bluuebunny/crossref_metadata_2025 huggingface dataset:
Évolution, modélisation et cartographie des rendements de l’oliveraie dans la province de Jaen en Espagne (1959-2018)
Authors: Arfaoui Fatma , Cohen Marianne , Oudin Ludovic , Ronchail Josyane
Published: February 2022

Les acteurs de l’oléiculture en Andalousie s’interrogent sur l’impact du changement climatique sur leur activité, très importante en termes de surfaces concernées, de production et de revenus. Pour tenter de leur répondre, ce travail décrit tout d’abord l’évolution du climat et des rendements annuels des oliveraies pluviales et irriguées dans la province de Jaén (Andalousie) depuis les années 50. Puis sont réalisées des modélisations des relations entre les rendements pluviaux et irrigués provinciaux et des variables climatiques TerraClimate (à résolution de 4 km), moyennées sur la zone oléicole de la province de Jaén. Enfin, les modèles permettent de calculer puis de cartographier la répartition théorique actuelle des rendements. Les rendements, très variables d’une année sur l’autre, plus élevés dans les vergers irrigués que dans les vergers pluviaux, ont fortement augmenté depuis la fin des années cinquante puis ils se sont stabilisés à partir de la fin des années 1990, avec en moyenne 30 q/ha en pluvial et 51 q/ha en irrigué pour la période 1996-2018. Par ailleurs, les températures, moyennées sur la zone oléicole de la province de Jaén, ont augmenté, surtout les températures diurnes, essentiellement durant la saison chaude. Les précipitations, très variables d’une année sur l’autre, ont diminué de 16% après 1979. Entre 1996 et 2018, les variables qui expliquent le mieux les rendements sont les pluies annuelles et les températures minimales d’automne et d’août dans les oliveraies pluviales, et les pluies et températures minimales d’automne, les températures maximales d’été et les températures minimales de février, dans les oliveraies irriguées. Des valeurs de rendement théoriques en pluvial et en irrigué sont calculées par régression multiple (1996-2018), validées par cross-validation. Les valeurs théoriques sont ensuite cartographiées sur des pixels de 4 km de côté. Si les valeurs simulées et moyennées (1996-2018) sont proches des valeurs provinciales observées, avec une erreur-moyenne de 6 q/ha en irrigué et en pluvial, leur répartition spatiale n’est pas tout à fait cohérente avec quelques informations disponibles à l’échelle communale. Il conviendra donc de perfectionner la modélisation des rendements et leur cartographie avant de passer à l’étape suivante : simuler et cartographier les rendements potentiels futurs, compte tenu du changement climatique, pour disposer d’un outil de discussion avec les oléiculteurs et les aider à préparer l’adaptation de leur activité.
Design science masterplan in improving online investing decision support services
Authors: Paatela Antti
Published: February 2022

Online services supporting consumer investing have proliferated during the last three decades. Empirical research has discovered that overperforming investors started to underperform after switching to online investing services. Recent studies have revealed that individuals ignore the decision support provided by incumbent investing platforms, relying on their instincts instead. In response, a research project was launched, with the main goal to define technology, acceptance and service ecosystem originated reasons for not meeting investor expectations. A 'design science master plan' process was developed to identify and filter critical developments from a large number of suggested improvements. The ultimate goal was to enable a self-directed investor to manage investing assets with a performance of a professional, but with better control than delegated or fully automated investing services allow. A sample of live online investing platforms was used for problem discovery. In remote-controlled experiments, ten investors representing five investor personas evaluated the selected services. Identified problems and opportunities were analysed and conceptualised, after which design evaluations were made. Participants prioritised the defined development initiatives in terms of relevance and expected personal acceptance. A suggestion for more modular and specialised service architecture was made.
The mutations of project-based learning in the context of information services
Authors: Szilas Nicolas
Published: February 2022

From a use case concerning a master level course on pedagogical video games, this article describes how Project-Based Learning uses Internet-based services. Initially, Information services have been mostly used to facilitate communication between the students and the teacher, and to provide support in the project management. More recently, Internet has more deeply changed the philosophy of PBL, towards an increased integration into the real world. An innovative approach has emerged, in which products delivered by the students are both disseminated and reused for the course itself, for future classes.
Towards Knowledge-based Smart Service Systems: The Case of a Recommender System for a Cultural Organization
Authors: Le Dinh Thang , Dam Nguyen Anh Khoa , Ho Gia Huan
Published: February 2022

Big data and artificial intelligence (AI) lead to a revolution that transforms conventional enterprises into data-driven organizations in which knowledge discovered from big data and processed by AI techniques will be integrated into traditional knowledge in order to provide smart services to business users. Consequently, a major concern is how to design and develop a knowledge-based smart service system for supporting AI-based applications. This paper proposes an approach for elaborating a knowledge-based smart service system and demonstrates the approach with a case study about a knowledge-based smart service system for a cultural organization. The proposed approach includes different layers such as Data-as-a-Service, Information-as-a-Service, Knowledge-as-a-Service, and Insight-as-a-Service.
Influence of laser surface structuring of steel sheets on the mechanical properties of electrodeposited ZnNi coatings
Authors: Stelter Christian , Dieckhoff Stefan
Published: February 2022

