bluuebunny/crossref_metadata_2025 huggingface dataset:
Bloodstream Infections with Opportunistic Pathogens in COVID-19 Era: A Real Challenge Necessitates Stringent Infection Control
Authors: Guchhait Partha , Chaudhuri Bhaskar Narayan , Das Satadal
Published: April 2023

Background: Bloodstream infections (BSI) due to opportunistic microbes in the coronavirus disease 2019 (COVID-19) pandemic lead to high morbidity and mortality among hospitalized patients. Thus, it is vital to find out the risk factors of BSI and to learn the ways to mitigate it.

Aim: The aim of this study was to evaluate important risk factors of BSI due to opportunistic pathogens and to assess the role of the rigid infection control program to deal with this issue.

Methods: A prospective, cross-sectional study was performed for 6 months on 150 patients admitted in both COVID-19 and non-COVID-19 intensive care units of our hospital. BSI was confirmed by the BACTEC and Vitek 2 compact system. Prospective surveillance and environmental sampling were carried out for source tracking along with rigorous infection control measures and the outcome was analyzed.

Findings: Burkholderia cepacia, Elizabethkingia meningoseptica, Candida auris, vancomycin-resistant Enterococcus, and Achromobacter xylosoxidans were the common opportunistic pathogens isolated from a single or paired blood sample(s) in our study. Key risk factors were prolonged intensive care unit stay, central venous access, mechanical ventilation, immune-compromised condition, and use of biologics. Reverse osmosis water and used normal saline bottles were the common environmental source of infection. Following the implementation of precise infection control measures, there was a sharp decline in BSI cases, which was not attributed to the downfall of COVID-19 cases.

Conclusion: Combined prospective surveillance and environmental sampling helped to find out the sources and implementation of an intensive and insistent infection control program that are needed to control opportunistic pathogens mediated BSI.
Beschaffungen im Krankenhauszukunftsfonds: KHZG-Finanzmittel klug statt hastig investieren
Authors: Gross Benedict , Levin Ilya
Published: April 2023

Die Milliarden aus dem Krankenhauszukunftsfonds fließen endlich an die Kliniken. Doch wenn das Geld angekommen ist, müssen neue Herausforderungen gelöst werden.
Digitale Transformation: Soziale Innovation durch Digital Patient Journey
Authors: Kriegel Johannes
Published: April 2023

Durch den Einsatz immer leistungsfähigerer digitaler Technologien werden auch veränderte soziale Praktiken bedingt, nicht nur der Health Professionals, sondern auch der Patienten. In diesem Zusammenhang kommt der Digital Patient Journey eine besondere Bedeutung im Rahmen der Krankenhausversorgung und Ausgestaltung der Patientenkarrieren zu.
Digitalisierung entlang der Lieferkette: E-Procurement vor dem nächsten Level
Authors: Otten Hubert , Schnee Nico
Published: April 2023

Die digitale Transformation im Klinikeinkauf begann bereits vor mehr als 20 Jahren. Der Automatisierungsgrad ist jedoch sowohl prozess- als auch artikel- bzw. lieferantenbezogen sehr unterschiedlich. Es stellt sich die Frage, ob anstehende Veränderungen im ERP-Bereich die aktuelle Situation verbessern werden.
Prozessoptimierung in der Krankenhauslogistik: Eine digitale Reise: Stillstand ist Rückschritt
Authors: Bräuer Mario
Published: April 2023

Von Transportaufträgen „per Zuruf„ bis zu vollständig digitalisierten Prozessen: Das Städtische Klinikum Dresden hat bei der Digitalisierung seiner Logistikprozesse einen weiten Weg zurückgelegt. Dieser war mitunter steinig, unterm Strich jedoch sehr erfolgreich – und ist noch lange nicht zu Ende.
Functional improvement in β cell models of type 2 diabetes using on-demand feedback control
Authors: Koyama K. , Ando H. , Fujiwara K.
Published: April 2023

The bursting activity of pancreatic β cells is correlated with insulin secretion. Although normal pancreatic β cells show periodic bursting, the bursting activity becomes irregular in dysfunctional pancreatic β cells of type 2 diabetic patients. In this study, we modeled the dynamics of dysfunctional pancreatic β cells using differential equations. We investigated it in terms of energy efficiency of control. The control method is considered for on-demand electrical stimulation using the methodology of chaos control. Numerical simulation results show that the bursts are controlled in a periodic rhythm by the feedback mechanism. In addition, we found input timings that induce energy efficient control for rhythmic bursts. These results suggest that chaos control can improve insulin secretion, which might contribute to type 2 diabetes treatment.
Numerical study on mechanisms of period-doubling bifurcation in pulsed dielectric barrier discharges at atmospheric pressure
Authors: Gao Shu-Han , Wang Xu-Cheng , Zhang Yuan-Tao
Published: April 2023

