bluuebunny/crossref_metadata_2025 huggingface dataset:
Early Clinical Experience with Gas-STAT™
Authors: Clark Charles L. , O’Brien Jerry , McCulloch James , Webster Michael , Gehrich John L.
Published: September 2023

The purpose of this study was to evaluate and report on the Gas-STAP™ continuous blood gas and pH monitoring system. This system was tested for accuracy, stability and reproducibility during extracorporeal circulation when compared to intermittent blood gas sampling. The Gas-STAT was used in conjunction with 44 clinical cardiopulmonary bypass procedures. There were 261 arterial and 259 venous blood samples obtained for analysis.

Early results comparing Gas-STAT versus intermittent samples analyzed on an IL813 blood gas analyserb showed less than ideal correlation. With continued clinical experience and further system refinements, data agreement improved substantially. This system provides valuable information to the perfusion team. Continuous blood gas and pH readings give the perfusionist immediate visualization of the effects of therapeutic interventions. Changes in gas flows and mixtures, blood flow, perfusate temperatures, hemodilution and the effects of pharmacologic agents all can affect the acid base and blood gas status of the patient. This system can be calibrated and employed without any substantial increase in time required by the perfusionist.
In Vitro Comparison of the Blood Handling by the Constrained Vortex and Twin Roller Blood Pumps
Authors: Hoerr Harry R. , Kraemer Michael F. , Williams J. Lynne , Sherman Mary L. , Riley Jeffrey B. , Crowley Jeffrey C. , Soronen Scott W.
Published: September 2023

(J. Extra-Corpor. Technol. 19[3] p. 316-321 Fall 1987, 30 ref.) Several authors and manufacturers refer to the superior blood handling capability of the constrained vortex blood pump (CVP) design compared to the roller pump (RP). Little, if any, scientific evidence has been presented to support this thinking. The hypothesis that the RP and the CVP are equivalent in regard to trauma to blood cellular elements and proteins was tested. The RP, a Cobe Roller Pump (CRP), was tested utilizing a new longterm formulation of PVC tubing. Two models of the CVP were tested, the Bio-Medicus Centrifugal Pump (BCP) and the Sarns Centrifugal Pump (SCP).

Similar circuits were constructed for the three pumps and fresh human blood was recirculated at 35°C for 48 hours. The circuits allowed control of pH, pCO2, pO2 and after load. An aliquot of test blood was maintained at 35°C for a control. The results from three separate trials were computed.

The BCP test blood exhibited less hemolysis (p<.05) than the CRP blood after 16 hours. The contents of all test circuits exhibited a significant increase in hemolysis over time (p<.01) and all circuits exhibited more hemolysis than the control (p<.03) after 16 hours. All 3 pumps were equivalent in platelet factor IV release. The CRP showed a significant decrease in convertible fibrinogen over time (p = .02). There was no significant difference (p>.05) in the titer of clottable fibrinogen between the other groups.

The SCP and the CRP were equivalent with regard to blood handling for up to 32 hours of in vitro recirculation. The BCP caused less alteration of red blood cells and fibrinogen than the SCP and CRP.
Is Your Oxygenator Failing? Diagnosis and Suggested Treatment
Authors: Higgins Michael , Tyndal Charles M. , Berryessa Richard G. , Hydrick Dan R.
Published: September 2023

(J. Extra-Corpor. Technol. 19[3] p. 330-337 Fall 1987, 3 ref.) Oxygenator failure during open heart surgery can be a serious complication but one with which perfusionists should be prepared to deal. We hypothesize that oxygenators are often replaced unnecessarily and when they are performing within the manufacturers' specifications. This suspicion was confirmed by surveying several oxygenator manufacturers. Discriminating between oxygenator and nonoxygenator problems is critical. In the face of the correct diagnosis of oxygenator failure a simple, safe, expedient, and familiar method of replacement is needed.

By using the gas transfer equations one can determine if the oxygenator is transfering adequate gas, after other associated problems are considered and ruled out.

After oxygenator failure has been diagnosed, a plan for replacement which has previously been established and practiced should be implemented. We studied 2 techniques for hollow fiber membrane oxygenation (HFMO) replacement and found the risk of micro-air, as a result of the changeout procedure, decreased when the new oxygenator was vacuumed.

The purpose of this paper is to help identify when/if an oxygenator is failing and suggest a planned replacement drill to help minimize confusion, delay and possible complications. We will also present a technique for decreasing the risk of micro-air which may result from a quick oxygenator changeout.
Limb Salvage in Osteogenic Sarcoma of Extremities: A New Therapeutic Approach Associating Infusion and Hyperthermic Antiblastic Perfusion
Authors: Vaglini M. , Bacci G. , Baldini M. , Belli F. , Cascinelli N. , Nava M. , Picci P. , Santinami M. , Campanacci M.
Published: September 2023

(J. Extra-Corpor. Technol. 19[3] p. 338-347 Fall 1987, 49 ref.) From August 1983 to September 1986, 17 patients affected by osteogenic sarcoma of extremities were admitted to our Division with only surgical alternatives of amputation or disarticulation due to the impressive local extension of disease.

