bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural and mechanistic basis of reiterative transcription initiation
Authors: Liu Yu , Yu Libing , Pukhrambam Chirangini , Winkelman Jared T. , Firlar Emre , Kaelber Jason T. , Zhang Yu , Nickels Bryce E. , Ebright Richard H.
Published: January 2022

Significance

In standard transcription initiation, RNA polymerase (RNAP) synthesizes an initial RNA product complementary to the DNA template. In an alternative pathway of transcription initiation, termed “reiterative transcription initiation,” observed at promoters containing homopolymeric sequences at the transcription start site, RNAP synthesizes an initial RNA product having a 5′ sequence containing a variable number, up to tens to hundreds, of nucleotides noncomplementary to the DNA template. Here, using crystallography, cryoelectron microscopy, photocrosslinking, and single-molecule DNA nanomanipulation, we show that RNA extension in reiterative transcription initiation involves slipping of RNA relative to DNA within a short RNA–DNA hybrid and generates RNA that exits RNAP through a previously unobserved RNA path (“alternative RNA path”) and previously unobserved RNA exit (“alternative RNA exit”).
Anomalous magnetic noise in an imperfectly flat landscape in the topological magnet Dy
2
Ti
2
O
7
Authors: Samarakoon Anjana M. , Grigera S. A. , Tennant D. Alan , Kirste Alexander , Klemke Bastian , Strehlow Peter , Meissner Michael , Hallén Jonathan N. , Jaubert Ludovic , Castelnovo Claudio , Moessner Roderich
Published: January 2022

Significance

Ultrasensitive low-temperature magnetic noise experiments on a network of atomic spins reveal how anomalous “glassy” dynamics can arise in a topological magnet, even in the absence of disorder. The results uncover an interplay of local dynamics with emergent topological degrees of freedom and a frustration-generated imperfectly flat energy landscape, and as such, they point to intriguing cooperative and memory effects for a broad class of magnetic materials.
Senescence induction dictates response to chemo- and immunotherapy in preclinical models of ovarian cancer
Authors: Paffenholz Stella V. , Salvagno Camilla , Ho Yu-Jui , Limjoco Matthew , Baslan Timour , Tian Sha , Kulick Amanda , de Stanchina Elisa , Wilkinson John E. , Barriga Francisco M. , Zamarin Dmitriy , Cubillos-Ruiz Juan R. , Leibold Josef , Lowe Scott W.
Published: January 2022

Significance

Efforts to understand and find new treatment options for high-grade serous ovarian cancer (HGSOC) have been confounded by a paucity of immune-competent models that accurately reflect the genetics and biology of the disease. Here, we leverage somatic tissue engineering to develop a fast and flexible immune-competent mouse model of HGSOC and reveal mechanistic insights into factors that dictate the response of ovarian tumors to conventional chemotherapy and immune checkpoint blockade. Our results identify a genotype-dependent therapy-induced senescence program that mediates sensitivity and resistance to first line chemotherapy and point to strategies to harness the senescence program to sensitize ovarian tumors to immune checkpoint blockade.
A widely distributed phosphate-insensitive phosphatase presents a route for rapid organophosphorus remineralization in the biosphere
Authors: Lidbury Ian D.E.A. , Scanlan David J. , Murphy Andrew R. J. , Christie-Oleza Joseph A. , Aguilo-Ferretjans Maria M. , Hitchcock Andrew , Daniell Tim J.
Published: January 2022

Significance

At several locations across the globe, terrestrial and marine primary production, which underpin global food security, biodiversity, and climate regulation, are limited by inorganic phosphate availability. A major fraction of the total phosphorus pool exists in organic form, requiring mineralization to phosphate by enzymes known as phosphatases prior to incorporation into cellular biomolecules. Phosphatases are typically synthesized in response to phosphate depletion, assisting with phosphorus acquisition. Here, we reveal that a unique bacterial phosphatase, PafA, is widely distributed in the biosphere and has a distinct functional role in carbon acquisition, releasing phosphate as a by-product. PafA, therefore, represents an overlooked mechanism in the global phosphorus cycle and a hitherto cryptic route for the regeneration of bioavailable phosphorus in nature.
A comparative genomics examination of desiccation tolerance and sensitivity in two sister grass species
Authors: Chávez Montes Ricardo A. , Haber Anna , Pardo Jeremy , Powell Robyn F. , Divisetty Upendra K. , Silva Anderson T. , Hernández-Hernández Tania , Silveira Vanildo , Tang Haibao , Lyons Eric , Herrera Estrella Luis Rafael , VanBuren Robert , Oliver Melvin J.
Published: January 2022

Significance

This is a significant sister group contrast comparative study of the underpinning genomics and evolution of desiccation tolerance (DT), a critical trait in the evolution of land plants. Our results revealed that the DT grass
Sporobolus stapfianus
is transcriptionally primed to tolerate a dehydration/desiccation event and that the desiccation response in the DT
S. stapfianus
is distinct from the water stress response of the desiccation-sensitive
Sporobolus pyramidalis
. Our results also show that the desiccation response is largely unique, indicating a recent evolution of this trait within the angiosperms, and that inhibition of senescence during dehydration is likely critical in rendering a plant desiccation tolerant.
Mythopoetic legitimation and the recontextualisation of Europe’s foundational myth
Authors: Bennett Samuel
Published: January 2022

