bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of di/trifluoromethyl bis(1,2,4-triazoline)spiranes and 1,2,4-triazoles via 1,3-dipolar cycloaddition of nitrilimines and carbodiimides
Authors: Zhou Yuxiu , Li Xiaoyong , Liu Xiaokang , Huang Danfeng , Wang Ke-Hu , Wang Junjiao , Hu Yulai
Published: February 2025

An efficient strategy for constructing di/trifluoromethyl bis(1,2,4-triazoline)spiranes and 1,2,4-triazoles via a 1,3-dipolar cycloaddition reaction of nitrilimines and carbodiimides was developed.
Direct α-C–H alkylation of alcohols via photoinduced hydrogen atom transfer
Authors: Wu Mingzhong , Wang Yaru , Lv Xin , Ma Zhengxian , Sheng Xiaojing , Wang Mengjie , Zhang Yalin , An Zhenyu , Wang Xuekun
Published: February 2025

A general strategy for direct α-C–H alkylation of alcohols promoted by a HAT catalytic cycle and a photoredox catalytic cycle has been developed.
An iterative synthesis of poly-substituted indole oligomers reveals a short effective conjugation length in eumelanin model compounds
Authors: Huang Haiyan , Kinziabulatova Lilia , Manickoth Anju , Zhang Yiming , Barilla Marisa A. , Blancafort Lluís , Kohler Bern , Lumb Jean-Philip
Published: February 2025

An iterative synthesis of poly-substituted indoles reveals a short effective conjugation length in the corresponding oligomers. Combined with DFT calculations, these results provide insights into the emergence of melanin's photophysical properties.
Orbital contributions to the magnetic shielding of cyclo[2n]carbons (n = 3–12)
Authors: Baranac-Stojanović Marija
Published: February 2025

A scheme is proposed for dissecting the total shielding values of cyclo[2n]carbons (n = 3–12) into orbital contributions to correct for the erroneous values of πin, σ and core orbitals given using natural chemical shielding (NCS) analysis.
Sequential adsorption of multiple CO molecules on Au10− and Au9Zn− triangular clusters: the crucial role of a single atomic impurity
Authors: Fernández Eva M. , Balbás Luis C.
Published: February 2025

Differences in geometrical and electronic properties of Au10(CO)n− and Au9Zn(CO)n− clusters are due to the Zn atom’s lower electronegativity than gold and carbon.
In pursuit of larger lipophilicity enhancement: an investigation of sugar deoxychlorination
Authors: Van De Velde Jonas , Calderón Rodríguez Ariadna , Wang Zhong , Wheatley David E. , Linclau Bruno
Published: February 2025

Carbohydrate deoxychlorination is shown to be a powerful tool to significantly increase sugar lipophilicities compared to analogous deoxyfluorinated monosaccharides.
Efficient 5-hydroxymethylfurfural production in ChCl-based deep eutectic solvents using boric acid and metal chlorides
Authors: Guo Hong , Ma Xinyi , Chen Zhipeng , Guo Jing , Lu Jianjun
Published: February 2025

This study reveals an efficient method for the production of 5-HMF in ChCl-based DESs using boric acid and metal chlorides, explores the reaction mechanism, and compares different deep eutectic solvent systems.
Retraction: Growth factors regional patterned and photoimmobilized scaffold applied to bone tissue regeneration
Authors: Zhang Ling-Kun , Chen Wu-Ya , Wang Hui-Min , Liu Chao , He Jiecheng , Tang Yunzhi , Jiao Yuxuan , Guan Yan-Qing
Published: February 2025

Retraction of ‘Growth factors regional patterned and photoimmobilized scaffold applied to bone tissue regeneration’ by Ling-Kun Zhang et al., J. Mater. Chem. B, 2020, 8, 10990–11000, https://doi.org/10.1039/D0TB02317E.
Parameter efficient face frontalization in image sequences via GAN inversion
Authors: Ahmadi Mohammadhossein , Kambarani Nima , Mohammadi Mohammad Reza
Published: February 2025

Processing facial images with varying poses is a significant challenge. Most existing face frontalization methods rely on heavy architectures that struggle with small datasets and produce low‐quality images. Additionally, although video frames provide richer information, these methods typically use single images due to the lack of suitable multi‐image datasets. To address these issues, a parameter‐efficient framework for high‐quality face frontalization in both single and multi‐frame scenarios is proposed. First, a high‐quality, diverse dataset is created for single and multi‐image face frontalization tasks. Second, a novel single‐image face frontalization method is introduced by combining GAN inversion with transfer learning. This approach reduces the number of trainable parameters by over 91% compared to existing GAN inversion methods while achieving far more photorealistic results than GAN‐based methods. Finally, this method is extended to sequences of images, using attention mechanisms to merge information from multiple frames. This multi‐frame approach reduces artefacts like eye blinks and improves reconstruction quality. Experiments demonstrate that this single‐image method outperforms pSp, a state‐of‐the‐art GAN inversion method, with a 0.15 LPIPS improvement and a 0.10 increase in ID similarity. This multi‐frame approach further improves identity preservation to 0.87, showcasing its effectiveness for high‐quality frontal‐view reconstructions.
DDPGAT: Integrating MADDPG and GAT for optimized urban traffic light control
Authors: Azad‐Manjiri Meisam , Afsharchi Mohsen , Abdoos Monireh
Published: February 2025

