bluuebunny/crossref_metadata_2025 huggingface dataset:
Room temperature chemoselective hydrogenation of CC, CO and CN bonds by using a well-defined mixed donor Mn(i) pincer catalyst
Authors: Shabade Anand B. , Sharma Dipesh M. , Bajpai Priyam , Gonnade Rajesh G. , Vanka Kumar , Punji Benudhar
Published: November 2022

Chemoselective hydrogenation of CC, CO and CN bonds in α,β-unsaturated ketones, aldehydes and imines is accomplished at room temperature (27 °C) using a well-defined Mn(i) catalyst and 5.0 bar H2.
High fibroin-loaded silk-PCL electrospun fiber with core–shell morphology promotes epithelialization with accelerated wound healing
Authors: Rajasekaran Ragavi , Dutta Abir , Ray Preetam Guha , Seesala Venkata Sundeep , Ojha Atul Kumar , Dogra Nantu , Roy Sabyasachi , Banerjee Mamoni , Dhara Santanu
Published: November 2022

High SF loaded-PCL electrospun fiber with core-shell morphology promotes epithelialization with accelerated wound healing.
Multicomponent carrier-free nanodrugs for cancer treatment
Authors: Huang Lifei , Hu Shuyang , Fu Ya-nan , Wan Yan , Li Guofeng , Wang Xing
Published: November 2022

This article outlines the construction strategies of multi-component carrier-free nanodrugs based on the fundamental properties of their constituent substances (organic/inorganic and hydrophilic/hydrophobic), and prospects for the development.
Hydroxide-based magneto-ionics: electric-field control of a reversible paramagnetic-to-ferromagnetic switch in α-Co(OH)2 films
Authors: Quintana Alberto , Firme Abigail A. , Jensen Christopher J. , Zheng Dongxing , Liu Chen , Zhang Xixiang , Liu Kai
Published: November 2022

Here we demonstrate highly effective hydroxide-based magneto-ionics in electrodeposited α-Co(OH)2 films. The α-Co(OH)2, which is a room temperature paramagnet, is reversibly switched between paramagnetic-ferromagnetic states after electrolyte gating.
Diketopyrrolopyrrole-based conjugated polymers containing planar benzo[c]cinnoline and tetraazapyrene structures for high-performance and long-term stable triboelectric nanogenerators
Authors: Cheng Kuang-Hao , Tsai Cheng-You , Wang Yu-Han , Pandey Shyam S. , Chang Chih-Yu , Chen Jyh-Chien
Published: November 2022

A promising strategy to simultaneously improve the performance and stability of a triboelectric nanogenerator is demonstrated by using DPP-based conjugated polymers containing planar BZC and TAP structures as the surface modification layer.
Threshold switching in chalcogenide GeTe and GeTeS thin films prepared via plasma enhanced atomic layer deposition
Authors: Ryu Jin Joo , Jeon Kanghyoek , Sohn Hyunchul , Kim Gun Hwan
Published: November 2022

Multi-component chalcogenide thin films of GeTex and GeTexS1−x are prepared by atomic layer deposition technique. With the conformal deposition characteristics, its electrical properties of threshold switching are demonstrated for emerging computing.
Highly efficient and stable binary all-polymer solar cells enabled by sequential deposition processing tuned microstructures
Authors: Zhao Chaoyue , Ma Ruijie , Oh Jiyeon , Wang Lihong , Zhang Guoping , Wang Yajie , He Siying , Zhu Liangxiang , Yang Changduk , Zhang Guangye , Li Gang
Published: November 2022

Sequential processing based devices show improved power conversion efficiency and stability compared to their blend casting counterparts. Systematic characterization reveals the underlying mechanism.
Le futur du travail en agriculture
Authors: Dedieu Benoît
Published: November 2022

Nous présentons une synthèse des discussions tenues lors du 2eSymposium international sur le travail en agriculture (29 mars–1eravril 2021). L’objectif est de rendre compte des thématiques et des idées échangées, dans un cadre pluridisciplinaire, et de construire une vision commune du futur du travail agricole à l’échelle mondiale. Les grandes dynamiques de changement structurel opposent, sur le plan du travail, les pays du Nord et du Sud, faisant émerger des questionnements différents (par exemple une agriculture sans agriculteurs dans les pays du Nord,versusun travail décent pour un population active agricole nombreuse dans les pays du Sud). Mais certaines questions sont transversales : la transition agroécologique, le genre, la révolution numérique, les migrations, changent le travail agricole en profondeur. Nous proposons quelques perspectives pour un agenda de recherche pour traiter le futur du travail agricole.
Dimini (Diabetes mellitus? – Ich nicht!): Aktivierung der Gesundheitskompetenz von Versicherten mit erhöhtem Risiko für Diabetes mellitus Typ 2 mittels Coaching in der Vertragsarztpraxis
Authors: Püschner Franziska , Urbanski-Rini Dominika , Dubois Clara , Schliffke Monika , Göhl Martin , Petersen Carsten
Published: November 2022

Einleitung Lebensstilveränderungen können das Risiko, an Diabetes mellitus Typ 2 (DMT2) zu erkranken, senken. Im Rahmen des Innovationsfondprojektes Dimini (Diabetes mellitus? Ich nicht!) wurde untersucht, ob Menschen mit einem erhöhten Diabetesrisiko frühzeitig und niedrigschwellig in der hausärztlichen Praxis identifiziert werden können und ob die Lebensstilintervention Dimini zu einer verbesserten Gesundheitskompetenz sowie einer Gewichtsreduktion führt.

