bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exact parameter identification in PET pharmacokinetic modeling using the irreversible two tissue compartment model
*
Authors: Holler Martin , Morina Erion , Schramm Georg 
Published: June 2024

Abstract

Objective. In quantitative dynamic positron emission tomography (PET), time series of images, reflecting the tissue response to the arterial tracer supply, are reconstructed. This response is described by kinetic parameters, which are commonly determined on basis of the tracer concentration in tissue and the arterial input function. In clinical routine the latter is estimated by arterial blood sampling and analysis, which is a challenging process and thus, attempted to be derived directly from reconstructed PET images. However, a mathematical analysis about the necessity of measurements of the common arterial whole blood activity concentration, and the concentration of free non-metabolized tracer in the arterial plasma, for a successful kinetic parameter identification does not exist. Here we aim to address this problem mathematically. Approach. We consider the identification problem in simultaneous pharmacokinetic modeling of multiple regions of interests of dynamic PET data using the irreversible two-tissue compartment model analytically. In addition to this consideration, the situation of noisy measurements is addressed using Tikhonov regularization. Furthermore, numerical simulations with a regularization approach are carried out to illustrate the analytical results in a synthetic application example.
Main results. We provide mathematical proofs showing that, under reasonable assumptions, all metabolic tissue parameters can be uniquely identified without requiring additional blood samples to measure the arterial input function. A connection to noisy measurement data is made via a consistency result, showing that exact reconstruction of the ground-truth tissue parameters is stably maintained in the vanishing noise limit. Furthermore, our numerical experiments suggest that an approximate reconstruction of kinetic parameters according to our analytic results is also possible in practice for moderate noise levels. Significance. The analytical result, which holds in the idealized, noiseless scenario, suggests that for irreversible tracers, fully quantitative dynamic PET imaging is in principle possible without costly arterial blood sampling and metabolite analysis.
Time-domain diffuse optical imaging technique for monitoring rheumatoid arthritis disease activity: experimental validation in tissue-mimicking finger phantoms
Authors: Ioussoufovitch S , Diop M 
Published: June 2024

Abstract

Objective. Effective treatment within 3–5 months of disease onset significantly improves rheumatoid arthritis (RA) prognosis. Nevertheless, 30% of RA patients fail their first treatment, and it takes 3–6 months to identify failure with current monitoring techniques. Time-domain diffuse optical imaging (TD-DOI) may be more sensitive to RA disease activity and could be used to detect treatment failure. In this report, we present the development of a TD-DOI hand imaging system and validate its ability to measure simulated changes in RA disease activity using tissue-mimicking finger phantoms. Approach. A TD-DOI system was built, based on a single-pixel camera architecture, and used to image solid phantoms which mimicked a proximal interphalangeal finger joint. For reference, in silico images of virtual models of the solid phantoms were also generated using Monte Carlo simulations. Spatiotemporal Fourier components were extracted from both simulated and experimental images, and their ability to distinguish between phantoms representing different RA disease activity was quantified. Main results. Many spatiotemporal Fourier components extracted from TD-DOI images could clearly distinguish between phantoms representing different states of RA disease activity. Significance. A TD-DOI system was built and validated using finger-mimicking solid phantoms. The findings suggest that the system could be used to monitor RA disease activity. This single-pixel TD-DOI system could be used to acquire longitudinal measures of RA disease activity to detect early treatment failure.
Conceptual design of visible spectroscopy diagnostics for DTT
Authors: Belpane A , Carraro L , Fassina A , Cavedon M , Senni L 
Published: June 2024