The influence of laser surface structuring on the formation and the internal strength of electrodeposited ZnNi coatings on steel sheets was investigated. Surface structuring by extended direct laser interference patterning (xDLIP) was used to modify the cohesive strength in the ZnNi layer. An SEM analysis of the crystal structures shows perpendicular nucleation during ZnNi layer formation and areas of crosslinked crystalline structures, which results in an interlocking of crystal structures within the layer. The interlocked crystalline structure leads to an increase of the cohesive strength in the ZnNi layer, which was observed in roller peel tests according to DIN 1464 for adhesively bonded joints.
Inventory decision for products with deterioration and expiration dates for pollution-based supply chain model in fuzzy environments
Authors: Choudhury Mukunda , De Sujit Kumar , Mahata Gour Chandra
Published: February 2022

The proposed study addresses a two-echelon sustainable supply chain (SC) model with a single-vendor and a single-buyer by considering the detrimental impacts of environmental pollution due to production. Moreover, an estimation function of pollution measure due to production is developed through a separate modelling. In the entire supply chain, we assume the deterioration rate increases with time and it also depends on the product’s expiration date. On the other hand, the demand for deteriorating items at the buyer’s end is assumed to be the dense fuzzy number because of learning effect. The model is developed by defining the exact profit functions for the vendor, the buyer and the entire supply chain and solved by classical method. These lead to the determination of individual optimal policies, as well as the optimal policy for the joint integrated supply chain. Fuzzifying the final objective function via dense fuzzy rule, we have employed extended ranking procedure for its defuzzification. A comparative study on numerical illustration of the proposed objective function under centralized and decentralized policies in both crisp and dense fuzzy environment has also been studied to validate the model. Finally graphical illustrations and sensitivity analysis have been made for its global justifications.
Epilepsien erkennen, einordnen und behandeln
Authors: Lauber Margarete
Published: February 2022

Epilepsie kann sich auf verschiedene Arten äußern. Oft ist es schwierig, sie zu diagnostizieren. Für eine bestmögliche Hilfe der betroffenen Kinder und ihrer Familien nehmen Pflegende eine Schlüsselrolle ein – von der Beobachtung der Anfälle über ihre Dokumentation und Begleitung bis hin zum Umgang mit den Auswirkungen.
Isolated Compounds from Buddleja Coriacea
with
Antibacterial and Anti-Inflammatory Activities in the Urinary
Tract
Authors: Ticona Luis Apaza , Rico Francisco Aguilar , Sánchez-Corral Javier Sánchez , Domenech Montserrat Ortega , Sánchez Ángel Rumbero
Published: February 2022

Buddleja coriacea Remy is one of the plant species used by the Bolivian
population for the treatment of urinary infections. This study aimed to identify
the extract, fractions, and compounds responsible for the antibacterial and
anti-inflammatory activities of B. coriacea leaves. Bioguided isolation
of compounds with antibacterial and anti-inflammatory activities was carried out
by measuring the antibacterial effect against specific pathogenic microbial
strains, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas
aeruginosa, and Serratia marcescens, and the inhibition of
NF-κB in RM-2 and MM.14Ov cells. Bioassay-guided isolation
led to the isolation and characterisation of
(4aR,4bS,5 S,6aS,6bS,9aR,10aS,10bS)-6b-glycoloyl-5-hydroxy-4a,6a-dimethyl-8-propyl-4a,4b,5,6,6a,6b,9a,10,10a,10b,11,12-dodecahydro-2H-naphtho
[2',1':4,5] indeno [1,2-d][1,3] dioxol-2-one (1),
3-[3-(2-dimethylaminoethyl)-1H-indol-5-yl]-N-(4-methoxybenzyl)
acrylamide (2), and
(1β,11β,12α)-1,11,12-trihydroxy-11,20-epoxypicrasa-3,13(21)-diene-2,16-dione
(3) by nuclear magnetic resonance and mass spectroscopy. All
compounds showed antibacterial activity with minimum inhibitory concentration
values of 11.64–11.81, 0.17–0.19, and
0.34–0.36 µM, respectively, on the tested
strains, while the positive control, ofloxacin, had a minimum inhibitory
concentration of 27.66 µM. Finally, all the compounds
showed NF-κB inhibitory activity with IC50 values of
11.25–11.34, 0.15–0.16, and
0.33–0.36 µM, respectively, in all cell
lines, while the positive control, celastrol, had an IC50 of
7.96 µM. Thus, this study managed to isolate and
evaluate for the first time the pharmacological potential of three compounds
present in the leaves of B. coriacea with antibacterial and
anti-inflammatory activities.
POCUS-Punktion
Authors: Spindler Beate , Rickert Kathleen , Shahverdyan Robert
Published: February 2022

Die POCUS-Punktion (POCUS: „point-of-care ultrasound“) ist die vierte Punktionstechnik des Dialyseshunts. Bisherige Techniken orientieren sich am Ort der Punktionsstelle. Die konventionelle Punktion basiert auf Erfahrung, Gefühl oder auch persönlichem Geschick – man kann auch „blind“ dazu sagen. Die POCUS-Punktion ist die einzige Punktionstechnik, welche mithilfe eines „real-time“ Bildes erfolgt. Mit diesem Artikel soll die vierte Punktionstechnik eingeführt werden. Neue endovaskuläre AV-Fistel-Anlage-Techniken führen vorübergehend zu schwierigen punktierbaren Gefäßverhältnissen. Es sind keine OP-Narben erkennbar und die Punktionsstrecke ist zunächst kaum tastbar. Neben der wissenschaftlichen Aufarbeitung des Themas gibt eine leitende Pflegekraft Einblicke in die Implementierung der POCUS-Punktion in einer Klinikdialyse.
Abstracts können eingereicht werden und Newsletter wird News
Authors: Nipshagen Sabine
Published: February 2022