In this paper, the mechanisms of the period-doubling bifurcation in pulsed Dielectric Barrier Discharges (DBDs) are numerically investigated at atmospheric pressure. Under the given discharge conditions, the pulsed DBDs could maintain a normal period-1 (P1) state at relatively larger repetition frequencies over 40 kHz, by decreasing the repetition frequency, namely, keeping the duration of the power-on phase unchanged but increasing the duration of the power-off phase, the simulation shows that the discharge bifurcates into a period-2 (P2) state after a transient period of instability. Although the charged particles can diffuse to the surface of dielectric plates more fully at a lower repetition frequency, the large quantities of ions in the sheath region produced by the relatively larger discharge current that have not yet dissipated completely before the next discharge event are proposed to play an important role in the discharge bifurcation process, and the spatial profiles of the charged particle density, electric field, and space charge density in the sheath region before the discharge ignition are examined deeply to further explore the corresponding underpinning physics. The large density of residual ions in the sheath region with the enhanced electric field can weaken the subsequent discharge event and induce the discharge to enter the period-doubling state. Moreover, the computational data indicate that the discharge evolves into the period-4 (P4) and period-8 (P8) state when the repetition frequency approaches 30 and 26 kHz at the given discharge conditions. The simulation data can effectively facilitate the understanding of the temporal nonlinear behaviors in pulsed DBDs and propose ways to further control the plasma stability in applications.
Recent progress in dielectric resonator antenna: Materials, designs, fabrications, and their performance
Authors: Shehbaz Muhammad , Du Chao , Zhou Di , Xia Song , Xu Zhuo
Published: April 2023

Dielectric resonator antenna (DRA) has secured an esteemed position in the field of antenna engineering technology due to its versatile features, including compactness, light-weight, low loss, high radiation efficiency, ease of excitation, diverse feeding techniques, multiple excitation modes, ease of integration with passive and active microwave integrated circuit components, a wide variety of available materials, simple fabrication techniques, and high degree of flexibility over wide frequency range. This article presents a comprehensive up-to-date review of research carried out in the field of DRA technology which includes an overview of DRA technology, its history, present status, and prospects. The basic parameters of microwave dielectric ceramic materials and the classification of materials based on utilization and material parameters are briefly discussed. The applications of DRA in different fields of science, engineering, and technology, overview of different reported DRA shapes, and the feeding techniques used to excite different modes of DRA are mentioned. Based on the control of DRA permittivity, shape/geometry, feeding techniques, and structural modifications, performance parameters engineering of DRA and its achievable performance in terms of low profile, compactness, high gain, wide beam, circular polarization, wide bandwidth, DRA decoupling methods for multiple input multiple output arrays, dielectric patch antenna, filtering DRA, and reconfigurable DRA are discussed. Different techniques used to attain and enhance the particular performance of DRA are highlighted. This review article also dilates upon the fabrication processes and characterization methods of DRA microwave dielectric ceramics, which play a very vital role in controlling the performance and properties of DRA.
Enhancement of guided electromagnetic wave by pre-plasma formation in laser–plasma interaction
Authors: Li Y. Z. , Wu M. J. , Li D. Y. , Yang T. , Cheng H. , Xia Y. D. , Yan Y. , Geng Y. X. , Zhao Y. Y. , Lin C. , Yan X. Q.
Published: April 2023

Previous studies have shown that adding a section of critical density plasma on the front surface of solid target can effectively improve the laser energy absorption efficiency. Here, we have investigated laser–plasma interactions with different scale lengths of plasma in front of the target created by a pre-ablation laser pulse. A variety of experimental diagnostics employed together with particle-in-cell simulations give us deep insight into these processes. We found that the laser-induced electromagnetic pulse (EMP) intensity inside the target chamber and the target normal sheath acceleration sheath field accelerated protons were promoted using pre-plasma. The transient current due to hot electron emissions is considered to be one of the main radiation sources of EMP emissions within our measurement bandwidth. In our experiment, this current was guided to a grounded conductive wire attached to the rear surface of the target and measured by proton dynamic imaging technique. The discharging currents together with the guided fields were enhanced more than twice. The reflection spectra of experiments and simulations are compared, which reveal that the energy absorption efficiency was increased with proper plasma scale length, resulting in all the measured signals promoted.
Enhanced extreme ultraviolet conversion efficiency of a 2
μ
m laser-driven preformed tin-droplet target using short picosecond pre-pulses
Authors: Shi Z. Y. , Yuan Y. , Wang W. P. , Ma Y. Y. , Sun X. Y. , Lin N. , Leng Y. X.
Published: April 2023

In this study, an extreme ultraviolet (EUV) conversion efficiency (CE) of 6.9% was obtained in simulation by controlling the delay between a picosecond pre-pulse and a main-pulse with a wavelength of 2 μm; this value is about 7.5% higher than the ns pre-pulse scheme of the EUV emission produced by a 2 μm laser-driven tin-droplet target. In the simulation, the tin droplet expanded into hollow spherical structures after irradiation with a picosecond pre-pulse laser. Notably, compared with a nanosecond pre-pulse, in this case, the density of the tin plasma was lower, and the expansion range was wider for the same delay. Therefore, ps pre-pulse can make the tin plasma reach the optimal state of EUV emission in a shorter delay. In both pre-pulse schemes, the CE value maintains a high value (>5.7%) within a certain delay range (800 ns) between pre-pulse and main-pulse. In this study, the FLASH radiation hydrodynamic code and FLYCHK atomic code were used to investigate the energy conversion and spectra. The results obtained can be potentially useful for EUV lithography under a two-pulse scheme.
On characterization of shock propagation and radiative preheating in x-ray driven high-density carbon foils
Authors: Mishra Gaurav , Ghosh Karabi
Published: April 2023