Using the example of the European Union’s foundational myth that post-war cooperation led to peace, in this paper I attempt to develop both a theory of mythopoetic legitimation and an analytical framework for its analysis. I start from the position that mythopoesis is a form of legitimation through history or, more specifically, through selective narratives of history. I utilise Berger and Luckmann’s social constructivism to show that myths are deeply sedimented narratives that integrate existing (objectivated) phenomena into a cohesive story. I then propose a framework for critically analysing myths as legitimation strategies. After detailing the EU’s origins story, the remainder of the paper operationalises the framework by analysing how the EU’s foundational myth is used in three, very different contexts: Brexit, the coronavirus pandemic, and a State of the Union address. In doing so, I argue that the EU has become a prisoner of the past it has mythologised.
Rapid solidification structure and grain refinement mechanism of undercooled Cu60Ni40 alloys
Authors: Wang Hongfu , Tang Cheng , An Hongen , Xu Xiaolong , Zhao Yuhong
Published: January 2022

Applying the composite technology of molten glass coating and superheating method, the molten Cu60Ni40 alloy has obtained different undercooling degrees. The microstructure of the alloy during rapid solidification was observed by metallographic microscope, and the evolution process of microstructure morphology was systematically studied. It is found that two significantly different grain refinement phenomena occur in the range of low undercooling and high undercooling. The characteristics of high proportion of large angle grain boundaries, random grain orientation and a large quantity of twin boundaries show that the grain refinement structure under high undercooling is due to recrystallisation. And the microhardness test results show that the average hardness of the grain refinement structure under large undercooling suddenly decreases sharply at the critical undercooling, which also confirms the recrystallisation mechanism of the refined grain under high undercooling.
Elda Grabocka: Stress-buffering comes in granules
Authors: Morgado-Palacin Lucia
Published: January 2022

Elda Grabocka investigates the role of stress granules in obesity and cancer.
Laser-induced activation of Mg-doped GaN: quantitative characterization and analysis
Authors: Nardo A , de Santi C , Carraro C , Sgarbossa F , Buffolo M , Diehle P , Gierth S , Altmann F , Hahn H , Fahle D , Heuken M , Fouchier M , Gasparotto A , Napolitani E , Meneghesso G , Zanoni E , Meneghini M
Published: January 2022

We investigate the effectiveness of laser-induced treatment as compared to rapid-thermal annealing (RTA) for the activation of p-type dopant in Mg-doped GaN layers. The study is based on a wide set of analytical techniques, including resistivity measurements, atomic force microscopy (AFM), scanning emission microscopy, dynamic secondary ion mass spectroscopy (SIMS), time-of-flight (TOF) SIMS and energy dispersive x-ray (EDX) spectroscopy in combination with scanning transmission electron microscopy (STEM). Samples are treated at different energy densities and in different atmospheres, to provide a comprehensive overview of the topic. The analysis is carried out on GaN-on-Si samples, to demonstrate the effectiveness of the treatment even in presence of high threading dislocation densities. The original results presented in this paper indicate that: (a) laser treatment is an effective process for activating the p-type dopant in Mg-doped GaN layers; even at low irradiation energy densities (400 mJ cm−2) the laser treatment can effectively activate the Mg doping, with the best resistivity results obtained (around 1.5 Ωcm) comparable with those obtained by optimized RTA; (b) resistivity varies with temperature with activation energy E
a = 0.14 eV, which is compatible with the MgGa acceptor in GaN; (c) TOF-SIMS, AFM, EDX-STEM analysis indicates that the laser treatment does not modify the concentration profile of magnesium and surface roughness for low and moderate laser energy densities; changes are detected only for energy densities above 600 mJ cm−2, for which a significant degradation of the surface is revealed. The experimental evidence collected within this paper provide an accurate assessment of the process conditions for effective laser activation of Mg-doped GaN, thus allowing the fine-tuning required for selective activation and for industrial applications.
High responsivity of hybrid MoTe2/perovskite heterojunction photodetectors
Authors: Xie An , Jian Yuxian , Cheng Zichao , Gu Yu , Chen Zhanyang , Song Xiufeng , Yang Zaixing
Published: January 2022

Two-dimensional (2D) van der Waals heterojunction offers alternative facile platforms for many optoelectronic devices due to no-dangling bonds and steep interface carrier gradient. Here, we demonstrate a 2D heterojunction device, which combines the benefits of high carrier mobility of 2D MoTe2 and strong light absorption of perovskite, to achieve excellent responsivity. This device architecture is constructed based on the charge carriers separation and transfer with the high-gain photogating effect at the interface of the heterojunction. The device exhibits high responsivity of 334.6 A W−1, impressive detectivity of 6.2 × 1010 Jones. All the results provide the insight into the benefits of interfacial carriers transfer for designing hybrid perovskite-2D materials based optoelectronic devices.
Generalized Gaussian decomposition for full waveform LiDAR processing
Authors: Gu Zhiyong , Lai Jiancheng , Wang Chunyong , Yan Wei , Ji Yunjing , Li Zhenhua
Published: January 2022