Methodik Dimini (01NVF17012) wurde vom 1. Juni 2017 bis zum 30. November 2020 in hausärztlichen Praxen in Hessen und in Schleswig-Holstein in Form einer randomisierten kontrollierten Studie umgesetzt. Zum Einschluss der Versicherten führten die Hausärztinnen und Hausärzte u.a. bei metabolisch auffälligen Personen ein Risikoscreening mittels FINDRISK-Tests durch (t0). Der 15-monatige Beobachtungszeitraum umfasste für die Interventionsgruppe eine dreimonatige Lebensstilintervention, optionale Coaching-Termine und drei Kontrolltermine in der Interventions- und Kontrollgruppe, zu denen die Datenerhebung erfolgte. Es wurden u.a. die Endpunkte Körpergewicht, Gesundheitskompetenz und der Grad der Zielerreichung untersucht.

Ergebnisse Von den 3349 Personen, die mit dem FINDRISK gescreent wurden, hatten 1430 (42,8%) Personen ein erhöhtes DMT2-Risiko (FINDRISK ≥ 12). Davon wurden 1170 Personen eingeschlossen. Das Durchschnittsgewicht sank im Interventionsverlauf (t0 zu t3) signifikant um 1,6 kg (1,1%) (V = 106721, p < 0,001). Der Mann-Whitney-U-Test (W = 49265, p = 0,036) zeigte eine signifikant größere Gewichtsabnahme in der Interventionsgruppe (IG) (Mt0-t3 = 2,06 kg, SD = 6,97) als in der Kontrollgruppe (KG) (Mt0-t3 = 1,18 kg, SD = 5,88). Die Gesundheitskompetenz verbesserte sich im Verlauf der Intervention nicht signifikant. 21 Teilnehmende (7,2%) erreichten ihr Gewichtsziel, 55 (18,8%) übertrafen und 217 (74,1%) verfehlten es. Das Ziel, 30 Minuten am Tag aktiv zu sein, erreichten laut eigenen Angaben 177 Teilnehmende (79,4%).

Schlussfolgerung Die Studie zeigt das Potential von flächendeckenden Risikoscreenings zur Früherkennung von Menschen mit erhöhtem DMT2-Risiko sowie einen geringen positiven Effekt der Intervention auf die Gewichtsreduktion. Subgruppenspezifische Präventionsansätze sollten im Anschluss an das Screening angeboten werden. Diese sollten bestehende Strukturen und verschiedene (ärztliche und therapeutische) Disziplinen und Fachrichtungen einbinden. Eine stärkere Ausrichtung des Gesundheitswesens hinsichtlich Gesundheitsförderung und Prävention scheint notwendig.
Überlastungssyndromen begegnen – Therapiekonzept: Selbstwirksam ohne Schmerz (SOS)
Authors: Aegler Barbara
Published: November 2022

Repetitive Belastungen, ungünstige Körperhaltungen, Stress oder psychosoziale Belastungen bei der Arbeit können zu Schmerzen in Nacken, Schultern, Armen und Händen führen – den sogenannten Überlastungssyndromen. Das ergotherapeutische Konzept „Selbstwirksam ohne Schmerz (SOS)“ leitet in diesem Fall durch den rehabilitativen Prozess.
Accurate prediction of histological grading of intraductal papillary mucinous neoplasia using deep learning
Authors: Schulz Dominik , Heilmaier Markus , Phillip Veit , Treiber Matthias , Mayr Ulrich , Lahmer Tobias , Mueller Julius , Demir Ihsan Ekin , Friess Helmut , Reichert Maximilian , Schmid Roland M. , Abdelhafez Mohamed
Published: November 2022

Background Risk stratification and recommendation for surgery for intraductal papillary mucinous neoplasm (IPMN) are currently based on consensus guidelines. Risk stratification from presurgery histology is only potentially decisive owing to the low sensitivity of fine-needle aspiration. In this study, we developed and validated a deep learning-based method to distinguish between IPMN with low grade dysplasia and IPMN with high grade dysplasia/invasive carcinoma using endoscopic ultrasound (EUS) images.

Methods For model training, we acquired a total of 3355 EUS images from 43 patients who underwent pancreatectomy from March 2015 to August 2021. All patients had histologically proven IPMN. We used transfer learning to fine-tune a convolutional neural network and to classify “low grade IPMN” from “high grade IPMN/invasive carcinoma.” Our test set consisted of 1823 images from 27 patients, recruiting 11 patients retrospectively, 7 patients prospectively, and 9 patients externally. We compared our results with the prediction based on international consensus guidelines.

Results Our approach could classify low grade from high grade/invasive carcinoma in the test set with an accuracy of 99.6 % (95 %CI 99.5 %–99.9 %). Our deep learning model achieved superior accuracy in prediction of the histological outcome compared with any individual guideline, which have accuracies between 51.8 % (95 %CI 31.9 %–71.3 %) and 70.4 % (95 %CI 49.8–86.2).

Conclusion This pilot study demonstrated that deep learning in IPMN-EUS images can predict the histological outcome with high accuracy.
Advanced serrated polyps as a target of screening: detection rate and positive predictive value within a fecal immunochemical test-based colorectal cancer screening population
Authors: van Toledo David E. F. W. M. , Breekveldt Emilie C. H. , IJspeert Joep E. G. , van Vuuren Anneke J. , van Kemenade Folkert J. , Ramakers Christian , Nagtegaal Iris D. , van Leerdam Monique E. , Spaander Manon C. W. , Lansdorp-Vogelaar Iris , Toes-Zoutendijk Esther , Dekker Evelien
Published: November 2022

Background Advanced serrated polyps (ASPs) have a comparable risk to advanced adenomas for progression to colorectal cancer (CRC). The yield of most CRC screening programs, however, is based on advanced adenomas and CRC only. We assessed the ASP detection rate, and positive predictive value (PPV) including ASPs in a fecal immunochemical test (FIT)-based screening program.