Trying to avoid this procedure we started a program of limb salvage as follows: two cycles of intraarterial cis-platinum (CCDP) plus systemic high dose of methotrexate (HDMTX) followed by hyperthermic antiblastic perfusion (HAP) with high dose COOP and for the majority of patients 2 more cycles of systemic HDMTX + COOP with or without radiotherapy on the primary.

Immediate response, evaluated both in terms of necrosis and of clinical and radiologic reduction of the tumor mass, was so impressive that in 10 patients it was possible to perform a conservative surgery, en bloc resection of the primary tumor plus endoprosthesis, with a satisfactory functional and cosmetic result.

None ofthe patients relapsed locally; 8 developed lung metastases that, whenever possible, were resected.
Uterine Leiomyomata as a Cause of Abdominal Compartment Syndrome in the Postpartum Period
Authors: Hui Mason , Sibai Baha , Montealegre Alvaro , Leon Mateo G.
Published: September 2023

Uterine leiomyomas are common benign smooth muscle tumors that often occur during the reproductive years. Although many cases may not result in significant complications, negative pregnancy outcomes have been associated with the size and location of the fibroids. Degeneration of fibroids can occur as early as the late first trimester when they undergo significant volumetric growth, contributing to pain during pregnancy. While myomectomy is typically avoided during pregnancy, conservative management with anti-inflammatory medications may be effective. Surgical removal or preterm delivery may be necessary if symptoms persist. Abdominal compartment syndrome (ACS) is a rare condition characterized by sustained elevated intra-abdominal pressure leading to organ failure. Although ACS resulting from large-volume leiomyomas in the postpartum period has not been previously described, we present a case of a 25-year-old patient with massive uterine fibroids who required indicated preterm delivery via primary cesarean section at 25 weeks gestation. Her postpartum course was complicated by ACS, requiring emergent surgical decompression. When a large fibroid burden is present during pregnancy or in the postpartum period, ACS should be considered in the differential diagnosis. Early diagnosis and timely surgical decompression are necessary to prevent organ dysfunction and worsening maternal outcomes.
A Simple Model for Understanding Cloud Diffusion on a Brown Dwarf
Authors: Landsittel Joseph A. , Coldren Ryan A.
Published: September 2023

Brown dwarfs in the L-T spectral class transition commonly experience photometric variability due to the active formation/dissipation of clouds that rotate in and out of our view. Measurements of these photometric oscillations, such as their frequency and amplitude, may help constrain the physical parameters of observed brown dwarfs through their associations with aspects such as rotational period and surface temperature. However, measurements of these oscillations and their significance are obscured by the inclination angle of observed brown dwarfs relative to us. By creating a simplistic model of 2D cloud formation on the surface of a toy model brown dwarf, this paper aims to further explore the relationship between oscillation amplitude and inclination angle for cloudy brown dwarfs and finds agreement with the correlation found observationally between the two factors in Vos et al., 2017.
An Introduction to Quantum Computing
Authors: Venterea Ricco , Ekka Urbas
Published: September 2023

We present an overview of quantum computing, including relevant physics, processes, and applications. This includes describing the basic framework of the quantum bit, which serves as the foundation for the rest of this paper. We found rapid developments in quantum computing, which will have important consequences for future applications in scientific fields.
Using γγ-Coincidence Spectroscopy to Identify Natural Radiation in Soils Near the Mississippi River
Authors: Singh Pranjal , Valmassei Daniel , Kuchera Anthony , Crider Ben
Published: September 2023

Naturally radioactive nuclides present in soils contain background radiation that humans are exposed to every day. Previous research suggests that there are high background radiation areas (HBRAs) caused by climate, geography, wind, and water currents that accumulate a higher concentration of these radionuclides. An investigation of the Nile Delta confirms the presence of minerals rich in U and Th from monazite and zircon, further suggesting that certain locations have a higher concentration of these radionuclides. The present work is a search for monazite in Great River Road State Park, near the Mississippi River. The acquired samples were measured with a low-background NaI(Tl) spectrometer and digital data acquisition system. Using γγ-coincidence spectroscopy to reduce background radiation, we were able to apply coincidence gates of known gamma-ray energies originating from 238U and 232Th decay chains to identify the presence of the radionuclides in the soil samples. From our results, we confirmed that there is an accumulation of minerals containing 238U and 232Th near the river. Our next steps will focus on calculating activities for quantitative results and collecting samples from an extended region along the river.
Design of a novel millimeter size wireless electrical stimulator and its targeting effect on the Schaffer-CA1 pathway in rat hippocampus
Authors: Dong Lei , Song Lin-Lin , Zhao Tong , Tian Lei , Zheng Yu
Published: September 2023