Urban traffic control is a complex and dynamic multi‐agent challenge, characterized by the need for efficient coordination and real‐time responsiveness in fluctuating traffic conditions. Traditional methods often fall short in adapting to these dynamic environments. This article introduces “DDPGAT”, a novel framework that merges Multi‐Agent Deep Deterministic Policy Gradients (MADDPG) with Graph Attention Networks (GATs) for optimized urban traffic control, further enhanced by a unique moral reward component. DDPGAT empowers traffic signal controllers as independent agents using GATs for dynamic road importance assessment. Shared attention scores during training enhance each agent's understanding of local and wider traffic patterns, essential for developing adaptive control policies. A key innovation in DDPGAT is the moral reward function, encouraging decisions that consider neighboring intersections' traffic, thus promoting ethical traffic management. The experiments demonstrate that DDPGAT significantly boosts traffic throughput and reduces congestion, confirming its effectiveness in diverse traffic conditions. The integration of MADDPG, GATs, and a moral reward strategy in DDPGAT presents a sophisticated, robust approach for managing the complexities of urban traffic control, marking a notable progression in intelligent traffic system technologies.
GA-NIFS: Multiphase analysis of a star-forming galaxy at z  ∼  5.5
Authors: Parlanti Eleonora , Carniani Stefano , Venturi Giacomo , Herrera-Camus Rodrigo , Arribas Santiago , Bunker Andrew J. , Charlot Stéphane , D’Eugenio Francesco , Maiolino Roberto , Perna Michele , Übler Hannah , Böker Torsten , Cresci Giovanni , Curti Mirko , Jones Gareth C. , Lamperti Isabella , Pérez-González Pablo G. , Del Pino Bruno Rodríguez , Zamora Sandra
Published: February 2025

In this study, we present a detailed multiphase analysis of HZ4, a main-sequence star-forming galaxy at z ∼ 5.5, known for being a turbulent rotating disk and having a detection of a [C II] outflow in the ALMA observations. We exploited JWST/NIRSpec observations in the integral field spectroscopy mode with low- and high-spectral resolution which allow us, for the first time, to spatially resolve the rest-frame UV and optical emission of the galaxy to investigate the galaxy properties. In particular, the high-resolution dataset allowed us to study the kinematics of the ionized gas phase, and the conditions of the interstellar medium, such as the excitation mechanism, dust attenuation, and metallicity. The lower spectral-resolution observations allowed us to study the continuum emission and infer the stellar populations’ ages and properties. Our findings suggest that HZ4 is a galaxy merger rather than a rotating disk as previously inferred from lower-resolution [C II] data. The merger is associated with an extended broad, blueshifted emission, potentially indicative of an outflow originating from a region of intense star formation and extending up to 4 kpc. In light of these new observations, we reanalyzed the ALMA data to compare the multiphase gas properties. If we interpret the broad components seen in [C II] and [O III]λ5007 Å as outflows, the neutral and ionized components are co-spatial, and the mass loading factor of the ionized phase is significantly lower than that of the neutral phase, aligning with trends observed in multiphase systems at lower redshifts. Nonetheless, additional observations and larger statistical samples are essential to determine the role of mergers and outflows in the early Universe and to clarify the origin of the broad emission components observed in this system.
Laboratory wastewater treatment: Study case of Environmental Engineering Department ITS
Authors: Dyah Prasetyati Herrani , Nurhayati Ervin
Published: February 2025

Laboratory wastewater contains organic and inorganic pollutants that can pollute the environment if not treated well. This study uses a coagulation-flocculation process to determine the proper operational condition for laboratory wastewater treatment in the Environmental Engineering Department of Institut Teknologi Sepuluh Nopember (ITS). The fluctuation of wastewater quality and quantity was observed consecutively for two weeks. Aluminum sulfate, poly aluminum chloride, and ferric chloride coagulant were applied with a pH variation, namely 6, 7, and 8, and a variation in coagulant dosage, namely 100, 300, and 500 mg/L. The quantity of wastewater produced is in the range of 918.33-32,045 L/day. Meanwhile, for the quality of wastewater, it has a pH in the range of 6.23-8.79, TDS 260-788 mg/L, TSS 40-380 mg/L, COD 97-611.7 mg/L, Cr0.0174-0.2053 mg/L, Fe 0.29-7.55 mg/L, Hg 0-0.0000392 mg/L, and Pb 0-0.084 mg/L. The results of this study showed that the optimum condition for the coagulation-flocculation process is using PAC coagulant, with the original pH of the wastewater being pH 6 and the coagulant concentration being 300 mg/L. In this treatment, the removal efficiency of TDS, TSS, and COD were 7.07%, 92.59%, and 27.45%, respectively.
Assessing the role of community resilience in marine debris management: Willingness to participate in Nusa Penida marine protected area
Authors: Setiawan Sophia Az-Zahro , Suryawan I Wayan Koko , Lee Chun Hung
Published: February 2025

This exploratory study examines the resilience of the Nusa Penida community in managing marine debris, focusing on how sociodemographic characteristics influence participation in debris management initiatives. A sample of 60 local residents was analyzed to assess the impact of factors such as gender, age, income, education, occupation, and marital status on their willingness to participate (WTP). Using Chi-square statistical analysis, the study revealed that traditional demographic variables did not significantly determine participation levels. Notably, although not reaching conventional statistical significance, occupational differences suggested a trend where specific job roles might influence engagement in environmental activities. This study underscores the importance of understanding community dynamics and resilience in environmental conservation efforts, offering insights that can guide more tailored and effective community engagement strategies.
Study of Biofouling on Fly ash – Bottom ash (FABA) Media Subtract
Authors: Selvia Mila , Saptarini Dian
Published: February 2025