Waveform decomposition techniques are commonly used to extract attributes of targets from light detection and ranging (LiDAR) waveforms. Since the shape of a real LiDAR waveform varies for different systems, the conventional models (e.g. the Gaussian function, lognormal function, and generalized normal function) cannot be universally used. In this paper, we present a generalized Gaussian decomposition (GGD) algorithm, which considers the received waveform as the convolution of an arbitrary system waveform with the target response assumed as a Gaussian mixture model. The proposed method was validated using the experimental waveforms sampled from our self-designed LiDAR system with two different system responses. Metrics, including the mean absolute error (MAE) for range retrieval and the root-mean-squared error (RMSE) for waveform fitting, were used to provide a comprehensive quantitative evaluation of the performance. Three classical models for waveform decomposition—the Gaussian, lognormal, and generalized normal functions—were introduced and studied for the comparison. As for the system waveform with a right-skewed profile, the experimental results showed that the GGD algorithm provided the lowest RMSE for waveform fitting, and the most accurate range estimates with an MAE of

0.030
 

m

. The Gaussian decomposition (GD), lognormal decomposition (LND), and generalized normal decomposition (GND) algorithms produced much worse results with MAEs of 0.362, 1.091, and

0.417
 

m

, respectively. As for the system waveform with a negative tail, the GGD algorithm also performed best with an MAE of

0.019
 

m

, while the GD, LND and GND algorithms provided much larger MAEs of 0.457, 0.489, and

0.354
 

m

, respectively. Therefore, the proposed method has the potential to extract more accurate model parameters from a variety of LiDAR waveforms regardless of the shape of the system waveform.
MEMS technology and applications in geotechnical monitoring: a review
Authors: Barzegar Milad , Blanks Stan , Sainsbury Bre-Anne , Timms Wendy
Published: January 2022

In-situ monitoring is an important aspect of geotechnical projects to ensure safety and optimise design measures. However, existing conventional monitoring instruments are limited in their accuracy, durability, complex and high cost of installation and requirement for ongoing real time measurement. Advancements in sensing technology in recent years have created a unique prospect for geotechnical monitoring to overcome some of those limitations. For this reason, micro-electro-mechanical system (MEMS) technology has gained popularity for geotechnical monitoring. MEMS devices combine both mechanical and electrical components to convert environment system stimuli to electrical signals. MEMS-based sensors provide advantages to traditional sensors in that they are millimetre to micron sized and sufficiently inexpensive to be ubiquitously distributed within an environment or structure. This ensures that the monitoring of the in-situ system goes beyond discrete point data but provides an accurate assessment of the entire structures response. The capability to operate with wireless technology makes MEMS microsensors even more desirable in geotechnical monitoring where dynamic changes in heterogeneous materials at great depth and over large areas are expected. Many of these locations are remote or hazardous to access directly and are thus a target for MEMS development. This paper provides a review of current applications of existing MEMS technology to the field/s of geotechnical engineering and provides a path forward for the expansion of this research and commercialisation of products.
Use of cubic structure with primitive nanochannels for fabrication of free standing 3D nanowire network of Pt with Pm3m symmetry
Authors: Akbar Samina , Elliott Joanne M , Squires Adam M , Anwar Aneela
Published: January 2022

In this work, we developed a lipid mixture based on phytantriol / polyoxyethylene surfactant (Brij-56) that forms a Im3m symmetry bicontinuous cubic phase based on the Schwartz primitive surface (Q

II

P
), from which we templated highly ordered 3D nanoporous platinum with a novel ‘single primitive’ morphology (Pm3m symmetry). The Q

II

P
template phase is obtained by incorporation of 17.5% w/w Brij-56 (C16EO10) (a type-I surfactant) into phytantriol under excess hydration conditions. Phytantriol alone forms the double diamond Q

II

D
(Pn3m) phase, and in previous studies incorporating Brij-56 at different compositions the cubic phase maintained this morphology, but increased its lattice parameter; mesoporous metals templated from these Q

II

D
lipid templates all exhibited the ‘single diamond’ (Fd3m) morphology. In contrast, the current paper presents the availability of our Q

II

P
cubic phases to template nanoporous materials of single primitive Pm3m morphology via chemical and electrochemical methods. To explore the structure porosity and morphological features of the templated Pt material, x-ray scattering and transmission electron microscopy are used. The resulting 3D nanoporous Pt materials are found to exhibit a regular network of Pt nanowires of ∼4 nm in diameter with a unit cell dimension of 14.8 ± 0.8 nm, reflecting the aqueous network within the Q

II

P
template.
A novel dealloying strategy for fabricating nanoporous Ag via ζ′-AgGa alloy
Authors: Jiang Zhongming , Zhang Jiamin , Wang Kaizhao , Chen Tianyou , Zhao Jiuwei , Wang Kaijun , Hu Jin
Published: January 2022

