bluuebunny/crossref_metadata_2025 huggingface dataset:
Cobb’s Ring … wer suchet, der findet!
Authors: Comploj Evi , Ladurner Christian , Pycha Armin
Published: December 2024

Einleitung Der Cobb’s Ring, auch Moormann-Ring genannt, ist eine sehr seltene membranöse Striktur der bulbären Urethra und weist, im Gegensatz zu der hinteren Harnröhrenklappe, keine direkte Verbindung zum Verumontanum auf. Das klinische Erscheinungsbild kann stark variieren. Das gleichzeitige Vorhandensein einer hinteren Harnröhrenklappe mit Cobb’s Ring ist noch seltener. Wir berichten unseres Wissens über den dritten Fall in der Literatur eines Kindes mit gleichzeitiger hinterer Harnröhrenklappe und Cobb’s Ring.

Fallvorstellung Wir stellen einen 3-jährigen Jungen mit wiederholten Episoden eines akuten Harnverhalts mit Restharnmengen bis zu 800 ml vor. Während einer auswärts durchgeführten Urethrozystoskopie, wurde nur ein spastisch wirkender Blasenhals beschrieben. Die neuropädiatrische Untersuchung wie auch die Magnetresonanz des Schädels und der Wirbelsäule waren negativ. Nach Legen eines suprapubischen Katheters wurde die Urethozystoskopie wiederholt und nun eine membranöse Striktur distal des äußeren Schließmuskels – ein sogenannter Cobb’s Ring – diagnostiziert und gleichzeitig inzidiert. Nach dem Eingriff konnte der Junge mit einem Restharn von 40–50 ml urinieren. Da jedoch 2 Wochen nach der Inzision, das Restharnvolumen wieder zunahm, erfolgte eine erneute Urethrozystoskopie, bei der, neben dem offen erscheinenden Cobb’s Ring, nun auch eine hintere Harnröhrenklappe zu erkennen war. Sie wurde endoskopisch mit dem Hakenmesser kalt inzidiert.

Schlussfolgerung Da das klinische Erscheinungsbild und der Grad der Obstruktion stark variieren können, ist die Diagnose des Cobb’s Ringes schwer zu stellen – es sei denn, der Urologe kennt diese seltene angeborene Anomalie der Harnröhre, und denkt auch daran.
Diagnostik, Therapie und onkologisches Outcome bei zervikalen CUP-Syndromen je nach p16-Status
Authors: Boosfeld Lukas , Lang Stephan , Mattheis Stefan , Peis Micheal , Zaun Gregor , Waßenberg Sebastian , Baba Hideo Andreas , Hussain Timon , Kürten Cornelius
Published: December 2024

Die Inzidenz zervikaler Plattenepithel (SCC)-CUP-Syndrome steigt mit einem relevanten HPV-assoziierten Anteil. In dieser 10 Jahre umfassenden retrospektiven Studie wurden klinische und therapeutische Parameter von Patienten mit zervikalen SCC-CUP erfasst. Neben einer Analyse der Primärtumordetektionsrate bei initialem SCC-CUP (SCC-CUPinit) wurde das mittlere Gesamtüberleben sowie das rezidivfreie Überleben bei Patienten ohne Primärtumordetektion nach erweiterter Diagnostik, also definitiven SCC-CUP (SCC-CUPdef), in Abhängigkeit vom p16-Status ausgewertet, um therapeutische Empfehlungen abzuleiten.

Bei 85% (n=131/155) der CUPinit handelte es sich histologisch um SCC, gefolgt von Adenokarzinommetastasen bei 7% (n=10/155). Bei 41% (n=54/131) der Patienten mit SCC-CUPinit wurde mittels erweiterter Diagnostik ein Primärtumor identifiziert; die Primärtumordetektionsrate war dabei bei p16-positiven vs. p16-negativen signifikant höher (63% vs. 23%, p<0,001). Die PET-Bildgebung wies eine Sensitivität bzw. Spezifität von je 73% auf. SCC-CUPdef wurden vorrangig primär chirurgisch mit adjuvanter Radio(chemo)therapie behandelt, SCC-CUPdef-Patienten mit positivem vs. negativem p16-Status wiesen ein signifikant längeres Gesamtüberleben auf (53 vs. 41 Monate, p=0,037), ebenso Patienten mit cN1- vs. cN3-Status und M0- vs. M1-Status.

Der p16-Status beeinflusst bei Patienten mit SCC-CUP die Diagnostik und Therapie: Bei p16-positiven SCC-CUPinit gelang signifikant häufiger eine Primärtumordetektion als bei p16-negativen SCC-CUPinit. Bei Patienten mit SCC-CUPdef war ein positiver p16-Status mit einem besserem Gesamtüberleben assoziiert, die Unterschiede rechtfertigen jedoch bislang keine Therapiedeeskalation.
Versorgungsrealität der Bronchoskopie in Deutschland – eine Umfrage der Deutschen Gesellschaft für Pneumologie und Beatmungsmedizin (DGP)
Authors: Boschung Kyrill , Hetzel Jürgen , Hübner Ralf-Harto , Pohl Frank , Treml Marcel , Darwiche Kaid , Eberhardt Ralf , Holland Angelique , Bauer Torsten , Randerath Winfried , Windisch Wolfram , Hagmeyer Lars
Published: December 2024

Ziel Aufgrund technischer Innovationen und des gesundheitsökonomischen Drucks hat sich die Bronchoskopie in den letzten Jahren deutlich gewandelt. Es gibt wenig aktuelle Informationen zur Versorgungsrealität in der Bronchoskopie in Deutschland.