Abstract
The project of the Visible Spectroscopy diagnostics for the Z
eff radial profile measurement and for the divertor visible imaging spectroscopy, designed for the new tokamak DTT (Divertor Tokamak Test), is presented. To deal with the geometrical constraints of DTT and to minimize the diagnostics volume inside the access port, an integrated and compact solution hosting the two systems has been proposed. The Z
eff radial profile will be evaluated from the Bremsstrahlung radiation measurement in the visible spectral range, acquiring light along ten Lines of Sight (LoS) in the upper part of the poloidal plane. The plasma emission will be focused on optical fibers, which will carry it to the spectroscopy laboratory. A second equipment, with a single toroidal LoS crossing the plasma centre and laying on the equatorial plane, will measure the average Z
eff on a longer path, minimizing the incidental continuum spectrum contaminations by lines/bands emitted from the plasma edge. The divertor imaging system is designed to measure impurity and main gas influxes, to monitor the plasma position and kinetics of impurities, and to follow the plasma detachment evolution. The project aims at obtaining the maximum coverage of the divertor region. The collected light can be shared among different spectrometers and interferential filter devices placed outside the torus hall to easily change their setup. The system is composed of two telescopes, an upper and a lower one, allowing both a perpendicular and a tangential view of the DTT divertor region. This diagnostic offers a unique and compact solution designed to cope the demanding constraints of this next-generation tokamak fusion devices, integrating essential tools for wide-ranging impurity characterization and versatile investigation of divertor physics.
A bidirectional-controllable magnetorheological elastomer-based quasi-zero-stiffness isolator
Authors: Fu Jie , Huang Zhen , Li Wang , Wang Wei , Zhong Can , Qi Song , Yu Miao 
Published: June 2024

Abstract
To enhance the low-frequency vibration isolation bandwidth of quasi-zero stiffness (QZS) isolators under variable amplitude excitations, this paper proposes an adaptive bidirectional-controllable QZS isolator (Bi-QZS) based on magnetic-controlled smart material named magnetorheological elastomer (MRE) as positive element and tilting spring as negative element. Firstly, the positive element of isolator is composed of laminated MRE and permanent magnet to realize bidirectional stiffness adjustment. Then the magnetic circuit of vibration isolator is designed and the specific parameters are obtained by taking the magnetic field and energy consumption as the optimization objectives. Secondly, a static theoretical model is established to calculate the achievable range of stiffness variation, and match the parameters of the negative element. Static analysis shows that bidirectional stiffness control is beneficial to achieve stiffness matching. Additionally, the adjustment of bidirectional stiffness variation on the dynamic response of the system is deduced by harmonic balance method. Numerical simulation results indicate that adjusting stiffness in reverse can increase the vibration isolation bandwidth when the excitation amplitude increases, and adjusting in forward can reduce the peak value of jump region. Also, increasing the damping ratio under reverse conditions has a certain contribution to reducing the response peak. Finally, static and dynamic tests are carried out, results reveal a bidirectional stiffness adjustment capability, with a 36.4% adjustment in reverse stiffness and a 70% adjustment in forward stiffness. The resonance frequency can be reduced from 14.4 Hz to 5.8 Hz by stiffness bidirectional-controllable.
Ti/Te effects on transport in EAST low q95 plasmas
Authors: He Y.F. , Qian J.P. , Li J.G. , Li P. , Gong X.Z. , Zhang B. , Zhang J.Y. , Chen J.L. , Bae Cheonho , Wu M.Q. , Yang X.D. , Jia T.Q. , Li G.S. , Jin Y.F. , Lin Z.C. , Fu S.Y. , Lin G.L. , Zang Q. , Zhong G.Q. , Wang S.X. , Li X. , Huang J. 
Published: June 2024

Abstract
Enhanced confinement is observed in EAST low

q

95

(

q

95

<
3.5

) plasmas with the temperature ratio (

T
i

/

T
e

) increasing. A statistically significant positive correlation between

H

98
y
2

and

T
i

/

T
e

has been established. Increased

T
i

triggerd by Neutral Beam Injection in experiments maintaining constant

T
e

leads initially to an improved

T
i

/

T
e

ratio, which subsequently mitigates heat transport in the ion channel. The Trapped Gyro–Landau Fluid transport model was applied to analyse the dependence of the turbulent transport on

T
i

/

T
e

. Simulation results demonstrate that the Ion Temperature Gradient mode is stabilized in high

