the tower pendulum bha is used. In the section below the second open hole, the MWD steering system is used to prevent deviation and reduce deviation, and in the second open large hole section, the slim hole is used first, after reaming, the difficulty of deviation control is reduced, the ROP is increased, and the contradiction between wellbore quality and ROP can be solved by using MWD steering system to prevent deviation and straighten, because the casing and the surface casing and the production casing belong to the large diameter thick wall casing, the rigidity is very big, and the casing is also the abnormal oil drilling pipe, this well summarizes the experience, after strengthening the well opening measures, the safe and smooth running.
Research on gas drainage technology and equipment of high-level directional drilling in coal mine
Authors: Song Yubo
Published: May 2024

The gas overrun at the upper corners of the goaf and return air lanes has been restricting the development of China's coal mining industry. To solve the problem of over-limit gas concentration at the upper corners, the fundamental reason is to reduce the gas concentration in the "fracture zone" of the coal roof . At present, the most commonly used methods such as high extraction roadway, buried pipe extraction, and high-level drilling in the "fracture zone" gas control of the goaf have the disadvantages of excessive cost and heavy workload, and the drilling trajectory of conventional drilling rigs cannot be accurately positioned problem. Therefore,it is proposed to use high-position roof directional long drilling technology to replace traditional high-drainage roadway for gas control, and analyze the influence of directional drilling diameter, position, depth and other parameters on gas drainage efficiency. Based on the analysis of four drilling cases of the directional drilling rig ZYWL-13000DS of China Coal Science and Industry Group Chongqing Research Institute Co., Ltd. at 33 (4) 13 working face of Shuangliu Coal Mine, from the perspective of construction effect,the directional drilling is a more reasonable construction level 5-8 times the mining height above the roof is appropriate; the construction diameter should be as large as possible when conditions permit;when the drilling depth is 20m deep into the fissure zone, the pumping capacity will increase greatly, and with the construction of the mining, pumping Capabilities tend to stabilize. Compared with the traditional high-drainage road control effect, the use of directional long drilling technology for gas drainage can reduce the cost by more than 70% and shorten the effective construction period by more than 75%. It is finally verified that the use of high-directional directional long drilling technology can replace the high-drainage roadway for "fracture zone" gas drainage.
Study on energy saving of non-uniform air supply in office environment
Authors: Wu Han , Wang Guiqiang
Published: May 2024

There is a situation that the personnel in the office building are not concentrated and scattered, and some personnel will not always work at the workstation, and the creation of local comfort at the unmanned workstation will only cause great waste, so it is necessary to create an environment with uneven distribution of indoor parameters. In view of this situation, we simulate two working conditions: uniform and inconsistent airflow provision within the office space. analyze the comfort of these two working conditions in the office room, discuss the unevenness and energy efficiency of the ventilation openings above and near personnel in the office room. The simulation results show that creating non-uniform indoor air supply can greatly save energy.
Study on synthesis and properties of environmental protection water treatment agent
Authors: Liu Zhan , Yan Meifang , Gao Yuhua , Li Na , Li Haihua , Liu Zhenfa
Published: May 2024

The copolymers were obtained by a water-based polymerization reaction using maleic anhydride and acrylic acid as the main raw materials. And the scale inhibition performance of the resulting scale inhibitor was investigated by static scale inhibition experiments. The experimental results proved that the scale inhibitor has good scale inhibition performance for calcium carbonate and calcium sulfate. When the dosage is 100mg/L, the scale inhibition rate of the agent reaches 100%. This avoids the hidden danger of affecting normal production due to system scaling.
Advancements in Substation Inspection Robots: A Review of Research and Development
Authors: Wei Xiaoyan , Rey William P.
Published: May 2024

The emergence of power station inspection robots signifies a significant leap forward in intelligent automation within the domain of substation maintenance. These robots are equipped with the capability to autonomously traverse through substations, conducting meticulous inspections of equipment and facilities. By replacing manual inspection methods, they bring forth a multitude of benefits including heightened efficiency, cost reduction, and enhanced personnel safety. As the realms of artificial intelligence and robotics continue to advance, the development of substation inspection robots has become a focal point in the power industry. This paper offers a comprehensive overview of the current landscape of inspection robots, offering insights from both domestic and international contexts. Furthermore, it delves deeply into the critical technologies that underpin substation inspection robots, showcasing the cutting-edge advancements driving their unparalleled performance. In addition to providing a comprehensive overview of existing technologies, this work offers a forward-looking perspective on the potential applications of these robots. It provides a glimpse into the future of substation maintenance practices, envisioning a landscape where these robots play an indispensable role in optimizing operational efficiency, ensuring regulatory compliance, and enhancing overall system reliability. Moreover, the paper outlines key areas for future technical development, paving the way for continued innovation and advancement in this dynamic and rapidly evolving field.
Research on evaluation methods for thermal bridge treatment measures for building envelopes
Authors: Cai Qian , Chen Lei , Wang Changjun , Ren Jing , Wang Siqi
Published: May 2024