Ich hoffe, Sie sind alle gut in das neue Jahr gestartet, und ich möchte Ihnen an dieser Stelle noch ein gutes und gesundes neues Jahr wünschen. Diesen Artikel schreibe ich Anfang Dezember mit dem Wissen, dass die Pandemie uns auch in diesem Winter wieder viel abverlangt. Umso mehr wünsche ich uns, dass wir jetzt im Februar einem entspannteren Frühjahr entgegensehen.
M-Sign in Middle Cerebral Artery Doppler Waveforms: A Sign of Fetal Vasoconstriction Before and After Open Fetal Spina Bifida Repair
Authors: Vonzun Ladina , Gonser Markus , Moehrlen Ueli , Mazzone Luca , Meuli Martin , Kandler Lukas , Wille David , Kraehenmann Franziska , Zimmermann Roland , Ochsenbein-Kölble Nicole
Published: February 2022

Background Increased pulse wave reflection in the fetal arterial
system, illustrated by a second systolic peak (M-sign) in middle cerebral artery (MCA) Doppler
waveforms, allows interpretation of fetal systemic vasoconstriction. Little is known about
fetal vascular regulation during fetal spina bifida (fSB) repair. Therefore, the aim of this
study was to analyze MCA-Doppler waveform changes before, during, and after fSB repair. Patients and Methods 31 pregnant women who underwent fSB repair were
included. Fetal MCA-Doppler waveforms were prospectively analyzed before, during and after
fSB repair, and categorized as follows: normal systolic downslope, systolic shoulder, second
systolic peak (M-sign), and concave systolic downslope. These MCA waveforms were related to
maternal and fetal characteristics, to anesthetic medication, and to umbilical artery (UA)
waveforms. Results Before fSB repair, all fetuses repeatedly
presented M-signs. After initiation of desflurane for general anesthesia, systolic shoulder
and the M-sign vanished in 24/31 (78%) fetuses and 19/31 (61%) showed transient UA ARED
flow. A significant association between these two Doppler findings was found (p=0.007). After
fSB repair, signs of increased pulse wave reflection reappeared but resolved over time (23
days ± 20, SD) in all fetuses. Conclusion Both fSB and intrauterine
repair influence fetal vascular regulation. This phenomenon can be illustrated by MCA-Doppler
waveforms. While anesthetic agents transiently eliminated M-signs and often provoked a UA ARED
flow, fSB repair finally led to normalization of MCA-Doppler waveforms indicating return to
normal fetal vascular regulation.
Impact of surgical versus endoscopic management of complex nonmalignant polyps in a colorectal cancer screening program
Authors: Buskermolen Maaike , Naber Steffie K. , Toes-Zoutendijk Esther , van der Meulen Miriam P. , van Grevenstein Wilhelmina M. U. , van Leerdam Monique E. , Spaander Manon C. W. , Lansdorp-Vogelaar Iris
Published: February 2022

Background When complex nonmalignant polyps are detected in colorectal cancer (CRC) screening programs, patients may be referred directly to surgery or may first undergo additional endoscopy for attempted endoscopic removal by an expert. We compared the impact of both strategies on screening effectiveness and costs.

Methods We used MISCAN-Colon to simulate the Dutch screening program, and projected CRC deaths prevented, quality-adjusted life-years (QALYs) gained, and costs for two scenarios: 1) surgery for all complex nonmalignant polyps; 2) attempted removal by an expert endoscopist first. We made the following assumptions: 3.9 % of screen-detected large nonmalignant polyps were complex; associated surgery mortality was 0.7 %; the rate of successful removal by an expert was 87 %, with 0.11 % mortality.

Results The screening program was estimated to prevent 11.2 CRC cases (–16.7 %) and 10.1 CRC deaths (–27.1 %), resulting in 32.9 QALYs gained (+ 17.2 %) per 1000 simulated individuals over their lifetimes compared with no screening. The program would also result in 2.1 surgeries for complex nonmalignant polyps with 0.015 associated deaths per 1000 individuals. If, instead, these patients were referred to an expert endoscopist first, only 0.2 patients required surgery, reducing associated deaths by 0.013 at the expense of 0.003 extra colonoscopy deaths. Compared with direct referral to surgery, referral to an expert endoscopist gained 0.2 QALYs and saved €12 500 per 1000 individuals in the target population.