Recently, much effort has been dedicated to the high-density carbon ablator coated fuel capsule in indirect drive inertial confinement fusion experiments due to its higher density compared to other ablators. By using detailed radiation hydrodynamic simulations over a broad range of drive and target parameters, a thorough analysis is performed on shock speed, shock breakout, and maximum preheating temperature in pure and tungsten doped high density carbon foils. The ablators are irradiated by a non-equilibrium x-ray temperature drive consisting of the usual Planckian plus an additionally imposed Gaussian distribution lying in the high frequency M-band region of the incident spectrum. All variables have shown a complex interdependence on strength of the drive, its spectral distribution, and the thickness of the target. Maximum preheating temperature, an important parameter in designing experiments, reduces up to 34% for thicker high-density carbon (HDC) foils, whereas a mere 0.44% doping of tungsten in pure HDC is able to reduce preheating up to 17% for extreme drive conditions. The results are explained on the basis of variation of average albedo/wall loss behavior in foils, an outcome of the interplay between total extinction coefficient and spectral intensity variation with photon energy. For a better understanding and comparison among different types of ablators, multi-parameter scaling relations are proposed for above-mentioned variables, which govern the dynamics of shock propagation and preheating phenomena in HDC based foils.
Time-domain motion of a floating or obliquely submerged non-uniform elastic plate
Authors: Singh Mansi , Meylan Michael H. , Gayen R.
Published: April 2023

We consider the motion of a thin elastic plate with non-uniform thickness. The plate is either submerged and has some inclination with the vertical or is floating on the upper surface of the water. Green's function arising from the fourth-order boundary condition for the non-uniform plate (which we refer to as plate Green's function) is determined using two different methods in terms of the vibrating modes of the plate. These, in turn, are derived from the modes of a plate with constant thickness. The problem is finally reduced to a boundary integral equation involving the plate Green's function and the fundamental Green's function. This equation is hypersingular in the case of a submerged plate. A numerical solution to the integral equation is used to find results for elastic plates with variable thicknesses. The results are validated by comparing them with those of an elastic plate with uniform thickness. We also present simulations of the time-domain motion when the plate–fluid system is subject to an incident wave pulse using Fourier transform.
An encodable superconducting nanowire trigger
Authors: Zhang Biao , Chen Qi , Zhang Labao , Yin Rui , Yin Wenlei , Guan Yanqiu , Hu Xiaowen , Li Chengxiu , Wang Hao , Tu Xuecou , Zhao Qingyuan , Jia Xiaoqing , Chen Jian , Kang Lin , Wu Peiheng
Published: April 2023

As a competitive technology, the superconducting nanowire single-photon detector (SNSPD) is developing from a single-pixel to array architecture; however, it is a major challenge for reading array detectors. We propose an encodable trigger through the thermal coupling of two adjacent superconducting nanowires, which can read a current pulse with microampere amplitude and code the current pulses of different positions with different output resistances simultaneously. At the same time, the influence of external noise on superconducting devices can be avoided for isolated circuits. As a demonstration, the response pulses of a 4-pixel SNSPD are read using this trigger in the absence of an amplifier, and the photon flux distribution of different pixels is accurately reconstructed, where the total power consumption is approximately 0.8 μW. The superconducting trigger is promising for application in integrated superconducting electronics and quantum optics in the future.
Comparison BIPM.RI(I)-K6 of the standards for absorbed dose to water of the ARPANSA, Australia, and the BIPM in accelerator photon beams
Authors: Kessler C , Burns D T , Roger P , Oliver C , Bailey T , Harty P , Vandenberg N , Takau V , Butler D
Published: April 2023

Main text

A key comparison has been made between the absorbed dose to water standards of the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), Australia, and the BIPM in accelerator photon beams. The results show the standards to be in agreement within the standard uncertainty of the comparison of 6.2 parts in 103. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Translation invariant diagonal frame decomposition of inverse problems and their regularization
Authors: Göppel Simon , Frikel Jürgen , Haltmeier Markus
Published: April 2023

Solving inverse problems is central to a variety of important applications, such as biomedical image reconstruction and non-destructive testing. These problems are characterized by the sensitivity of direct solution methods with respect to data perturbations. To stabilize the reconstruction process, regularization methods have to be employed. Well-known regularization methods are based on frame expansions, such as the wavelet–vaguelette decomposition, which are well adapted to the underlying signal class and the forward model and furthermore allow efficient implementation. However, it is well known that the lack of translational invariance of wavelets and related systems leads to specific artifacts in the reconstruction. To overcome this problem, in this paper we introduce and analyze the translation invariant diagonal frame decomposition (TI-DFD) of linear operators as a novel concept generalizing the singular value decomposition. We characterize ill-posedness via the TI-DFD and prove that a TI-DFD combined with a regularizing filter leads to a convergent regularization method with optimal convergence rates. As illustrative example, we construct a wavelet-based TI-DFD for one-dimensional integration, where we also investigate our approach numerically. The results indicate that filtered TI-DFDs eliminate the typical wavelet artifacts when using standard wavelets and provide a fast, accurate, and stable solution scheme for inverse problems.
Capping-layer-mediated lattice mismatch and redox reaction in SrTiO3-based bilayers
Authors: Huang Jingwen , Dai Song , Xu Chengcheng , Du Yongyi , Xu Zhipeng , Han Kun , Xu Liqiang , Wu Wenbin , Chen Pingfan , Huang Zhen
Published: April 2023