Along with the promotion of low-carbon and zero carbon buildings such as ultra-low energy buildings, near zero energy buildings, and zero energy buildings, there is higher and higher demand to the thermal performance of building envelopes. Thermal bridges have a crucial impact on the thermal performance of building envelope structures. In order to achieve the goal of energy conservation and carbon dioxide reduction in building structures, it is necessary to conduct refined calculations and evaluations on thermal bridge treatment measures. In this paper, three thermal bridge treatment measures evaluation methods from different dimensions are presented: evaluation method based on reduction degree of thermal bridge effect, evaluation method based on carbon dioxide emissions from thermal bridges, and evaluation method based on technical economy of thermal bridges.
Problems and solutions in the development of new-energy vehicles in China
Authors: Shao Amin
Published: May 2024

Over decades of development, China has topped the world in energy generation and consumption. Despite the great achievements that China has made in the development of energy, there remain salient problems, such as energy shortage, unreasonable energy structure, and environmental pollution, making it imperative to develop new energies. This paper analyzes the development status-quo of new-energy vehicles (NEVs), unveils the problems in the development of the NEV sector, and puts forth solutions to these problems from both the microscopic and macroscopic angles, with a vision to find a path of development featuring higher production, increased prosperity, and ecological well-being.
The Dilemmas and Countermeasures of China’s Energy Development under the Background of Sustainable Development
Authors: Pan Xiangchao
Published: May 2024

Energy is a vital resource for human survival as well as the material basis of all production and life. Environmental pollution and excessive resource consumption have become major issues in China due to the rapid consumption of energy driven by the deepening of reform and opening up and the acceleration of economic development. Problems and response strategies in the development and use of renewable energy have been analyzed from the perspective of sustainable environmental development in response to the existing situation of energy scarcity and environmental pollution in China. This analysis stresses the necessity of using renewable energy and its influence on environmentally sustainable development. It also provides prospects to achieve sustainable development in terms of energy utilization, the environment, and energy.
Study on the predicament and sustainable development of the alumina smelting industry in China
Authors: Yao Jingwu , He Huasha , Liu Xiaohui , Yao Liwen
Published: May 2024

On the basis of a comprehensive review of the production and technology status of China's alumina industry, the main contradictions and challenges in the development of China's alumina industry in terms of resources, energy and environmental governance are analyzed, and the production cost is compared and analyzed worldwide. It is believed that the main factors restricting the sustainable development of alumina industry in China are the lack of sufficient high-quality bauxite resources in China, the production technology needs to be further optimized, and the generated solid and hazardous waste is difficult to realize harmless and resource utilization. In this regard, this paper puts forward the strategy for the sustainable development of China's alumina industry, that is, strictly control the disorderly and rapid expansion of production capacity and reasonable layout, optimize the resource and energy supply structure, implement the industrial development strategy of high quality, energy saving and low consumption to improve the core competitiveness, and accelerate the realization of the standard discharge and resource utilization of waste gas, wastewater and solid waste. The results of this paper are of great significance to the strategy of industrial structure adjustment and sustainable development of alumina industry in China.
Design and optimization of intelligent ventilation system in coal mine
Authors: Wan Yong
Published: May 2024

With the continuous development of the coal industry, coal mine safety and environmental protection have gradually become the focus of important attention. The design and optimization of mine ventilation systems is a key factor in ensuring air quality and safety in the working area. In order to improve the application level of automation and intelligent equipment of mine ventilation system, under the existing conditions of mine, the design significance and goal of mine intelligent ventilation system are taken as the starting point, and the design and application effects are analyzed. By optimizing the layout of ventilation routes, increasing the number of sensors, building an intelligent ventilation system, optimizing the ventilation scheme in the main production scenarios such as coal face, driving face and opening up main roadway in the daily production process of the mine, realizing rapid wind regulation and wind counteraction when disasters occur, and using air flow short circuit to form protective measures, effectively avoiding the expansion of disasters and accidents. At the same time, remote automatic control of ventilation facilities and equipment is carried out to effectively improve the optimal utilization of air supply, avoid the phenomenon of insufficient air supply and waste of air volume, and improve the intelligent level of mine ventilation system.
Optimization of Initial Carbon Emission Allowance Allocation in Industrial Industries: A Case Study of Zhejiang Province, China
Authors: Hu Kaiheng , Li Qifen , Yang Yongwen , Deng Junkai
Published: May 2024