A mild strategy for fabricating nanoporous silver (np-Ag) pieces was reported via preparation of Ag–Ga alloys in relatively low temperature and subsequent electrochemical dealloying in nitric acid (HNO3) aqueous solution. After selectively etching Ga out of the Ag–Ga alloy, a typical three-dimensional (3D) bicontinuous nanoporous structure with a pore size of ∼67.21–159.33 nm was observed. A series of studies have shown that the addition of sodium dodecyl sulfate (SDS) results in minimum pore size. The coarsen exponent (n) is 1.61, and the activation energy was calculated to be 27.04 kJ mol−1. Theζ′-AgGa alloy prepared at low temperature can be used as the precursor for the preparation of fine np-Ags, and this method provides a new strategy for the industrial production of dealloyed np-Ag.
A probabilistic approach for determining Monte Carlo beam source parameters: I. Modeling of a CyberKnife M6 unit
Authors: Duchaine Jasmine , Markel Daniel , Bouchard Hugo
Published: January 2022

Objective. During Monte Carlo modeling of external radiotherapy beams, models must be adjusted to reproduce the experimental measurements of the linear accelerator being considered. The aim of this work is to propose a new method for the determination of the energy and spot size of the electron beam incident on the target of a linear accelerator using a maximum likelihood estimation. Approach. For that purpose, the method introduced by Francescon et al (2008 Med. Phys.
35 504–13) is expanded upon in this work. Simulated tissue-phantom ratios and uncorrected output factors using a set of different detector models are compared to experimental measurements. A probabilistic formalism is developed and a complete uncertainty budget, which includes a detailed simulation of positioning errors, is evaluated. The method is applied to a CyberKnife M6 unit using four detectors (PTW 60012, PTW 60019, Exradin A1SL and IBA CC04), with simulations being performed using the EGSnrc suite. Main results. The likelihood distributions of the electron beam energy and spot size are evaluated, leading to

E

ˆ

=
7.42
±
0.17

MeV

and

F

ˆ

=
2.15
±
0.06

mm

. Using these results and a 95% confidence region, simulations reproduce measurements in 13 out of the 14 considered setups. Significance. The proposed method allows an accurate beam parameter optimization and uncertainty evaluation during the Monte Carlo modeling of a radiotherapy unit.
An abdominal phantom with anthropomorphic organ motion and multimodal imaging contrast for MR-guided radiotherapy
Authors: Weidner Artur , Stengl Christina , Dinkel Fabian , Dorsch Stefan , Murillo Carlos , Seeber Steffen , Gnirs Regula , Runz Armin , Echner Gernot , Karger Christian P , Jäkel Oliver
Published: January 2022

Purpose. Improvements in image-guided radiotherapy (IGRT) enable accurate and precise treatment of moving tumors in the abdomen while simultaneously sparing healthy tissue. However, the lack of validation tools for newly developed MR-guided radiotherapy hybrid devices such as the MR-Linac is an open issue. This study presents a custom developed abdominal phantom with respiratory organ motion and multimodal imaging contrast to perform end-to-end tests for IGRT treatment planning scenarios. Methods. The abdominal phantom contains deformable and anatomically shaped liver and kidney models made of Ni-DTPA and KCl-doped agarose mixtures that can be reproducibly positioned within the phantom. Organ models are wrapped in foil to avoid ion exchange with the surrounding agarose and to provide stable T1 and T2 relaxation times as well as HU numbers. Breathing motion is realized by a diaphragm connected to an actuator that is hydraulically controlled via a programmable logic controller. With this system, artificial and patient-specific breathing patterns can be carried out. In 1.5 T magnetic resonance imaging (MRI), diaphragm, liver and kidney motion was measured and compared to the breathing motion of a healthy male volunteer for different breathing amplitudes including shallow, normal and deep breathing. Results. The constructed abdominal phantom demonstrated organ-equivalent intensity values in CT as well as in MRI. T1-weighted (T1w) and T2-weighted (T2w) relaxation times for 1.5 T and CT numbers were 552.9 ms, 48.2 ms and 48.8 HU (liver) as well as 950.42 ms, 79 ms and 28.2 HU (kidney), respectively. These values were stable for more than six months. Extracted breathing motion from a healthy volunteer revealed a liver to diaphragm motion ratio (LDMR) of 64.4% and a kidney to diaphragm motion ratio (KDMR) of 30.7%. Well-comparable values were obtained for the phantom (LDMR: 65.5%, KDMR: 27.5%). Conclusions. The abdominal phantom demonstrated anthropomorphic T1 and T2 relaxation times as well as HU numbers and physiological motion pattern in MRI and CT. This allows for wide use in the validation of IGRT including MRgRT.
Dictionary-based software for proton dose reconstruction and submilimetric range verification
Authors: Onecha V V , Galve P , Ibáñez P , Freijo C , Arias-Valcayo F , Sanchez-Parcerisa D , España S , Fraile L M , Udías J M
Published: January 2022