Traditional tethered nerve implants have many limitations since they rely on physical wires for power and signal transmission. Wireless stimulation technology can promote the exploration of neurological diseases and meet patient requirements, stemming from its portability and efficiency. In this paper, the link transmission characteristics of a sub-millimeter inductor are investigated by simulation, electrical tests, and theoretical analysis. The inductor acts as the receiving coil of a wireless stimulation device, and the wireless energy transmission process based on magnetic induction coupling is analyzed. Second, a novel millimeter-scale wireless stimulator device for neuromodulation is designed based on the parameters of transmitting and receiving coils obtained from the simulation. Finally, rat electrophysiological experiments are conducted to assess the feasibility of the device. The field Excitatory Post Synaptic Potential baseline is first recorded in the CA1 radiation area for 10 min, followed by the addition of high-frequency stimulation, and after successful induction of long-term potentiation (LTP) and recording for 10 min, the two coils are fixed at a distance of 1 cm and the hippocampal Schaffer-CA1 pathway is added. The experimental results show that the addition of wireless stimulation can modulate the transmission of synaptic electrical activity in the hippocampal Schaffer-CA1 pathway and significantly increase the level of (LTP) induction. A millimeter-scale wireless stimulation device is investigated and designed in this paper, the feasibility of the device is demonstrated through ex vivo electrophysiological experiments, and its effects on the targeted modulation of the Schaffer-CA1 pathway in the rat hippocampus are described.
The pre-launch on-ground characterization of Ma_MISS spectrometer for ExoMars-Rosalind Franklin Rover mission. II. Radiometric calibration
Authors: De Angelis S. , De Sanctis M. C. , Altieri F. , Ferrari M. , Ammannito E. , Novi S. , Dami M. , Antonacci F. , Villa F. , Meini M. , Ruggiero F. , Fonte S. , Formisano M. , Frigeri A. , Tinivelli P. , Giardino M. , Mugnuolo R. , Pirrotta S.
Published: September 2023

The Ma_MISS miniaturized spectrometer is integrated within the Drilling System of the ExoMars Rosalind Franklin Rover for Mars exploration. Here we focus on the on ground calibration campaign to obtain radiometric and linearity calibrations of the Ma_MISS instrument, while the first paper dealt with the spectral calibration [De Angelis et al., Rev. Sci. Instrum. 93, 123704 (2022)]. The experimental setup used to carry out radiometric calibration is described, as are the methods used for data processing and key parameter retrieval. In particular, the Spectrometer Transfer Function (Responsivity), Signal-to-Noise Ratio, and detector linearity are determined. In a third paper [De Sanctis et al., Planet. Sci. J. 3, 142 (2022)], validation of the Ma_MISS calibration results through spectral measurements performed on rock and synthetic targets during the radiometric calibration campaign is described.
Research on pulse laser cleaning and rust removal technology in power systems
Authors: He Yuhang , Cai Xuan , Ye Jianfeng
Published: September 2023

In this paper, pulse laser cleaning and angle grinder polishing were used to clean the surface rust of carbon steel, and the cleaning effects of different cleaning methods for carbon steel surface rust were studied. The change of the micro-region morphology and element composition of the cleaned surface was analyzed. Comparative experiments were conducted on the corrosion resistance and paint anticorrosion ability of cleaned metal surfaces. Through comparison and analysis, the use of laser cleaning technology can improve the surface cleanliness and corrosion resistance of metals, reduce maintenance times, and extend service life. Laser cleaning machines with a power of 100 W or above can effectively perform precision cleaning and can be widely promoted in the field of power systems.
Flat bands of periodic graphs
Authors: Sabri Mostafa , Youssef Pierre
Published: September 2023

We study flat bands of periodic graphs in a Euclidean space. These are infinitely degenerate eigenvalues of the corresponding adjacency matrix, with eigenvectors of compact support. We provide some optimal recipes to generate desired bands and some sufficient conditions for a graph to have flat bands, we characterize the set of flat bands whose eigenvectors occupy a single cell, and we compute the list of such bands for small cells. We next discuss the stability and rarity of flat bands in special cases. Additional folklore results are proved, and many questions are still open.
Ultra-rapid freezing of Al and Al–Si12: Formation of nanocrystals and metastable solid solutions
Authors: Rothe Erhard W.
Published: September 2023

We report effects of ultra-rapid melt–freeze cycles on pure aluminum and on aluminum alloy 4047 (which contains ≈12 at. % Si) caused by a series of ≈15 ns-long pulses of 308-nm laser light at a fluence of around 3 J cm−2. This process achieves a calculated cooling rate of about 109 K s−1, which is much faster than splat cooling or melt spinning. The focus here is on the reduction in the lattice parameters of the resulting crystals. In pure aluminum, this reduction is caused by the formation of nanocrystals, whose sizes are determined by the magnitude of the change in the lattice parameter. However, for the alloy, previous investigators have also found a comparable reduction in the lattice parameter but attributed it, instead, to the formation of metastable solutions of Si in Al. We find that the effect in the Al–Si alloy is caused by an unknown combination of size and composition dependence, but it is possible that there is no size dependence in the alloy.
Assessment of microbial species inactivation and purification of sewage by a gas–liquid diaphragm discharge plasma
Authors: Li Zhuo , Zhang Xinying , Qi Miao , Zhao Xinyi , Qu Zhongping , Wang Xiangyu , Li Wanchun , Xu Dehui
Published: September 2023