The construction of carbon market is one of the important means for China to reach the goal of carbon peaking and carbon neutrality, and the allocation of initial carbon emission right quota is the key link in carbon market transaction. At present, the historical method is the commonly used allocation method of initial carbon emission rights in China, and the use of this method is unfair and inefficient. Therefore, this paper proposes an allocation optimization model, selects a number of indicators, and optimizes the allocation of initial carbon emission rights based on the hierarchical analysis method and entropy weight method. Example analysis shows that the allocation optimization model helps to share the carbon emission responsibility and improve the allocation efficiency, realizes the optimal allocation of initial carbon emission rights among industrial sectors, and provides support for the emission reduction of industrial sectors.
Finite Element Simulation and Analysis of RC Beams with Modified Stirrups
Authors: Bello Bonjoebee , Dela Cruz Orlean
Published: May 2024

This paper uses the finite element simulation to examine the effects of modified stirrups on RC beams. There are seventeen (17) FE models, including various stirrup configurations such as traditional, spiral, and truss systems, as well as advanced modifications, were thoroughly analyzed using Abaqus software to evaluate parameters such as loaddeflection relationship, ductility, strength, failure modes, and crack patterns. Among these models, the BT-X design with a 125 mm spacing inclination of 72.10° demonstrated a remarkable load capacity of 110.856 kN, outperforming BN by 7.637%. Notably, throughout the simulation, the BT-R and BT-X designs were shown to be effective at increasing load-carrying capacity. Stirrup spacing and inclination angles are essential influences on RC beam performance. Specifically, the BT-X 125 design significantly improved flexural capacity and ductility. Furthermore, a uniform failure mode was identified across all models, highlighting the positive effect of modified stirrups on RC beam behavior. These findings highlight the importance of changing the stirrup design and selecting spacing and inclinations to improve RC beam performance.
Die Behandlung in zertifizierten Brustkrebszentren verbessert die Überlebenschancen von Patient*innen mit Brustkrebs
Authors: Schoffer Olaf , Wimberger Pauline , Gerken Michael , Bierbaum Veronika , Bobeth Christoph , Rößler Martin , Dröge Patrik , Ruhnke Thomas , Günster Christian , Kleihues-van Tol Kees , Link Theresa , Scharl Anton , Inwald Elisabeth C. , Kast Karin , Papathemelis Thomas , Ortmann Olaf , Klinkhammer-Schalke Monika , Schmitt Jochen
Published: May 2024

Zertifizierte Brustkrebszentren bieten spezifische Qualitätsstandards für die Struktur,
Diagnostik und Behandlungsverfahren, beispielsweise der Mammachirurgie, medikamentösen
Tumortherapie, Strahlentherapie und psychosozialen Unterstützung, mit dem Ziel, die
Behandlungsergebnisse für Brustkrebspatient*innen zu verbessern. Die Frage ist jedoch, ob
Patient*innen mit primärem Brustkrebs ein längeres Überleben haben, wenn sie in einem
zertifizierten Brustkrebszentrum behandelt werden, im Vergleich zur Behandlung außerhalb
dieser Zentren.

Wir verwendeten patient*innenspezifische Informationen (demografische Merkmale,
Diagnosen, Behandlungen) aus den Daten der gesetzlichen Krankenversicherung (GKV) und
klinischer Krebsregister (KKR) für den Zeitraum 2009–2017 sowie Krankenhausmerkmale aus den
Standardisierten Qualitätsberichten. Wir untersuchten mittels multivariabler
Cox-Regressionen Unterschiede im Überleben zwischen Patient*innen, die in Kliniken mit und
ohne Zertifizierung als Brustkrebszentrum der Deutschen Krebsgesellschaft (DKG) behandelt
wurden.