Methods We analyzed the findings of follow-up colonoscopies of FIT-positive screenees in the Dutch CRC screening program from 2014 until 2020. Data were retrieved from the national screening and pathology database. An ASP was defined as any serrated polyp of ≥ 10 mm, sessile serrated lesion with dysplasia, or traditional serrated adenoma. The ASP detection rate was defined as the proportion of colonoscopies with ≥ 1 ASP. PPV was originally defined as the proportion of individuals with a CRC or advanced adenoma. The updated PPV definition included CRCs, advanced adenomas, and/or ASPs.

Results 322 882 colonoscopies were included in the analyses. The overall detection rate of ASPs was 5.9 %. ASPs were detected more often in women than men (6.3 % vs. 5.6 %; P < 0.001). ASP detection rates in individuals aged 55–59, 60–64, 65–69, and 70 + were 5.2 %, 6.1 %, 6.1 %, and 5.9 %, respectively (P < 0.001). The PPV for CRCs and advanced adenomas was 41.1 % and increased to 43.8 % when including ASPs. The PPV increase was larger in women than in men (3.2 vs. 2.4 percentage points).

Conclusions 5.9 % of FIT-positive screenees had ASPs, but half of these were detected in combination with a CRC or advanced adenoma. Therefore, including ASPs results in a small increase in the yield of FIT-based screening.
Complications during Induction Chemotherapy in Acute Promyelocytic Leukemia: An Institutional Experience
Authors: Yedla Rajani Priya , Bala Stalin Chowdary , Pydi Venkateswara Rao , Chennamaneni Rachana , Kuruva Siva Prasad , Konatam Meher Lakshmi , Gundeti Sadashivudu
Published: November 2022

Introduction Acute promyelocytic leukemia (APL) has transformed from a highly fatal disease to a highly curable one. Induction deaths continue to represent one of the major impediments in modern therapy of APL. Sepsis, hemorrhage, and differentiation syndrome are the major complications during induction therapy in APL. The present study reports the incidence and prognostic factors of major complications during induction chemotherapy in patients with newly diagnosed APL.

Materials and Methods The present study was a single institutional, observational, retrospective study. All cases of APL diagnosed by morphology and confirmed by RT PCR (PML RARα) were included in this study. Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 25.

Results A total of 73 patients were analyzed. The median age at presentation was 30 years (range, 3–60 years) with a female to male ratio of 1.02:1. The most common symptom at presentation was fever (80%), followed by fatigue (56%) and gum bleeding (37%). The majority of the patients at presentation were high risk (42.4%), followed by intermediate risk (38.4%) and low risk (19.2%). Fifty-seven (78%) patients achieved complete hematological remission and 16 (22%) succumbed during induction chemotherapy. Infection was the most common cause of induction death (50%), followed by hemorrhage (37.5%) and differentiation syndrome (12.5%). On univariate analysis of prognostic factors, bcr3 variant, grade 3/4 bleeding during induction, and low levels of albumin at presentation were significant for induction mortality (p = 0.034, 0.041, and 0.008 respectively). On multivariate analysis, only serum albumin < 3.5 g/dL was an independent predictor for induction mortality (p = 0.043).

Conclusion The majority of patients were high risk at presentation. Sepsis was the most common complication during induction and also the leading cause of induction death. Identifying induction complications at the earliest and providing aggressive supportive measures can further improve outcomes in APL.
Clinical Outcomes of Uterine Body Cancers Treated in a Tertiary Cancer Center
Authors: Muthulingeshkumar K. , Pandjatcharam Jagadesan , Chaturvedula Latha
Published: November 2022

Objectives This article reports the clinical outcomes of uterine body cancers in South Indian population. The primary outcome of our study was overall survival (OS). The secondary outcomes were disease-free survival (DFS), patterns of recurrence, toxicities of radiation treatment, and the association of patient, disease, and treatment characteristics with survival and recurrence.

Materials and Methods Records of the patients diagnosed as malignancy in uterus and treated with surgery alone or with adjuvant treatment from January 2013 to December 2017 were retrieved after Institute Ethics Committee approval. Demographic, surgical, histopathology, and adjuvant treatment details were retrieved. Patients of endometrial adenocarcinoma were stratified according to the European Society of Medical Oncology/European Society of Gynaecological Oncology/European Society for Radiotherapy and Oncology consensus for analysis and overall outcomes irrespective of histology were also analyzed.

Statistical Analysis For the survival analysis, Kaplan–Meier survival estimator was used. Cox regression was used to test the significance of association of factors with outcomes in terms of hazard ratio (HR).

Results A total of 178 patient records were retrieved. The median follow-up of all patients was 30 months (0.5–81 months). The median age of the population was 55 years. Most common histology was endometrioid type of adenocarcinoma (89%), sarcomas comprised only 4%. The mean OS of all patients was 68 months (n = 178), median was not reached. Five-year OS was 79 %. Five-year OS rates observed in low, intermediate, high-intermediate, and high-risk were 91, 88, 75, and 81.5%, respectively. The mean DFS was 65 months, median not reached. The 5-year DFS was 76%. The 5-year DFS rates observed were 82, 95, 80, and 81.5% for low, intermediate, high-intermediate, and high-risk, respectively. Univariate analysis using Cox regression showed increase in hazard for death in case of node positivity, HR 3.96 (p 0.033). The HR for disease recurrence was 0.35 (p = 0.042) in patients who had received adjuvant radiation therapy. No other factors had any significant impact on death or disease recurrence.