T
i

/

T
e

plasma, with ion flux results from predictive modelling further validating this effect. These findings corroborate the Weiland model and complement one another. This study contributes to a deeper understanding of how the dimensionless parameter

T
i

/

T
e

influences plasma transport, and helps demonstrate the feasibility of operations under the low

q

95

condition required for the ITER-inductive scenario in the new

T
i

/

T
e

regime.
Validation of the ERO2.0 code using W7-X and JET experiments and predictions for ITER operation
Authors: Romazanov J. , Brezinsek S. , Baumann C. , Rode S. , Kirschner A. , Wang E. , Effenberg F. , Borodin D. , Navarro M.X. , Xie H. , Groth M. , Kumpulainen H. , Schmid K. , Pitts R.A. , Terra A. , Knieps A. , Gao Y. , Krychowiak M. , Pandey A. , Linsmeier Ch. 
Published: June 2024

Abstract
The paper provides an overview of recent modelling of global material erosion and deposition in the fusion devices Wendelstein 7-X (W7-X), JET and ITER using the Monte-Carlo code ERO2.0. For validating the modelling tool in a three-dimensional environment, W7-X simulations are performed to describe carbon erosion from the graphite test divertor units, which were equipped in operational phase OP 1.2 and analysed post-mortem. Synthetic spectroscopy of carbon line emission is compared with experimental results from the divertor spectrometer measurement system, showing a good agreement in the e-folding lengths in the radial intensity profiles of carbon. In the case of metallic wall materials, earlier modelling of the Be/W environment in JET and ITER is revisited and extended with an updated set of sputtering and reflection data, as well as including the mixing model for describing the Be/W dynamics in the divertor. Motivated by recent H/D/T isotope experiments in JET, limited and diverted configuration pulses are modelled, showing the expected trend of both Be and W erosion increasing with isotope mass. For the JET diverted configuration pulses, it is shown that Be migrates predominantly to the upper part of the inner divertor where it initially leads to strong W erosion. With longer exposure time, the growth of a Be deposited layer leads to a reduction of W erosion in that region. A similar trend is observed in simulations of the ITER baseline Q = 10 scenario, however with a more symmetric Be migration pattern leading to deposition also on the outer divertor.
The new layout and regulation of the ‘pulsating’ power conversion system of EU DEMO WCLL for an effective and safe control of pulse-dwell transitions and increase in plant efficiency
Authors: Barucca L. , D’Alessandro A. , Burlando A. , Traverso A. 
Published: June 2024

Abstract
EUROFUSION DEMO is a Fusion Power Plant concept under assessment, based on Tokamak technology. Regarding the Balance of Plant definition, particular effort has been posed to the design of the Power Conversion System (PCS), thermally coupled to the Primary Heat Transport System. Several architectures of the PCS have been assessed, and the present work is focused on the PCS, based on the Rankine Cycle technology and equipped with a Small Energy Storage System (ESS) operated with Molten Salt. A new Energy Map has been released in 2021, revealing uncertainties on the thermal power deposited on the different in-Vacuum Vessel components (i.e. Breeding Blanket, Divertor, Limiters and Vacuum Vessel) and rejected to the coolant of related cooling circuits. This fact leads to several (12) possible operating scenarios. The following treatment will be analyzed the 2022 PCS Small ESS concept design review, performed by the industry with the main aim to align the new layout with the updated thermal inputs and its comparison with the preliminary design developed in 2018. Design novelties will be highlighted, especially those that dealt with improving the cycle control, robustness, safety of the operation and efficiency. The outcomes of the transient analysis will be shown and compared, to verify the mechanical and thermal stress during the DEMO period (pulse/dwell). Finally, a performance and efficiency analysis of the 2022 PCS layout is also presented and compared to 2018 configuration.
Optimized hybrid plasmonic waveguide-based ring resonator for advanced refractive index sensing
Authors: Butt M A , Kozłowski Ł , Piramidowicz R 
Published: June 2024