Methodik Im September 2022 wurden die bronchoskopisch tätigen Standorte in einer anonymisierten Erhebung der DGP mit 33 Fragen systematisch zu Merkmalen der Struktur- und Prozessqualität befragt. Die erhobenen Daten wurden deskriptiv ausgewertet.

Ergebnisse Von 196 teilnehmenden wurden an 180 Standorten regelmäßig Bronchoskopien durchgeführt. Ein Großteil der Standorte sind Krankenhäuser der Grund- und Regelversorgung (n=51) sowie Maximalversorger (n=43) (Leistungsspektrum: diagnostische Bronchoskopie, 80% inklusive der endobronchialen ultraschallgesteuerten transbronchialen Nadelaspiration [EBUS-TBNA]). Für den Akutfall sind erweiterte Behandlungsmöglichkeiten an >90% dieser Standorte sichergestellt. Universitätskliniken (n=24) und Lungenfachkliniken (n=35) erbringen darüber hinaus aufwendigere diagnostische Verfahren sowie therapeutisch-interventionelle Techniken. Dabei sind die Leistungszahlen an den Lungenfachkliniken signifikant höher (Lungenfachkliniken: 62%: >2000 Bronchoskopien/Jahr; Unikliniken: 25%: >2000 Bronchoskopien/Jahr; p<0,001). An den Praxisstandorten (n=21, teils kooperativ an Kliniken) werden <500 Bronchoskopien/Jahr durchgeführt.

Am Standort sind in 97% der Kliniken Intensivstationen vorhanden. 88% der Kliniken verfügen im Bronchoskopieraum über eine Durchleuchtungsmöglichkeit. Für die Sedierung werden bevorzugt Propofol (91%) und/oder Midazolam (62%) verwendet. An 21% der Standorte werden >200 Bronchoskopien/Jahr unter Beatmung durchgeführt. BAL und transbronchiale Zangenbiopsien erfolgen überwiegend über den nasalen oder oralen Zugang, EBUS-TBNA über einen Bronchoskopietubus oder den oralen Zugang, die EBUS-Minisonde/Navigation, komplexere Interventionen über das starre Rohr oder einen Bronchoskopietubus. Bei nach ASA >2 klassifizierten Patienten ziehen 46% der klinischen Standorte einen zweiten Arzt hinzu, 47% der Standorte bei einer ASA-Klassifikation >3.

Schlussfolgerung Ein Großteil der Bronchoskopien wird von pneumologischen Abteilungen an Krankenhäusern der Grund- und Regelversorgung sowie der Maximalversorgung durchgeführt. Für aufwendigere Verfahren ist die Kooperation mit Kliniken mit ausgewiesenem Schwerpunkt im Bereich der Bronchologie und Interventionellen Pneumologie, wie er häufig an Universitätskliniken oder Lungenfachkliniken angeboten wird, sinnvoll.
Empfehlungen zu Trainingskursen in der Bronchoskopie – Update 2024
Authors: Hagmeyer Lars , Hübner Ralf-Harto , Darwiche Kaid , Eberhardt Ralf , Gebhardt Andreas , Herth Felix , Holland Angelique , Krist Joanna , Pizarro Carmen , Zimmermann Gregor , Wagner Manfred
Published: December 2024

Bronchoskopiekurse sollten einen festen Bestandteil der bronchoskopischen Ausbildung darstellen. Kursabsolventen sollen nach dem Bronchoskopiekurs mit den Indikationsfeldern, Voraussetzungen und technischen Möglichkeiten der Bronchoskopie vertraut sein. Neben theoretischen Inhalten werden in Kleingruppen am Bronchoskopiemodell unter Supervision praktische bronchoskopische Fertigkeiten vermittelt und am Simulationsmodell trainiert. Die Grundlage der vermittelten Inhalte sind dabei die aktuellen Leitlinien und Empfehlungen der DGP sowie die geltenden Richtlinien und KRINKO-Empfehlungen. Die Vereinheitlichung zentraler Kurselemente dient der flächendeckenden Qualitätssicherung, dennoch sollen lokale standortspezifische Schwerpunktsetzungen explizit unterstützt werden.
Posttransplant Erythrocytosis after Allogenic Stem Cell Transplant for Acute Myeloid Leukemia: A Case Report and Review of Literature
Authors: Abraham Sherry S. , Soman Saikumar , Ajish Akshaya B. , Nair Sreejith G.
Published: December 2024

Postallogenic hematopoietic stem cell transplant (post-allo-HSCT) erythrocytosis is a rare phenomenon mostly seen in cases of aplastic anemia. It is a well-known complication in renal transplant recipients. Clinical evaluation, serum erythropoietin (EPO) level, and Janus kinase 2 (JAK 2) mutation are important to differentiate between primary and secondary erythrocytoses. Treatment aims at normalizing the clinical, physical, and laboratory parameters and minimizing thromboembolic complications. The majority of the patients have a favorable outcome with phlebotomies and low-dose aspirin. We report a rare case of post-allo-HSCT erythrocytosis in a patient who underwent related allo-HSCT for acute myeloid leukemia.
Quantized vortices in a spherical superfluid volume
Authors: Kiknadze L. V. , Mamaladze Yu. G.
Published: December 2024