Die Stichprobe umfasste 143720 (GKV-Daten) bzw. 59780 (KKR-Daten) Patient*innen mit
Brustkrebs, die in 1010 Krankenhäusern behandelt wurden (280 DKG-zertifiziert, 730 nicht
DKG-zertifiziert). 63,5% (GKV-Daten) bzw. 66,7% (KKR-Daten) der Patient*innen wurden in
DKG-zertifizierten Brustkrebszentren behandelt. Cox-Regressionen für das Gesamtüberleben,
bei denen Patienten- und Krankenhausmerkmale berücksichtigt wurden, ergaben ein signifikant
niedrigeres Sterberisiko für Patient*innen, die in DKG-zertifizierten Brustkrebszentren
behandelt wurden (GKV-Daten: HR = 0,77, 95%-KI = 0,74–0,81; KKR-Daten: HR = 0,88,
95%-KI = 0,85–0,92). Dieses Ergebnis blieb auch in mehreren Sensitivitätsanalysen stabil,
einschließlich stratifizierter Schätzungen für Untergruppen von Patient*innen und
Krankenhäusern. Für das rezidivfreie Überleben war der Effekt noch stärker ausgeprägt
(KKR-Daten: HR = 0,78, 95%-KI = 0,74–0,82).

Patient*innen, die von einem interdisziplinären Team in einem DKG-zertifizierten
Brustkrebszentrum behandelt wurden, wiesen ein deutlich und statistisch signifikant
verbessertes Überleben auf. Die Zertifizierung ist somit ein wirksames Mittel zur
Verbesserung der Versorgungsqualität, und es sollten mehr Patient*innen in zertifizierten
Brustkrebszentren behandelt werden.
Overcoming Resistance to Immune Checkpoint Blockade in Liver Cancer with Combination Therapy: Stronger Together?
Authors: Werner Wiebke , Kuzminskaya Maria , Lurje Isabella , Tacke Frank , Hammerich Linda
Published: May 2024

Primary liver cancer, represented mainly by hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (CCA), is one of the most common and deadliest tumors worldwide. While surgical resection or liver transplantation are the best option in early disease stages, these tumors often present in advanced stages and systemic treatment is required to improve survival time. The emergence of immune checkpoint inhibitor (ICI) therapy has had a positive impact especially on the treatment of advanced cancers, thereby establishing immunotherapy as part of first-line treatment in HCC and CCA. Nevertheless, low response rates reflect on the usually cold or immunosuppressed tumor microenvironment of primary liver cancer. In this review, we aim to summarize mechanisms of resistance leading to tumor immune escape with a special focus on the composition of tumor microenvironment in both HCC and CCA, also reflecting on recent important developments in ICI combination therapy. Furthermore, we discuss how combination of ICIs with established primary liver cancer treatments (e.g. multikinase inhibitors and chemotherapy) as well as more complex combinations with state-of-the-art therapeutic concepts may reshape the tumor microenvironment, leading to higher response rates and long-lasting antitumor immunity for primary liver cancer patients.
Homeopathy as a Means to Improve Quality of Life
Authors: Fujino Fernanda Maria Simões da Costa , Ribeiro Ana Paula , Armond Jane de Eston , Souza Patrícia Colombo de
Published: May 2024

Quality of life is a fundamental aspect of good health and differs from person to person, highlighting the importance of individualisation, which is one of the principles of homeopathic doctrine. Homeopathy aligns with the principles of the Brazilian public health system, reflecting the latter's ethos of universality, accessibility, care coordination, and comprehensiveness, offering a whole-person approach to health care. Homeopathy's individualised approach and expanded view of the health–disease process, with emphasis on healthy lifestyle guidance, contributes to the promotion of individual good health and quality of life. These attributes of homeopathy make it a valuable therapeutic option, with relevance to the health service of Brazil as well as to that of other countries across the world.
Hybrid device allows drug toxicity testing in liver cells
Authors: Johnson-Groh Mara
Published: May 2024

Designed to be low cost, a microfluidic device can test spheroid liver cell cultures on a chip for long-term drug toxicity experimentation.
High-entropy oxide (FeCoNiCrMn)3O4 for room-temperature NO2 sensors
Authors: Li Xinchao , Chang Xiao , Liu Xianghong , Zhang Jun
Published: May 2024