Conclusion The survival outcomes in terms of DFS and OS were comparable with other Indian and Western data reported in the published literature.
Improving the User Experience with Discount Site-Specific User Testing
Authors: Pierce Robert P. , Eskridge Bernie R. , Ross Brandi , Day Margaret A. , Dean Brooke , Belden Jeffery L.
Published: November 2022

Objectives Poor electronic health record (EHR) usability is associated with patient safety concerns, user dissatisfaction, and provider burnout. EHR certification requires vendors to perform user testing. However, there are no such requirements for site-specific implementations. Health care organizations customize EHR implementations, potentially introducing usability problems. Site-specific usability evaluations may help to identify these concerns, and “discount” usability methods afford health systems a means of doing so even without dedicated usability specialists. This report characterizes a site-specific discount user testing program launched at an academic medical center. We describe lessons learned and highlight three of the EHR features in detail to demonstrate the impact of testing on implementation decisions and on users.

Methods Thirteen new EHR features which had already undergone heuristic evaluation and iterative design were evaluated over the course of three user test events. Each event included five to six users. Participants used think aloud technique. Measures of user efficiency, effectiveness, and satisfaction were collected. Usability concerns were characterized by the type of usability heuristic violated and by correctability.

Results Usability concerns occurred at a rate of 2.5 per feature tested. Seventy percent of the usability concerns were deemed correctable prior to implementation. The first highlighted feature was moved to production despite low single ease question (SEQ) scores which may have predicted its subsequent withdrawal from production based on post implementation feedback. Another feature was rebuilt based on usability findings, and a new version was retested and moved to production. A third feature highlights an easily correctable usability concern identified in user testing. Quantitative usability metrics generally reinforced qualitative findings.

Conclusion Simplified user testing with a limited number of participants identifies correctable usability concerns, even after heuristic evaluation. Our discount usability approach to site-specific usability has a role in implementations and may improve the usability of the EHR for the end user.
Indentation response of model oxide dispersion strengthening alloys after ion irradiation up to 700 °C
Authors: Robertson C. , Mathon M. H. , Panigrahi B. K. , Amirthapandian S. , Sojak S. , Santra S.
Published: November 2022

This paper presents an experimental investigation of irradiation-induced evolutions in three different oxide dispersion strengthening (ODS) alloys. High-dose, dual beam Ni–He ion irradiations are carried out up to 700 °C. The significant dose-dependent changes in the ODS particle size and number density are documented and interpreted in terms of specific point defect transport mechanisms, from small angle neutron scattering, TEM, and pulsed low-energy positron system measurements combined. The corresponding micro-mechanical changes in the alloys are evaluated based on the indentation response, which is, in turn, interpreted in terms of related, sub-grain plasticity mechanisms. The room temperature tests (without dwell time) reveal that the microscale work-hardening rate increases with decreasing the particle number density and pronounced strain localization effect. The elevated temperature tests (up to 600 °C, with dwell time) show that the indentation creep compliance is mostly temperature-independent after irradiation up to 25 dpa at Tirr = 500 °C and markedly temperature-dependent, after irradiation beyond 40 dpa at Tirr = 600 °C. This effect is ascribed to particular creep mechanisms associated with indent-induced plasticity, i.e., high stress and high dislocation density conditions.
Combined pressure and magnetic field induced caloric effects in Fe7Se8 single crystals doped with Ni and Co ions
Authors: Konopelnyk Y. , Iwanowski P. , Diduszko R. , Zajarniuk T. , Fink-Finowicki J. , Radelytskyi I. , Szewczyk A. , Szymczak H. , Pękala M. , Puzniak R.
Published: November 2022

The influence of Co and Ni ion doping on the crystal structure, phase transitions, and magnetic properties of the Fe7Se8 system has been investigated. The compounds studied are (Fe0.987Ni0.013)7Se8, (Fe0.955Ni0.045)7Se8, (Fe0.915Ni0.085)7Se8, (Fe0.89Ni0.11)7Se8, (Fe0.79Ni0.21)7Se8, (Fe0.975Co0.025)7Se8, (Fe0.951Co0.049)7Se8, and (Fe0.91Co0.09)7Se8 as well as the parent compound Fe7Se8. The crystals are grown using a modified Bridgman method and exist as a hexagonal NiAs-like structure with an ordered distribution of Fe vacancies that determine their magnetic properties. The substitution effect, inducing a systematic decrease in the unit-cell volume due to the ionic radii of doping ions being smaller than the radii of Fe2+ ions, is a source of chemical pressure, acting on the magnetic subsystem and determining the magnetic ordering temperature TC and the spin-reorientation temperature (TSRT). As the most important result of this paper, it was shown that hydrostatic and chemical pressures are strongly correlated in the investigated system. The character of magnetic phase transitions has been designated in the vicinity of TC and TSRT temperatures, and the magnetic entropy change ΔSm and refrigeration potential magnitudes have been determined for this temperature range. These magnetocaloric parameters were shown to depend strongly on chemical pressure. A phenomenological model developed based on the experimental measurements demonstrated that the magnetic properties of the system depend strongly on the crystal field acting on Fe2+ ions and the ratio of the numbers of Fe2+ and Fe3+ ions.
Marine self-potential measurement tool for autonomous underwater vehicle
Authors: Song Sixuan , Deng Xianming , Su Zhaoyang , Deng Ming , Chen Kai
Published: November 2022