The critical rate of vortex formation and the width of the irrotational domain are determined. An equation governing the shape of the vortex line is obtained and solved under boundary conditions corresponding to a spherical geometry.
Study of electron–phonon interaction in nickel and iron by microcontact spectroscopy
Authors: Lysykh A. A. , Yanson I. K. , Shklarevskii O. I. , Naidyuk Yu. G.
Published: December 2024

Microcontact spectroscopy is used to obtain the electron–phonon interaction spectra of the ferromagnetic metals nickel and iron. The data obtained are compared to known phonon state density functions F(ω). The mean squares of the electron–phonon interaction matrix elements are calculated as functions of energy. The presence in the experiments of a “structural” broadening connected with imperfection of the metal structure in the microcontact region is noted.
An analytic equation of state for dense gases and liquids with consideration of quantum corrections in first order perturbation theory
Authors: Rogovin M. D. , Rabinovich V. A.
Published: December 2024

A system with an effective pair interaction potential in the form of a rectangular well with the hard sphere diameter σ a function of temperature is considered. Perturbation theory is employed to obtain a three-parameter analytic equation of state for this system with quantum corrections in first order perturbation theory. The equation developed may be used for the description of the thermodynamic surface of low temperature materials—dense gases and liquids—at temperatures where the condition ϵ/kT≪ 1 is satisfied. The ability of the equation obtained to describe experimental data within the limits of experimental accuracy is demonstrated by a calculation of the compressibility z along He4 isotherms over a wide density range ρ ≃0−2.4 ρcr).
3D rigid-fluid method offers more accurate modeling of landslide-induced tsunamis
Authors: Thompson Avery
Published: December 2024

Integrating both solid and fluid dynamics allows detailed simulations of a less common, but more complex type of tsunami.
Interpolation of compound semiconductor alloy parameters from those of their constituents
Authors: Olesberg Jonathon T.
Published: December 2024

Several methods have been proposed for interpolation of the value of physical parameters of quaternary alloys from those of their constituent ternary and binary sub-alloys. These expressions agree when non-linear bowing terms are not required; they differ in how the bowing terms of the bounding ternaries should be utilized. Common interpolation expressions for quaternaries can be generalized into two groups: (1) those that use a linear interpolation of the nearest ternary parameter values and (2) those that interpolate over binary values with a bowing term derived from the bounding ternaries. The second group of methods is equivalent to a polynomial expansion over the alloy’s interpolation space. For compound semiconductor alloys, the geometry of the composition space is the direct sum of the group-III and group-V mixture sub-spaces. The mixture sub-spaces are best described using barycentric coordinates on a regular simplex. A general polynomial expansion of the value of an alloy parameter using barycentric coordinates for the group-III and group-V simplex spaces is described along with an algorithm to generate interpolation expressions for alloys with arbitrary numbers of elements, including quinary and senary alloys. It is shown that a polynomial expansion produces values in closer agreement with the direct gap of quaternaries lattice-matched to common substrates than do approaches using an interpolation of the ternary values, despite a prominent recommendation to the contrary. Finally, a quaternary correction term is described that improves the predicted direct bandgap energies of GaInAsSb for compositions near those lattice matched to InP, InAs, and GaSb.
Small-signal model for inhomogeneous helix traveling-wave tubes using transfer matrices
Authors: Marosi Robert , Rouhi Kasra , Mealy Tarek , Figotin Alexander , Capolino Filippo
Published: December 2024

We introduce a practical method for modeling the small-signal behavior of frequency-dispersive and inhomogeneous helix-type traveling-wave tube (TWT) amplifiers based on a generalization of the one-dimensional (1D) Pierce model. Our model is applicable to both single-stage and multi-stage TWTs. Like the Pierce model, we assume that electrons flow linearly in one direction, parallel and in proximity to a slow-wave structure (SWS) that guides a single dominant electromagnetic mode. Realistic helix TWTs are modeled with position-dependent and frequency-dependent SWS characteristics, such as loss, phase velocity, plasma frequency reduction factor, interaction impedance, and the coupling factor that relates the SWS modal characteristic impedance to the interaction impedance. For the multi-stage helix TWTs, we provide a simple lumped element circuit model for combining the stages separated by a sever, or gap, which attenuates the guided circuit mode while allowing the space-charge wave on the beam to pass freely to the next stage. The dispersive SWS characteristics are accounted for using full-wave eigenmode simulations for a realistic helix SWS supported by dielectric rods in a metal barrel, all of which contribute to the distributed circuit loss. We compare our computed gain vs frequency, computed using transfer matrices, to results found through particle-in-cell simulations and the 1D TWT code LATTE to demonstrate the accuracy of our model. Furthermore, we demonstrate the ability of our model to reproduce gain ripple due to mismatches at the input and output ports of the TWT.
The effects of flexibility on the formation and evolution of wake vortices behind a heaving plate
Authors: Li Xintian , He Guosheng
Published: December 2024