The presence of bacteria and viruses in water has caused many large-scale water disease outbreaks. Cold atmospheric plasma has received much attention as an emerging non-thermal purification technology capable of eliminating micro-organisms, non-ferrous fuels, and heavy metals from water. In this study, a novel gas–liquid diaphragm discharge device that generates air plasma driven by a sinusoidal AC power supply was designed, and its sterilizing effect was investigated. First, the concentrations of reactive oxygen and nitrogen species in the diaphragm discharge were characterized, and the physicochemical properties of activated water were explored. Next, experiments on the inactivation of Pseudomonas aeruginosa were carried out using the device. Finally, pond sewage was treated with the device, and the diversity of micro-organisms in the water was analyzed using 16S rRNA assays to further investigate its applicability. The results showed that the species and quantities of micro-organisms in the water significantly reduced after discharge treatment, with the most significant changes occurring in the Bacillus and Firmicutes species. Thus, this study provides an alternative method for microbial inactivation in sewage treatment.
Characterizing current noise of commercial constant-current sources by using an optically pumped rubidium atomic magnetometer
Authors: Zhao Ni , Zhang Lulu , Yang Yongbiao , He Jun , Wang Yanhua , Li Tingyu , Wang Junmin
Published: September 2023

This paper introduces a method for characterizing the current noise of commercial constant-current sources (CCSs) using a free-induction-decay (FID) type optically pumped rubidium atomic magnetometer driven by a radio frequency magnetic field. We convert the sensitivity of the atomic magnetometer into the current noise of CCS by calibrating the coil constant. At the same time, the current noise characteristics of six typical commercial low-noise CCSs are compared. The current noise level of the Keysight model B2961A is the lowest among the six tested CCSs, which is 36.233 ± 0.022 nA/Hz1/2 at 1–25 Hz and 133.905 ± 0.080 nA/Hz1/2 at 1–100 Hz. The sensitivity of the atomic magnetometer is dependent on the current noise level of the CCS. The CCS with low noise is of great significance for high-sensitivity atomic magnetometers. This research provides an important reference for promoting the development of high precision CCS, metrology, and basic physics research.
Hysteresis effect on airfoil stall noise and flow field
Authors: Yang Y. , Li C. , Pröbsting S. , Liu X. , Liu Y. , Arcondoulis E. J. G.
Published: September 2023

The effect of hysteresis on the lift coefficient of an airfoil is well-known, i.e., the lift coefficient is higher during the upstroke than during the downstroke for the same angle of attack (AoA). In contrast, the effect of hysteresis on the noise emission has not been reported before. In order to investigate this effect, a NACA 0012 airfoil is investigated during upstroke and downstroke between zero and post-stall AoA at a constant Reynolds number of 5.1×105. A map of the noise emission vs AoA is presented revealing tonal noise emission at low AoA, and broadband noise beyond the linear range of lift coefficient. The trend of overall sound pressure level vs AoA shows two local peaks: one at 4.4° with high tonal noise and a second one at 12.6° where the maximum lift coefficient is observed. Flow measurements near the leading edge and trailing edge by particle image velocimetry show that the airfoil noise trend vs AoA is dominated by the trailing-edge flow features. The magnitude of noise emission during the upstroke is higher than that during the downstroke in the hysteresis loop, although the velocity fluctuation magnitude is smaller. This implies that the vortex coherence during upstroke is higher than downstroke, which is evidenced by a more coherent vortex during the upstroke.
Vorticity dynamics and stability of the leading-edge vortex on revolving wings
Authors: Chen Long , Cheng Bo , Wu Jianghao
Published: September 2023

The leading-edge vortex (LEV) is well known for its contribution to the high-lift generation in a wide variety of biological organisms, such as flying insects, auto-rotating samaras, and gliding snakes. Based on revolving wings, the temporal–spatial evolution of the LEV, including the fundamental vorticity dynamics and stabilizing mechanisms, is reviewed here, considering the effects of Reynolds number (Re), Rossby number (Ro), and aspect ratio (AR). The literature agrees that the saturation of LEV intensity at the steady state can be predicted by the chord length of travel at the radius of gyration, which falls between 2 and 4 within a large variety of wing geometries and kinematics. In contrast, the lift almost arrives at a constant value by the end of acceleration. These findings indicate distinct mechanisms for the steady-state LEV vorticity and constant lift. For the stabilizing mechanisms of LEV, four existing hypotheses are reviewed, followed by the introduction of a novel vorticity transport-based perspective. Two vortex-tilting-based mechanisms, named planetary vorticity tilting and dual-stage radial-tangential vortex tilting, were recently proposed to expand our understanding of LEV stability. It is concluded that the vorticity transport inside the LEV is strongly correlated with the local Ro as well as Re and AR. This review presents a comprehensive summary of existing work on LEV dynamics, stabilizing mechanisms, and high-lift generation.
Comprehensive spectral decomposition analysis of gate modulation spectra measured in a pentacene organic field-effect transistor by Bayesian spectroscopy
Authors: Iwamitsu Kazunori , Kumazoe Hiroyuki , Kanemoto Katsuichi , Akai Ichiro
Published: September 2023