High-entropy oxides (HEOs) with a multi-cation structure have attracted significant attention in the fields of electrochemistry owing to their high entropy stability and cocktail effect. However, there has been very limited research on the use of HEO in the field of sensing. In this work, we utilized FeCoNiCrMn high-entropy alloys as the precursor to synthesize (FeCoNiCrMn)3O4 HEO and investigated their crystal structure, microscopic morphology, elemental valence state information, and gas sensing performance. The sensor exhibited decent response to NO2 at room temperature (RT) without any modification or sensitization methods. To verify the gas sensing mechanism, we simulated the interaction between five metal elements in HEO and the NO2 molecules by density functional theory, which reveals a crucial synergistic effect from the multiple cations to enhance the adsorption and charge transfer of NO2 molecules. This work explores the application potential of (FeCoNiCrMn)3O4 in low-power gas sensors and enriches the material selection for RT sensors.
How does the diurnal biological clock influence electrokinetics in a living plant?
Authors: Guha Aniruddha , Bandyopadhyay Saumyadwip , Bakli Chirodeep , Chakraborty Suman
Published: May 2024

The existence of electrical potential in plant tissues has been studied for decades to understand its contribution toward the plants' health and developmental aspects. This potential is profoundly controlled and modulated by the electrokinetics involved in the flow navigated through the narrow conduits of a plant, which in turn is primarily governed by circadian rhythms. However, the interconnection between electrokinetics and the diurnal biological clock is yet to be understood. In this work, we unraveled the electrokinetics in response to the diurnal variations of a plant. Experiments conducted on water hyacinth stem indicate a cyclic variation of streaming potential synchronized with the changes introduced by circadian rhythm. In further efforts toward understanding the variation of streaming potential at different flow conditions, experiments were conducted on excised stem segments of Dracaena sanderiana, where the generated potential was studied against varying flow rates with different constitutive features of the flowing electrolyte. Notably, the resulting streaming potential from the flow of electrolytic solutions of different ionic strengths, species, and pH was found to align well with the fundamental premises of electrokinetics. These results are likely to expand our current knowledge of plant hydraulics by diligently examining the electrokinetics involved in the flow circuits of plants that undergo cyclic variations in close association with the circadian rhythms.
Effects of ferrohydrodynamics on drug transport and retention in drug eluting stents
Authors: Vahedi Seyed Masoud , Azaiez Jalel
Published: May 2024

This study examines the transport of magnetized drug particles (MPs) in drug-eluting stents (DESs). The governing equations for multi-species transport in a two-domain consisting of a polymer and media are formulated and solved using the finite volume method. The effects of an external magnetic field (MF) on the distribution of different drug species are analyzed. The MF was found to increase MP concentrations in the tissue and, unexpectedly, in the polymer at the same time. This counterintuitive finding was explained by analyzing the rates of transport through the polymer topcoat and the media top-layer. It was revealed that the rates of transport into and out of the media layer initially decrease and then increase with the MF, with an intermediate regime where the dynamics resemble those without MF. The maximum averaged free drug concentration in the tissue and that of the dissolved drug in the polymer were observed to increase exponentially with the MF implying on the fact that drug delivery becomes more sensitive to the MF at its larger strength. Tracking the drug center of mass revealed a nonmonotonic variation with time consisting of two linear regimes on a time log scale. The slopes of the first regime decreases with the MF while that of the second one is unaffected by the MF. The transition time was shown to increase almost linearly with the MF. The results of this study have promising applications in palliating the tendency for low drug retention from which current DES suffers.
Experimental and numerical study on cavity dynamics during near-water-surface skipping motion of a non-spinning disk
Authors: Li Conghui , Wang Cong , He Liling , Yan Yixia , Li Jicheng
Published: May 2024

In this paper, we present a comprehensive set of experimental and numerical studies on the near-water-surface skipping motion of three-dimensional, non-spinning disks. Qualitative analyses were conducted on the experimental results to examine the effects of inclination angle on cavity evolution. Additionally, numerical results are utilized to study the impact of the attack angle on hydrodynamic forces and motion characteristics of the disk. Key findings of this study include the following: (1) an asymmetric cavity will be formed during the near-water-surface skipping motion of the disk; (2) two distinct cavity shapes, U-shaped and W-shaped, emerge under varying initial inclination angles; (3) decreasing the inclination angle reduces the angle between the splash and the water surface, improving the possibility of a successful skipping motion; (4) disks with excessively large positive or negative inclination angles tend to dive into the water; (5) an instantaneous significant reduction in inclination angle during impact results in dual peaks of vertical force, with corresponding increases in hydrodynamic forces and pitching moments as the impact angle increases; and (6) disks with extremely small impact angles are prone to overturning and diving into the water.
Introducing CRC SAAFE: a new Cooperative Research Centre (CRC) focused on managing AMR in agriculture and the environment
Authors: Donner E. , Soares Magalhães R. J. , Barnes A. C. , Jex A. , Jarocki V. , Drigo B. , Djordjevic S. , Ashbolt N. J.
Published: May 2024