Objective. This paper presents a new method for fast reconstruction (compatible with in-beam use) of deposited dose during proton therapy using data acquired from a PET scanner. The most innovative feature of this novel method is the production of noiseless reconstructed dose distributions from which proton range can be derived with high precision. Approach. A new MLEM & simulated annealing (MSA) algorithm, developed especially in this work, reconstructs the deposited dose distribution from a realistic pre-calculated activity-dose dictionary. This dictionary contains the contribution of each beam in the plan to the 3D activity and dose maps, as calculated by a Monte Carlo simulation. The MSA algorithm, using a priori information of the treatment plan, seeks for the linear combination of activities of the precomputed beams that best fits the observed PET data, obtaining at the same time the deposited dose. Main results. the method has been tested using simulated data to determine its performance under 4 different test cases: (1) dependency of range detection accuracy with delivered dose, (2) in-beam versus offline verification, (3) ability to detect anatomical changes and (4) reconstruction of a realistic spread-out Bragg peak. The results show the ability of the method to accurately reconstruct doses from PET data corresponding to 1 Gy irradiations, both in intra-fraction and inter-fraction verification scenarios. For this dose level (1 Gy) the method was able to spot range variations as small as 0.6 mm. Significance. out method is able to reconstruct dose maps with remarkable accuracy from clinically relevant dose levels down to 1 Gy. Furthermore, due to the noiseless nature of reconstructed dose maps, an accuracy better than one millimeter was obtained in proton range estimates. These features make of this method a realistic option for range verification in proton therapy.
Detection of solvated electrons below the interface between atmospheric-pressure plasma and water by laser-induced desolvation
Authors: Inagaki Yoshinobu , Sasaki Koichi
Published: January 2022

We have developed a new method to detect solvated (hydrated) electrons at the plasma–water interface. The method is based on laser-induced desolvation followed by the release of free electrons into the plasma. We employed an atmospheric-pressure dc glow discharge, in which the water surface worked as the cathode, in the experiment. When the region just below the water cathode was irradiated with a pulsed laser beam, we observed the pulsed increase in the discharge current. The increase in the discharge current was caused by the release of free electrons, which were produced from hydrated electrons by the laser-induced desolvation. The pulsed increase in the discharge current was sensitive to the laser wavelength. We compared the relationship between the pulsed increase and the laser wavelength with the distribution of the solvation energy of hydrated electrons using Monte Carlo simulation on the transport of free electrons in water. As a result, it was concluded that hydrated electrons produced under the experimental conditions were located at a distance of 7–15 nm from the plasma–water interface.
Standard measurement method for normal state resistance and critical current of resistively shunted Josephson junctions
Authors: Ohkubo M , Uehara G , Beyer J , Mimura M , Tanaka H , Ehara K , Tanaka S , Noguchi T , Mitchell E E , Foley C P , Fagaly R L
Published: January 2022

An important parameter of Josephson junctions (JJs) is the product of normal state resistance (R
n) and critical current (I
c) for designing superconductor analogue devices or digital circuits. Determination of R
n and I
c from voltage–current (U–I) characteristic curves often faces difficulties; in particular I
c is considerably reduced by intrinsic thermal or extrinsic electrical noises. Here, we propose a standard measurement method of R
n and intrinsic critical current (I
ci) for high-T
c superconductor (HTS) grain boundary JJs operated in liquid nitrogen and low-T
c superconductor (LTS) multilayer superconductor/normal-conductor/superconductor (SNS) JJs in liquid helium. The applicable condition of this method is that both HTS and LTS JJs have U–I curves compatible with resistively-shunted junction (RSJ) model. Both R
n and I
ci values are extracted by combining a geometric mean criterion to select a data set and a least-squares fitting method with the RSJ model, eliminating two distortion effects on U–I curves: noise-rounding and self-heating. The combined method ensures relative standard uncertainty values of 1.9% for R
n and 8% for I
ci or better, when the users follow the standard protocol. It is demonstrated that the combined method is valid for d-wave HTS JJs near 77 K, regardless of peculiarities such as 0–π junction transition in d-wave superconductors at lower temperatures, and s-wave LTS SNS JJs with a wide range of junction parameters. This work is the first step to facilitate standardization for superconductor electronics with JJs.
Thermal-hydraulic models for the cooling of HTS power-transmission cables: status and needs
Authors: Savoldi Laura , Placido Daniele , Viarengo Sofia
Published: January 2022

An overview of the main peculiarities of the models currently available in the literature for the thermal-hydraulic analysis of the cooling of the high critical temperature superconducting power transmission cables, mainly in nominal operating conditions, is performed. Several models address specific issues such as the temperature distribution along or across the cables, and their pressure drop, typically with a simplified approach. The verification and validation of the models has not been systematically addressed so far. From analysis of the available literature, the lack of a general model, capable to address thermal-hydraulic transients for the cooling of the different possible cable designs, with the capability to capture both the behaviour of the cable solid components and different cryogens, is highlighted. The main ingredients that such a general thermal-hydraulic model should not miss are presented, also based on the know-how on, and comparison to, similar tools for low critical temperature cables for nuclear fusion applications.
Optimization study of the main parameters of different types of wind turbine generators
*
Authors: Xu Yuanyuan , An Lian-Tong , Jia Xiao-Ping , Jia Bao-Zhu , Maki Naoki
Published: January 2022

The research and development of large-scale wind turbine generators have become a future trend in green renewable energy field from the dual perspectives of the environment and economics. In this work, an electrical design method is first proposed and applied to different types of wind turbine generators, including the high-temperature superconducting (HTS), the permanent magnet, and the traditional copper generators. The optimal electrical designs of the three types of 10 MW wind turbine generators are then created based on the developed design program. Second, the influences of the rated revolution on the basic performance parameters of the HTS generator are investigated, and the results are compared with those of the other two types of generators. It is found that the generator weight decreases with the increases of the rated revolution and the stator outer diameter, and the optimal rated revolution for a generator with a large stator outer diameter is determined to be 40 min−1. Moreover, the weight of the field parts is found to have the same regulation rule as the generator weight. Finally, the design results of the three types of wind turbine generators are comparatively discussed, and it is found that the HTS wind turbine generator is superior to its two counterparts.
Quantum Brownian motion for magnets
Authors: Anders J , Sait C R J , Horsley S A R
Published: January 2022