Biofouling is the process of attachment and growth of organisms on the surface of living and non-living objects. Biofouling is one of the biggest issues found on the surface of structures and unwanted organisms. The biofouling process starts from the information of microfouling biofilm (colonization of bacteria and microalgae) and the bacterial biofilm will facilitate the colonization of micro and macroorganisms such as cyanobacteria, fungi, diatoms, barnacles, algae, and protozoa. PLTU is the sector that uses the most coal and has utilized many coastal areas. The combustion results of coal emissions are in the form of fly ash and bottom ash. Fly ash has pozzolan properties containing silica or aluminium reacting with calcium hydroxide, while bottom ash has characteristics resembling sand so that it can be used as a substitute for aggregate and both ashes have the potential as a mixture of concrete substrates and artificial reefs. However, fly ash – bottom ash also contains radioactive pollutants and toxic barium elements that may interfere with the life of biota and the surrounding environment. As in the biota of clams (Mytilus californianus) at the larval level which will be disturbed in the formation of its shell. Marine organisms have a certain influence on the dose value of ash waste received by each biota. It was revealed that there was still accumulation of tube worms and bryozoans in the fly ash – bottom ash concrete substrate, but there was a decrease in diversity, and found eight types of macrofouling in twenty-two concrete feed media, namely tube worms, barnacles, crabs, bryozoans, green algae, tunicates, hydroids, brown algae, sponges, and red algae.
Eucalyptus gasification using a multi-stage air gasifier: An experimental study
Authors: Andini A. , Aminuddin  , Helios M.P. , Sajjakulnukit B. , Nasir S.
Published: February 2025

Eucalyptus is a fast-growing plant with high energy, so it is potential as a renewable energy source. Eucalyptus can be converted into synthesic gas containing CO and H2 for direct fuel or raw chemical production materials with gasification techniques. This paper reveals an experiment in which wood chips and pellets from Eucalyptus were processed in a multi-air-stage fixed bed downdraft gasifier to produce high-quality syngas. The temperature profile along the gasifier’s wall is measured, and the gas composition and the tar produced are analyzed. The result indicates that the eucalyptus biomass gasification in the proposed multi-stage-air gasifier adhered to the proper sequence of the downdraft gasifier and processed the biomass effectively, characterized by a low level of tar in the product gas.
Analysis of the corrosion rate of SS 316l metal in a tsunami detection tool in seawater media
Authors: Gusti Ayu Arwati I , Alfattah Muhammad , Maryani Yeyen , Suprihatiningsih Wiwit , Yuliarty Popy
Published: February 2025

Indonesia frequently faces tsunami disasters, making the need for early detection tools essential. As a technological innovation, the inabuoy was created. This device uses underwater sensors to provide early warnings for tsunamis. Inabuoy is installed in areas prone to tsunamis and uses a 316L stainless steel frame submerged in seawater. Due to its underwater position, it is subject to corrosion from seawater with a pH of 7 to 8.5. This study aims to determine the corrosion rate of stainless steel 316L, a wmical method with seawater media with variations of 0, 24, 48, 72, and 96 hours of immersion. Analysis of the corrosion rate of 316L stainless steel specimens in seawater media with immersion of 0, 24, 48, 72, and 96 hours by potentiodynamic electrochemical method. It was found that the lowest corrosion rate data occurred on specimens of 0 hours of immersion with an average value of 4.5681 x 10-3 mmpy while the highest corrosion rate occurred in specimens that were immersed for 96 hours, showing an average value of 8.6811x10-3 mmpy, this shows the value of the corrosion rate that occurs increases with the length of immersion time. This research contributes to achieving SDGs 9, 11, 13, and 14.
TAVI: Ist das Verfahren eine Alternative bei Patienten ohne erhöhtes Operationsrisiko?
Authors: Strohleit Daniel , Seiffert Moritz
Published: February 2025

Die kathetergestützte Aortenklappenimplantation (TAVI) hat sich als sichere und effektive Prozedur zur Behandlung der hochgradigen symptomatischen Aortenklappenstenose etabliert und wird mittlerweile auch bei Patienten niedrigen und intermediären Risikos eingesetzt. Die verfügbaren Studien hierzu umfassen mittlerweile mehr als 9000 Patienten mit sehr vielversprechenden Ergebnissen für das kathetergestützte Verfahren im Vergleich mit dem operativen Aortenklappenersatz. Inwieweit sich diese Ergebnisse auch über einen langfristigen Nachbeobachtungszeitraum bestätigen, bleibt derzeit noch abzuwarten. Auch darüber hinaus wird das interdisziplinäre Herzteam integraler Bestandteil der Indikationsstellung und Therapieplanung bleiben.
Transkathetergestützter Mitralklappenersatz (TMVR): Chancen, Herausforderungen und innovative Entwicklungen
Authors: Mehrkens Dennis , Adam Matti
Published: February 2025