Conclusion Referring patients with complex polyps to an expert endoscopist first reduced some surgery-related deaths while substantially improving cost-effectiveness of the screening program.
DGfN hat 10-Punkte-Plan vorgelegt
Authors: Albers Bettina
Published: February 2022

Heimdialyseverfahren sind in Deutschland unterrepräsentiert. Die im Rahmen des Innovationsfonds geförderte MAU-PD-Studie identifizierte Faktoren für den geringen Anteil der Heimverfahren. Die Deutsche Gesellschaft für Nephrologie (DGfN) zog Konsequenzen und entwickelte einen 10-Punkte-Plan zur Stärkung der Heimdialyse und Nierentransplantation.
Functionalized d- and l-Arabino-Pyrrolidines as Potent and Selective Glycosidase Inhibitors
Authors: Lindbäck Emil , Sydnes Magne O. , Haarr Marianne B. , Lopéz Óscar , Fernández-Bolaños Jóse G.
Published: February 2022

The efficient synthesis of enantiomeric pairs of iminosugars including 1,4-dideoxy-1,4-imino-d-arabinitol (DAB) and 1,4-dideoxy-1,4-imino-l-arabinitol (LAB) analogues with an amidine, hydrazide, hydrazide imide, or amide oxime moiety is described. The preparation of DAB and LAB analogues commenced from l-xylose and d-xylose, respectively. The obtained iminosugars are tested against a panel of glycosidases with pharmaceutical relevance, revealing enhanced activity for the DAB analogues in comparison with the LAB analogues. In particular, the d-arabino-configured amidine behaved as a potent (submicromolar range) and selective inhibitor of α-mannosidase.
From Ring-Expansion to Ring-Contraction: Synthesis of γ-Lactones from Cyclobutanols and Relative Stability of Five- and Six-Membered Endoperoxides toward Organic Bases
Authors: Ferrié Laurent , Jamey Nicolas
Published: February 2022

Cyclobutanols undergo ring expansion with molecular oxygen in the presence of Co(acac)2 to afford 1,2-dioxane-hemiperoxyketals. In the course of acylation, we observed that endoperoxides rearranged into γ-lactone in the presence of triethylamine. Thus, a generalization of this ring contraction through a Kornblum–DeLaMare rearrangement is here reported. Application of this transformation to monosubstituted 1,2-dioxane derivatives also led to 1,4-ketoaldehydes, in proportions depending on the nature of the substituent. These same conditions applied to five-membered dioxolane analogues led to fragmentation instead, through a retro-aldol type process. This study emphasizes the difference of stability of 1,2-dioxane and 1,2-dioxolane against organic bases, 1,2-dioxolanes having proved to be particularly reactive whereas 1,2-dioxanes showed a relative tolerance under these conditions.
Adjunctive Middle Turbinectomy for Endoscopic Medial Orbital Wall – Thyroid Eye Disease Decompression
Authors: Tooley Andrea A. , Kim Matthew , Tran Ann Q. , Kazim Michael , Gudis David A.
Published: February 2022

Introduction Middle turbinate resection (MTR) is commonly performed during endonasal endoscopic sinus and skull base surgery.

Objective The purpose of this study was to characterize the additional orbital soft-tissue volume expansion during endoscopic medial orbital wall decompression with adjunctive MTR.

Methods A retrospective review of patients who underwent endoscopic medial wall decompression with MTR was performed. The imaging software AW (GE Healthcare, Chicago, IL, USA) was used to overlay pre and postoperative orbital computed tomography (CT) images to visualize the preoperative position of the middle turbinate and the postoperative orbital soft tissue in the ethmoid bed. The imaging software Vitrea (Vital Images Inc., Minnetonka, MN, USA) was used to manually segment postoperative scans to determine the volume of orbital tissue which had filled the space previously occupied by the middle turbinate or medial to it.

Results Nine orbits from 5 patients were included in this study; all patients were female with a history of hyperthyroidism. The average age was 55.6 years (range 32–74). Of the 9 orbits, 7 (78%) had orbital soft tissue within the space of the resected middle turbinate postoperatively. The average volume of orbital tissue within or medial to this space was 0.83 +/− 0.67 cc. No patients had any postoperative complications.

Conclusions In this patient cohort, adjunctive middle turbinate resection for endoscopic medial orbital wall decompression added ∼ 0.83 cc of volume for orbital soft tissue after medial wall decompression. Middle turbinate resection is a useful adjunct to the orbital surgeon's armamentarium to augment the results of a medial orbital decompression for select patients.
Bacterial Spectrum and Infective Foci in Patients Operated for Infective Endocarditis: Time to Rethink Strategies?
Authors: Schulze Marco H. , Niehaus Heidi , Saha Shekhar , Dudakova Anna , Danner Bernhard C. , Kutschka Ingo
Published: February 2022

Objective The rising incidence of infective endocarditis (IE) accompanied by the de-escalation of antibiotic prophylaxis and the complexity of surgical treatment makes IE a daunting foe. We reviewed all patients who underwent cardiac surgery for IE at our institution with a focus on causative organisms and infective foci.

Methods A review of 3,952 consecutive patients who underwent cardiac surgery at our institution between January 2013 and December 2017 revealed 160 patients (4%) who were operated for IE.

Results The predominantly affected valves were the aortic (30%) and mitral valve (26.9%) as well as a combination of both (8.8%). A total of 28.8% of patients suffered from prosthetic valve endocarditis (PVE). The most frequently identified causative organisms were Staphylococcus (45.7%), Streptococcus (27.5%), and Enterococcus species (16.7%), which was predominantly associated with PVE (p = 0.050). In 13.1% of patients, a causative organism has not been detected. The most frequent infective foci were dental (15%), soft-tissue infections (15%), spondylodiscitis (10%), and infected intravascular implants (8.8%). Relevant predisposing factors were immunosuppression (9.4%) and intravenous drug abuse (4.4%). Septic cerebral infarctions were diagnosed in 28.8% of patients. Postoperative mortality was 22.5%.