Antimicrobial resistance (AMR) is a complex challenge that poses a critical threat to food and water safety and security as well as to human, animal and environmental health. It is projected to cost the global economy US$100 trillion by 2050. Australia’s new Cooperative Research Centre (CRC) for Solving Antimicrobial Resistance in Agribusiness, Food and Environments (SAAFE) is part of Australia’s One Health approach to mitigating AMR. SAAFE’s 10-year, A$150-million industry-led program will help protect Australia’s food and agribusiness industries, and the environments in which they operate, from the growing threat of AMR. Through its research programs, CRC SAAFE uses a partner-based approach to assist industries to monitor, analyse and mitigate AMR, with projects spanning horticulture, viticulture, aquaculture, animal industries, water and waste.
Extremely asymmetric absorption and reflection near the exceptional point for three-dimensional metamaterial
Authors: Wu Yanjie , Zhang Ding , Li Qiuyu , Lin Hai , Shi Xintong , Xiong Jie , Hu Haoquan , Tian Jing , Wu Bian , Liu Y
Published: May 2024

In recent years, particular physical phenomena enabled by non-Hermitian metamaterial systems have attracted significant research interests. In this paper, a non-Hermitian three-dimensional metamaterial near the exceptional point (EP) is proposed to demonstrate extremely asymmetric absorption and reflection. Unlike its conventional counterparts, this proposed metamaterial is constructed with a loss-assisted design. Localized losses are introduced into the structure by combining our technique of graphene-based resistive inks with conventional printed circuit board process. Extremely asymmetric absorption and reflection near the EP are experimentally observed by tuning the loss between split ring resonators in the meta-atoms. Simultaneously, by linking the equivalent circuit model (ECM) with the quantum model, an equivalent non-Hermitian transmission matrix is constructed. We show that tuning the structure parameters of the ECM produces a metamaterial system with EP response. Our system can be used in the design of unidirectional metamaterial absorbers. Our work contributes to future works on the manipulation of EP to develop precision sensing and other applications in the 3D metamaterial platform.
Improved mixture correntropy cubature Kalman filter for attitude estimation
Authors: Qiao Meiying , Gao Kefei , Qiu Yunqiang , Han Haotian
Published: May 2024

This work proposes an algorithm based on improved mixture correntropy cubature Kalman filtering to address the issues of low accuracy and susceptibility to complex non-Gaussian noise and outlier interference in inertial navigation attitude estimation. First, a combination of Gaussian kernel and Cauchy kernel is proposed to construct the mixture correntropy, aiming to address the issue of single kernel-based correntropy being inadequate when dealing with complex non-Gaussian noise. Second, the objective function is established utilizing the model fitting loss based on mean square error and measurement fitting loss based on mixture correntropy. The maximum correntropy criterion is utilized to replace the minimum mean square error criterion, and the fixed-point iteration method is used to solve the objective function. This process derives the mixture correntropy matrix, which adjusts the measurement noise covariance. Finally, a membership function is used to determine the mixture correntropy coefficient. Accordingly, the algorithm can adaptively select the proportions of each kernel function based on the respective noise interference scenario. Simulations and dynamic–static experiments have been conducted. The algorithm has been compared with single kernel-based correntropy algorithms and other robust algorithms to confirm its superior precision and stability under complex non-Gaussian noise and outlier interference conditions.
A model-data combination driven digital twin model for few samples fault diagnosis of rolling bearings
Authors: Shi Huaitao , Yang Tianyi , Hu Yunjian , Song Zelong
Published: May 2024

Deep learning-based fault diagnosis methods for rolling bearings are widely utilized due to their high accuracy. However, they have limitations under conditions with few samples. To address this problem, a model-data combination driven digital twin model (MDCDT) is proposed in this work for fault diagnosis with few samples of rolling bearings. The simulation signals generated by different fault dynamic models of rolling bearings and the measured signals are mixed through MDCDT. The MDCDT generates virtual signals to bridge the gap between the simulated signals and the measured signals by combining their respective advantages. This paper also proposes image coding method based on the Markov transfer matrix (MTMIC) to convert one-dimensional vibration signals into two-dimensional images with both frequency domain information and time domain information, making it easier to extract fault features in neural network training. In the end, the developed MDCDT was evaluated using real rolling bearing data. Experiments show that the MDCDT can generate virtual data for fault diagnosis, and the fault diagnosis accuracy is significantly improved.
A novel stick-slip piezoelectric actuator is developed based on a parallelogram flexible drive mechanism to minimize shear force
Authors: Zhang Tao , Ma Rui , Wang Yang , Bian Donglong , Zhang Jian , Wang Yuhang
Published: May 2024