The kinematics of vortical structures behind heaving plates with different flexibility has been investigated using particle image velocimetry. The rectangular plates with different thicknesses undergo a trapezoidal velocity profile (acceleration–steady–deceleration). The Reynolds number Rec based on the chord length and the steady velocity is 5330. The formation and evolution processes of the wake vortices are investigated, with the focus on the comparison between the rigid wing and flexible wings. Wake vortices for the rigid wing initiated near the plate edges, while for flexible wings vortices initiated near the quarter-chord from the edges and slid toward the edges as the plates deform and move forward. During the first half cycle (moving forward), both the vortex trajectories and circulation indicate a global two-stage growth of the starting vortices for all the plates, corresponding to the acceleration and steady motion stages, respectively. The flexible plates have larger wake width and attain higher peak circulation initially; however, the circulation for the rigid plate achieves higher peak value during the steady stage. During the second half cycle (moving backward), the vortex trajectories present a two-stage process; however, the circulation is a single growth and decay process. Besides, detailed study reveals that during the acceleration, the circulation grows rapidly and there is a small decay at the end of the acceleration, thus forming the local peak for the first stage. The vortex trajectories for the flexible plates show greater range transversely, as well as the motion reversal in the streamwise direction.
Flow prediction and dimensionless feature analysis in orifice microchannels under cavitation conditions based on similarity criteria
Authors: Wang Yifan , Yu Yulong , Zhang Tianyi , Chen Lei , Tao Wen-Quan
Published: December 2024

A novel set of dimensionless numbers for predicting cavitation flow in gas-liquid flow through a throttling orifice is proposed. Multiple sets of cavitation data are obtained from the literature, and eight dimensionless groups are extracted using dimensional analysis. Subsequently, self-similarity among these groups is established, leading to the proposal of new dimensionless correlations (CfW and CfWd). Investigation results indicate that the established correlations between dimensionless groups can predict cavitation flow in orifices under a wide range of hydrodynamic and geometric conditions. The predictive model is validated using different sets of experimental data, improving accuracy (average relative error decreased by more than 57%) and covering more physical conditions compared to previous correlation predictions. Furthermore, dimensionless parameters with significant influence on the cavitation discharge coefficient are identified by the explanatory machine learning technique SHapley Additive exPlanations (SHAP) and sensitivity analysis. Based on these findings, this investigation contributes to a reduction in the number of variables involved in cavitation experiments or simulations.
An experimental investigation into filament formation during drop generation by pseudo-plastic viscoelastic biofluid at T-junction generators
Authors: V Giri Nikhil , Cui Weijia , Ren Carolyn L.
Published: December 2024

The advancements in droplet microfluidics have made it an eminent technology for high-throughput biomedical applications involving biofluids such as blood, saliva, tear film, and synovial fluid, all characterized by their non-Newtonian/viscoelastic properties. However, most existing models for the design and optimization of droplet microfluidic systems are primarily based on Newtonian fluids. Therefore, studies that systematically explore the dynamics underlying biofluid droplet formation and manipulation are critically important, both fundamentally and practically. This study uses artificial tear films to experimentally investigate the effects of operational parameters such as geometric conditions (width ratio Λ = wdwc and aspect ratio h* = hwc), fluid properties (viscosity ratio η = μdμc), and flow rate ratios (ϕ = QdQc) on filament formation during droplet generation in a T-junction geometry. All the experiments were conducted at a constant capillary number of the continuous phase (Ca = μcQcwchγ). The results indicate that filament growth and rupture characteristics are determined by the predominance of two distinct regions: pre-stretch, governed by the interplay between inertial and capillary forces, and elastocapillarity, regulated by elastic and capillary forces. Specifically, filament rupture is influenced by inertia–capillary effects at low flow rates and viscosity ratios. In contrast, the domination of elastic effects is more pronounced at higher flow rates and viscosity ratios. Additionally, reductions in the width (Λ) and aspect (h*) ratio when Λ≥0.5 and h*≥0.4 increase the elastic effects within the filaments while inertial effects dominate for Λ<0.5 and h*<0.4. The relaxation times (λ) are obtained from the exponential thinning curve, with longer times observed for cases with high elastic effects. Finally, the filament collapses into satellite droplets, and their monodispersity increases with elasticity.
A hybrid approach portraying the dynamics of free convection condensation around a circular cylinder
Authors: Sengupta Sayantan , Kar Uttam Kumar
Published: December 2024

We introduce a hybrid framework to model the fluid dynamics of free convection condensation of saturated steam outside a circular cylinder. The liquid film is modeled analytically, and the adjacent vapor flow field is resolved numerically. The model incorporates temperature-dependent thermophysical properties of the condensate. We explore the subtle role of Jakob number (Ja) and Weber number (We) in the two-phase flow and establish the criteria for dynamic similarity of the flow field with two new dimensionless numbers, viz., free-fall Reynolds number and similarity number. For fixed base Prandtl number of the condensate, the increases in the subcooling rate with Ja and the cylinder's surface area to volume ratio with We cause film thickening. We develop a theoretical correlation to predict the average film thickness (δm). We identify entrainment and bypass zones in the vapor flow field demarcated by a separating streamline. The entrainment zone's streamlines converge to the interface, yielding a net condensate drainage. The bypass streamlines never reach the interface and reduce the condensation efficiency. The results show that the tangential velocity is dominant within the liquid film, the radial velocity is dominant within the vapor flow field, and they are of the same order at the interface. We locate the point of flow separation influenced by a surface tension-induced adverse pressure gradient. The location of the flow separation point shifts upstream, and the separating streamlines become steeper with the increase in We. Our investigation reveals the zone of tangential flow reversal near the interface, promoted with increasing We.
An analytical model for estimating aerodynamic damping of wind turbines in the shutdown state
Authors: Long Tao , Jiang Yan , Huang Guoqing , Peng Liuliu , Wang Hao , Yang Hongying
Published: December 2024