Using Bayesian spectroscopy, we performed spectral decomposition of gate modulation (GM) spectra measured in a pentacene organic field-effect transistor to understand comprehensively the optical nonlinear response due to GM and hole injection. Although GM spectra contain a variety of spectral components, by Bayesian spectroscopy, we can specify the role of each component in the nonlinear response by performing model selection that chooses the spectral components needed to explain the data without preconceptions. For a GM spectrum under positive GM, Bayesian spectroscopy shows that nonlinear responses by the change in polarizability dominate the GM spectrum among several types of Stark signals induced by the GM electric field, which is a physically valid conclusion. For GM spectra under negative GM where gate-induced carriers are injected, Bayesian spectroscopy succeeds in completely elucidating the spectral structure, which is composed of the two types of Stark signals due to changes in the polarizability and the dipole moment, bleaching, and gate-induced absorption signals. A pentacene film is known to have solid and isolated molecular phases, which may give different spectral responses. Therefore, we compared a model that treats these responses equally and a model that distinguishes them. Bayesian spectroscopy selects the latter models for all GM spectra, revealing statistically that nonlinear optical effects and hole injection effects are different in these phases.
A numerical study of sample preconcentration using ion concentration polarization in single microfluidic channels with dual ion-selective membranes
Authors: Dang Van-Truong , Pham Van-Sang
Published: September 2023

In this work, we investigated three single straight microchannel designs for the microfluidic biomolecule concentration device, including one traditional single channel and two innovative channels. These microchannels utilized the ion concentration polarization (ICP) phenomenon to preconcentrate very dilute sample biomolecules. By numerically solving coupled equations, Nernst–Planck, Poisson, and Navier–Stokes with appropriate boundary conditions, we provide insight into the ICP phenomenon and the preconcentration mechanism. From the detailed modeling results, we clarify the influence of important working parameters, including electric potentials, the ion-selective membrane dimensions, the channel dimensions, and the ionic strength of buffer solution on the formation of ICP and the enrichment rate of the charged biomolecules. These modeling results for various working conditions of the preconcentration systems highlight the advantage of generating a stronger electric field to preconcentrate biomolecules of two innovative channel designs over the conventional one. The findings are useful tips for the design and optimization of preconcentration microfluidic devices.
Faraday polarization rotation control of 1529 nm wavelength between excited states of Rb atoms
Authors: Liu Chenxu , Dang Anhong
Published: September 2023

Faraday polarization rotation control of 1529 nm wavelength has been obtained using the 5S1/2→5P3/2→4D5/2 transition of rubidium. The traditional off-resonant polarization rotation method commonly used in the Faraday effect for direct transitions of atoms is not applicable to the transitions between excited states. In this study, we proposed a near-resonant polarization rotation method using the Faraday effect between excited states of atoms, by which the polarization rotation of the rubidium 5P3/2→4D5/2 transition can be controlled from 0° to 90° with low distortion. The 780 nm pump light corresponding to the 5S1/2→5P3/2 transition can also be used simultaneously as a control source to manipulate the polarization state of the 1529 nm optical signal.
Thermohaline convection of a Casson fluid in a porous layer: Linear and non-linear stability analyses
Authors: Reddy G. Shiva Kumar , Ragoju Ravi , Shekhar Suman
Published: September 2023

The study investigates the thermosolutal convection of a Casson fluid in a horizontal layer that is heated and salted from below. Both linear and non-linear analyses are performed using the method of normal modes to solve the governing equations. Interestingly, the study demonstrates that the linear and non-linear stability thresholds coincide. To solve the differential eigenvalue problem for linear theory, a one-term Galerkin approach is employed. Meanwhile, for the eigenvalue problem of non-linear instability, a numerical solution is obtained using the bvp4c routine in MATLAB. The results reveal some important findings. First, the Casson parameter is shown to destabilize the flow, leading to instability. However, the Darcy number and solutal Rayleigh number are found to have a stabilizing effect on the system. Furthermore, the study develops a weakly non-linear theory using multiple scale analysis to investigate heat and mass transport, offering valuable insight into these transport phenomena within the context of the system under consideration.
A study on the solidification shapes of molten metal droplet impacting at low weber number
Authors: Huang Jieguang , Qi Lehua , Luo Jun , Wang Qian
Published: September 2023

In uniform molten metal micro droplet deposition manufacturing (UDDM), the control of droplet solidification shape is essential to meet the forming requirements in different application scenarios to achieve a high forming quality. However, although the prediction of droplet solidification shape has been clearly mastered in a high Weber number application scenario such as thermal spray, droplets generally impact on a substrate at a low Weber number level of 2–10 in UDDM, where the droplet will solidify into various shapes under different processing parameter combinations. Here, to uncover the differentiation mechanism and establish a prediction strategy of the geometric shape of a solidified droplet during print process, the impact events under common forming conditions were systematically investigated by numerical and experimental methods. The solidification shapes of the droplets were roughly assorted into three major categories and a subtype. Results indicate that the solidification shapes are very sensitive to the footprint diameter of the droplet, thereafter an empirical formula for which was derived. On this basis, a mapping of droplet solidification shape to droplet footprint diameter was further developed, which was experimentally verified to be accurate and effective. This work shares a panorama of the solidification shapes of molten droplets impacting at low Weber number. It provides a convenient approach to automatically recognize the contour of a solidified droplet only through measuring the droplet footprint diameter, and more than that, lays a way to artificially tailor the droplet morphology in printing.
Quantum dynamics simulations of the 2D spectroscopy for exciton polaritons
Authors: Mondal M. Elious , Koessler Eric R. , Provazza Justin , Vamivakas A. Nickolas , Cundiff Steven T. , Krauss Todd D. , Huo Pengfei
Published: September 2023

