bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new resilient time and frequency infrastructure for UTC(NPL)
Authors: Jones D J M , Aikomo M , Ashford S , Ashkhasi A , Davis J A , Devine B , Eglin B , Everett S B , Foot R , Galbraith D , Hendricks R J , Khatry K , Langham C , Lewis R , Newton-Griffiths J , Owen H , Shemar S L , Sheppard A , Smyth C , Szymaniec K , Walby S , Weston D F M , Whale J , Whibberley P B , Wilson A , Wilson C , Margolis H S 
Published: November 2024

Abstract
The Resilient Enhanced Time Scale Infrastructure (RETSI) is an atomic clock network distributed geographically in secure locations, that is being developed as part of work in the National Timing Centre programme. It will become the source of UTC(NPL), the physical realisation of Coordinated Universal Time (UTC) maintained by the National Physical Laboratory (NPL) in the United Kingdom (UK). Dissemination points called User Access Nodes will link to RETSI via Orchestration Nodes, allowing users to access time and / or frequency references traceable to UTC(NPL). This will help to improve security and resilience in national time and frequency generation and distribution, enabling the UK to reduce its dependence on timing signals from Global Navigation Satellite Systems.
Proposal for a computable optical Clock
Authors: Amit Omer , Wirthl Vitaly , Taray Derya , Weis Vincent , Sarkar Soumyadeep , Kim Min–Cheol , Syed Mustafa Waqar , Moreno Jorge , Egli Florian , Weitenberg Johannes , Thariq Muhammad , Strobl Theodor , Bieringer Malte , Hein Linus , Karshenboim Savely , Pohl Randolf , Yost Dylan C. , Ozawa Akira , Hänsch Theodor W. , Udem Thomas 
Published: November 2024

Abstract
With the recent update of the SI system, all but one of the units are now based on defining the values of some fundamental constants. This development began in 1983 when the speed of light was assigned an exact fixed value. The advantage of this method is that it separates the definition from the realization, allowing new realizations to be introduced as technology advances without further redefinition. In addition, it allows unit realizations that are adapted to the scale of their intended use. Because of these advantages, we expect that one day also the last remaining object in the current SI system, the caesium atom, will also disappear. The purpose of this proposal is to outline possible paths for realizations of a future SI second based on the definition of the value of the Rydberg constant. Hydrogen and hydrogen–like systems would be the obvious candidates. The emphasis here is on the development of optical clock systems that circumvent difficulties associated with the short wavelength lasers otherwise required for cooling and driving the clock transition. The proposed clock systems based on atomic hydrogen and hydrogen–like He+, should be no more complex than current optical lattice clocks.
Field-deployable interferometric fibre link terminals with very low temperature sensitivity
Authors: Kuhl A , Kronjäger J 
Published: November 2024

Abstract
We present a novel setup for optical frequency transfer through fibre which is free from uncompensated paths and, as a result, extremely insensitive to the environment. Our test setup involving a 75 km spooled fibre link achieves an instability approaching 10−21 at 104 s of averaging, even with one of the terminals temperature-cycled over 15 K. The temperature coefficient of the phase error is estimated at approximately 2 as/K, without any active temperature stabilization or thermal shielding. Fibre link terminals using the topology presented here are suitable for field deployment, for example in geodetic applications together with transportable optical clocks.
Active optical clock: seventeen years of progress and next steps
Authors: Zhang Jia , Shi Tiantian , Miao Jianxiang , Guan Xiaolei , Gao Xun , Chen Jingbiao 
Published: November 2024

Abstract
The concept of the active optical clock (AOC) was proposed seventeen years ago by prof. Jingbiao Chen. After early calculations and experiments that demonstrated the advantages of “cavity-pulling suppression” and “narrower linewidth”, the development of AOCs soon became an active competition involving many research groups that proposed schemes based on different atomic species, and different energy-level structures. In this paper, after a brief background introduction, we will mainly focus on the most recent experimental and theoretical progress of AOCs in Peking University. In addition, we give an outlook on AOCs based on cold atoms that can be operated continuously, and report a novel AOC scheme based on diffuse laser cooling that can be operated continuously for the first time, which is proposed and performed by Peking University. The AOC has great promise for applications in quantum metrology, as it can overcome the thermal noise of the reference cavity that limits conventional lasers, making AOC a promising candidate for future atomic optical clocks.
Progress on cadmium-ion and ytterbium-ion Microwave Frequency Standards at Tsinghua University
Authors: Miao S. N. , Zheng Y. , Chen Y. T. , Shi W. X. , Zhang J. W. , Wang L. J. 
Published: November 2024

Abstract
As a candidate for the next generation microwave clock, microwave atomic clocks based on trapped ions are currently studied worldwide. Since 2010, our team at Tsinghua University has been committed to developing a high-performance 113Cd+ microwave ion clock. In 2021, the laser-cooled cadmium-ion microwave clock constructed in our laboratory demonstrated remarkable performance, with a short-term instability of