Spin precession in magnetic materials is commonly modelled with the classical phenomenological Landau–Lifshitz–Gilbert (LLG) equation. Based on a quantized three-dimensional spin + environment Hamiltonian, we here derive a spin operator equation of motion that describes precession and includes a general form of damping that consistently accounts for memory, coloured noise and quantum statistics. The LLG equation is recovered as its classical, Ohmic approximation. We further introduce resonant Lorentzian system–reservoir couplings that allow a systematic comparison of dynamics between Ohmic and non-Ohmic regimes. Finally, we simulate the full non-Markovian dynamics of a spin in the semi-classical limit. At low temperatures, our numerical results demonstrate a characteristic reduction and flattening of the steady state spin alignment with an external field, caused by the quantum statistics of the environment. The results provide a powerful framework to explore general three-dimensional dissipation in quantum thermodynamics.
Few-photon storage on a second timescale by electromagnetically induced transparency in a doped solid
Authors: Hain Marcel , Stabel Markus , Halfmann Thomas
Published: January 2022

We present the experimental demonstration of light storage towards the single photon level at a long storage time by electromagnetically induced transparency in a rare-earth ion-doped Pr3+:Y2SiO5 crystal. We apply decoherence control by static magnetic fields and appropriately designed radio-frequency composite pulse sequences to prolong the storage time in the memory. A rare-earth ion-doped filter crystal prepared by optical pumping serves to efficiently separate the signal at the single photon level from optical noise. Multipass setups around the memory and the filter crystal improve the storage efficiency and filter selectivity. Already without decoherence control, the setup permits storage of single photons in the microsecond regime at a storage efficiency of 42%. With decoherence control we demonstrate storage of weak coherent pulses containing some 10 photons for up to 10 s at a storage efficiency of several percent. The experimental data clearly demonstrate the applicability of EIT light storage to implement a true quantum memory in Pr3+:Y2SiO5 at long storage times. The scientific findings and technical developments are of relevance also to other protocols and media for quantum information storage.
Mathematical modelling and optimal control of the transmission dynamics of enterovirus
Authors: Mabotsa Malebese , Munganga Justin Manango W , Shitu Hassan Adamu
Published: January 2022

We propose a mathematical model for the transmission dynamics of enterovirus, with novelty of incorporating indirect transmission from the environment, inclusion of control interventions (sanitation and hygiene) and optimal control study. We prove that if the basic reproduction number



0

≤
1

, a suitable Lyapunov function is used to establish the global stability of the disease free equilibrium, in which case the infection will die out over time. Our analysis further establish the global stability of the endemic equilibrium based on the approach of Volterra-Lyapunov matrices if



0

>
1

. Our findings show that when



0

>
1

, the endemic equilibrium is globally asymptotically stable. In this case, the enterovirus will invade the population. It is shown that by reducing direct transmission rate by 80%, the basic reproduction number can be reduced below one and thus controlling the infection. Using optimal control, it is shown that the disease can be controlled within a shorter period of time as compared to minimizing the direct contact rate by 80%. Numerical simulations are provided to illustrate the results.
Study of anisotropic polytropes in f (, T) Theory
Authors: Sharif M , Majid Amal , Shafaqat M
Published: January 2022

This paper examines the general formalism and applications of isotropic as well as anisotropic polytropic stars in curvature-matter coupled gravity. For this purpose, we consider static spherical and Schwarzschild spacetimes in the interior and exterior regions, respectively. We use two polytropic equations of state to obtain physically viable solutions of the field equations. The hydrostatic equilibrium and Lane-Emden equations are developed for both isotropic as well as anisotropic cases. We study the effects of anisotropic pressure on the stellar structure. Moreover, we graphically inspect the physical behavior of isotropic as well as anisotropic polytropes through energy conditions and stability criterion. Finally, we discuss Tolman mass to explore some characteristics of the models. It is concluded that more viable and stable polytropes are found in this theory as compared to general relativity.
The vibrational and thermodynamic properties of hydrogen adsorbed on the Pt(100) surface: a theoretical study
Authors: Nguyen Van Hoa , Nguyen Minh Phi , Lam Toan Vi , Tran Thi Thu Hanh
Published: January 2022

The adsorption of hydrogen on the Pt(100) surface is investigated theoretically within the conventional ultrahigh vacuum (UHV) surface modeling. Both density functional theory (DFT) and Monte Carlo (MC) simulation are implemented to determine the stability, the vibrational properties of the adsorbed hydrogen atom, and the H-H pair interactions. From the converged data, it is found that the H adsorbed on the bridge sites (B sites) have the strongest binding energy. Meanwhile, the H adsorbed on the top sites (T sites) have the highest vertical stretching frequency. In the increment of H coverage (