We develop an accurate and numerically efficient non-adiabatic path-integral approach to simulate the non-linear spectroscopy of exciton–polariton systems. This approach is based on the partial linearized density matrix approach to model the exciton dynamics with explicit propagation of the phonon bath environment, combined with a stochastic Lindblad dynamics approach to model the cavity loss dynamics. Through simulating both linear and polariton two-dimensional electronic spectra, we systematically investigate how light–matter coupling strength and cavity loss rate influence the optical response signal. Our results confirm the polaron decoupling effect, which is the reduced exciton–phonon coupling among polariton states due to the strong light–matter interactions. We further demonstrate that the polariton coherence time can be significantly prolonged compared to the electronic coherence outside the cavity.
ChecMatE: A workflow package to automatically generate machine learning potentials and phase diagrams for semiconductor alloys
Authors: Guo Yu-Xin , Zhuang Yong-Bin , Shi Jueli , Cheng Jun
Published: September 2023

Semiconductor alloy materials are highly versatile due to their adjustable properties; however, exploring their structural space is a challenging task that affects the control of their properties. Traditional methods rely on ad hoc design based on the understanding of known chemistry and crystallography, which have limitations in computational efficiency and search space. In this work, we present ChecMatE (Chemical Material Explorer), a software package that automatically generates machine learning potentials (MLPs) and uses global search algorithms to screen semiconductor alloy materials. Taking advantage of MLPs, ChecMatE enables a more efficient and cost-effective exploration of the structural space of materials and predicts their energy and relative stability with ab initio accuracy. We demonstrate the efficacy of ChecMatE through a case study of the InxGa1−xN system, where it accelerates structural exploration at reduced costs. Our automatic framework offers a promising solution to the challenging task of exploring the structural space of semiconductor alloy materials.
Modulating above-room-temperature magnetism in Ga-implanted Fe5GeTe2 van der Waals magnets
Authors: Yuan Yanan , Liu Daxiang , Yu Jingjing , Zhang Guanhua , Chen Xiang , Liu Ruiqi , Wang Siyu , Pei Fangfang , Wei Long , Li Zhi , Guo Junming , Wang Shouguo , Liao Zhaoliang , Yan Wensheng , Qiu Ziqiang , Yang Mengmeng , Li Qian
Published: September 2023

The creation of van der Waals (vdW) ferromagnets with tunable Curie temperature (TC) and magnetic anisotropy is essential in developing vdW magnet-based devices. Here, we report an effective and reliable method for modulating the magnetic properties of vdW Fe5GeTe2 by site-specific Ga+ implantation. In this study, we report an easy axis in the ab-plane for bulk Fe5GeTe2 (TC = 310 K) and an axis out of the plane for thin Fe5GeTe2 flakes (TC = 290 K). Combining element-resolved photoemission electron microscopy and spatially resolved magneto-optic Kerr microscopy, we find that the implantation of a tiny amount of 10−3 Ga+·Å−3 in Fe5GeTe2 greatly enhances the TC from 290 to 360 K and switches the magnetic easy axis from the out-of-plane c axis to the ab-plane. The room-temperature x-ray magnetic circular dichroism signal is enhanced from 0% to 9% at an implantation level of 10−2 Ga+·Å−3. These results provide new opportunities for tailoring the magnetic properties of vdW materials beyond room temperature.
Impending ship retirement leaves ocean-drilling researchers adrift
Authors: Means Hannah H.
Published: September 2023

Scientists may have to wait more than a decade for the launch of a new vessel capable of collecting samples below the ocean floor.
Connecting extreme weather events to climate change
Authors: Wehner Michael
Published: September 2023

Advances in attribution science are improving understanding of human influence on our planet.
Entrepreneurial leadership of academic managers in cram schools under double reduction policy in China: conceptualizing competencies and resilience (El liderazgo emprendedor de los gestores académicos en los centros de apoyo al estudio ante una política de reducción doble en China: conceptualización de las competencias y la resiliencia)
Authors: Kwok Percy-Lai-Yin , Wang William-Wei-Lin
Published: September 2023

Leadership issues in shadow education are under-researched in national, regional and international contexts. In China, local and central governments have imposed stringent control on academic K9 paid tutorial lessons, provided by cram schools under the new double reduction policy (DRP). Many large-scale cram schools have undergone drastic changes in their organizational structure, marketing strategies and the working environment under the COVID-19 attack and DRP. This study aims to conceptualize how their academic managers in some regions of China exhibited traits of entrepreneurial leadership involving competence and resilience. Qualitative research methods included content analysis of policy documents, observation of tutorial lessons and semi-structured interviews with academic managers. Without overgeneralization, this study merely acts as a motivational guide for complementing the existing research literature on cram schools in China and enriching the international research literature on entrepreneurial leadership in mass tutoring.
Introduction to the special issue: nuances of social class and socioeconomic status (Introducción a este monográfico: los matices del concepto de clase social y del nivel socioeconómico)
Authors: Easterbrook Matthew J. , Kuppens Toon , Grigoryan Lusine
Published: September 2023