Conclusions As the bacterial spectrum and the infective foci are still the “old acquaintances,” and with regard to the increasing incidence of IE, current risk–benefit evaluations concerning antibiotic prophylaxis may need to be revisited.
Extended many-body superradiance in diamond epsilon near-zero metamaterials
Authors: Mello Olivia , Li Yang , Camayd-Muñoz Sarah Alejandra , DeVault Clayton , Lobet Michaël , Tang Haoning , Lonçar Marko , Mazur Eric
Published: February 2022

We theoretically and numerically demonstrate enhanced extended superradiance using a diamond epsilon near-zero metamaterial design. Due to the large spatial coherence in this metamaterial, we experience an ultra-high superradiant decay rate enhancement over distances greater than 13 times the free-space wavelength for both two emitters and many-body configurations of emitters. We observe a power enhancement three orders of magnitude higher than an incoherent array of emitters in bulk diamond, corresponding to an N2 scaling with the number of emitters characteristic of superradiance.
ΔNO and the complexities of electron correlation in simple hydrogen clusters
Authors: Elayan Ismael A. , Gupta Rishabh , Hollett Joshua W.
Published: February 2022

The Δ natural orbital (ΔNO) two-electron density matrix (2-RDM) and energy expression are derived from a multideterminantal wave function. The approximate ΔNO 2-RDM is combined with an on-top density functional and a double-counting correction to capture electron correlation. A trust-region Newton’s method optimization algorithm for the simultaneous optimization of ΔNO orbitals and occupancies is introduced and compared to the previous iterative diagonalization algorithm. The combination of ΔNO and two different on-top density functionals, Colle–Salvetti (CS) and Opposite-spin exponential cusp and Fermi-hole correction (OF), is assessed on small hydrogen clusters and compared to density functional, single-reference coupled-cluster, and multireference perturbation theory (MRMP2) methods. The ΔNO-CS and ΔNO-OF methods outperform the single-reference methods and are comparable to MRMP2. However, there is a distinct qualitative error in the ΔNO potential energy surface for H4 compared to the exact. This discrepancy is explained through analysis of the ΔNO orbitals, occupancies, and the two-electron density.
Theory, observations, and simulations of kinetic entropy in a magnetotail electron diffusion region
Authors: Argall M. R. , Barbhuiya M. H. , Cassak P. A. , Wang S. , Shuster J. , Liang H. , Gershman D. J. , Torbert R. B. , Burch J. L.
Published: February 2022

We examine velocity-space kinetic entropy, a spatially local measure of entropy for systems out of thermal equilibrium, during an encounter of an electron diffusion region at a magnetic reconnection site in Earth's magnetotail by the Magnetospheric Multiscale (MMS) mission. We start by generalizing the theory of kinetic entropy to the case of non-uniform velocity space grids and transforming the equations into spherical energy coordinates useful to experimental plasma detectors. The theory is then applied to MMS data and compared to particle-in-cell simulations of reconnection. We demonstrate that the entropy-based non-Maxwellianity measure from the MMS data is of sufficiently high precision to reliably identify non-Maxwellian distributions and therefore the measurements when kinetic effects are most significant. By comparing two different non-Maxwellian measures, we show that total entropy density suffers from “information loss” because it lacks a dependence on the velocity space grid, and so has lost information about how well a distribution function is resolved. Local velocity-space kinetic entropy density recovers this information. We quantify information loss and argue that the considerations needed to minimize it are crucial for instruments designed to measure distribution functions in situ.
Occurrence characteristics of gaseous cavitation in oil shear flow
Authors: Iga Yuka , Okajima Junnosuke , Takahashi Shunpei , Ibata Yousuke
Published: February 2022

In the present study, a decompression experiment involving two rotating concentric cylinders with hydraulic oil between the clearances was performed. The dependency of the occurrence condition of gaseous cavitation in the oil was investigated not only based on rotation speed, which corresponds to the shear strength of a flow, but also on decompression speed, which corresponds to the pressure history in a flow. As a result, the characteristics of occurrence of gaseous cavitation were found to be divided into two regions of separation: equilibrium separation in which the occurrence pressure is constant with respect to the decompression speed, which occurs under lower decompression conditions, and non-equilibrium separation in which the occurrence pressure decreases according to the increase in the decompression speed, which occurs under higher decompression conditions. In addition, the boundary decompression speed between the equilibrium and non-equilibrium separations and the non-equilibrium separation pressure were formulated.
Dynamic tensorial eddy viscosity model: Effects of compressibility and of complex geometry
Authors: Abbà A. , Cimarelli A. , Germano M.
Published: February 2022