Θ

H

), up to 1 ML, only the H on the B sites are counted. The shape of the g-value curve obtained by MC simulation shows a good agreement with the result of the cyclic voltammetry (CV) measurement. Reducing the pair interaction parameters by about 30%, the g-value is also decreased. From 0.3 to 0.6 with respect to

Θ

H

,

the g-value is extremely fitted to the experimental data. This indicates that the interactions of H-H on the Pt(100) surface within the range of

0.3
<

Θ

H

<
0.6

are mainly attributed to those hydrogen atoms adsorbed on the B sites.
Bouncing cosmological isotropic solutions in scalar-tensor gravity
Authors: Polarski D. , Starobinsky A.A. , Verbin Y.
Published: January 2022

Bouncing non-singular isotropic cosmological solutions are investigated in a simple model of scalar-tensor gravity. New families of such solutions are found and their properties are presented and analyzed
using an effective potential as the main tool.
Bouncing solutions are shown to exist for a Higgs-like self-interaction
potential which is bounded from below, in contrast to previous solutions that appeared in the literature based on potentials which were unbounded from below. In the simplest version of a scalar field with the quartic potential and conformal coupling to gravity, bouncing spatially flat solutions either have the Hubble function diverging in the past before
the bounce, but with a well-behaved future, or are globally regular but unstable with respect to anisotropic or inhomogeneous
perturbations at some finite values of the scalar field and curvature. Regular solutions can only exist in the part of the parameter space where the maximum of
the effective potential is larger than the first zero of the potential, and gravity becomes
repulsive at the bounce.
On the duality of massive Kalb-Ramond and Proca fields
Authors: Hell Anamaria
Published: January 2022

We compare the massive Kalb-Ramond and Proca fields with a quartic self-interaction and show that the same strong coupling scale is present in both theories. In the Proca theory, the longitudinal mode enters the strongly coupled regime beyond this scale, while the two transverse modes propagate further and survive in the massless limit. In contrast, in case of the massive Kalb-Ramond field, the two transverse modes become strongly coupled beyond the Vainshtein scale, while the pseudo-scalar mode remains in the weak coupling regime and survives in the massless limit. This indicates a contradiction with the numerous claims in the literature (see eg. [3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21]) that these theories are dual to each other.
Gravitational waves from melting cosmic strings
Authors: Emond William T. , Ramazanov Sabir , Samanta Rome
Published: January 2022

Appearance of cosmic strings in the early Universe is a common manifestation of new physics typically linked to some high energy scale. In this paper, we discuss a different situation, where a model underlying cosmic string formation is approximately scale free. String tension is naturally related to the square of the temperature of the hot primordial plasma in such a setting, and hence decreases with (cosmic) time. With gravitational backreaction neglected, the dynamics
of these melting strings in an expanding Universe is equivalent to the dynamics of constant tension strings in a Minkowski spacetime.
We provide an estimate for the emission of gravitational waves from string loops. Contrary to the standard case, the resulting spectrum is markedly non-flat and has a characteristic falloff
at frequencies below the peak one. The peak frequency is defined by the underlying model and lies in the range accessible by the future detectors for very weak couplings involved.
Cytoskeletal proteins: lessons learned from bacteria
Authors: Ramos-León Félix , Ramamurthi Kumaran S
Published: January 2022

Cytoskeletal proteins are classified as a group that is defined functionally, whose members are capable of polymerizing into higher order structures, either dynamically or statically, to perform structural roles during a variety of cellular processes. In eukaryotes, the most well-studied cytoskeletal proteins are actin, tubulin, and intermediate filaments, and are essential for cell shape and movement, chromosome segregation, and intracellular cargo transport. Prokaryotes often harbor homologs of these proteins, but in bacterial cells, these homologs are usually not employed in roles that can be strictly defined as ‘cytoskeletal’. However, several bacteria encode other proteins capable of polymerizing which, although they do not appear to have a eukaryotic counterpart, nonetheless appear to perform a more traditional ‘cytoskeletal’ function. In this review, we discuss recent reports that cover the structures and functions of prokaryotic proteins that are broadly termed as cytoskeletal, either by sequence homology or by function, to highlight how the enzymatic properties of traditionally studied cytoskeletal proteins may be used for other types of cellular functions; and to demonstrate how truly ‘cytoskeletal’ functions may be performed by uniquely bacterial proteins that do not display homology to eukaryotic proteins.
Extension of NIM illuminance scale to very low levels (1 × 10−10 lx to 2 lx)
Authors: Lv Liang , Jiang Xiaomei , Lin Yandong , Li Jian , Lin Xiaofeng , Xu Ning
Published: January 2022

The realization of the low light level illuminance scale of the National Institute of Metrology (NIM, China) is presented. Two methods were used to achieve the photometric scale covering (1 × 10−10–2 × 100) lx, the first method based on the luminance adjustable two-stage integrating sphere source was used to realize the illuminance scale down to 1 × 10−6 lx, while the other method based on a twin-source superposition linearity measurement facility was applied to extend the scale from 1 × 10−6 lx to 1 × 10−10 lx. The expanded relative uncertainty of the (1 × 10−10–2 × 100) lx illuminance scale was evaluated to be from 1.0 % to 0.8 % varying with range (coverage factor k = 2). As part of our research work, a photon counting type photometer was developed and calibrated in the (2 × 10−10–1 × 10−6) lx range using this low light level illuminance scale with expanded relative uncertainty 13 % to 1.4 % (k = 2). This low light level photometric scale can meet the calibration requirement of high sensitivity photometers such as the micro-lux photometers and photon counting type photometers.
Quality assessment of cadmium telluride as a detector material for multispectral medical imaging
Authors: Kirschenmann S. , Bezak M. , Bharthuar S. , Brücken E. , Golovleva M. , Gädda A. , Kalliokoski M. , Karadzhinova-Ferrer A. , Koponen P. , Kramarenko N. , Luukka P. , Ott J. , Tikkanen J. , Turpeinen R. , Winkler A.
Published: January 2022