4.2
×

10

−
13

/

τ

and a relative frequency uncertainty of 1.8 × 10−14, improving nearly three orders of magnitude compared to the result from JPL. The 0-0 ground-state hyperfine splitting frequency of 113Cd+ was determined to be 15199862855.02799(27) Hz, currently the most accurate measurement result for this transition frequency. Apart from that, we introduced the sympathetic cooling technology into the experiment of cadmium-ion microwave clock. Using 40Ca+ as the coolant ion, we obtained Ramsey patterns with a free evolution time of up to 100 seconds, ultimately improving the short-term instability of the system to

3.48
×

10

−
13

/

τ

. Moreover, a microwave frequency standard based on laser-cooled 171Yb+ ions has also been developed in our laboratory since 2021. The short-term frequency instability was measured to be

8.5
×

10

−
13

/

τ

. The ground-state hyperfine splitting frequency of 171Yb+ was determined to be 12642812118.4674(8) Hz with a fractional frequency uncertainty of 6.33 × 10−14.
Duty cycle engineering for improved optical lattice clock stability
Authors: Butuc-Mayer Filip , Johnson Matthew , Feng Chen-Hao , Bowden William , Hobson Richard , Hill Ian R 
Published: November 2024

Abstract
We describe a method of duty cycle engineering in optical lattice clocks to reduce clock instability through tailoring of the Dick effect noise contribution. We apply dynamically decoupled interrogation sequences to realise an estimated improvement in single clock instability approaching a factor of two, as well as providing a route to zero dead-time operation for two interleaved clocks which are otherwise unable to reach the required duty cycle. We show through simulations and synchronous measurements of clocks NPL-Sr1 and NPL-Sr2 that a quantum projection noise limited instability < 3 − 10−17
τ
−1/2 can be realised in a near ideal zero dead-time configuration.
Testing novel high-reflectivity mirror technologies from room-temperature to 4 K
Authors: Kempkes M , Legero T , Sterr U , Nicolodi D 
Published: November 2024

Abstract
We present a setup based on a low-vibration closed-cycle cryostat for the characterization of mirror coatings and for the direct measurement of Brownian thermal noise from room-temperature to 4 K. Using a dual frequency modulation scheme allows us to lock a laser to two eigenmodes of a high-finesse optical resonator simultaneously and to track the line splitting between the two modes. This facility will enable to investigate the temperature and power dependence of the birefringent line splitting and noise in AlGaAs/GaAs multilayer coatings across a broad temperature range.
The effects of grading on the energy absorption of nylon body centered cubic and simple cubic plate lattices fabricated by material extrusion - Numerical analysis
Authors: Abdelmageed Mohamed , Zain Elabdeen Ibrahim H. , Zaki Wael , Cantwell Wesley 
Published: November 2024

Abstract
The ongoing need for better protective structures has led to the development of various methods to improve specific energy absorption, including functional grading. This study explores how axial grading affects the energy absorption of simple cubic (SC) and body-centered cubic (BCC) plate lattices, comparing them to their uniform counterparts of the same relative density. Using ABAQUS, a numerical analysis simulates the quasi-static compression of plate lattices made from tough Nylon through material extrusion 3D printing. The results show that severe axial grading can increase the specific energy absorption of BCC plate lattices by up to 32% while grading with less severity reduces it. SC plate lattices show unstable behavior due to the vertical walls buckling and the grading also shows an unstable effect. This study highlights the impact of axial grading on these lattices and provides useful information for designing better protective structures.
Enhancing technological plasticity in the production of AISI 420 stainless steel through the use of asymmetric rolling
Authors: Pesin A.M. , Pustovoytov D.O. , Brevnov K.Yu. , Pesin I.A. , Tsaturyants M.S. , Nosov L.V. , Lokotunina N.M. 
Published: November 2024

Abstract
In the Zhilyaev Laboratory of Gradient Nanomaterials at Nosov Magnitogorsk State Technical University, the possibility of reducing the production chain for cold-rolled stainless steel strip of grade AISI 420 has been demonstrated. The study concentrated on increasing technological plasticity with implementation of asymmetric rolling. The study showed the effect of asymmetric rolling and provided comparative analysis to the traditional symmetric rolling. Experimental studies on the production of AISI 420 steel strip in have shown the potential for reducing a number of operations compared to the standard technological process and increase of technological plasticity. Corresponding technological regimes have been developed.
Why Using Spiro Compounds as Interlayers Can Enhance the Performance of Perovskite Solar Cells?
Authors: Li Yang , Zhang Lixin , Wang Bingzhe , Li Jingyun , Fu Yajie 
Published: November 2024