A previous paper by Cimarelli et al. [“General formalism for a reduced description and modelling of momentum and energy transfer in turbulence,” J. Fluid Mech. 866, 865–896 (2019)] has shown that every decomposition of turbulent stresses is naturally approximated by a general form of tensorial eddy viscosity based on velocity increments. The generality of the formalism is such that it can also be used to give a reduced description of subgrid scalar fluxes. In the same work, this peculiar property of turbulent stresses and fluxes has been dynamically exploited to produce tensorial eddy viscosity models based on the second-order inertial properties of the grid element. The basic idea is that the anisotropic structure of the computational element directly impacts, although implicitly, the large resolved and small unresolved scale decomposition. In the present work, this new class of turbulence models is extended to compressible turbulence. A posteriori analysis of flow solutions in a compressible turbulent channel shows very promising results. The quality of the modeling approach is further assessed by addressing complex flow geometries, where the use of unstructured grids is demanded as in real world problems. Also in this case, a posteriori analysis of flow solutions in a periodic hill turbulent flow shows very good behavior. Overall, the generality of the formalism is found to allow for an accurate description of subgrid quantities in compressible conditions and in complex flows, independent of the discretization technique. Hence, we believe that the present class of turbulence closures is very promising for the applications typical of industry and geophysics.
Current distribution at underwater electrical explosion of wires with different diameter connected in parallel
Authors: Yin Guofeng , Shi Huantong , Li Tuan , Hu Yujia , Wu Guangning , Li Xingwen , Wu Jian
Published: February 2022

Underwater electrical wire explosion is usually used as a source of underwater shock waves, and the generated shock wave intensity can be regulated by adopting a wire array. In this paper, the dynamics of the electrical explosion of two wires with different diameters connected in parallel were studied. The current flowing through each wire was measured to study the current distribution, and the self-emission image and laser backlight shadow image was obtained to observe the evolution of the wires. A numerical model was built to make explanations and predictions. The results showed that due to the presence of wire inductance and contact resistance between the wire and electrode, the wires are with different current densities and undergo asynchronous heating from the beginning of the discharge. Furthermore, the variation of current distribution among the wires was divided into six stages according to the moment the wire melted and exploded, and analyzed stage by stage. The unbalanced energy deposition results in obvious differences in thermal dynamic parameters, which explains the gradual “extinguishment” of the thinner wire in the self-emission image.
A mechanical model of partially liquefied vitreous dynamics induced by saccadic eye movement within a realistic shape of vitreous cavity
Authors: Bayat Javad , Emdad Homayoun , Abouali Omid
Published: February 2022

The vitreous undergoes physical and biochemical changes with age. The most important of such degenerative changes is vitreous liquefaction or synchysis, in which pockets of liquid known as lacunae form in the vitreous gel. The movement mechanism and characteristics of vitreous liquefaction are quite complex. In this study, the flow dynamics of partial vitreous liquefaction (PVL) as two-phase viscoelastic-Newtonian fluid flow are investigated in the human eye. A reliable three-dimensional (3D) numerical procedure is developed for capturing the interface effects and dynamic characteristics of these two-phase complex fluid flows. In the present work, two different configurations of the PVL including liquefied pocket in the central and the posterior portions of the vitreous cavity are considered. The effects of lens indentation on the flow field and interface deformation of PVL inside the vitreous cavity are investigated. The results show that the curvature of the vitreous cavity due to the lens capsule increases shear and normal stresses in comparison with those for the PVL in a sphere as a simplified model. It is observed that the presence of lens indentation and the location of liquefied region are two factors that can produce conditions of asymmetry inside the vitreous body. In a realistic model of vitreous cavity, although the velocity magnitude inside the liquefied vitreous region increases when the liquefied pocket is in the posterior portion of the vitreous cavity, the stress values and the asymmetric condition of flow field become more significant for the liquefied pocket located close to the posterior lens curvature.
Wind tunnel study on the wake characteristics of a wind turbine model subjected to surge and sway motions
Authors: Meng Haoran , Su Hao , Qu Timing , Lei Liping
Published: February 2022

An experimental study was performed in a uniform incoming flow wind tunnel to investigate the effect of surge and sway motions on the wake characteristics of a wind turbine model. The platform surge and sway motions can be simulated at prescribed amplitudes and frequencies through a translation stage mounted on the base of the turbine model. The flow fields of near, intermediate, and far wakes of the turbine model were characterized by a particle image velocimetry system. Results show that the mean velocity profiles during the whole surging and swaying process of the downwind wakes were almost unchanged with that of a base-fixed turbine; however, the maximum mean velocity differences appeared near the blade tips for both motions compared with the base-fixed cases. Little difference was found between the mean velocity profiles of the turbine model while moving in different directions, for both the surge and sway motions. Later, the characteristics of instantaneous velocity profiles were investigated, and the lateral offset of the instantaneous velocity profiles for the swaying turbine at the two ends of the sway motion was observed. The offset distance was very close to sway amplitudes within the near wake, and it gradually decreased until it disappeared as the downstream distance increases. This work may provide an instrumental guide in the further research on the wake of floating offshore wind turbines.
Emergent magnetic monopole and dipole screening by free electrons in aluminum/artificial spin ice heterostructures
Authors: Martins Fernando F. , Paiva Teônis S. , Duarte Daniel G. , Rodrigues João H. , Mól Lucas A. S. , de Araujo Clodoaldo I. L.
Published: February 2022