It is well known that the traditional two-dimensional electron system (2DES) hosted by the SrTiO3 substrate can exhibit diverse electronic states by modifying the capping layer in heterostructures. However, such capping layer engineering is less studied in the SrTiO3-layer-carried 2DES (or bilayer 2DES), which is different from the traditional one on transport properties but more applicable to the thin-film devices. Here, several SrTiO3 bilayers are fabricated by growing various crystalline and amorphous oxide capping layers on the epitaxial SrTiO3 layers. For the crystalline bilayer 2DES, the monotonical reduction on the interfacial conductance, as well as carrier mobility, is recorded on increasing the lattice mismatch between the capping layers and epitaxial SrTiO3 layer. The mobility edge raised by the interfacial disorders is highlighted in the crystalline bilayer 2DES. On the other hand, when increasing the concentration of Al with high oxygen affinity in the capping layer, the amorphous bilayer 2DES becomes more conductive accompanied by the enhanced carrier mobility but almost constant carrier density. This observation cannot be explained by the simple redox-reaction model, and the interfacial charge screening and band bending need to be considered. Moreover, when the capping oxide layers have the same chemical composition but with different forms, the crystalline 2DES with a large lattice mismatch is more insulating than its amorphous counterpart, and vice versa. Our results shed some light on understanding the different dominant role in forming the bilayer 2DES using crystalline and amorphous oxide capping layer, which may be applicable in designing other functional oxide interfaces.
Feasibility of size-specific organ-dose estimates based on water equivalent diameter for common head CT examinations: a Monte Carlo study
Authors: Tahiri M , Benameur Y , Mkimel M , El Baydaoui R , Mesardi M R
Published: April 2023

Computed tomography dose index (CTDI) is an unreliable dose estimate outside of the standard CTDI phantom diameters (16 and 32 cm). Size-specific dose estimate (SSDE) for head computed tomography (CT) examination was studied in the American Association of Physicists in Medicine Report 293 to provide SSDE coefficient factors based on water equivalent diameter as size metrics. However, it is limited to one protocol and for a fully irradiated organ. This study aimed to evaluate the dependency of normalized organ dose (ND) on water equivalent diameter as a size metric in three common protocols: routine head, paranasal sinus, and temporal bone. CTDIw measurements were performed for outlined protocols in the Siemens Emotion 16-slice-configuration scanner. Geant4 Application for Tomographic Emission Monte Carlo simulation platform, coupled with ten GSF patient models, was used to estimate organ doses. CT scanner system was modeled. Helical CT scans were simulated using constructor scan parameters and calculated scan lengths of each patient model. Organ doses provided by simulations were normalized to CTDIvol. The water equivalent diameters (D
w) of patient models were obtained via relationships between D
w and both effective diameter for a sample of patients’ data.NDs received by fully, partially, and non-directly irradiated organs were then reported as a function of D
w. For fully irradiated organs, brain (R
2 > 0.92), eyes (R
2 > 0.88), and eye lens (R
2 > 0.89) correlate well with D
w. For the rest of the results, a poor correlation was observed. For partially irradiated organs, the exception was scalp (R
2 = 0.93) in temporal bone CT. For non-directly irradiated organs, the exception was thyroid (R
2 > 0.90) and lungs (R
2 > 0.91) in routine head CT. ND correlates well in routine head CT than other protocols. For the most part, no relationship seems to exist between R
2 and scan percentage coverage. The results have revealed additional factors that may influence the ND and D
w relationship, which explains the need for more studies in the future to investigate the effect of scan conditions and organ anatomy variation.
Strongly anisotropic ultrafast dynamic behavior of GaTe dominated by the tilted and flat bands
Authors: Zhang Peiran , Zhang Shen , Lai Kang , Lei Lingxiao , Zheng Zhenfa , Kang Dongdong , Zhao Zengxiu , Dai Jiayu
Published: April 2023

The anisotropic transport properties of gallium telluride (GaTe) have been reported by several experiments, giving rise to many debates recently. The anisotropic electronic band structure of GaTe shows the extreme difference between the flat band and tilted band in two distinct directions,

Γ

¯

-

X

¯

and

Γ

¯

-

Y

¯

, and which we called as the mixed flat-tilted band (MFTB). Focusing on such two directions, the relaxation of photo-generated carriers has been studied using the non-adiabatic molecular dynamics (NAMD) method to investigate the anisotropic behavior of ultrafast dynamics. The results show that the relaxation lifetime is different in flat band direction and tilted band direction, which is evidence for the existence of anisotropic behavior of the ultrafast dynamic, and such anisotropic behavior comes from the different intensities of electron–phonon coupling of the flat band and tilted band. Furthermore, the ultrafast dynamic behavior is found to be affected strongly by spin–orbit coupling (SOC) and such anisotropic behavior of the ultrafast dynamic can be reversed by SOC. The tunable anisotropic ultrafast dynamic behavior of GaTe is expected to be detected in ultrafast spectroscopy experiments and it may provide a tunable application in nanodevice design. The results may also provide a reference for the investigation of MFTB semiconductors.
Correction of JET bolometric maximum likelihood tomography for local gas puffing
Authors: Peluso Emmanuele , Murari Andrea , Craciunescu Teddy , Carvalho Pedro , Gelfusa Michela , Gaudio Pasqualino , Wyss Ivan
Published: April 2023