Die Therapie der Mitralklappeninsuffizienz (MI) mittels transvenöser
Mitralklappenprothesen (TMVR) bietet eine vielversprechende minimalinvasive Option für
Hochrisikopatienten, die keine Operation erhalten können. Die komplexe Anatomie der
Mitralklappe und ihre Nähe zum linksventrikulären Ausflusstrakt (LVOT) stellen jedoch
technische Herausforderungen dar. Verkalkungen des Mitralklappenanulus erschweren zudem
die Behandlung. TMVR-Systeme zeigen vielversprechende Ergebnisse, wobei innovative
Verankerungsmechanismen die Risiken, wie die LVOT-Obstruktion, minimieren. Dennoch
bleibt die Patientenauswahl problematisch, da viele Patienten aufgrund anatomischer
Einschränkungen für TMVR ungeeignet sind. Zukünftige Entwicklungen in der
Prothesentechnologie und Zugangsverfahren könnten diese minimalinvasive Therapieoption
weiter verbessern. Langfristige Daten und technologische Fortschritte sind notwendig, um
TMVR als Standardbehandlung zu etablieren und die Therapie von MI zu
revolutionieren.
Trikuspidalklappeninsuffizienz – Optimierung der Ergebnisse durch individualisierte Therapie
Authors: Stocker Thomas J. , Stolz Lukas , Hausleiter Jörg
Published: February 2025

Die hochgradige Trikuspidalklappeninsuffizienz ist eine schwerwiegende Erkrankung und mit einer ungünstigen Prognose vergesellschaftet. Mit der Entwicklung neuer interventioneller Therapieoptionen nimmt die Erkrankung innerhalb der Kardiologie einen zunehmenden Stellenwert ein. Das heterogene Erscheinungsbild und das Auftreten im Kontext unterschiedlicher Begleiterkrankungen bedürfen einer detaillierten diagnostischen Aufarbeitung. Dabei sollte die Erkrankung in einem möglichst frühen Stadium der Rechtsherzinsuffizienz identifiziert und weiterführend abgeklärt werden, um durch eine rechtzeitige Therapie mögliche Endorganschäden zu verhindern. Nach interdisziplinärer Falldiskussion und Abwägung aller medikamentösen, chirurgischen und interventionellen Optionen findet die individualisierte Therapie und anschließende strukturierte Nachverfolgung der Patienten im Herzklappenzentrum statt. Nachdem der Behandlungserfolg von der Erfahrung des Herzklappenzentrums abhängig ist, sollten interventionellen Eingriffe vorrangig in hochvolumigen Zentren mit hoher Expertise durchgeführt werden. Nur so kann der nach wie vor hohen Morbidität und Letalität der Rechtsherzinsuffizienz und Trikuspidalklappeninsuffizienz begegnet werden.
Evaluation of the Impact of Implementing Electronic Prescription in an Oncology Referral Hospital in Recife, Brazil
Authors: Falcão Diana Carla Gouveia , Soares Ana Lara Vieira , Araujo-Junior Hermes Castro de , Souza-Filho José Kilderlan Nascimento de , Medeiros Natália Moura Farias de , Mota Paulo Victor Brasileiro , Madeira-Neto Rodolfo Basílio , Maia Tiago Costa , Pereira Marcio Roberto Pinho , Medeiros Maria Angelina Silva
Published: February 2025

Introduction The occurrence of errors in the prescription of antineoplastic oncological drugs constitutes a serious public health problem, directly affecting patient safety. In Brazil, the Protocol for the Safety in Prescription, Use, and Administration of Medications, established in 2013, aims to improve care related to medication use in healthcare facilities. This study aims to evaluate the prescription profiles of patients undergoing antineoplastic chemotherapy treatment admitted to the Pernambuco Cancer Hospital before and after the implementation of electronic prescription.

Materials and Methods The present cross-sectional study was conducted by analyzing manual and electronic prescriptions collected from the clinical oncology ward of the Pernambuco Cancer Hospital during the periods from March to May 2016 and from June to August 2016, respectively. The data collected were extracted into a specific instrument, previously adapted for the study, containing information related to patients, prescribers, and medications. Descriptive statistics were used for data analysis.

Results Among the 694 prescriptions analyzed, prescription errors were found in at least one item, with the omission of the patients' sex and bed number being the most common findings.

Conclusion All of the prescriptions analyzed, both pre- and postcomputer standardization, contained errors in their completion. With the standardized prescriptions, a significant impact was observed in reducing these rates, especially regarding omission of items and information.
1.7 Synthesis of Difluoromethylene-Containing Compounds
Authors: Luo Y.-C. , Zhang X.
Published: February 2025

The difluoromethylene group (CF2) is a valuable fluorinated motif that is widely present in pharmaceuticals, agrochemicals, and advanced functional materials because of the unique properties of fluorine atoms. Consequently, considerable efforts have been dedicated to introducing the difluoromethylene group into organic molecules. This review summarizes progress in the synthesis of difunctionalized difluoromethane (R1−CF2−FG) compounds, including methods for the difluoroalkylation of C—X and unsaturated bonds, and gem-difluorination reactions.
1.10 The Pentafluorosulfanyl Group (SF5)
Authors: Kordnezhadian R. , De Borggraeve W. M. , Ismalaj E.
Published: February 2025

The pentafluorosulfanyl group imparts exceptional thermal, chemical, and metabolic stability to organic scaffolds. Despite being first described seven decades ago, it remains an under-utilized motif in organofluorine chemistry, primarily due to a lack of efficient synthetic routes that proceed under mild reaction conditions. Nonetheless, the renewed interest in pentafluorosulfanyl scaffolds over the last decade has enabled the preparation of important pentafluorosulfanyl building blocks. Herein, the major synthetic strategies for the preparation of pentafluoro-λ6-sulfanyl-containing compounds are reviewed, including the synthesis of (pentafluorosulfanyl)arenes via oxidative halogenation and the direct pentafluorosulfanylation of aliphatic cores, achieved mainly using pentafluorosulfanyl chloride as a reagent.
1.8 Synthesis of (Trifluoromethyl)sulfanyl (SCF3) Compounds
Authors: Xu C. , Shao X. , Shen Q.
Published: February 2025