Abstract
In this study, we conducted a comprehensive numerical analysis employing the finite element method to explore the characteristics of a hybrid plasmonic waveguide (HPWG)-based ring resonator (RR) structure. Our investigation reveals that the device’s sensitivity can be significantly augmented through strategic geometric modifications. The device exhibits sensitivities of approximately 176 nm RIU−1 and 238 nm RIU−1 when utilizing WG widths of 300 nm and 270 nm, respectively, in forming the ring structure. Through optimization efforts aimed at enhancing the overlap between the dielectric and plasmonic modes, the device’s sensitivity reaches an optimized level of around 316 nm RIU−1 by reducing the ring width to 250 nm. Overall, our findings underscore the potential for leveraging geometric adjustments to enhance the sensitivity and functionality of HPWG-based RRs, thereby advancing their utility in diverse sensing applications.
Large effective length and high efficiency by embedding L-shaped radiating blocks in subwavelength grating slot waveguide
Authors: Chen Zhipeng , Wang Dongkai , Liu Pengfei , Ji Zhangjie , Ma Li , Shi Yiming , Xie Lu , Qian Qinyu , Chen Haitao , Cheng Liwen 
Published: June 2024

Abstract
Integrated optical antennas featuring large effective lengths and high radiation efficiency (RE) are essential to chip-scale light detection and ranging technology. However, there are challenges in simultaneously achieving both large effective length and high RE in silicon photonics platforms with high refractive index contrast. For traditional silicon waveguide grating antennas based on silicon photonics, the RE is relatively low and the antenna effective lengths are constrained to several hundred micrometers because of the high refractive index contrast. In this article, an embedded grating waveguide antenna which is L-shaped radiating blocks embedded in the slot gap of a silicon subwavelength grating slot waveguide is proposed and investigated numerically. Simulation results indicate the antenna’s effective length is above 4.25 mm, and the far-field divergence angle is near 0.0197°. Using L-shaped radiation blocks can break the diffraction’s perpendicular symmetry and increase the antenna’s RE to near 0.75 at 1550 nm compared to traditional design. Meanwhile, the antenna’s field-of-view reaches around 17.5° × 48.15° (θ× ϕ) to satisfy the needs of conventional optical phased arrays.
Filter-free lens-free polarimetric incoherent digital holography
Authors: Tahara Tatsuki 
Published: June 2024

Abstract
I propose an incoherent digital holography (IDH) technique in which four-dimensional (4D, three-dimensional (3D) coordinates and polarization) information is simultaneously obtained using neither polarization filters nor lenses. A filter-free lens-free self-interference incoherent interferometer for 4D imaging is designed and developed. Four-dimensional (4D) information is multiplexed in recorded phase-shifted incoherent holograms and extracted by polarization-selective phase-shifting interferometry. The validity of the proposed holography for multiplexed 4D imaging is experimentally demonstrated by the constructed filter-free lens-free self-interference IDH system and a randomly polarized light-emitting diode.
Research on the process and mechanism of preparing titanium-rich materials from complex ilmenite
Authors: Wei Mei , Liu Chenhui , Yang Qinsheng , Li Zhongwei , Li Yingwei 
Published: June 2024

Abstract
A new process for the development and utilization of titanium-iron sand ore from Yunnan province is proposed. We provide a detailed analysis of the chemical composition and mineral structure of the raw material, and describe a pretreatment involving low-temperature oxidation and reduction, hydrofluoric acidolysis, and hydrochloric acid leaching to remove impurities and generate titanium-rich materials. Hydrofluoric acid was used to break down the complex titanite, silica-titanium, and calcium-titanium mixture in the starting mineral into simple oxides. The results have indicated that the thermal reduction process should not be conducted at elevated temperatures. Optimal process conditions are established for the leaching process: leaching temperature of 80 °C; leaching time of 240 min; hydrofluoric acid concentration of 3%; liquid–solid ratio of 6 m l/g. Under these conditions, the extent of TFe leaching reached 96%, while the leaching of Ca and Mg reached 94%. The TiO2 grade of the final titanium-rich material was 89.95%, with a CaO content of 0.39%, a MgO content of 0.15%, and a TFe content of 7.5%. This material can serve as raw material for subsequent chlorination.
Conflicted Callings: Purity of Heart Is to Will Several Things
Authors: Miller-McLemore Bonnie J 
Published: June 2024