Marine self-potential (SP) measurement is commonly conducted for seafloor sulfide detection and hydrothermal vent studies in deep water using instruments towed close to the seafloor. However, this method has the following shortcomings: (1) It relies on ships for deep towing, and the need for a dedicated ship time lowers its efficiency. (2) Owing to complex topography, most towed instruments are located far from the seafloor to ensure safety, resulting in large effective signal attenuation and low signal-to-noise ratio. (3) The measurement direction is generally a single axis, with only the electric field of the axial component observed, providing limited information. With the gradual maturity of autonomous underwater vehicle (AUV) technology, it has become possible to mount marine SP measurement tools on AUVs for detection. Compared with conventional methods, this method has significant advantages in terms of efficiency, signal-to-noise ratio, and multicomponent observation. The proposed tool is a lightweight underwater device having a compact design and low power consumption, making it suitable for AUVs. The overall volume of the tool is D50 mm × L350 mm, and the underwater weight is 0.6 kg. Chopper amplification technology ensures the low-noise measurement of electric field signals. In addition, the reformed electrodes enhance stability, thereby reducing the mechanical vibration noise. Laboratory test results show that the noise of the data logger is 7.8 nV/rt (Hz)@1 Hz. The marine test conducted in the southwest Indian Ocean verified the reliability of the proposed marine SP measurement tool. The maximum working depth was 4000 m. The test lasted ∼25 h, and the effective electric field data were collected for ∼17 h. This survey found a maximum SP anomaly of 0.55 mV/m in the Yuhuang hydrothermal field, which provided effective data support for the discovery of new seafloor sulfide anomalies.
System-on-chip approach microwave imaging reflectometer on DIII-D tokamak
Authors: Zhu Y. , Chen Y. , Yu J.-H. , Domier C. , Yu G. , Liu X. , Kramer G. , Ren Y. , Diallo A. , Luhmann N. C. , Li X.
Published: November 2022

System-on-chip millimeter wave integrated circuit technology is used on the two-dimensional millimeter-wave imaging reflectometer (MIR) upgrade for density fluctuation imaging on the DIII-D tokamak fusion plasma. Customized CMOS chips have been successfully developed for the transmitter module and receiver module array, covering the 55–75 GHz working band. The transmitter module has the capability of simultaneously launching eight tunable probe frequencies (>0 dBm output power each). The receiver enclosure contains 12 receiver modules in two vertical lines. The quasi-optical local oscillator coupling of previous MIR systems has been replaced with an internal active frequency multiplier chain for improved local oscillator power delivery and flexible installation in a narrow space together with improved shielding against electromagnetic interference. The 55–75 GHz low noise amplifier, used between the receiver antenna and the first-stage mixer, significantly improves module sensitivity and suppresses electronics noise. The receiver module has a 20 dB gain improvement compared with the mini-lens approach and better than −75 dBm sensitivity, and its electronics noise temperature has been reduced from 55 000 K down to 11 200 K. The V-band MIR system is developed for co-located multi-field investigation of MHD-scale fluctuations in the pedestal region with W-band electron cyclotron emission imaging on DIII-D tokamak.
Analysis method for calculating radial correlation length of electron temperature turbulence from correlation electron cyclotron emission radiometer
Authors: Wang G. , Rhodes T. L. , Peebles W. A.
Published: November 2022

The radial correlation length (Lr) is one of the essential quantities to measure in order to more fully characterize and understand turbulence and anomalous transport in magnetic fusion plasmas. The analysis method for calculating Lr of electron temperature (Te) turbulence from correlation electron cyclotron emission (correlation ECE or CECE) radiometer measurements has not been fully developed partly due to the fact that the turbulent electron temperature fluctuations are generally imbedded in much larger amplitude thermal noise, which leads to a greatly reduced cross correlation coefficient (ϱ) between two spatially separated ECE signals. This work finds that this ϱ reduction factor due to thermal noise is a function of the local relative temperature fluctuation power and CECE system bandwidths of intermediate and video frequencies, independent of radial separations. This indicates that under the approximation of constant relative temperature fluctuation power for a small radial range of local CECE measurements, the original shape of ϱ as a function of radial separation without thermal noise is preserved in the CECE data with thermal noise present. For Te turbulence with a Gaussian radial wavenumber spectrum, a fit function using the product of Gaussian and sinusoidal functions is derived for calculating Lr. This analysis method has been numerically tested using simulated ECE radiometer data over a range of parameters. Using this method, the experimental temperature turbulence correlation length Lr in a DIII-D L-mode plasma is found to be ∼10 times the local ion gyroradius.
Non-linear finite-amplitude oscillations of the large beam arrays oscillating in viscous fluids
Authors: Ande Raghu , Gutschmidt Stefanie , Sellier Mathieu
Published: November 2022

Over the past decade, several studies have been conducted on a single and multiple oscillating thin cantilever beams in an unbounded viscous fluid. With an increase in the applications of large array oscillators in a fluid environment for fields like medicine, biology, and energy harvesting devices, it is crucial to understand the nature of the surrounding fluid dynamics. In this present study, we perform a two-dimensional computational fluid dynamics (CFD) analysis of an array of beams oscillating in an unbounded viscous fluid. The two-dimensional Navier Stokes and continuity equations are solved to investigate the hydrodynamic forces exerted on the array members from interaction with the fluid environment. A complex hydrodynamic function is proposed here to represent the distributed hydrodynamic loading experienced by the oscillating beams. Results suggest that there is an increase in viscous damping with an increase in the size of the array. In addition, the nonlinearities become dominant when an array of beams is subjected to large amplitude oscillations. The number of beams in an array determines the overall hydrodynamics and the array effect. CFD analysis can predict the non-linearities unlike boundary integral method (BIM) approach, which is limited for low amplitudes. The results from the full Navier–Stokes simulations compared favorably with results using the BIM for the time-harmonic linearized Stokes equations.
Interaction between NV centers and substituting nitrogen complexes in diamond as a diagnostic probe of the local nitrogen concentration
Authors: Babunts R. A. , Breev I. D. , Kramushchenko D. D. , Bundakova A. P. , Muzafarova M. V. , Anisimov A. N. , Baranov P. G.
Published: November 2022