(Trifluoromethyl)sulfanyl compounds have garnered significant attention in medicinal chemistry, agrochemistry, and materials science due to their unique physicochemical properties, including high lipophilicity, metabolic stability, and strong electron-withdrawing ability. This review pro-vides a comprehensive overview of the current methods for the synthesis of (trifluoromethyl)sulfanyl compounds, highlighting recent advances and emerging strategies. Key synthetic approaches, such as direct (trifluoromethyl)sulfanylation, transition-metal-catalyzed processes, and radical-based methods are discussed with an emphasis on the substrates and reagents. The chapter also briefly introduces the mechanistic insights and the role of novel reagents in enhancing the efficiency and selectivity of these synthetic transformations.
About the hump in the low-temperature isochoric heat capacity of Ne cryocrystals
Authors: Barabashko M. S. , Krivchikov A. I.
Published: February 2025

The low-temperature dependence of the heat capacity of Ne cryocrystals was analyzed. A hump that appears as a local maximum in the heat capacity curve is shown as C/T3 vs T at Tmax. It was observed that with increasing molar volume, the Tmax shifts to lower temperatures. A universal empirical relation Δ∗ was proposed to describe the excess (non-Debye) heat capacity at low temperatures. It was shown that the value of the universal function Δ∗ depends on both the magnitude of the heat capacity anomaly and the temperature at which the hump occurs, but remains universal and independent of molar volume for noble gas cryocrystals. This study provides new information about the potential origins of the hump in the heat capacity as a manifestation of the first van Hove singularity. The study’s results may be useful in addressing the issue of the calorimetric boson peak in amorphous and disordered solids.
Determination of the Urbach energy Eu and the optical band gap Eg of submicron C60 and C70 fullerene films
Authors: Gorishnyi M. P.
Published: February 2025

The spectra of long-wavelength absorption edge in the range of 1.62–2.08 eV of C60 and C70 films with a thickness of 20–900 nm were studied in detail. The Eg and Eu values of these films were determined for the first time. It was established that the Eu of submicron films C70 and C60 decreases if their thickness increases. The Eg values of these films were obtained by Tauc, classical, and Cody methods. The average ⟨Eg⟩ value coincides with Eg for the classical method. The average values of absorption coefficient ⟨α0⟩ were estimated, which are significantly larger for C70 films. This is due to the stronger absorption of C70 compared to that of C60. Absorption spectra of these films were approximated by exponential lines with parameters ⟨α0⟩, ⟨Eg⟩, and Eu.
Raman non-coincidence effect of C ˭ O stretching modes of ethyl, butyl, and amyl acetate
Authors: Jumabaev A. , Doroshenko I. , Absanov A. , Holikulov U. , Yormatov Sh.
Published: February 2025

Raman non-coincidence effect of the C ˭ O stretching mode of ethyl, butyl, and amyl acetate was studied. The Raman non-coincidence effect decreased when these liquids were dissolved in a non-polar carbon tetrachloride solvent. That is, it was determined that the structure-breaking effect is observed in this solution. Density functional theory (DFT) analysis was performed in order to further understand the Raman non-coincidence effect. DFT analysis of the dimers of the studied liquids strongly supported their isotropic and anisotropic Raman spectral properties. Topological analyses, such as non-covalent interaction and reduced density gradient, were performed in order to understand the nature of intermolecular interactions in these selected dimers.
Investigation of relaxation processes and phase transition in the polyethylene glycol 400 using IR spectra in a wide temperature range
Authors: Sobchuk A. O. , Andrusenko D. A. , Shevchenko V. B. , Alekseev S. A. , Yablochkova K. S. , Lysenkov E. A. , Dinzhos R. V. , Ublekov Filip , Tuleshkov P. , Koseva N. , Gregirchak N. M. , Lazarenko M. V. , Alekseev O. M. , Lazarenko M. M.
Published: February 2025

We examined the amorphocrystalline structures of polyethylene glycol 400 (PEG-400) using thermogravimetric, calorimetric, X-ray phase analysis, dielectric and IR spectroscopies. The physical properties of such a system are affected by the presence of water, due to the formation of the hydration shell. When the amorphic-crystalline PEG-400 is heated, it undergoes first low-temperature and then high-temperature dielectric relaxation. We demonstrate that the low-temperature dielectric relaxation is due to conformational motion of the PEG molecule’s HO–CH2–CH2– end groups. In contrast to that, the high-temperature relaxation is due to the conformational motion in the central parts of the PEG molecule, due to the motion of local topological defects along the backbone of the molecule.
Solvent effect on transformations of triazenes as studied by means of physical chemistry and quantum chemical calculations
Authors: Maga I. M.
Published: February 2025

We found that triazenes can undergo heterolytic transformations in the presence of diazonium cations, in particular, in the hydrophilic organic solvents. This effect depends on the nature of the solvents (i.e., protic or aprotic). It was proved by the methods of high performance liquid chromatography, spectrophotometry, and quantum-chemical calculations of model systems. Our work demonstrated a correlation between the inductive constant of substitutive in azo-component and the yield of reaction product, namely triazene of 4 nitroaniline (1,3-bis-(4-nitrobenzene)-triazene). We have proposed a mechanism of the transformations of these triazenes.
A systematic dataset generation technique applied to data-driven automotive aerodynamics
Authors: Benjamin Mark , Iaccarino Gianluca
Published: February 2025