Cadmium telluride (CdTe) is a high-Z material with excellent photon radiation absorption properties, making it a promising material to include in radiation detection technologies. However, the brittleness of CdTe crystals as well as their varying concentration of defects necessitate a thorough quality assessment before the complex detector processing procedure. We present our quality assessment of CdTe as a detector material for multispectral medical imaging, a research which is conducted as part of the Consortium Project Multispectral Photon-counting for Medical Imaging and Beam characterization (MPMIB). The aim of the project is to develop novel CdTe detectors and obtain spectrum-per-pixel information that make the distinction between different radiation types and tissues possible. To evaluate the defect density inside the crystals — which can deteriorate the detector performance — we employ infrared microscopy (IRM). Posterior data analysis allows us to visualise the defect distributions as 3D defect maps. Additionally, we investigate front and backside differences of the material with current-voltage (IV) measurements to determine the preferred surface for the pixelisation of the crystal, and perform test measurements with the prototypes to provide feedback for further processing. We present the different parts of our quality assessment chain and will close with first experimental results obtained with one of our prototype photon-counting detectors in a small tomographic setup.
Design of a new reflectometric system for real time plasma position control on the RFX-mod2 device
Authors: De Masi G. , Cavazzana R. , Abate D. , Bernardi M. , Marchiori G. , Moresco M. , Tiso A. , Peruzzo S.
Published: January 2022

RFX-mod2 (R = 2.0 m, a = 0.49 m), the upgraded version of the previous RFXmod fusion device, will be equipped with a new reflectometry system specifically designed for plasma position control purposes. Featuring a high temporal and spatial resolution and being suitable for harsh fusion reactor experimental conditions (long pulses, high neutron fluxes), reflectometry has been proposed as a good candidate for this task. On RFX-mod2 the diagnostic system will consist of four bistatic ultrafast independent reflectometric units working in the frequency range (16–26.5 GHz) and installed in four different poloidal locations at the same toroidal angle: two on the equatorial plane (high field side/low field side) and two at the vertical top/bottom ports. Standard pyramidal horns will be installed in the external midplane and in the vertical ports, while parabolic hoghorn reflectors have been designed for the internal midplane. Different technical solutions for the integration in the machine, as the additive manufacturing for the antenna production, are presented. Despite the differences with respect to the application on large Tokamaks like DEMO, the RFX-mod2 plasma position reflectometer can contribute to test on a simple machine some of the issues related to the development of a reflectometry based plasma position and shape control.
A 5-Gbps serializer ASIC in 130 nm for high-speed front-end readout applications
Authors: Meng C. , Guo T. , Xiong T. , Chen Q. , Guo Z. , Zhao C. , Guo D.
Published: January 2022

This paper presents the design and the test results of a low-power 5 Gbps 10:1 serializer chip with the self-check function based on a standard 130 nm CMOS technology. This serializer chip adopts a multi-level design scheme with a combination of the multi-phase structure (5:1 module) in the low data rate part and the tree structure (2:1 module) in the high date rate part. The high data rate 2:1 module adopts a latch-induced latency control circuit to ensure the timing margin across corners. The serializer chip has been fully tested, wide-open 5 Gbps output eye diagram has been captured, and the logic function has also been verified. The measured power consumption of the whole chip is 42 mW including Rx/Tx, and the power consumption of the serializer core is around 12.1 mW.
First GEM measurements at WEST and perspectives for fast electrons and heavy impurities transport studies in tokamaks
Authors: Mazon D. , Chernyshova M. , Jardin A. , Peysson Y. , Król K. , Malard P. , Czarski T. , Wojeński A. , Malinowski K. , Colette D. , Poźniak K.T. , Kasprowicz G. , Zabołotny W. , Krawczyk R.D. , Kolasiński P. , Gąska M. , Linczuk P. , Bielecki J. , Scholz M. , Dworak D.
Published: January 2022

Soft X-ray (SXR) radiation emitted from tokamak plasmas contains very useful information about plasma stability, shape and impurity content, all key parameters to improve plasma performance. In the deuterium-tritium phase of ITER, the high neutron fluxes, gamma and hard X-ray emission will constitute too harsh an environment to permit the use of classical semiconductor detectors. New SXR detector technologies, more robust to such environments, should thus be investigated. First GEM (Gas Electron Multiplier) measurements performed at WEST were successful and showed that both spatially and spectrally resolved calibrated data could be acquired. Strategies to reconstruct tungsten (W) impurity radiation synthetic diagnostics, modelling and real measurements based on multiple diagnostics are proposed.