In this work, we present screening of magnetic monopole and dipole by the presence of a 20 nm aluminum cover layer on square artificial spin ice systems. Our measurements were performed by magnetic force microscopy on samples with and without aluminum at remanence, after application of successive external magnetic field steps. Experimental results show that both evolution of magnetization and monopole population under external field are affected by the aluminum presence. Very good agreement between those results and excitation model simulations was found when both emergent magnetic monopole and dipole strengths decrease on the presence of the aluminum cap. We suggest that the observed strength weakening of emergent particles occurs due to its field screening by aluminum-free electrons. The screening on the presented heterostructure could be used for devices design with different magnetic monopole mobility or for selective thermodynamic activation in samples close to superparamagnetic regime.
Robust valley polarization induced by super-exchange effects in HfNX (X = Cl, Br, I)/FeCl2 two-dimensional ferrovalley heterostructures
Authors: Sun R. J. , Lu J. J. , Zhao X. W. , Hu G. C. , Yuan X. B. , Ren J. F.
Published: February 2022

The enthusiasm for predicting the properties of valley materials continues to grow due to the much attention of valley degrees of freedom. In this Letter, a two-dimensional ferromagnetic half-metal 1T-FeCl2 with super-exchange interactions and high Curie temperature is used to construct ferrovalley heterostructures under the means of magnetic proximity effects. The valley polarization up to 47.6 meV can be achieved in the HfNX (X = Cl, Br, I)/FeCl2. Meanwhile, we modulate the valley polarization by changing the interlayer spacing, applying biaxial strain, and changing the magnetization directions. Surprisingly, we find that the super-exchange interactions of the 1T-FeCl2 lead to particular robustness of the valley polarization, so the valley signals in this structure are nonvolatile. Finally, the Berry curvature demonstrates that the HfNI/FeCl2 is capable of achieving the anomalous valley Hall effect. The controllability and the robustness of the valley polarization in HfNX/FeCl2 heterostructure are expected to overcome the volatility of the valley signals, which will be of great help for future applications in spintronics and valleytronics.
Electromigration reliability and activation energy of Bi2Te3 thermoelectric film
Authors: Ren Chaojie , Zhu Wei , Zhou Jie , Wu Xue , Deng Yuan
Published: February 2022

Reliability problems caused by metal electromigration failure have attracted much attention, but it is barely investigated for thermoelectric semiconductors with increased current density in micro thermoelectric devices. Herein, we investigate electromigration reliability of a Bi2Te3 thermoelectric film with the current densities of ∼104 A/cm2. The failure mechanism and thermoelectric performance change of the Bi2Te3 film at different current densities by controlling the temperature are discussed, indicating the reliability issue is a comprehensive problem involving multiphysics effects. In addition, the activation energy of Bi2Te3 materials, as an essential electromigration parameter, is measured and calculated to be about 0.8 eV by the resistance change method. This work provides much guidance to the reliable service of thin-film TE devices operating under high current density.
Real-space density kernel method for Kohn–Sham density functional theory calculations at high temperature
Authors: Xu Qimen , Jing Xin , Zhang Boqin , Pask John E. , Suryanarayana Phanish
Published: February 2022

Kohn–Sham density functional theory calculations using conventional diagonalization based methods become increasingly expensive as temperature increases due to the need to compute increasing numbers of partially occupied states. We present a density matrix based method for Kohn–Sham calculations at high temperatures that eliminates the need for diagonalization entirely, thus reducing the cost of such calculations significantly. Specifically, we develop real-space expressions for the electron density, electronic free energy, Hellmann–Feynman forces, and Hellmann–Feynman stress tensor in terms of an orthonormal auxiliary orbital basis and its density kernel transform, the density kernel being the matrix representation of the density operator in the auxiliary basis. Using Chebyshev filtering to generate the auxiliary basis, we next develop an approach akin to Clenshaw–Curtis spectral quadrature to calculate the individual columns of the density kernel based on the Fermi operator expansion in Chebyshev polynomials and employ a similar approach to evaluate band structure and entropic energy components. We implement the proposed formulation in the SPARC electronic structure code, using which we show systematic convergence of the aforementioned quantities to exact diagonalization results, and obtain significant speedups relative to conventional diagonalization based methods. Finally, we employ the new method to compute the self-diffusion coefficient and viscosity of aluminum at 116 045 K from Kohn–Sham quantum molecular dynamics, where we find agreement with previous more approximate orbital-free density functional methods.
Quantum state-dependent anion–neutral detachment processes
Authors: Hassan Saba Zia , Tauch Jonas , Kas Milaim , Nötzold Markus , Wester Roland , Weidemüller Matthias
Published: February 2022

The detachment loss dynamics between rubidium atoms (Rb) and oxygen anions (O−) are studied in a hybrid atom–ion trap. The amount of excited rubidium present in the atomic ensemble is actively controlled, providing a tool to tune the electronic quantum state of the system and, thus, the anion–neutral interaction dynamics. For a ground state Rb interacting with O−, the detachment induced loss rate is consistent with zero, while the excited state Rb yields a significantly higher loss rate. The results are interpreted via ab initio potential energy curves and compared to the previously studied Rb–OH− system, where an associative electronic detachment reactive loss process hinders the sympathetic cooling of the anion. This implies that with the loss channels closed for ground-state Rb and O− anion, this system provides a platform to observe sympathetic cooling of an anion with an ultracold heavy buffer gas.
Graph-theoretical exploration of the relation between conductivity and connectivity in heteroatom-containing single-molecule junctions
Authors: Okazawa Kazuki , Tsuji Yuta , Yoshizawa Kazunari
Published: February 2022