Tomography is applied daily to bolometric data in magnetically controlled nuclear fusion devices to infer important quantities of the studied plasmas, such as the emissivity profiles or the radiated power in different locations of the main chamber. Tomographic reconstructions are also crucial for power balance analysis and to estimate heat fluxes for turbulence studies. One of the issues, associated with any tomographic technique, resides in the ill-posed nature of the mathematical problem, meaning that more than one possible emissivity profile is compatible with the measurements within the estimated uncertainties. Therefore, a careful evaluation of the quality of the obtained reconstructions is an important step of the analysis. On Joint European Torus (JET), since the two cameras are located in different toroidal locations, axial symmetry of the plasma radiation must be assumed to perform traditional tomographic reconstructions. Such a specific hypothesis, however, cannot be guaranteed in the case of symmetry-breaking mechanisms, such as strong local gas puffing for fuelling. The present contribution addresses this problem of local plasma fuelling, focusing on the observed significant mismatch between measured and back-calculated projections in specific pulses, including the last JET DT campaign (DTE2) carried out in 2021. The analysis indicates that the observed discrepancy, due to the gas injected primarily from valves located in the same octant where one of the bolometer arrays is located, can be rectified acceptably well by a physically-based correction. The sensible improvements in the bolometric maximum likelihood tomography’s outputs are also documented, and the possible physical explanation for such a phenomenon is discussed. The study performed in this article is expected to have a significant impact on the analysis of JET data and on the physical interpretation of the results obtained during the recent DTE2 experiments, for which a proper evaluation of the radiated power estimates is of non-negligible relevance.
Influence of magnetic field gradient on the capacitive argon discharge at 8 MHz and 40 MHz
Authors: Wu Huanhuan , Lin Hanlei , Zhang Tianxiang , Wu Hao , Yang Shali
Published: April 2023

A one-dimensional implicit particle-in-cell/Monte Carlo collision model is used to study the effects of magnetic field gradients on the capacitively coupled argon plasma at 8  MHz and 40 MHz. The magnetic field strength at the powered electrode is fixed at 10 G, while varies from 30 to 100 G at the grounded electrode. The simulations show that the magnetic field with variable gradient can produce controllable asymmetry in the plasma density and ion flux profiles to each electrode. Increasing the magnetic field gradient will generate a significant dc self-bias, which results in a large ion bombardment energy at the powered electrode. The magnetic field gradients have been demonstrated to be an approach to create the dc self-bias and also effectively improve the plasma density. It is also found that at a higher frequency of 40 MHz, the dc self-bias voltage decreases, due to the fact that high collision rate of electrons with background gas will disturb the cyclotron motion of electrons, so the effect of the magnetic field is weakened. As a result, the ability to independently control ion energy and flux is weakened.
Design of a networking bolted joints monitoring method based on PZT
Authors: Yang Yang , Zhang Guangmin , Wang Yu , Ren Bin , Zhou Haoyu , Xie Andi , Xie Wen
Published: April 2023

As the failure of bolt connections by corrosion can result in major disasters and cause casualties and property damage, monitoring bolted joints is of great importance. However, current researches on lamb wave based bolted joint monitoring mainly focused on single-input-single-output (SISO) systems, which require a long diagnosis time and numerous transducers. To reduce the number of transducers on monitoring, the multiple-input systems, i.e. multiple-input-multiple-output (MIMO) system and multiple-input-single-output (MISO) system, can be adopted. However, both multiple-input systems are prone to failure due to the interference among the excited waves generated from multiple simultaneously-operated actuators. To remove such interference, an orthogonal variable spreading factor (OVSF) code based bolted joint monitoring method is proposed here. Firstly, instead of using the same detection signal, multiple detection signals generated using OVSF codes are emitted from different input ports. Then, for each considered input port, the corrosion information carrying waveforms are recovered from the acquired signals via timing acquisition and demodulation and utilized to reveal the status of the bolted joints via wavelet packet based analysis. To validate the proposed method, experiments with a MIMO system (i.e. three-input-two-output system) and a MISO system (i.e. six-input-single-output system) were conducted to simultaneously reveal six given bolted joint corrosion status in this research. Since the proposed method effectively suppresses the interference, the MIMO/MISO bolted joint monitoring system can present a performance similar to that of the SISO monitoring system but require fewer transducers.
Recent progress on epitaxial growth of Fe-based superconducting thin films
Authors: Iida Kazumasa , Hänisch Jens , Hata Satoshi , Yamamoto Akiyasu
Published: April 2023