As wind farms are constantly being constructed, the risk of tower failure for wind turbines increases significantly under strong winds. Compared with the extensively concerned wind-induced behaviors during the operating state, those ones during the shutdown state attract little attention but may lead to serious problems of damages or even collapse. To clearly grasp the aero-structure interaction in the shutdown state, this paper develops an analytical model for estimating aerodynamic damping of wind turbines. In this method, an analytical expression of aerodynamic damping coupling matrix is derived via the combination of multibody dynamics and first-order Taylor expansion. This matrix is further quantified as the ratio of modal aerodynamic damping with the aid of state-space equation and complex eigenvalue analysis. This treatment can facilitate the straightforward application of efficient calculation methods, such as frequency domain analysis and uncoupled analysis. More importantly, the developed model is able to simultaneously consider multiple realistic factors, such as blade flexibility, tower top rotation, yaw error, wind shear, and pitch angle. This model may have the high calculation efficiency and accuracy, as well as strong applicability for estimating the aerodynamic damping. Numerical examples based on a typical 5 MW wind turbine are employed to validate the effectiveness of the developed model. Experimental analyses demonstrate that this model outperforms the existing formula and presents a high consistency with OpenFAST in the estimation of aerodynamic damping. Meanwhile, the influence of multiple realistic factors is quantitatively analyzed, which even makes the estimation error exceed 70%.
Density amplifiers of cooperation for spatial games
Authors: Svoboda Jakub , Chatterjee Krishnendu
Published: December 2024

Spatial games provide a simple and elegant mathematical model to study the evolution of cooperation in networks. In spatial games, individuals reside in vertices, adopt simple strategies, and interact with neighbors to receive a payoff. Depending on their own and neighbors’ payoffs, individuals can change their strategy. The payoff is determined by the Prisoners’ Dilemma, a classical matrix game, where players cooperate or defect. While cooperation is the desired behavior, defection provides a higher payoff for a selfish individual. There are many theoretical and empirical studies related to the role of the network in the evolution of cooperation. However, the fundamental question of whether there exist networks that for low initial cooperation rate ensure a high chance of fixation, i.e., cooperation spreads across the whole population, has remained elusive for spatial games with strong selection. In this work, we answer this fundamental question in the affirmative by presenting network structures that ensure high fixation probability for cooperators in the strong selection regime. Besides, our structures have many desirable properties: (a) they ensure the spread of cooperation even for a low initial density of cooperation and high temptation of defection, (b) they have constant degrees, and (c) the number of steps, until cooperation spreads, is at most quadratic in the size of the network.
Proteomic characterization of a foraminiferal test’s organic matrix
Authors: Prada Fiorella , Haramaty Liti , Livnah Oded , Shaul Racheli , Abramovich Sigal , Mass Tali , Rosenthal Yair , Falkowski Paul G.
Published: December 2024

Foraminifera are unicellular protists capable of precipitating calcite tests, which fossilize and preserve geochemical signatures of past environmental conditions dating back to the Cambrian period. The biomineralization mechanisms responsible for the mineral structures, which are key to interpreting palaeoceanographic signals, are poorly understood. Here, we present an extensive analysis of the test-bound proteins. Using liquid chromatography–tandem mass spectrometry, we identify 373 test-bound proteins in the large benthic foraminifer
Amphistegina lobifera
, the majority of which are highly acidic and rich in negatively charged residues. We detect proteins involved in vesicle formation and active Ca
2+
trafficking, but in contrast, do not find similar proteins involved in Mg
2+
transport. Considering findings from this study and previous ones, we propose a dual ion transport model involving seawater vacuolization, followed by the active release of Ca
2+
from the initial vacuoles and subsequent uptake into newly formed Ca-rich vesicles that consequently enrich the calcification fluid. We further speculate that Mg
2+
passively leaks through the membrane from the remaining Mg-rich vesicles, into the calcifying fluid, at much lower concentrations than in seawater. This hypothesis could not only explain the low Mg/Ca ratio in foraminiferal tests compared to inorganic calcite, but could possibly also account for its elevated sensitivity to temperature compared with inorganically precipitated CaCO
3
.
Unveiling task value and self-regulated language learning strategies among Japanese learners of English
Authors: Fukuda Akiko
Published: December 2024

The present study explored different types of task value and their associations with the use of self-regulated
learning (SRL) strategies across various English as a foreign language (EFL) learning scenarios. The application of SRL strategies
is supported by motivational beliefs, including task value. Although prior research has demonstrated the importance of
motivational beliefs in SRL, there remains a need for further clarification regarding the characteristics and role of task value,
particularly the cost (i.e., a negative aspect of task value) in relation to SRL. Furthermore, given the context-dependent nature
of SRL, both values and strategies should be adapted to specific learning environments. In this study, 12 Japanese EFL university
students participated in two rounds of semi-structured interviews. The first session focused on their English learning
experiences, expectations, and perceptions of the value and cost associated with learning English. In the second session, they
roleplayed four scenarios — a homework assignment, an in-class task, preparation for an English certification exam, and learning
for personal growth — while using a think-aloud protocol to express their thoughts and feelings. Follow-up interviews were
conducted after each roleplay. Thematic analysis was used to identify the participants’ values and costs and to analyze their use
of SRL strategies. The findings revealed that participants concurrently hold multiple types of task value, which were tied to and
shaped by their past learning experiences. Several patterns were also identified for SRL strategies in each scenario,
corresponding to task value.
The readability of books for immersion schools
Authors: Dressler Roswita , Nuss Bernd , Mueller Katherine
Published: December 2024