In this study, we employ the Sachs graph theory to formulate the conduction properties of a single-molecular junction consisting of a molecule in which one carbon atom of an alternant hydrocarbon is replaced with a heteroatom. The derived formula includes odd and even powers of the adjacency matrix, unlike the graph of the parental structure. These powers correspond to odd- and even-length walks. Furthermore, because the heteroatom is represented as a self-loop of unit length in the graph, an odd number of passes of the self-loop will change the parity of the length of the walk. To confirm the aforementioned effects of heteroatoms on conduction in an actual sample, the conduction behavior of meta-connected molecular junctions consisting of a heterocyclic six-membered ring, whose conductive properties have already been experimentally determined, was analyzed based on the enumerated number of walks.
Native surface oxidation yields SiC–SiO2 core–shell quantum dots with improved quantum efficiency
Authors: Li Yuanyuan , Liu Xiaoyu , Liang Tianyuan , Liu Wenjie , Fan Jiyang
Published: February 2022

Silicon carbide is an important wide-bandgap semiconductor with wide applications in harsh environments and its applications rely on a reliable surface, with dry or wet oxidation to form an insulating layer at temperatures ranging from 850 to 1250 °C. Here, we report that the SiC quantum dots (QDs) with dimensions lying in the strong quantum confinement regime can be naturally oxidized at a much lower temperature of 220 °C to form core/shell and heteroepitaxial SiC/SiO2 QDs with well crystallized silica nanoshells. The surface silica layer enhances the radiative transition rate of the core SiC QD by offering an ideal carrier potential barrier and diminishes the nonradiative transition rate by reducing the surface dangling bonds, and, as a result, the quantum yield is highly improved. The SiC/SiO2 QDs are very stable in air, and they have better biocompatibility for cell-labeling than the bare SiC QDs. These results pave the way for constructing SiC-based nanoscale electronic and photonic devices.
Energy transfer and thermoelectricity in molecular junctions in non-equilibrated solvents
Authors: Kirchberg Henning , Nitzan Abraham
Published: February 2022

We consider a molecular junction immersed in a solvent where the electron transfer is dominated by Marcus-type steps. However, the successive nature of the charge transfer through the junction does not imply that the solvent reaches thermal equilibrium throughout the transport. In our previous work [Kirchberg et al., J. Phys. Chem. Lett. 11, 1729 (2020)], we have determined the nonequilibrium distribution of the solvent where its dynamics, expressed by a friction, is considered in two limiting regimes of fast and slow solvent relaxation. In dependence of the nonequilibrium solvent dynamics, we investigate now the electrical, thermal, and thermoelectric properties of the molecular junction. We show that by suitable tuning of the friction, we can reduce the heat dissipation into the solvent and enhance the heat transfer between the electrodes. Interestingly, we find that the Seebeck coefficient grows significantly by adapting the solvent friction in both regimes.
Barriers and facilitators to nurse-led advance care planning and palliative care practice change in primary healthcare: a qualitative study
Authors: Nagarajan Srivalli V. , Lewis Virginia , Halcomb Elizabeth , Rhee Joel , Morton Rachael L. , Mitchell Geoffrey K. , Tieman Jennifer , Phillips Jane L. , Detering Karen , Gavin Jennifer , Clayton Josephine M.
Published: February 2022

Primary care settings are ideal for initiating advance care planning (ACP) conversations and assessing palliative and supportive care needs. However, time constraints and a lack of confidence to sensitively and efficiently initiate such discussions are noted barriers. The Advance Project implemented a national multicomponent training package to support Australian general practice nurses (GPNs) to work with GPs to initiate ACP and palliative care conversations in their practice. This paper reports on semistructured interviews conducted with 20 GPNs to explore barriers and facilitators to implementing the Advance Project model. Participants identified a range of factors that affected implementation, including lack of time, limited support from colleagues, lack of knowledge about systems and funding processes in general practice and a need for better alignment of the Advance Project resources and practices with general practice information management platforms. Barriers related to professional roles, particularly the lack of clarity and/or limitations in the scope of practice of GPNs, highlighted the importance of defining and supporting the roles that different primary health practice staff could play to support implementation of the model. The findings underline the need for complementary training in the Advance Project model for GPs and practice managers to enable a team-based approach to implementation.
Nitric oxide stimulates type IV MSHA pilus retraction in
Vibrio cholerae
via activation of the phosphodiesterase CdpA
Authors: Hughes Hannah Q. , Floyd Kyle A. , Hossain Sajjad , Anantharaman Sweta , Kysela David T. , Zöldi Miklόs , Barna Lászlό , Yu Yuanchen , Kappler Michael P. , Dalia Triana N. , Podicheti Ram C. , Rusch Douglas B. , Zhuang Meng , Fraser Cassandra L. , Brun Yves V. , Jacobson Stephen C. , McKinlay James B. , Yildiz Fitnat H. , Boon Elizabeth M. , Dalia Ankur B.
Published: February 2022

Significance

All organisms sense and respond to their environments. One way bacteria interact with their surroundings is by dynamically extending and retracting filamentous appendages from their surface called pili. While pili are critical for many functions, such as attachment, motility, and DNA uptake, the factors that regulate their dynamic activity are poorly understood. Here, we describe how an environmental signal induces a signaling pathway to promote the retraction of mannose-sensitive hemagglutinin pili in
Vibrio cholerae
. The retraction of these pili promotes the detachment of
V. cholerae
from a surface and may provide a means by which
V. cholerae
can respond to changes in its environment.