Since the discovery of Fe-based superconductors, a lot of effort has been devoted to growing single crystals and epitaxial thin films of them for fundamental studies and applied research of superconductivity. As a result, epitaxial thin films of the most of Fe-based superconductors have been realized. However, some of the materials, namely pristine and transition-metal-doped (Li,Fe)OHFeSe, hydrogen-doped LnFeAsO (Ln = Nd and Sm), Co-doped SmFeAsO, and K-doped BaFe2As2 have been available only in the form of single crystals due to, e.g. the difficulty in doping hydrogen, obtaining high-quality sintered bulks for the target used for pulsed laser deposition, and controlling volatile elements. By solving those issues, the aforementioned compounds have been successfully fabricated as epitaxial thin films in recent years. Unlike single crystals, transport critical current measurements are relatively easy on thin films, which can help evaluate the application potential. In this article, we give an overview over the growth methods for epitaxial thin films of those compounds, followed by their physical properties, especially focusing on electrical transport.
Search for the evaporation of primordial black holes with H.E.S.S.
Authors: Aharonian F. , Ait Benkhali F. , Aschersleben J. , Böttcher M. , Backes M. , Barbosa Martins V. , Batzofin R. , Becherini Y. , Berge D. , Bi B. , Boisson C. , Bolmont J. , de Bony de Lavergne M. , Borowska J. , Bradascio F. , Brose R. , Brun F. , Bruno B. , Bulik T. , Burger-Scheidlin C. , Caroff S. , Casanova S. , Celic J. , Cerruti M. , Chand T. , Chen A. , Chibueze O. , Cotter G. , Damascene Mbarubucyeye J. , Djannati-Ataï A. , Egberts K. , van Eldik C. , Ernenwein J.-P. , Füßling M. , Fiasson A. , Fichet de Clairfontaine G. , Fontaine G. , Gabici S. , Ghafourizadeh S. , Giavitto G. , Glawion D. , Glicenstein J.F. , Grolleron G. , Grondin M.-H. , Haerer L. , Haupt M. , Hinton J.A. , Hofmann W. , Holler M. , Horns D. , Huang Z.-Q. , Jamrozy M. , Jankowsky F. , Joshi V. , Jung-Richardt I. , Kasai E. , Katarzyński K. , Khélifi B. , Klepser S. , Kluźniak W. , Komin N. , Kosack K. , Kostunin D. , Holch T.L. , Lang R.G. , Le Stum S. , Leitl F. , Lemière A. , Lenain J.-P. , Leuschner F. , Lohse T. , Luashvili A. , Lypova I. , Mackey J. , Malyshev D. , Marandon V. , Marchegiani P. , Marinos P. , Martí-Devesa G. , Marx R. , Mitchell A. , Moderski R. , Mohrmann L. , Montanari A. , Moulin E. , Muller J. , Nakashima K. , de Naurois M. , Niemiec J. , O'Brien P. , Ohm S. , Olivera-Nieto L. , de Ona Wilhelmi E. , Ostrowski M. , Pühlhofer G. , Panny S. , Panter M. , Parsons R.D. , Peron G. , Priyana Noel A. , Prokhorov D.A. , Prokoph H. , Punch M. , Quirrenbach A. , Reichherzer P. , Reimer O. , Rieger F. , Rowell G. , Rudak B. , Rueda Ricarte H. , Sahakian V. , Salzmann H. , Sanchez D.A. , Santangelo A. , Sasaki M. , Schutte H.M. , Schwanke U. , Shapopi J.N.S. , Sol H. , Specovius A. , Spencer S. , Stawarz Ł. , Steenkamp R. , Steinmassl S. , Steppa C. , Sushch I. , Suzuki H. , Takahashi T. , Tanaka T. , Tavernier T. , Thorpe-Morgan C. , Tsuji N. , Uchiyama Y. , Vecchi M. , Veh J. , Venter C. , Vink J. , Wagner S.J. , White R. , Wierzcholska A. , Wong Y.W. , Zacharias M. , Zargaryan D. , Zdziarski A.A. , Zech A. , Zouari S. , Żywucka N.
Published: April 2023

Primordial Black Holes (PBHs) are hypothetical black holes predicted to have been formed from density fluctuations in the early Universe.
PBHs with an initial mass around 1014–1015 g are expected to end their evaporation at present times in a burst of particles and very-high-energy (VHE) gamma rays.
Those gamma rays may be detectable by the High Energy Stereoscopic System (H.E.S.S.), an array of imaging atmospheric Cherenkov telescopes.
This paper reports on the search for evaporation bursts of VHE gamma rays with H.E.S.S., ranging from 10 to 120 seconds, as expected from the final stage of PBH evaporation and using a total of 4816 hours of observations.
The most constraining upper limit on the burst rate of local PBHs is
2000 pc-3 yr-1 for a burst interval of 120 seconds, at the 95% confidence level. The implication of these measurements for PBH dark matter are also discussed.
LitePIG: a lite parameter inference system for the gravitational wave in the millihertz band
Authors: Wang Renjie , Hu Bin
Published: April 2023

We present a Python based parameter inference system for the gravitational wave (GW) measured in the millihertz band. This system includes the following features: the GW waveform originated from the massive black hole binaries (MBHB), the stationary instrumental Gaussian noise, the higher-order harmonic modes, the full response function from the time delay interferometry and the Gaussian likelihood function with the dynamic nested parameter sampler. In particular, we highlight the role of higher-order modes. By including these modes, the luminosity distance estimation precision can be improved roughly by a factor of 50, compared with the case with only the leading order (ℓ = 2, ∣m∣ = 2) mode. This is due to the response functions of different harmonic modes on the inclination angle are different. Hence, it can help to break the distance-inclination degeneracy. Furthermore, we show the robustness of testing general relativity (GR) by using higher-order harmonics. Our results show that the GW from MBHB can simultaneously constrain four of the higher harmonic amplitudes (deviation from GR) with 95% confidence level of

c

21

=

0.54

−
1.05

+
0.82

,

c

32

=
−

0.65

−
1.42

+
3.02

,

c

33

=

0.56

−
0.96

+
0.79

and

c

44

=

1.57

−
2.19

+
3.22

, respectively.
Temperature-insensitive reading of a flash memory cell
Authors: Zhang Weiyan , Yu Tao , Zhu Zhifeng , Li Binghan
Published: April 2023