The social psychological study of social class and socioeconomic status (SES) has burgeoned in the last 15 years and much progress has been made. Yet, researchers rarely explain their theoretical standpoint, clearly define social class and/or SES or justify their choice of how to measure it. This, we argue, is holding back progress. We suggest that social class should be considered a social category into which we are socialized that affords differing amounts of economic, social and cultural resources, while SES only captures one’s current access to various forms of capital. We briefly review literature that suggests that the meanings, understandings and thus operationalizations of social class and SES vary across groups and contexts. We then give an overview of the special issue, which documents the advances that can be gained from taking a more nuanced and theoretically informed approach to studying social class and SES.
Mitochondrial double membrane fission: A mystery solved?
Authors: Westermann Benedikt
Published: September 2023

It has long been an unresolved question whether the division machineries that assemble on the mitochondrial surface cooperate with factors inside the organelle. Now, two studies by Connor et al. (2023. J. Cell Biol.https://doi.org/10.1083/jcb.202303147) and Fukuda et al. (2023. Mol. Cell.https://doi.org/10.1016/j.molcel.2023.04.022) have identified an intermembrane space protein that is crucial for mitochondrial double membrane division.
Bifunctional metasurface with ultra-broadband electromagnetically induced transparency and perfect transmissive polarization conversion
Authors: Li Wei , Zhang Bin , Yao Boyi , Chang Rui , Wang Jiayun , Duan Junping , Qu Zeng , Zhang Binzhen
Published: September 2023

This paper proposes a metasurface that can simultaneously realize the dual functions of ultra-broadband electromagnetic induced transparency (EIT) and perfect transmission linear polarization conversion (LPC). The metasurface can be regarded as two identical layers separated by air, and each layer is composed of two N-type copper resonators rotated 45° counterclockwise immediately on both sides of the F4B dielectric layer. The simulation results show that the rotating N-type resonator causes the destructive interference of the electric resonance unit’s near-field coupling magnetic resonance unit, resulting in an ultra-wideband EIT effect with a maximum transmission coefficient of 0.93 and a relative bandwidth of 40.03%. It was also found that a near-perfect transmission LPC with a polarization conversion ratio of 99.97% was obtained near the 9.06 GHz frequency. The physical mechanisms of the EIT phenomenon and LPC are analyzed using the surface current distribution and magnetic field, and the frequency dependence of some structural parameters is also analyzed to illustrate the spectral properties of the depression. The metasurface was fabricated and measured to verify its bifunctional performance. This simultaneous implementation of EIT and LPC on the metasurface provides a new approach for applications in communications, multifunctional device design, and antennas.
Development of interference-free rotational and vibrational thermometry for studies on shock-heated thermochemical non-equilibrium CO
Authors: He Dong , Si Ting , Li Fei , Luo Xisheng
Published: September 2023

A mid-infrared interference-free laser absorption technique for simultaneously measuring rotational temperature, vibrational temperature, and CO concentration was developed for application to shock-tube studies on thermochemical non-equilibrium CO over 1000–3000 K. Three transition lines in the fundamental vibrational band of CO (P(0, 21), near 4.87 μm, P(1, 21), near 4.93 μm, and P(0, 37), near 5.05 μm) were selected. The P(0, 21)/P(1, 21) line pair was used for vibrational temperature measurements whereas the P(0, 21)/P(0, 37) line pair was used for rotational temperature measurements. Spectroscopic parameters for developing the technique were measured: line strengths and collisional broadening data in Ar were obtained at 1040–2940 K. Validation experiments for the thermometry system were performed in shock-heated thermal-equilibrium CO/Ar mixtures at 1050–3010 K and 1.1–2.8 bar. The time-dependent rotational and vibrational temperatures were measured during the vibrational relaxation processes of CO. The technique showed high sensitivity in detecting the rotational and vibrational temperatures. The measured rotational temperature agreed well with the temperature calculated using the measured pressure and isentropic relationship. The measured vibrational temperature showed good agreement with the predictions using the Landau and Teller theory and Millikan and White relationship. The time-dependent CO concentration during the oxidation processes of n-heptane over a wide temperature range (1350–2750 K) was measured considering n-heptane as one of the alternative fuels for the scramjet. The interference-free laser absorption strategy showed good flexibility in detecting the CO concentration at ultra-high temperatures. The measured results showed overall good agreement with the predictions from two detailed mechanisms and one skeletal mechanism. The reactivity of n-heptane was found to be insensitive to the temperature increase at ultra-high temperatures (>2100 K).
Convex computation of maximal Lyapunov exponents
Authors: Oeri Hans , Goluskin David
Published: September 2023

We describe an approach for finding upper bounds on an ODE dynamical system’s maximal Lyapunov exponent (LE) among all trajectories in a specified set. A minimisation problem is formulated whose infimum is equal to the maximal LE, provided that trajectories of interest remain in a compact set. The minimisation is over auxiliary functions that are defined on the state space and subject to a pointwise inequality. In the polynomial case—i.e. when the ODE’s right-hand side is polynomial, the set of interest can be specified by polynomial inequalities or equalities, and auxiliary functions are sought among polynomials—the minimisation can be relaxed into a computationally tractable polynomial optimisation problem subject to sum-of-squares constraints. Enlarging the spaces of polynomials over which auxiliary functions are sought yields optimisation problems of increasing computational cost whose infima converge from above to the maximal LE, at least when the set of interest is compact. For illustration, we carry out such polynomial optimisation computations for two chaotic examples: the Lorenz system and the Hénon–Heiles system. The computed upper bounds converge as polynomial degrees are raised, and in each example we obtain a bound that is sharp to at least five digits. This sharpness is confirmed by finding trajectories whose leading Lyapunov exponents approximately equal the upper bounds.
Strong degenerate constraining in Lagrangian dynamics
Authors: Burgos J M
Published: September 2023