Few books are available to support reading instruction in minority language immersion programs. Since North
American teachers provide children with a choice of books scaffolded in difficulty and suited to their interests, they must resort
to creating or adapting their own minority language materials, networking, or spending hours online or in bookstores. A more
systematic approach would be based on an interdisciplinary understanding of the concept of readability. We focus on German as a
minority language in North America and examined research published in both German and English to develop a conceptual framework of
readability as comprising text complexity, context, and literary aspects. Using this framework, we conceptualize a research
program for investigating readability of books in minority languages. This research program would be language-specific, but
adaptable to other minority languages, thereby serving as a call to action for researchers interested in the readability of
books.
Effects of variable blowouts on aerodynamic loss reduction performance of compressor bionic blades
Authors: Li KeXin , He Xing , Jia Yuhao , Xia Ge , Lu Hang
Published: December 2024

A passive flow control method inspired by blowouts was employed to eliminate flow separation and reduce the losses associated with higher compressor loads. The flow characteristics of a dimple-shaped cascade were investigated by implementing bionic blowout dimples on a blade suction surface and the loss-generation mechanism was analyzed. First, the reliability of the numerical simulation was confirmed via experimental validation. Subsequently, biomimetic principles were applied to arrange dimples on the suction surface of cascade blades, and the effects of several blowouts were analyzed. The analysis revealed that vortices within the dimples induced external fluid into the dimples, thereby increasing the turbulent kinetic energy of the external fluid and improving wall-adjacent flow adherence. The bionic-blowout variant dimples created a ‘rolling bearing’ effect that reduced frictional losses and effectively controlled flow separation. Within a certain blowout range, the bionic blowout variant dimples significantly improved the flow characteristics. At a −6° angle of attack, the total pressure loss of the dimple-structured cascade decreased by 35.85%, and the pressure ratio increased by 2.35%. The bionic blowout-variant dimples on the blade suction surface exhibited a three-dimensional disturbance effect. The induced vortex structures regulated the boundary layer transition and suppressed the formation of laminar separation bubbles, thereby enhancing the flow conditions near the corner region.
Underwater-MLA: lightweight aggregated underwater object detection network based on multi-branches for embedded deployment
Authors: Chen Xiao , Fan Chenye , Shi Jingjing , Chen Xingwu , Wang Haiyan
Published: December 2024

In response to the limited memory and computing capabilities of underwater devices, as well as the various target leakage issues caused by complex underwater environments, we propose a lightweight aggregation underwater target detection algorithm called multi-branch lightweight aggregate networks underwater (underwater-MLA). The algorithm designs a new mixed convolutional fusion with contextual attention module. It constructs a multi-branch structure that integrates mixed convolutions and contextual attention to enhance the feature extraction capability for complex underwater targets. Additionally, to address the shortcomings of information loss and significant target localization errors during detection, we propose the SPPELAN efficient aggregation module to improve the model’s perception of target localization and background discrimination ability. Furthermore, targeting the issues of blurred boundaries and sample imbalance in underwater targets, we introduce the Focaler-IoU module to focus more on the distribution of sample boundaries. Finally, we deploy the underwater-MLA algorithm on a Raspberry Pi 4B development board and utilize a camera for real-time underwater target detection. Simulation results on the URPC dataset demonstrate that this method achieves an 85.86% detection accuracy, a 2.94% improvement over the original architecture. The computational complexity and parameter count are reduced by 32.94% and 11.31%, respectively. Moreover, it achieves satisfactory target detection performance on embedded terminals. Link to open-source code: https://github.com/fanchenye/fanchenye.
Quenching for axisymmetric hypersurfaces under forced mean curvature flows
Authors: Mitake Hiroyoshi , Oka Yusuke , Tran Hung V
Published: December 2024

Here, we study the motion of axisymmetric hypersurfaces

{

Γ
t

}

t
⩾
0

evolved by forced mean curvature flows in the periodic setting. We establish conditions that quenching occurs or does not occur in terms of the initial data and forcing term. We also study the locations where the quenching happens in some special cases.
Inter-valley phonon scattering limited performance of n-channel WS2 monolayer transistors
Authors: Alam Khairul
Published: December 2024

In addition to the K conduction band valley of monolayer WS2, there is a remote Q valley located 0.1 eV above the K valley. We investigate the effects of intra- and inter-valley phonon scattering, including

K
↔
Q

inter-valley scattering, on monolayer WS2 device performance using a recursive Green’s function algorithm and the Büttiker probe scattering model. Our analysis reveals that ballisticity drops to 54% when only intra-valley phonon scattering is considered. When inter-valley phonon scattering (excluding

K
↔
Q

inter-valley scattering) is added, ballisticity decreases to 42%. This further declines to 12% with the inclusion of

K
↔
Q

inter-valley scatterings. Similarly, low-field mobility values decrease successively from 395 cm

2

(
V
⋅
s
)

−
1

to 223 cm

2

(
V
⋅
s
)

−
1

and then to 110 cm

2

(
V
⋅
s
)

−
1

at a sheet density of 109 cm−2. The primary scattering mechanism responsible for this degradation is

K
→
Q

inter-valley acoustic phonon scattering, characterized by a high deformation potential of