Abstract
Lattice defects in perovskite solar cells (PSCs) impede charge carrier recombination, thus limiting power conversion efficiency (PCE) enhancements. Herein, spiro[fluorene-9,9 ‘ - xanthene]-based molecules S1 and S2 were introduced as interfacial materials, improving perovskite crystallization, reducing trap density, and decreasing defects. The integration of S2 as an interlayer increases the average PCE to 21.06% under maximum power point (MPP) tracking, significantly higher than control devices with enhanced photostability.
Effective Material Properties for the Thermal-magneto-electro-elastic (TMEE) Laminates
Authors: Liu Mei-Feng 
Published: November 2024

Abstract
In this study, the effective material properties for a linear thermo-magneto-electro-elastic (TMEE) heterogeneous laminate made of thermo-piezoelectric (PZT) and thermo-piezomagnetic (PMT) continua are investigated. A procedure converting conventional constitutive equations into alternative constitutive equations is presented by using matrix notation, furthermore, micromechanical approach for finding the alternative effective properties of a multilayered TMEE composite is employed. Concise matrix expressions for the effective properties of the layered TMEE composite are eventually retrieved by reversing the transformation procedure back to conventional form. Bi-layered TMEE laminates made of BaTiO3 and CoFe2O4 are demonstrated to validate the proposed methodology, and the material constants are tabulated with respect to various volume fractions of BaTiO3. It is found that the coupling effects such as magnetoelectric (ME) and pyroelectric (ET) / pyromagnetic (MT) properties are detected in the TMEE laminates despite the no-show in neither of the single phases. Distributions for the coupling effects varying with volume fractions are depicted, results are compared with existing literature, agreement and discrepancy are discussed.
On dynamic responses of gear transmission system during rough tooth surface worn
Authors: Meng Fanshan , Yi Wenhao , Zhang Xin , Wang Jiaxu 
Published: November 2024

Abstract
This study investigates the dynamic responses of gear systems while considering the morphology of worn gear tooth surfaces after different working times. Specifically, the anisotropic three-dimensional micro-morphology of the rough tooth surface model is established based on the W-B fractal theory. The non-uniform wear of the rough tooth surface under different rotational speeds and working hours is quantified according to Archard’s theory. The time-varying meshing stiffness (TVMS) and backlash are calculated with the wear values and then serve as internal excitation input parameters of the dynamic model. The dynamic responses are solved with the variable step Runge-Kutta algorithm. The results show that with increasing gear rotational speed and durations, the depth of tooth surface wear increases gradually, leading to a decrease in TVMS and an increase in backlash. The gear transmission system, considering the micro-morphology of the tooth surface, exhibits diverse dynamic response characteristics as speeds vary. With prolonged working hours, the system’s dynamic response transitions from periodic motion to chaotic motion, manifesting as chaotic vibrations, which are detrimental to steady operation. Transmission systems in chaotic motion can be transformed into stable periodic motion by adjusting the torque or rotational speed of the gears. The findings can provide theoretical guidance for selecting suitable operating conditions for gears subject to different wear degrees.
Diagnosis of loose pedestals in two-dimensional engineering structures with nonlinear vibration transmissibility functions
Authors: Li Quankun , Wang Siji , Chen Xi , Hong Liang , Shi Bin , Pueh Lee Heow 
Published: November 2024

Abstract
Referring to existing vibration transmissibility function-based approaches, which are frequently applied to diagnose fatigue crack and joint loosening faults in two-dimensional engineering structures such as aluminium plates and steel frames, a novel approach applying nonlinear vibration transmissibility functions is developed to diagnose potential loose pedestals in this paper. Firstly, the two-dimensional structural dynamic model, which simulates effects of loose pedestals as equivalent loads, is obtained through the lumped mass method. Secondly, exciting the dynamic model three times with different extra masses, the transmissibility function-based matrix of one sub-model to be diagnosed is obtained, and then a novel damage index is defined based on the matrix singularity. Lastly, a novel approach with particular procedures is proposed. Through three numerical cases on a two-dimensional dynamic model with multiple degrees of freedom (MDOFs), validity and applicability of the proposed approach are shown. As a result, this paper provides a totally new idea to diagnose loose pedestals, which can ensure structures’ smooth operation.
Numerical investigation of air flow within a human nasal cavity
Authors: Niegodajew Paweł 
Published: November 2024

Abstract
This work employs large eddy simulations to explore the flow inside a human nasal cavity with the goal to determine such breathing cycle conditions that ensure maximising the airflow within the olfactory region. The reason for doing so is that this process is critical for the optimum delivery of drugs through a nasal spray. For the purpose of the study, the human nasal passage geometry was reconstructed using magnetic resonance imaging scans from a healthy adult female. The obtained preliminary results indicated that not only a proper inlet location but also a certain time instance, within the inspiration cycle, are important when considering drag delivery via internasal administration.
Application of the model of trapped vortices to the control of flow around a bridge pier
Authors: Gorban Iryna 
Published: November 2024