A novel strategy for generating datasets has been developed within the context of drag prediction for automotive geometries using neural networks. A primary challenge in this field is constructing a training database of sufficient size and diversity. Our method relies on a small number of initial data points and provides a recipe to systematically interpolate between them, generating an arbitrary number of samples at the desired quality. We tested this strategy using a representative automotive geometry and demonstrated that convolutional neural networks perform exceptionally well at predicting drag coefficients and surface pressures. Promising results were obtained in testing extrapolation performance. Our method can be applied to other problems of aerodynamic shape optimization.
First-wall fluxes from large and small ELMs
Authors: Perillo R. , Boedo J. A. , Lasnier C. J. , McLean A. , Marini C. , Bykov I. , Glass F. , Kapat A. , Nelson A. O. , Rudakov D. L.
Published: February 2025

Experimental analysis at DIII-D shows that small edge localized modes (ELMs) deposit a larger fraction of their energy to the first wall, compared to type-I ELMs in similar magnetic configuration and input power. The energy (λQ) and particle (λΓ) flux decay lengths in the scrape-off layer (SOL) are up to 3 and 5 times larger, respectively, for small ELMs than for larger type-I ELMs. Transport dynamics of ELM filaments in the SOL are found to be related to divertor conditions, where high divertor collisionality, typical for partially detached plasmas, is associated with increased cross field ELM radial fluxes. Results show that a sufficiently large outer wall gap and/or limiters might be needed in future scenarios to protect the first wall, if operating with small ELMs and a cold divertor. This might also have implications for RF heating in future devices, where the coupling efficiency is dependent to some degree to the outer-wall gap.
Machine learning-based prediction for airflow velocity in unpressured water-conveyance tunnels
Authors: Qian Shangtuo , Meng Xianghu , Li Pengcheng , Huang Biao , Xu Hui , Feng Jiangang
Published: February 2025

Spillway and drainage tunnels have an open-channel flow pattern when operating under unpressured condition, above which air flow is driven and resisted by water flow, wall friction, and pressure difference. Unpressured tunnels present many airflow-related safety and environmental issues, including water flow fluctuation, gate vibration, shaft cover blow-off, and odor emission; therefore, it is valuable to study and predict their airflow velocity. Given the difficulty in accurate prediction of airflow velocity in unpressured tunnels and complicated influences of hydraulic, structural, and boundary pressure parameters, this study focuses on establishing high-performance prediction models and understanding the importance and independent and coupled influences of each parameter using machine learning. It is found that the water Froude number, ratio of free-surface width to unwetted perimeter, relative ventilation area, and relative tunnel length are four key parameters. By including these parameters in the input parameter combination, the machine learning models can well predict the airflow velocity in unpressured tunnels, achieving significantly higher performance than the existing empirical and theoretical models. Among these models, the models built by Random Forest and XGBoost demonstrate best performance with R2 ≥ 0.911. The interpretability analysis reveals the highest importance of the water Froude number and the ratio of free-surface width to unwetted perimeter, increases in which generally result in enhancement of the airflow velocity. The water Froude number plays a dominant role when it is ≤11.5, and a continuous increase exhibits a significantly marginal effect. The relative ventilation area and relative length of tunnels have close importances, with an increase in either generally promoting the airflow velocity. To help researchers and engineers unfamiliar with machine learning to easily and accurately predict the airflow velocity in unpressured tunnels, GPlearn algorithm is employed to establish explicit expressions, which is validated to have good performance with R2 close to 0.900.
Thermodynamic adsorption mechanism of supercritical methane and application to Ordos coal
Authors: Dai Anna , Wang Zhiming , Huang Tianhao , Cai Xianlu , Zeng Wenting
Published: February 2025

Coal, as a heterogeneous porous medium, exhibits substantial adsorption capacity for coalbed methane, highlighting the necessity to comprehend methane storage mechanisms for reserve evaluation and production optimization. To investigate the adsorption characteristics of methane, a novel approach for calculating thermodynamic parameters is developed based on phase equilibrium and fugacity principles. Isothermal adsorption experimental results are utilized to assess the influence of moisture on the adsorption mechanism, disclosing variations in enthalpy, entropy, and Gibbs free energy for supercritical methane. The findings reveal a pronounced reduction in adsorption capacity under hydrated conditions. Methane adsorption onto coal is identified as an exothermic, entropy-decreasing, non-spontaneous process dominated by microporous filling and monolayer adsorption. The supercritical Langmuir and Dubinin–Radushkevich model confirms that microporous filling accounts for over 10% of the total adsorption capacity under high-temperature and high-pressure conditions. Additionally, temperature changes within coal seams during distinct production phases, ranging from 1 to 18 K, are quantified. A predictive method for isothermal adsorption curves using thermodynamic parameters is introduced, with an accuracy within a 6% error margin. These insights offer theoretical support for modeling gas–water flow dynamics in coalbed methane reservoirs.
Inverse numerical model for isothermal adsorption experiment and its application in gas diffusion kinetics
Authors: Han Peizhuang , Liu Qingquan , Lv Biao , Liu Chenghao , Cheng Yuanping , Wang Liang
Published: February 2025