We study the strong constraining problem in Lagrangian dynamics in the degenerate codimension one case. This is the first time that degenerate potentials at the constraint are considered for this problem. Besides the total degenerate cases, these new results cover several real analytic potentials that the previous do not. Some counterintuitive effects of the degenerate constraining are discussed.
Primordial black holes and inflation from double-well potentials
Authors: Karam Alexandros , Koivunen Niko , Tomberg Eemeli , Racioppi Antonio , Veermäe Hardi
Published: September 2023

We investigate the formation of large peaks in the inflationary curvature power spectrum from double-well potentials. In such scenarios, the initial CMB spectrum is created at large field values. Subsequently, the inflaton will cross one of the minima and will decelerate rapidly as it reaches the local maximum at the origin, either falling back or crossing it. During this final phase, a significant peak in the curvature power spectrum can be generated. Our analysis reveals that this class of models produces more pronounced peaks than most quasi-inflection point scenarios with less tuning for the model parameters. Finally, we construct an explicit theoretically motivated inflationary scenario that is consistent with the latest CMB observations and capable of generating sufficiently large curvature perturbations for primordial black holes.
Quantifying Roman WFI Dark Images with the Wavelet Scattering Transform
Authors: Velicheti Phani Datta , Wu John F. , Petric Andreea
Published: September 2023

The Nancy Grace Roman Space Telescope will survey a large area of the sky at near-infrared wavelengths with its Wide Field Instrument (WFI). The performance of the 18 WFI H4RG-10 detectors will need to be well-characterized and regularly monitored in order for Roman to meet its science objectives. Weak lensing science goals are particularly sensitive to instrumental distortions and patterns that might masquerade as astronomical signals. We apply the wavelet scattering transform in order to analyze localized signals in Roman WFI images that have been taken as part of a dark image test suite. The scattering transform quantifies shapes and clustering information by reducing images into nonlinear combinations of wavelet modes on multiple size scales. We show that these interpretable scattering statistics can separate rare correlated patterns from typical noise signals, and we discuss the results in context of power spectrum analyses and other computer vision methods.
Asymmetric bidirectional quantum
1⇔2
qubit teleportation scheme via six-qubit Bell-cluster state
Authors: Yuan Hao , Zhang Zhanjun
Published: September 2023

Using a six-qubit Bell-cluster state, we proposed an asymmetric bidirectional quantum teleportation scheme. Two participants Anne and Benson are both the sender and receiver. Only applying Bell-state measurement, single- and two-qubit unitary operations as well as classical communication, Anne can transmit an arbitrary two-qubit unknown state to Benson, meanwhile Benson can also send an arbitrary single-qubit unknown state to Anne. Analysis shows that our scheme is feasible with the present experiment technologies.
Internal quantum efficiency of silicon photodetectors at ultraviolet wavelengths
Authors: Korpusenko Mikhail , Vaskuri Anna , Manoocheri Farshid , Ikonen Erkki
Published: September 2023

We determine experimentally the internal quantum efficiency of a 3-element trap detector made of Hamamatsu S1337 photodiodes and of a predictable quantum efficient detector (PQED) over the wavelength range of 250–500 nm using an electrically calibrated pyroelectric radiometer as reference detector. The PQED is made of specially designed induced junction photodiodes, whose charge-carrier recombination losses are minimized. The determined internal quantum efficiency of PQED is always 1 or larger, whereas the 3-element trap detector has internal quantum efficiency smaller than 1 in the spectral range of 330–450 nm. This finding demonstrates the advantages of PQED photodiodes for studying the quantum yield due to impact ionization by charge carriers in the silicon lattice. For this purpose, we develop an extrapolation model for the charge-carrier recombination losses of the PQED, which allows us to separate the quantum yield from the measured internal quantum efficiency. Measurements of PQED spectral responsivity thus allow to determine the quantum yield in silicon, which can be further used for quantifying the charge-carrier recombination losses in the 3-element trap detector. Numerical values of the latter are from 6% to 2% in the spectral range from 250 nm to 380 nm. Finally, our results are encouraging for the aim of developing the PQED to a primary detector standard also at ultraviolet wavelengths.
Illuminance scale development from 1 klx to 200 klx
Authors: Lv Liang , Jiang Xiaomei , Li Jian , Lin Yandong , Lin Xiaofeng , Pang Bowen
Published: September 2023

A calibration facility and associated measurement procedures have been established at the National Institute of Metrology (NIM, CHINA) to provide high illuminance calibrations in the range from 1 klx to 200 klx. An adjustable high illuminance source based on flux addition of LEDs in an integrating sphere has been developed, and the characteristics of the high illuminance source have been tested and analyzed. A correction method for the issues caused by the inherent structure of the light source has been proposed. A photometer was calibrated using the superposition method in the range (1–200) klx with a relative uncertainty from 0.5% to 1.0% varying with range (coverage factor k = 2).