The temperature characteristics of the read current of the NOR embedded flash memory with a 1.5T-per-cell structure are theoretically analyzed and experimentally verified. We verify that for a cell programmed with a “10” state, the read current is either increasing, decreasing, or invariable with the temperature, essentially depending on the reading overdrive voltage of the selected bitcell, or its programming strength. By precisely controlling the programming strength and thus manipulating its temperature coefficient, we propose a new setting method for the reference cells that programs each of reference cells to a charge state with a temperature coefficient closely tracking tail data cells, thereby solving the current coefficient mismatch and improving the read window.
The effect of elevated initial vortex shapes on its evolution
Authors: Elikashvili A , Golbraikh E
Published: April 2023

The formation and evolution of helical vortices in various media is an important hydrodynamic problem. A separate problem is the study of the behavior of the initial vortex, which is elevated above the surface. The evolution of such vortices is a complex multiparameter phenomenon. Based on a simple hydrodynamic model (or minimal model) in Elikashvili et al (2017 Phys. Fluids
29 026602) have been studied the formation of vorticity near the surface as a function of the initial height of the vortex and the Reynolds number. However, the influence of the parameters of the initial vortex profile on its evolution was not considered. In this paper, based on a simple hydrodynamic model, we study the evolution and formation of vortices near a solid surface for various initial vorticity profiles. The most widespread vortex profiles of Rankine, Burgers, and Vatistas were chosen for research. The simulation shows that the evolution of the vortex depends on its initial profile.
Research on TA1 mesh low-melting-point alloy filling incremental forming process for cranial prosthesis
Authors: Ruxiong Li , Tao Wang , Feng Li
Published: April 2023

The single point incremental forming (SPIF) process is a flexible and progressive manufacturing technique in the monolithic molding domain of heterogeneous metal pressing panels, which can contribute to the monolithic molding of metal pressing panels with complex contour and applicable to the fabrication of a small amount of titanium mesh plates for cranial prosthesis. A sandwich construction of titanium mesh was proposed in this paper for the purpose of inhibiting the indentation on the product surface and the deformation extent of mesh opening, as well as the forming accuracy of titanium mesh. The method of finite element modelling was applied to analyze the influence rules of low-melting-point alloy/synergistic deformation mechanism of titanium mesh as well as low-melting-point alloy layer on titanium mesh incremental forming quality. At last, the horizontal arrangement of significance regarding process parameters on sandwich titanium mesh wall thickness and rebound ratio effects was confirmed.
Nobel laureates warn Ukraine war increases nuclear threat
Authors: Banks Michael
Published: April 2023

A group of Nobel laureates have signed an open petition calling for an immediate ceasefire in the Ukraine war and warn of the risk of nuclear escalation.
UK must embrace overseas talent to be a ‘science superpower’
Authors: Hiscott Laura
Published: April 2023

The UK must attract highly qualified workers from abroad if the country wants to have a flourishing industry and economy, according to a report by the House of Lords Science and Technology Committee.
What goes up...
Authors: Cartwright Jon
Published: April 2023

Financial bonds are usually seen as safe and dependable investments, but a recent crash in the value of “ultra-long” bonds was bigger than conventional mathematical models could have predicted. They should have used rollercoaster physics, as Jon Cartwright explains.
Quantum entanglement maps gluons inside nuclei
Authors: Jarman Sam
Published: April 2023

Physicists in the US have used quantum entanglement to map the distribution of gluons within atomic nuclei at higher precision than previously possible.
The problem with brilliance in physics
Authors: Smith Amy
Published: April 2023

Amy Smith argues that we need to rethink how we mark achievements in physics.
Efficiency versus cost
Authors: McKenzie James
Published: April 2023

Why do some technologies succeed and others fail? It’s often all down to economics, says James McKenzie.
Typographic changes
Authors: Crease Robert P
Published: April 2023

Did you spot a recent change to this magazine? Robert P Crease reveals all.
Low-cost thin film patch antennas and antenna arrays with various background wall materials for indoor wireless communications
Authors: Kerminen Juho , Xie Boxuan , Mela Lauri , Karakoç Alp , Ruttik Kalle , Jäntti Riku
Published: April 2023