Diffusion plays a crucial role in the mass transfer and migration of coalbed methane within coal-rocks. The diffusion coefficient is a key parameter that influences the diffusion of CH4 in porous media, including coal-rock. Conventional experimental approaches, reliant on theoretical solutions for diffusion coefficient determination, exhibit inherent limitations including theoretical constraints, protracted experimental procedures, and susceptibility to errors. Addressing these shortcomings, this study introduces a numerical method based on inverse problem calculation, the core of this method lies in an optimization process that adjusts model parameters by minimizing the error between observed data and model predictions, ensuring that the model output closely matches the actual observed values. Building on the traditional isothermal adsorption experiment for CH4, we use isothermal adsorption pressure fluctuation data as a penalty factor, inverse problem numerical optimization techniques are employed to determine the coal particle diffusion coefficient. The results indicate that during the initial adsorption stage, CH4 molecules rapidly penetrate into coal particles, followed by a diffusion and adsorption process. The flow sequence of CH4 over different time periods adheres to a sequential transport mode of “free flow, permeation, diffusion, adsorption.” Using this model, we determined the diffusion coefficient of coal particles to be 1.295 × 10−13 m2/s through reverse optimization. The fitting accuracy (R2) with experimental data was 0.973, which indicates the reliability of the results. This new method effectively determines the diffusion coefficient of gases in coal samples and offers valuable guidance for the development and utilization of unconventional natural gas.
A data-driven prediction method over the lifecycle of fracturing and production of horizontal wells in shale
Authors: Zhao Mingze , Yuan Bin , Zhang Wei , Wu Shuhong , Fan Tianyi , Xiong Haonan , Jin Aoran
Published: February 2025

Efficient determination of hydraulic fracture lengths and comprehensive comprehension of post-fracturing production performance are crucial for optimizing fracturing design and maximizing ultimate recovery. Nevertheless, numerical simulation methods demand high professional expertise and entail significant computational resources. Meanwhile, the complex coupling of multiple factors makes the direct application of existing neural networks to hydraulic fracturing scenarios challenging. To efficiently forecast the post-fracturing fracture network and the dynamic evolution of the pressure field during production, an intelligent prediction model for post-fracturing fractures is developed by integrating the fast Fourier transform structure, convolutional auto-encoder, and U-Net structure. This model is capable of predicting the intricate fracture morphology after fracturing. Furthermore, leveraging a feature fusion architecture combining the convolutional long short-term memory neural network and the channel attention module, a dynamic prediction model for the pressure field during post-fracturing production is proposed to capture pressure field fluctuations over time. The combination of these two models yields an intelligent prediction approach for horizontal well fracturing. The performance of the intelligent prediction model for post-fracturing fractures is evaluated by means of the F1 score, and a score higher than 0.90 is accomplished. The absolute error is used to assess the dynamic prediction model of the pressure field during post-fracturing production, with a single grid pressure error less than 1.0 MPa. The research findings suggest that the proposed intelligent prediction method for fracturing operations can enhance prediction efficiency and provide novel insight for optimizing fracturing design and augmenting final production capacity.
An integrated computational fluid dynamics model for predicting wax deposition in throttling valves
Authors: Zhang Yongxing , Gu Hongbo , Chen Xiaoling , Moghtaderi Behdad
Published: February 2025

Natural gas is a vital component of the global energy landscape. To meet the growing demand for natural gas, complex and highly engineered transmission pipelines are used to efficiently transport large quantities of natural gas from production sites to end users. The cooling induced by throttling natural gas in transmission pipelines may cause the spontaneous formation of wax crystals in throttle valves, impacting pipeline transmission efficiency and posing risks to production. However, explaining the complex process from wax precipitation to deposition requires more than just considering condensation or deposition alone. In this computation fluid dynamics (CFD) study, we have examined the condensation parameters of natural gas mixtures in a traditional orifice plate throttle valve and evaluated the effects of varying inlet pressures, gas models, and wax content on deposition. The results indicate that nucleation predominantly occurs at the throat and throat outlet of the throttle valve. As inlet pressure increases, the nucleation zone at the throat outlet expands toward the pipe wall. A ring-shaped wax deposition zone forms at the throat exit and 0.9 m from the entrance. With rising inlet pressure, this deposition zone becomes more pronounced but narrower. For low wax content, the deposition rate decreases with increasing inlet pressure and varies with different gas models. Conversely, at higher wax content, the deposition rate increases with higher inlet pressure. The primary contribution of this paper is the use of CFD methods to comprehensively describe the processes of wax crystal precipitation, growth, deposition, and stripping in waxy natural gas following throttling.
Enhancing oil recovery and carbon sequestration through alternating injection of methane-rich associated gas and CO2 in deep reservoirs
Authors: Li Zongfa , Chen Zhiwei , Yang Guihua , Lv Zhenhu , Huang Lijuan , Li Maoheng
Published: February 2025