Abstract
A passive scheme of flow control near a bluff body is proposed. It is aimed at creating the new flow topology in front of the body with the help of two attached plates. The substantiation of this technique is carried out for the rectangular prism of aspect ratio 3:1 with the help of both the reduced order model and 2D numerical simulation of viscous flow by the vortex method.
Composition tracking of CO2-rich streams in large-scale pipeline networks under steady-state conditions
Authors: Osiadacz Andrzej J. , Chaczykowski Maciej , Kotyński Łukasz , Bleschke Tomasz , Uilhoorn Ferdinand , Kwestarz Małgorzata 
Published: November 2024

Abstract
In this paper we are reporting a simulation study of a large-scale pipeline network transporting CO2 streams for carbon capture and storage. Simulations of the networks with tree-type and looped structures, representative for hub and cluster approach, are conducted. Composition tracking using nodal mixing rules is presented. The development of the GIS graphical user interface for incorporating spacial data on the topology of the network is presented. A case study examines conceptual Polish country-wide CO2 transport infrastructure and shows the functionality of the computational code.
5G FR1 Exposure Measurements: Comparison of Different IEC 62232:2022 Extrapolation Methods
Authors: Ruttner M. , Keller H. , Strutz B. , Šuka D. , Qahtan S. 
Published: November 2024

Abstract
Currently, mMIMO (massive Multiple Input Multiple Output) antennas with beamforming are primarily used in 5G NR (New Radio) in the sub-6 GHz range at 3.5 GHz (Frequency Range 1, FR1). The assessment of the theoretical or actual maximum of human exposure to RF field strength or power density according to international standard IEC 62232:2022 is significantly more difficult at base stations (BSs) with beamforming technology than with conventional antenna technologies. This study compares different measurement and exposure evaluation methods from IEC 62232:2022 with in-situ measurements. A case study, developed for the IEC TR 62669 Ed. 3 originally included an analysis of exposure levels at 4 measurement points (A, B, C and D) in the surroundings of three 5G NR BSs, whereas this study includes analysis from both the original and one additional measurement point (E).
Spatial coherence measurement of divergent x-ray beam without prerequisite source information
Authors: Li Qingcheng , Wang Pei , Lu Yonghua 
Published: November 2024

Abstract
Understanding the spatial coherence of synchrotron x-ray sources is crucial for both source characterization and coherent experimental techniques. Here, we present a method to probe the two-dimensional spatial complex coherence factor (CCF) of divergent x-ray beams without prerequisite source information. Phases of the divergent beams are obtained by the transport-of-intensity equation, which is indispensable for the retrieval of the CCF from the diffraction intensity of a Poisson-disk binary phase mask. Our method has been validated through simulations and is expected to be widely used in measuring coherence for fourth-generation synchrotron x-ray sources.
Governing the Palliative State
Authors: O’Neill Ciaran 
Published: November 2024

Abstract
This chapter examines the personnel that governed Ireland and the spaces in which they worked and shaped its governance. The chapter is influenced by Timothy Mitchell’s and Patrick Joyce’s scholarship, and it is particularly interested in those people who occupied key roles in the Irish administration and the Irish executive, arguing that their work amounted to the ‘domination of familiars’. It also interrogates the forgotten history of the Irish Office in London. By exploring these dynamics, this chapter sheds light on the complex power structures that shaped Ireland’s governance and history.
Wilful Subjects
Authors: O’Neill Ciaran 
Published: November 2024

Abstract
This chapter employs Sara Ahmed’s concept of ‘willful subjects’ to challenge the contemporary notion of Irish ‘ungovernability’ over the course of the Union. This reputation endures all the way to the present. If not represented in popular culture as stubborn, wild, obstinate, or wilful, the Irish are invariably cast as illogical, anti-authority, or irrationally and casually violent. By examining the case studies of Irish travellers at Puck Fairs and the treatment endured by Irish suffragettes, it reveals the agency and resistance of marginalized Irish groups. This chapter also ultimately demonstrates how the trope of Irish ‘ungovernability’ serves as a tool for perpetuating systemic oppression and reinforcing dominant power structures.
The challenges of evidence
Authors: Davies Wendy 
Published: November 2024

Abstract
This chapter explains the characteristics of different types of evidence used in the book and explains the different techniques that are needed to use them well. Differentiating garden from field is a problem for archaeological field survey and excavation, but identifying intensive cultivation practices is useful; differential recovery is a problem in using archaeobotanical material, but careful attention to even minimal presence of macrobotanic remains allows us to interrogate this rich data source. The available written texts are mostly charters, although there are also some manuscript illustrations; transmission and preservation of text is explained, as is the importance of awareness of the inconsistencies of scribal practice and the instability of terms used.