The present study introduces an inkjet-printed flexible coplanar waveguide patch antenna array concept. Single antenna and four-element antenna arrays were characterized, which were attached to a subminiature version A connector via an innovative solderless, 3D-printed ‘plug-and-play-type’ tightener. Furthermore, indoor wireless communication and Internet of Things scenarios with commonly used wall materials including gypsum and plywood boards, on which patch antennas and antenna arrays can be attached, were also presented. In order to validate the concept, design and fabrication iterations in parallel with numerical and experimental investigations were executed. To elaborate, single antenna and antenna array configurations without and with wall materials were characterized to see their functionality at 2.4 GHz resonance frequency and beyond 300 MHz bandwidth, respectively. The results demonstrate that the investigated configurations fulfill short-range radio transmission and can be utilized, e.g., for indoor backscattering-type communications and wireless sensing applications, as an affordable and versatile alternative to their conventional counterparts. Being attached to their corresponding background materials, single-antenna specimens were measured to have return losses beyond 18 dB and peak gains around 1 dBi, while higher peak gains above 6 dBi were detected for antenna arrays. Moreover, the antenna arrays can enable multiple-input and multiple-output communication. The proposed arrays had diversity performance in terms of return losses higher than 15 dB, isolation of more than 20 dB, envelope correlation coefficient

<
0.001

, diversity gain

>
9.95

dB, mean effective gain

<
−
3

dB, power ratio factor

<
0.5

dB, and channel capacity loss

<
0.4

bits/s/Hz.
Extended-charge-transfer excitations in crystalline non-fullerene acceptors
Authors: Liu Zhixing , Zhang Chunfeng
Published: April 2023

In organic solar cells with non-fullerene acceptors (NFAs), an intra-moiety excited state, originating from intermolecular interactions in the acceptor domain, acts as a key immediate for charge separation. However, the nature of the intra-moiety state remains elusive. Here, we employ a model Hamiltonian with parameters derived from a model system of Y6 crystal to study the nature of low-lying excited states in NFAs. We find the intra-moiety excited state is mixed with local excitation and charge-transfer excitation (CTE) characters with nonnegligible contributions from extended CTEs with spatially-separated electrons and holes. The spatial extent of such a loosely bound state is susceptible to the intermolecular electronic interaction and electron–vibration interaction, which may be promoted by molecule engineering and morphology control. The findings provide an alternative strategy towards device optimization by manipulating the delocalization of intra-moiety state in organic photovoltaic materials.
Machine learning integrated laser speckle image analysis for the simultaneous extraction of flow and scatterer concentration from capillary phantoms
Authors: Hegde Anoosha Venkatraman , Unni Sujatha Narayanan
Published: April 2023

Laser speckle imaging is one of the powerful non-invasive imaging techniques to monitor and assess microcirculation parameters. Qualitative analysis of perfusion parameters has been carried out in the recent past. But the quantitative estimation of tissue perfusion parameters like flow velocity and scatterer concentration simultaneously from laser speckle images remains challenging. The introduction of machine learning methods into laser speckle image analysis can help meet these challenges to a great extent. This paper presents an approach for the simultaneous extraction of perfusion parameters, using multi-target regression techniques applied to the extracted features from acquired laser speckle images after Eigen-decomposition filtering. The multi-target regression trees are identified as an effective tool for the simultaneous extraction of flow velocity and scatterer concentration with adequate mean absolute percentage error. Besides the achieved speed and computational efficiency, our work demonstrates the viability of this approach in quantifying perfusion parameters simultaneously. Due to its simple, non-invasive, and cost-effective nature, the proposed technique could be used in the real-time assessment of tissue health.
Non-equilibrium thermodynamics in a single-molecule quantum system
Authors: Pyurbeeva E , Thomas J O , Mol J A
Published: April 2023

Thermodynamic probes can be used to deduce microscopic internal dynamics of nanoscale quantum systems. Several direct entropy measurement protocols based on charge transport measurements have been proposed and experimentally applied to single-electron devices. To date, these methods have relied on (quasi-)equilibrium conditions between the nanoscale quantum system and its environment, which constitutes only a small subset of the experimental conditions available. In this paper, we establish a thermodynamic analysis method based on stochastic thermodynamics, that is valid far from equilibrium conditions, is applicable to a broad range of single-electron devices and allows us to find the difference in entropy between the charge states of the nanodevice, as well as a characteristic of any selection rules governing electron transfers. We apply this non-equilibrium entropy measurement protocol to a single-molecule device in which the internal dynamics can be described by a two-site Hubbard model.
Mechanism of the wintertime subseasonal surface air temperature variability over Eurasia
Authors: Guan Weina , Wang Lin
Published: April 2023

The formation mechanism responsible for the leading mode of the subseasonal variability of wintertime surface air temperature (SAT) over Eurasia is investigated. The leading SAT mode over Eurasia is characterized by a triple pattern with strong cold anomalies centered over northern Eurasia and weaker warm anomalies over the Arctic and East Asia, respectively, which has a deep barotropic structure and extends from the surface to the upper troposphere. It is tightly coupled to a wave-like atmospheric circulation, which stretches from the North Atlantic to East Asia and resembles the Scandinavia teleconnection pattern. Its formation mechanism is further revealed through the analysis of the temperature budget. The atmospheric circulation-induced horizontal advection is found to be the primary driver of the cold anomalies over northern Eurasia associated with the leading SAT mode in two steps. First, the advection of the climatological temperature by the mode-associated meridional wind anomalies triggers the cooling in the western part of Eurasia. Second, the advection of the above cold anomalies by background westerly winds from west Eurasia to the east further redistributes the cold anomalies. The meridional and zonal advection eventually causes the mode-associated strong cold anomalies over northern Eurasia.