The direct emission of methane-rich associated gas from oil fields is a significant contributor to the greenhouse effect. Currently, alternative gas flooding predominantly employs CO2 and N2 as displacement phases, with limited research focusing on the alternating injection of methane-rich associated gas and CO2 tailored for oil field production. This study investigates the feasibility of enhancing oil recovery and mitigating the greenhouse effect through the alternating injection of methane-rich associated gas and CO2 into reservoirs using experimental and numerical simulation approaches. Initially, core-scale laboratory experiments were conducted on the alternating injection of methane-rich associated gas and CO2, followed by establishing a corresponding numerical simulation model. The results indicate that, compared to continuous CO2 injection, the alternating injection method results in a 2.48% reduction in oil recovery efficiency. However, this method demonstrates superior control over the mobility of oil, gas, and water. This is because there are two ways to enhance oil recovery efficiency: improve extraction efficiency and increase the swept area. CO2 has a high extraction efficiency but a relatively small swept area. Therefore, we aim to increase the swept area by using an alternating injection method of CO2 and associated gas, where mobility is a key factor in expanding the swept area. Specifically, the mobility ratio between oil and gas decreases from 9.65 to 8.24, and the ratio of oil mobility in the remobilized zone to water mobility in the unswept zone reduces from 0.770 to 0.441, suggesting significant potential for improving the sweep efficiency of heterogeneous reservoirs through alternating injection. Subsequently, numerical simulations were performed at the reservoir scale to investigate the alternating injections of methane-rich associated gas and CO2 with varying slug sizes. At the reservoir scale, compared to continuous CO2 injection, the alternating injection method increases the swept area of injected gas from 4.72 to 7.82 km2, consequently resulting in an additional production of 18 969 m3 of oil and sequestration of 9.0619 × 108 kg CO2 equivalents, representing increases of 15.6% and 460.4%, respectively. Finally, the slug ratio for alternating injection was optimized using the surrogate optimization method in MATLAB. After optimization, the cumulative oil production increased by 31.6% and the carbon sequestration capacity increased by 74.1%, compared to continuous CO2 flooding. This study offers valuable theoretical support for improving oil recovery through gas injection and facilitating carbon sequestration in reservoirs.
Mechanical properties of stenosed coronary arterial walls with slip velocity
Authors: S Shankar Narayan , R Aishwarya , Vaishnaw Nidhi S , S Chandankumar
Published: February 2025

In the present manuscript, a detailed exploration of the non-Newtonian blood flow along an elastic, stenosed branched coronary artery is undertaken. The study involves the coupling of the laminar flow model with the solid mechanics model to achieve the fluid–structure interaction through the arbitrary Lagrangian–Eulerian approach. The characteristics of fluid flow, including velocity, pressure, and wall shear stress are examined in relation to the elastic properties of the arterial wall. The changes in several biomechanical parameters, such as principal strain, solid velocity, deformation gradient, Cauchy–Green stress tensor, and Von Mises stress along the intima layer, highlight areas vulnerable to endothelial dysfunction. The upper branch of the bifurcation is observed to carry only around 10% of the total blood flow, resulting in the formation of recirculation zones at the junction where oscillatory shear stress is elevated. Flow separation is noticed at the point on the junction wall opposite the stream experiencing an increased pressure of 1.79% of that of the neighborhood. The wall displacement profiles indicate a 37.5% rise along the lower wall with a decrease at the throat of the stenosis and a decreasing profile along the downstream. The peak Von Mises stress is reached at the stenosis inlet, and the outlet along the branches experiences relatively low Von Mises stress values. The results suggest that the pre-stenotic region along the upstream is more susceptible to undergoing endothelial dysfunction across the lower and upper arterial walls with the lower wall confining higher probability.
A coupled particle dynamics-lattice Boltzmann method model for particle-resolved direct numerical simulation of gas–liquid–solid flow with an irregular particle expressed by multi-sphere algorithm
Authors: Yong Yumei , Mo Hanyang , Dai Jialin , Chen Wenqiang , Li Menghui , Ma Baocang , Yang Chao
Published: February 2025

In this paper, we develop a lattice Boltzmann (LB) model for simulating the gas–liquid–solid three-phase flow. Based on the gas–solid two-phase fluid model in the framework of the lattice Boltzmann method (LBM), a multiphase fluid–solid two-way coupling algorithm is proposed. In this model, the fluid–fluid interface is tracked using a phase-field method. Kinetic-theory-based boundary treatment, such as the interpolated bounce back, combined with the momentum exchange methods handle flow–particle interactions. Particle dynamics (PD) equation depicts the particle's movement and direction. Multi-sphere algorithm is inserted into the LBM frame to efficiently express the irregular particle borrowing from the idea of multi-sphere model in a discrete element method frame. Several typical benchmark cases are used to validate the present model, including the flow around the static and rotating cylinder, the wetting behavior of regular and irregular particles on the liquid–gas interface, the setting of a cylindrical particle, and regular and irregular particles sinking into and pulled out water. The numerical results show that the model agrees well with analytical solutions, experimental data, and published literature. The coupled PD-LBM model is validated and can accurately simulate any gas–liquid–solid three-phase flow system containing moving contact line phenomena.
Tip vortex cavitation control by the micro vortex generator
Authors: Wang Yuwei , Ye Qingqing , Shao Xueming
Published: February 2025

The present study investigates the control effect of a vane-shaped micro vortex generator (VG) on the inception and development of tip vortex cavitation. Five different arrangements were tested by varying the position and installation angle near the tip of a NACA (National Advisory Committee for Aeronautics) 662-415 hydrofoil. The spatial and temporal evolution of the tip vortex cavity was captured using high-speed imaging. The result shows that VG can induce both streamwise vortices and bubbles that affect the cavitation inception. When the VGs are aligned parallel to the incoming flow direction, the generated bubble content is relatively small. Meanwhile, due to the interaction between the tip vortex and the streamwise vortex induced by the VG, the vortex cavity in these cases exhibits notable deformation and diameter fluctuations compared with the smooth case. As a result, the inception of cavitation is significantly delayed, resulting in a notable reduction in the sound pressure level. The optimal control is achieved when the VG is placed at the tip. Conversely, the VG mounted at a larger alignment angle generates bubbles at a high cavitation number, which causes the premature onset of vortex cavitation and results in a detrimental effect.