7.3
×

10
8

eV

cm

−
1

and a low energy of 16.76 meV. Additionally,

K
→
Q

inter-valley scattering significantly populates the Q valley, which presents a higher potential barrier in the on-state conduction band profile, resulting in a lower on-state current. Our analysis shows that approximately 40% of the on-state total power dissipated within the device is due to phonon scattering effects, with the remainder being released through thermalization in the device’s contacts.
Forbidden Lines are not Quenched
Authors: Spyromilio Jason
Published: December 2024

There is no such thing as “quenching” of forbidden lines.
Downhole vibration analysis based on near bit measurement data
Authors: Pang Haibo , Xu Zhaohui , Fang Chao , Fan Jinchao , Lin Zili
Published: December 2024

The efficiency of down-hole drilling has always been a focus of attention in real time drilling field. With the number of deep and ultra deep wells increasing, real time drilling environment has become exceptionally complex, and the decrease of drilling efficiency has always been a difficult problem that troubles drilling field construction. The working status of bits is closely related to factors such as drilling parameters, drilling encountered lithology, and drilling tool wear. However, due to the limited working conditions underground, it is difficult to evaluate the working status of bit in a timely manner. In the article, by analyzing the near bit data measured by down-hole tools, we explore the vibration of drilling tools under different drilling conditions, analyze the vibration intensity of drilling tools at different time periods, statistically analyze the vibration types and intensities of drilling tools, and explore the correlation between drilling parameters, analyzing the impact of drilling parameters on drilling tool vibration.
Study on laser induced breakdown spectrum analysis of lithium in drilling cuttings
Authors: Min Mao , Pengbo Ni , Li Zhongbing , Yu Yi
Published: December 2024

The elements of drilling cuttings are crucial information to be obtained in the downhole measurement while drilling for eological interpretation, resource assessment, and development decisions. However, it is difficult to achieve the analysis of light elements within natrium (Na) by the existing elemental analysis technology. So this paper studies the analysis of lithium by the laser-induced breakdown spectroscopy (LIBS) to promote the discovery, exploration and development of lithium resources. The spectra of 20 lithium-containing ore compositional analysis standards are collected to discuss the impact of the baseline correction methods such as the asymmetric least squares method (AsLS), adaptive iteratively reweighted penalized least squares method (airPLS), and asymmetrically reweighted penalized least squares method (arPLS), and the quantitative analysis models of multivariate linear regression (MLR), Bayesian regression (BPR) and Gaussian process regression (GPR), to verify the accuracy and reliability of the lithium analysis results. The results show that the baseline correction method can improve the analysis accuracy of lithium element, and the preferred AsLs+Gaussian regression is more suitable for the prediction of Li element concentration, with the correlation coefficient of 0.9300. As an effective strategy for high-precision prediction of lithium element concentration, it is applied to the drilling field data for the prediction of lithium element. This research provides an important theoretical support for the application of LIBS technology to lithium element analysis of drilling cutting.
Application of Integrated Directional and Guide Drilling Technology in Deep Coalbed Methane
Authors: Zhu Weixing , Wang Zhuang , Wu Dong , Lin Wang , Wang Yaxuan , Huang Kai , He Jiayu , Xue Hongzhi
Published: December 2024

Deep coalbed methane is characterized by deep burial, complex and diverse microstructures, significant lateral variations in reservoirs, and the development of internal interlayers. Current seismic exploration methods suffer from severe high-frequency signal attenuation in coal layers, resulting in low seismic resolution, which severely limits the precision of geological models for coalbed methane and the encounter rate of reservoirs in horizontal wells. Based on this, this paper introduces an integrated directional and guide drilling technology and applies it to horizontal well operation, achieving excellent results. Firstly, in the pre-drilling phase, we utilize well-seismic integrated reservoir and structural prediction techniques to meticulously characterize coal seam distribution patterns and subtle geological structures. This enables the construction of a geo-steering model specifically for horizontal wells, optimizing the locations of target points, designing well trajectories, and selecting the optimal configuration of geological steering tools. Secondly, in the drilling operation stage, this system iteratively refines the depth-domain seismic section based on real-time measure while drilling (for short MWD). This process reconstructs the geological steering model, precisely predicts the position of coal seams at the bottom of the well, continuously optimizes the well trajectory design in real-time, and ultimately generates geo-steering instructions. Finally, after the completion of drilling operations, the system evaluates the coal seam area and iteratively refines the three-dimensional geological model. This process provides technical support for the deployment of the next well and the design of the target trajectory. After verification through multiple horizontal wells targeting deep coalbed methane, the guiding model reconstructed by this technology has achieved a fitting rate of over 95%, significantly enhancing the reservoir encounter rate to above 90%. This remarkable achievement underscores the technology’s precision and effectiveness in accurately guiding drilling operations toward targeted coal seam reservoirs.
Progress in multiphase flow measurement research and its application prospects in the chad digital oilfield
Authors: Geng Jie
Published: December 2024

In the field of oilfield development, the measurement of mixed-phase flow media has always been a hot and difficult issue. Multiphase flow technology is useful for measuring drilling flowback fluid, as it can help engineers analyse the geological structure during the drilling process. This paper summarizes the current status of domestic and international online multiphase flow measurement, introduces new types of equipment and methods for online multiphase flow measurement in China in recent years, and on the basis of analyzing the current status of production measurement in the Chad oilfield, proposes measures and approaches for the localization and digitalization of the Chad oilfield production measurement system. This provides ideas to help Chinese technology, equipment and solutions go global in the oil and gas multiphase flow measurement field.
Investigation of Pressure Pulsation and Vibration of the Internally Geared Screw Compressor
Authors: Zhu J , Read M , Kovacevic A , Sishtla V
Published: December 2024