A piezoelectric actuator utilizing a parallelogram flexible mechanism is proposed. This actuator harnesses the parasitic motion generated by a parallelogram driven by a piezoelectric element. It differs from existing actuation mechanisms based on a similar principle in that the piezoelectric stack is positioned on the outside of the parallelogram flexible mechanism, thus protecting it from shear forces. Finite element simulations and experiments confirm this. The analysis was conducted using theoretical analysis and finite element simulation. The optimal drive angle for the parallelogram flexible mechanism was determined through finite element simulation. Additionally, a prototype actuator and an experimental measurement system were developed to assess the operational performance of the proposed piezoelectric actuator. When the driving frequency is 475 Hz and the locking force is 5 N, the motion of the actuator achieves a maximum speed of 5.65 mm s−1 and a maximum horizontal load of up to 113 g; when the input frequency is 1 Hz and the input minimum starting voltage is 8 V, the minimum displacement resolution is 30 nm. A comparative analysis of experimental results, theoretical calculations, and finite element simulation results demonstrates the feasibility of the structural design.
Nonreciprocal collective dynamics in a mixture of phoretic Janus colloids
Authors: Tucci Gennaro , Golestanian Ramin , Saha Suropriya
Published: May 2024

A multicomponent mixture of Janus colloids with distinct catalytic coats and phoretic mobilities is a promising theoretical system to explore the collective behavior arising from nonreciprocal interactions. An active colloid produces (or consumes) chemicals, self-propels, drifts along chemical gradients, and rotates its intrinsic polarity to align with a gradient. As a result the connection from microscopics to continuum theories through coarse-graining couples densities and polarization fields in unique ways. Focusing on a binary mixture, we show that these couplings render the unpatterned reference state unstable to small perturbations through a variety of instabilities including oscillatory ones which arise on crossing an exceptional point or through a Hopf bifurcation. For fast relaxation of the polar fields, they can be eliminated in favor of the density fields to obtain a microscopic realization of the Nonreciprocal Cahn–Hilliard model for two conserved species with two distinct sources of non-reciprocity, one in the interaction coefficient and the other in the interfacial tension. Our work establishes Janus colloids as a versatile model for a bottom-up approach to both scalar and polar active mixtures.
A new approach to solve time-fractional Navier–Stokes equation
Authors: Sawant S , Deshpande R
Published: May 2024

This article presents a new technique for the solution of Time Fractional Navier–Stokes equation. The approach is a combination of Adomian decomposition method (ADM) with Kamal integral transform (KIT). The proposed method is implemented on time-fractional Navier–Stokes equation (TFNSEs) to yield the analytical solution. Illustrative examples in TFNSEs are discussed to validate the applicability of the technique. The graphical visualization of the solutions is also presented. Further, the obtained results are compared with the existing solution methods.
Nonzero current due to coherent dynamic electron transport through a dimer with no external bias
Authors: Karmakar Anirban , Gangopadhyay Gautam
Published: May 2024

We have proposed a mechanism of the interplay of injected coherence and decoherence dynamics of the system in electron transport through an excitonic dimer when it is simultaneously connected to thermocoherent electron source and a thermal electron sink. Due to such an interplay, the variation of current with the energy gap between two excitonic states which is the internal bias of the system, is largely affected and it markedly bears the signature of the decoherence dynamics. We have also shown an extension in the modification of Landauer conductance formula for electron transport through excitonic dimer. The current has the property of an asymmetry in spectral width which can be understood in terms of sum of two Lorentzian profiles. More remarkably we have shown that current due to electron transport through the dimer can also arise at zero external bias which is a purely quantum coherent effect of the source fermionic reservoir having zero thermal occupation number.
Impact of seasonal variations on low and mid-latitudes ionospheric electric field satellite measurements
Authors: Makhlouf Soraya , Djebli Mourad
Published: May 2024