A non-destructive method is proposed for express diagnostics of the local concentration of substituting nitrogen donors (P1 centers) in diamond under environmental conditions by the relative intensity of sideband satellites in the optical detection of magnetic resonance spectrum of the nitrogen vacancy (NV) center. It is shown that the internal satellites which are separated from the central line at a distance of ∼±A/2, where A is the hyperfine (HF) interaction constant for the P1 center, can be explained by the interaction between the NV center and an exchange-coupled P1 pair. The pair of P1 centers strongly interacting with each other leads to the appearance of a state with spin 1 which can be observed in the electron paramagnetic resonance spectra of nitrogen in diamond as additional HF lines. As a result, both interacting spin systems, NV and P1 pair, are characterized by unit spins. The transitions induced by microwave power in two coupled triplet states, which are allowed in spin, lead to the appearance of internal satellites at low microwave powers. These conclusions are confirmed by calculations performed using the EasySpin software package.
Miniaturized ultra-thin metamaterial absorber for low frequency using the technique of shifted opposite layers
Authors: Fu Bin , Wan Guo-Bin , Ma Xin , Chen Yu-Xu , Jiao Xin-Hui , Wang Lu
Published: November 2022

A technique of interdigital shifted opposite layers (SOLs) to design the miniaturized ultra-thin metamaterial absorber (MA) is proposed in this article. To meet the demanding requirements of small dimensions at low frequency, SOLs are first employed in MAs to achieve superior miniaturization. They consist of two identical layers printed on both sides of a thin substrate with relative lateral displacement. Compared with previously published MAs, the displacement substantially increases the equivalent capacitance of the unit cell, thus leading to a lower resonant frequency. To further miniaturize the unit cell, an ultra-thin MA using interdigital SOLs is optimized with a small cell size of 0.036λ0 × 0.036λ0 and a low profile of 0.0053λ0 (where λ0 corresponds to the free-space wavelength at a resonant frequency), exhibiting perfect absorption at 0.868 GHz. The equivalent circuit model shows that the dramatically increased equivalent capacitance and inductance down-shift the resonant frequency. Meanwhile, the current flow and field distribution are investigated to explain the absorption mechanism. Finally, to validate the design concept, the fabricated prototype of the proposed MA has been measured and compared with the simulation result. The measured and simulated results show good agreement.
Oxygen vacancy levels mediated photophysical pathways of NIR-II responsive broadband upconversion
Authors: Bae Hyeongyu , Lee Eunsang , Ahn Sungyoung , Jung Young Gwon , Yim Sang-Youp , Lee Joo-Hyoung , Lee Kang Taek
Published: November 2022

The photon upconversion (UC) is the process that has been known for a long time. Especially, lanthanide-based UC materials recently have attracted huge interest of scientific community due to their narrow visible emission bands upon near-infrared (NIR) excitation. However, the excitation in the high excitation power of NIR can cause highly bright and broad emission (B-UC). Such explosive B-UC was distinct at high excitation condition with UC wavelength encompassing the entire visible range. Previously, the proposed model of B-UC origination includes heat, multi-photon absorption, and accumulated thermal energy transfer. In this article, we will show various experimental and theoretical evidence supporting the idea that B-UC arises from photophysical pathways. Here, the key experimental evidence for photophysical pathways model of B-UC is to measure B-UC in the low-temperature environment (22 K). In addition, the density functional theory was used to regenerate energy levels which would be compared to the absorption spectral bands in Er2O3. As a result, we are confident of an electron tunneling model from 2P3/2 of Er3+ to oxygen vacancy level (VO) of Er2O3. Then, VO electrons are sequentially excited to the conduction band of Er2O3 by energy transfer from 4F9/2 of Er3+. Finally, the electrons return to the VO of Er2O3 with concomitant B-UC.
Polarization dependent photoemission as a probe of the magnetic ground state in the van der Waals ferromagnet VI3
Authors: Bergner Derek , Kong Tai , Ai Ping , Eilbott Daniel , Fatuzzo Claudia , Ciocys Samuel , Dale Nicholas , Stansbury Conrad , Latzke Drew W. , Molina Everardo , Reno Ryan , Cava Robert J. , Lanzara Alessandra , Ojeda-Aristizabal Claudia
Published: November 2022

Van der Waals ferromagnets are thrilling materials from both a fundamental and technological point of view. VI3 is an interesting example, with a complex magnetism that differentiates it from the first reported Cr based layered ferromagnets. Here, we show in an indirect way through angle resolved photoemission spectroscopy experiments, the importance of spin–orbit coupling setting the electronic properties of this material. Our light polarized photoemission measurements point to a ground state with a half-filled e±′ doublet, where a gap opening is triggered by spin–orbit coupling enhanced by electronic correlations.
Effect of dopant redistribution in gate electrode on surface plasmon resonance in InGaZnO thin-film transistors
Authors: Su Hui , Tang Wing Man , Lai Pui To
Published: November 2022