The Internally Geared Screw Machine (IGSM) is a relatively novel and promising type of positive displacement compressor concept that takes inspiration from classic gerotor pumps. The IGSM uses two rotors rotating in the same direction about parallel axes while maintaining continuous contact between both rotors which isolates several working chambers. By using ported end plate, the IGSM can determine the timing of the fluid entering and exiting the working chamber. There are several key advantages to the IGSM over traditional twin-screw compressors including reduction of the rotor to casting leakage, elimination of the blow hole area, reduction in sliding velocity at the point of contact, and a uniform circumferential rotor temperature profile. Although there is some research regarding the geometric profiling and chamber modeling of this type of machine, there is no research currently available on the pressure pulsation and vibration characteristics of the IGSM. The purpose of this paper is to provide an initial look into the pressure pulsation and vibration characteristics of the IGSM and how they differ from that of a traditional twin-screw machine. By explicating the key differences between the IGSM and the industry standard twin-screw compressor, this paper aims to better understand an important yet underdeveloped area of IGSM design.
Astigmatism Quantification for Depth Localization of Bubbles and Tracers across Curved Surfaces
Authors: Lange H , Sax C , Brümmer A , Kriegseis J
Published: December 2024

The present combined theoretical/experimental study addresses the impact of astigmatism on the two-phase flow diagnostics across the curved surfaces of liquid test-rig containments. In the present context, the target application is the two phase leakage-flow diagnostics across the annular housing gaps of oil-injected rotary positive displacement compressors (RPDC). Earlier studies by the authors identified the Defocusing Particle Tracking Velocimetry (DPTV) and Interferometric Particle Imaging (IPI) as particularly promising combination of flow measurement techniques to investigate the liquid and disperse gas phases inside the annular housing gap of RPDCs. The test-rig-specific influence of astigmatism on the resulting optical transfer function for a quantitative evaluation of the recorded defocused particle images (PI) is first compared to the theoretically derived circular PI diameter upon pure defocussing and subsequently tested for both classes of PIs, i.e DPTV and IPI. To mimic the optical configuration of optically accessible lateral surfaces of typical RPDC test rigs, a circular beaker glass (CBG) of comparable diameter is chosen for the experimental campaign. The results are discussed and future efforts for advanced PI-evaluation strategies are outlined on the grounds of the drawn conclusions.
Yet another structured mesh generator for screw machines simulation
Authors: Ji Y , Möller M
Published: December 2024

High-quality structured mesh generation is essential for the numerical simulation and design optimization of screw machines, particularly rotary twin-screw compressors used in high-pressure gas production. Existing meshing techniques often struggle to accurately capture their intricate geometries, limiting their application potential. This paper proposes a novel Isogeometric Analysis (IGA)-based mesh generation approach specifically tailored for twin-screw compressors. Our method leverages high-order B-spline parameterizations derived from boundary representations to enable efficient and precise mesh generation. A novel boundary correspondence technique using Schwarz-Christoffel mapping is introduced to further enhance mesh quality and preserve critical profile features. Additionally, we integrate elliptic grid generation techniques within the IGA framework, combined with a block-diagonal Jacobian-preconditioned Anderson acceleration algorithm, to efficiently solve the associated nonlinear systems. This approach, built upon the open source Geometry + Simulation Modules (G+Smo) library, demonstrates its effectiveness in generating high-quality structured meshes that meet stringent requirements for screw machine simulations, providing a viable alternative for design optimization.
A New Era in Federal Quarantine and State Certification Diagnostics at Clean Plant Centers in the USA
Authors: Al Rwahnih Maher , Klaassen Vicki , Erickson Teresa , Alabi Olufemi Joseph , Stevens Kristian , Hwang Min Sook , Port Lauren
Published: December 2024

Quarantine and certification programs exist to prevent the entry or spread of harmful pests and pathogens into agricultural systems. Their common objective is to identify pathogen-free source material through the application of validated testing methods for subsequent release for propagation. Tests must be accurate, efficient and cost-effective. In recent decades, the best tests have been biological assays in conjunction with PCR testing. High throughput sequencing (HTS) has now become a reliable and cost-effective diagnostic method having greater accuracy and efficiency than biological assays. In this article, we review the role of clean plant centers in quarantine and certification programs, as well as the process by which HTS was evaluated as a testing method to replace biological assays for screening source material. The data from this evaluation included a side-by-side comparison of HTS and biological assays for cultivars of grapevine, Prunus and rose, and intra- and inter-laboratory validations of an HTS protocol. Based on the results of these evaluations, in 2021 USDA-APHIS and several state regulatory agencies accepted the use of HTS and quantitative polymerase chain reaction (qPCR) to test new introductions of source material, replacing biological indexing. This new protocol requires testing at two timepoints within at least a six-month interval and a dormancy separating the two tests. Under ideal conditions, testing can be completed in 18-24 months with subsequent release from quarantine of plant material that has tested negative for regulated pathogens. This new testing protocol has a profound impact on quarantine and certification programs, facilitating quicker access of stakeholders to clean materials for propagation and increasing the number of pathogens that are detected, and even discovered, with reduced cost, effort, and time.