Abstract
This chapter engages the difficulties of having multiple callings (e.g., work, family, social justice activism, spiritual practices). Different from missed or blocked callings, the challenge is not restriction or limitation but overabundance and depletion. How does one follow more than one calling well without serious cost or consequence? Reigning myths obscure this dilemma. It’s amazing how often term calling, singular, rather than callings, plural, is used. The chapter focuses initially on the clash of commitments in middle adulthood with job entry and advancement, householding, partner relationships, avocational pursuits, parenting, care of parents and close friends, and political or religious commitments. The chapter also considers the conflicts caused by devoting ourselves to larger causes such as social justice. It concludes with suggestions about compromise, imperfection (being “good enough”), protest, solidarity, reform, and everyday practices.
Austinian Themes
Authors: Sbisà Marina 
Published: June 2024

AbstractThis book offers a reconstruction of John L. Austin’s philosophy organized thematically. It explores his works comparing them with one another and comparing the views they express with their elaborations and developments in more recent philosophy. In dealing with speech acts, it relies not only on published work but also on Austin’s manuscript notes. It defends Austin’s speech act theory and his notion of illocution against some main criticisms. It reconstructs Austin’s responsibility-based conception of action drawing on his remarks on acts and actions. It explores Austin’s contributions to epistemology and the philosophy of perception (including his realist stance, anti-scepticism, presentational view of perception, and the roles that he assigns to knowledge in the dynamics of assertion). It explicates Austin’s claims on truth and the ways in which he deals with sense, reference, ‘family resemblances’, truth–falsity assessments, and context-dependency. It argues for a reading of Austin’s characterization of his Ordinary Language Philosophy as a ‘linguistic phenomenology’ that takes it to be analogous to Husserl’s phenomenology and adopt an epochē that does not isolate consciousness, but language. It approaches the Ordinary through the consideration of the by-default nature of the social bond and conversational cooperation as well as something that philosophers should be consistent with in their claims if they rely upon it in their everyday life. In the conclusions, it highlights recurrent aspects of Austin’s philosophy such as the opposition to dichotomies, the attention to intersubjectivity, the commitment to a ‘sober’ philosophy, and a strong sense of human situatedness.
Speech as Action
Authors: Sbisà Marina 
Published: June 2024

AbstractThis chapter deals with the connections of Austin’s speech act theory with his philosophy of action (focused on excuses, that is, the ways in which language extenuates action) and examines the conception of action that is implicit in How to Do Things with Words. It remarks that in the case of the locutionary act, Austin individuates subordinate acts by means of the ways in which we report on them and that his introduction of the perlocutionary act relies mainly on the identification of certain consequential effects of the illocution. It argues that Austin’s appreciation of the ‘total speech act’ does not exclude an analytical approach based on the distinction of effects of diverse kinds within its overall effect. It accounts for Austin’s claim that the acts he is dealing with are actions by examining the relationship between the notions of act, action, and activity, and focusing on their aspectual properties.
Introduction
Authors: Rovny Jan 
Published: June 2024

AbstractThis chapter introduces the puzzle of the book, asking whether and how ethnic minority status—belonging to a group that is culturally distinct from most of the population—influences political outlooks and behavior. It underlines the contradiction between the expectation that ethnicity is a troublemaker in politics, while ethnic identity is at times an important and stable human characteristic. The chapter introduces the argument of the book that under a set of conditions ethnicity does not lead to group particularism, but, on the contrary, can influence the formation of ideological preferences. When minorities are permanent, they seek protection from the tyranny of the majority, which induces them toward what I call ethnic liberalism, seeking constitutional liberal arrangements that would protect individual and group rights and liberties.