To study the effect of dopant redistribution at/near the gate-dielectric/gate-electrode interface during high-temperature processing on surface plasmon resonance in InGaZnO thin-film transistor, boron-doped Si wafers (resistivity = 0.02–0.021 Ω·cm) are annealed in N2 at different temperatures (900, 1000, 1050, and 1100 °C) to achieve lower surface doping concentrations via dopant out-diffusion and then used as the gate electrodes. Compared with the unannealed device, the devices fabricated on 900, 1050, and 1100 °C-annealed wafers show lower carrier mobility because the reduced doping concentrations at/near their gate-dielectric/gate-electrode interfaces weaken the gate screening effect on the remote phonon scattering (RPS) of the gate dielectric on the neighboring channel electrons. However, the device annealed at 1000 °C unexpectedly shows much lower carrier mobility. This result together with process simulation, Secondary Ion Mass Spectrometry analysis, and Fourier-transform infrared spectroscopy implies that the hole plasma at/near the surface of its p-Si gate electrode can oscillate with a frequency equal/close to the vibration frequency of the atoms in the gate dielectric, and the consequent surface plasmon resonance can greatly enhance the RPS to produce a large mobility reduction. In summary, for all the annealing temperatures, the mobility reduction caused by the lower gate-surface doping concentration indicates the larger impact of the holes at/near the gate-electrode surface than those in the gate-electrode bulk on the RPS.
The mechanism of improving germanium metal–oxide–semiconductor field-effect transistors’ reliability by high-k dielectric and yttrium-doping: From the view of charge trapping
Authors: Xiong Tao , Yang Juehan , Deng Hui-Xiong , Wei Zhongming , Liu Yue-Yang
Published: November 2022

The application of germanium (Ge)-based transistors has long been restricted by the poor reliability of the gate dielectrics. One solution proposed in the experiment is capping the GeO2 layer with high-k dielectrics and further doping the dielectric with yttrium (Y) atoms. However, the strategy only works at a very small doping concentration window, and the underlying mechanism remains unclear. Here, we carry out first-principles calculations on a concrete Ge/GeO2/ZrO2 stack to study the structural and electronic properties of various defects before and after Y-doping and further calculate their exact charge-trapping rates by the Marcus charge transfer theory. We show that the Y atoms can effectively weaken the charge-trapping capability of vacancy defects in the ZrO2 layer, but on the other hand, they can induce some new types of active defects if the density is high. In addition, it is found that the Y atoms can have a very different effect even when doped to the same material. These results indicate that a precise control of the doping position and doping concentration is necessary to promote the reliability of Ge transistors.
Validation of a torsional balance for thrust measurements of Hall effect and microwave-based space propulsion systems
Authors: Masillo S. , Stubbing J. , Swar K. , Staab D. , Garbayo A. , Lucca Fabris A.
Published: November 2022

A torsional thrust balance has been designed and validated by Surrey Space Centre and Added Value Solutions UK Ltd. in collaboration with the UK Space Agency. The thrust stand has been tested with two electric propulsion (EP) systems operating with xenon: the Halo thruster and the XJET thruster. The first consists of a low-power (<1 kW) Hall effect-based thruster, whose thrust level is between 3 and 20 mN, depending on the power of the system. The second is an electron cyclotron resonance thruster whose operative point is in the 0.3–1.5 mN thrust range. The thruster is mounted on a titanium rotating beam, whose movement is measured by an optical fiber displacement sensor. The thrusters’ direct current electrical connections are routed through room temperature liquid metal pots and microwave power is transmitted via a wireless transfer system, minimizing friction effects. To reduce thermal issues during long thruster operations, the torsional thrust balance is designed with a water-cooling hub around the flex pivot. Noise from the laboratory environment is lessened by using four vibration-dampening spring systems as thrust balance feet. The tests on the two EP systems have shown accurate and repeatable results, demonstrating that the balance can be used to characterize different EP systems in the μN–mN thrust range.
Extended Tauc–Lorentz model (XTL) with log-normal distributed bandgap energies for optical permittivity in polycrystalline semiconductors
Authors: Xu Chencheng , Min Byungsul , Reineke-Koch Rolf
Published: November 2022

An extended Tauc–Lorentz model is proposed to incorporate the bandgap variation in different grains in the polycrystalline semiconductors. The probability of a certain bandgap in the Tauc–Lorentz model is assumed to follow a log-normal distribution. After a Kramer–Kronig transform, the real part of this model is suggested as well. A comparison between this model and the experimental data in polycrystalline Si is carried out to validate this model. The experimental variation of grain size in the polycrystalline Si thin film can be correlated with the width of log-normal distribution of bandgap energies.
Wave-supported hybrid fast-thermal p-11B fusion
Authors: Kolmes E. J. , Ochs I. E. , Fisch N. J.
Published: November 2022

The possibility of fusion ignition in proton–Boron11 plasma is strongly enhanced if the energy from the fusion-produced α particles is channeled to fast protons, but in an environment in which most of the protons are thermally distributed. This hybrid of thermonuclear fusion and beam-plasma fusion offers surprisingly large advantages to either purely thermonuclear or purely beam-plasma fusion, neither of which can by themselves significantly exceed the large bremsstrahlung radiation emitted by the proton–Boron11 plasma. The hybrid scheme has the potential to reduce the confinement time of the reactants that is required to achieve ignition by an order of magnitude.
A general relation between the largest nucleus and all nuclei distributions for free energy calculations
Authors: Puibasset Joël
Published: November 2022