Ionospheric electric field measurements are provided by the Langmuir probe onboard the DEMETER satellite. Because there are four probes, various combinations of them form double probes that yield measurements. However, only the combination of probe antennas (E3) and (E4) enables possible measurements of the ambient (natural) ionospheric electric field. For other combinations, the measured field is almost identical to the induced field resulting from satellite motion. On the basis of this, we conducted comparative studies of the measured and induced electric fields during different seasons (summer, autumn, winter, and spring) to determine the best period for ionospheric electric field measurements. Multiple orbits were selected during different periods when the satellite was exposed to solar radiation. In all seasons except winter, the profiles of the induced and measured ionospheric electric field are similar. This masking effect leads to an underestimation of the ambient electric field. However, the highest accuracy for the ambient field can be obtained during winter, when solar flux radiation is weaker than that during other seasons. The probe position and orbital altitude also play important roles in the behavior of the induced electric field.
Tunneling conductance of hybrid bilayer-single graphene junctions
Authors: Benlakhouy Nadia , Jellal Ahmed
Published: May 2024

We study the tunneling effect of two different junctions based on graphene. Firstly, we consider gapped monolayer graphene (MLG) bridging AA-bilayer graphene (BLG), and secondly, AB stacking. These two systems display a significant decrease in transmission in both setups, showing the adjustability of conductance through gap size manipulation. Furthermore, we identify distinct characteristics in both stackings, including Fano resonances and Fabry-Pérot-like oscillations. Examining conductance as a function of BLG region width gives away varying peaks in the conductance profile for both stackings, exhibiting diverse periods and shapes. We demonstrate that under specific parameter conditions, tunneling leads to zero conductance, contrasting with the case without bias. The coexistence of gap and bias introduces a complex pattern in conductance peaks, reflecting fluctuations in amplitude and frequency. Notably, our findings indicate that the gap induces a noteworthy shift in the conductance profile in AB stacking, suggesting a modification of electronic properties. In AA stacking, minima are particularly evident in the conductance profile, especially for small bias values.
Antiproton bounds on dark matter annihilation from a combined analysis using the DRAGON2 code
Authors: De La Torre Luque Pedro , Winkler Martin Wolfgang , Linden Tim
Published: May 2024

Early studies of the AMS-02 antiproton ratio identified a possible excess over the expected astrophysical background that could be fit by the annihilation of a weakly interacting massive particle (WIMP). However, recent efforts have shown that uncertainties in cosmic-ray propagation, the antiproton production cross-section, and correlated systematic uncertainties in the AMS-02 data, may combine to decrease or eliminate the significance of this feature. We produce an advanced analysis using the DRAGON2 code which, for the first time, simultaneously fits the antiproton ratio along with multiple secondary cosmic-ray flux measurements to constrain astrophysical and nuclear uncertainties. Compared to previous work, our analysis benefits from a combination of: (1) recently released AMS-02 antiproton data, (2) updated nuclear fragmentation cross-section fits, (3) a rigorous Bayesian parameter space scan that constrains cosmic-ray propagation parameters.

We find no statistically significant preference for a dark matter signal and set strong constraints on WIMP annihilation to bb̅, ruling out annihilation at the thermal cross-section for dark matter masses below ∼ 200 GeV. We do find a positive residual that is consistent with previous work, and can be explained by a ∼ 70 GeV WIMP annihilating below the thermal cross-section. However, our default analysis finds this excess to have a local significance of only 2.8σ, which is decreased to 1.8σ when the look-elsewhere effect is taken into account.
Singular space-times with bounded algebraic curvature scalars
Authors: Magalhães Renan B. , Ribeiro Gabriel P. , Lima Junior Haroldo C.D. , Olmo Gonzalo J. , Crispino Luís C.B.
Published: May 2024

We show that the absence of unbounded algebraic curvature invariants constructed from polynomials of the Riemann tensor cannot guarantee the absence of strong singularities. As a consequence, it is not sufficient to rely solely on the analysis of such scalars to assess the regularity of a given space-time. This conclusion follows from the analysis of incomplete geodesics within the internal region of asymmetric wormholes supported by scalar matter which arise in two distinct metric-affine gravity theories. These wormholes have bounded algebraic curvature scalars everywhere, which highlights that their finiteness does not prevent the emergence of pathologies (singularities) in the geodesic structure of space-time.
By analyzing the tidal forces in the internal wormhole region, we find that the angular components are unbounded along incomplete radial time-like geodesics. The strength of the singularity is determined by the evolution of Jacobi fields along such geodesics, finding that it is of strong type, as volume elements are torn apart as the singularity is approached. Lastly, and for completeness, we consider the wormhole of the quadratic Palatini theory and present an analysis of the tidal forces in the entire space-time.