Prediction of nucleation rates in first order phase transitions requires the knowledge of the barrier associated with the free energy profile W. Molecular simulations offer a direct route through W = −kT ln pa, where k is Boltzmann’s constant, T is temperature, and pa is the probability distribution of the size of any nucleus. However, in practice, the extremely scarce spontaneous occurrence of large nuclei impedes the full determination of pa, and a numerical bias must be introduced, which is generally done on the size of the largest nucleus in the system, leading to the probability size distribution of the largest nucleus pl. Although pl is known to be system size dependent, unlike pa, it has extensively been used as an approximation for pa. This communication demonstrates an improved relation between pa and pl, which cures this approximation and allows an accurate calculation of free energy barriers from biased simulations.
Finite difference alternative unequal-sized weighted essentially non-oscillatory schemes for hyperbolic conservation laws
Authors: Wang Zhenming , Zhu Jun , Wang Chunwu , Zhao Ning
Published: November 2022

In this paper, two unequal-sized weighted essentially non-oscillatory (US-WENO) schemes are proposed for solving hyperbolic conservation laws. First, an alternative US-WENO (AUS-WENO) scheme based directly on the values of conserved variables at the grid points is designed. This scheme can inherit all the advantages of the original US-WENO scheme [J. Zhu and J. Qiu, “A new fifth order finite difference WENO scheme for solving hyperbolic conservation laws,” J. Comput. Phys. 318, 110–121 (2016).], such as the arbitrariness of the linear weights. Moreover, this presented AUS-WENO scheme enables any monotone fluxes applicable to this framework, whereas the original US-WENO scheme is only suitable for the more dissipative smooth flux splitting. Therefore, the method in this paper has a smaller L1 and L∞ numerical errors than the original scheme under the same conditions. Second, in order to further improve the computational efficiency of the above AUS-WENO scheme, a hybrid AUS-WENO scheme is proposed by combining a hybrid strategy. This strategy identifies the discontinuous regions directly based on the extreme points of the reconstruction polynomial corresponding to the five-point stencil, which brings the important advantage that it does not depend on the specific problem and does not contain any artificial adjustable parameters. Finally, the performance of the above two AUS-WENO schemes in terms of low dissipation, shock capture capability, discontinuity detection capability, and computational efficiency is verified by some benchmark one- and two-dimensional numerical examples.
First-principles determination of high thermal conductivity of PCF-graphene: A comparison with graphene
Authors: Chen Xue-Kun , Hu Xiao-Yan , Jia Pin-Zhen , Xie Guo-Feng
Published: November 2022

Poly-cyclooctatetraene framework (PCF)-graphene, an emerging all-sp2 hybridized two-dimensional (2D) carbon allotrope, possesses an intrinsic direct bandgap (0.77 eV) and excellent mechanical properties, indicating great potential in nanoelectronics. Understanding the thermal transport behavior of PCF-graphene is of vital importance for determining the reliability of related devices based on it. In this work, the thermal transport in PCF-graphene is systematically studied using the Boltzmann transport theory combined with first-principles calculations. The results show that the room-temperature thermal conductivity of PCF-graphene with only considering three-phonon scattering is as high as 1587.3 W/m K along the zigzag direction, and decreases by 27.1% (1157.4 W/m K) when including four-phonon scattering, indicating the four-phonon scattering plays a non-negligible role in in thermal transport. Although the thermal conductivity of PCF-graphene is not as large as that in graphene, it still exceeds most common 2D materials and makes it suitable for applications in the thermal management of microelectronics. Analyses of phonon group velocity and phonon scattering rates are conducted to reveal the high thermal conductivity of PCF. Moreover, as the temperature increases to 800 K, the reduction of thermal conductivity is close to 50% after including four-phonon scattering. The analysis of phonon group velocity and phonon scattering rates are conducted to reveal the underlying mechanism. Our results provide insights for constructing high-thermal-conductivity materials based on 2D carbon allotropes.
Hard- and soft-breakdown modeling in <001> oriented β-Ga2O3 Schottky barrier diode
Authors: Sugiura Takaya , Nakano Nobuhiko
Published: November 2022

Gallium oxide (Ga2O3) attracts considerable technological interest because of its high Baliga’s figure-of-merit and high breakdown voltages. As the models for the breakdown behavior of n-doped Ga2O3 that consider soft (barrier lowering) and hard (avalanche effect) breakdowns are still lacking, in this study, we model the breakdown operations in <001> oriented Schottky barrier diodes considering both the soft- and hard-breakdown phenomena. The completion of the impact ionization model of β-Ga2O3 in <001> orientation is proposed by determining the hole impact ionization coefficient, thereby reproducing hard breakdown operations. Moreover, a barrier lowering model is determined for reproducing soft breakdown operations. The outcomes of the proposed modeling investigation are expected to be crucial for predicting the reverse-biased operations of β-Ga2O3 in <001> orientation to facilitate further technological development and applications of Ga2O3.
Spectroscopic detection of the stannylidene (H2C=Sn and D2C=Sn) molecule in the gas phase
Authors: Smith Tony C. , Gharaibeh Mohammed , Clouthier Dennis J.
Published: November 2022

The H2CSn and D2CSn molecules have been detected for the first time by laser-induced fluorescence (LIF) and emission spectroscopic techniques through the B̃1B2−X̃1A1 electronic transition in the 425–400 nm region. These reactive species were prepared in a pulsed electric discharge jet using (CH3)4Sn or (CD3)4Sn diluted in high-pressure argon. Transitions to the electronic excited state of the jet-cooled molecules were probed with LIF, and the ground state and low-lying Ã1A2 state energy levels were measured from single vibronic level emission spectra. We supported the experimental studies by a variety of ab initio calculations that predicted the energies, geometries, and vibrational frequencies of the ground and lower excited electronic states. The spectroscopy of stannylidene (H2CSn) is in many aspects similar to that of silylidene (H2CSi) and germylidene (H2CGe).