bluuebunny/crossref_metadata_2025 huggingface dataset:
Julkaisusarjojen arviointi toi uutta tietoa julkaisujen käytöstä
Authors: Hilska-Keinänen Katja , Pitkänen Henri
Published: December 2023

Tutkimuslaitosten omat julkaisusarjat ovat keskeisiä tiedonvälittämisen kanavia ja samalla laitoksissa tehtävän työn vakaita todistajia. Julkaisusarjojen käyttäjäyleisöt ovat usein hyvinkin tunnistettuja, mutta vähemmälle selvitykselle on jäänyt se, miten nämä kohderyhmät käyttävät kyseisiä tietolähteitä ja minkälaisia toiveita heillä on niitä kohtaan. Suomen ympäristökeskus Sykessä toteutettu julkaisusarjojen arviointi pyrki tuomaan ymmärrystä tähän kysymykseen.
Kuvailutyöllä parempi maailma – kuvailun merkityksestä ja mahdollisuuksista
Authors: Harjuniemi Marja-Leena
Published: December 2023

Vuosi kuvailutyötä ja pää täynnä kysymyksiä. Miten tästä on saatu näin monimutkaista? Miten ikinä oppia RDA-standardin säännöt? Miksi todentavaa järjestelmää vieläkään ei ole? Entä mitä tekee tekoäly? Kuvailutyö on globaalisti merkityksellistä. Kyse on sisällöistä, tiedon tasa-arvosta – jopa demokratiasta. Tavoitteista ei kuitenkaan juuri puhuta. Ymmärrys avoimen kokoelmadatan merkityksestä, huoli kuvailutyön asemasta ja kuvailuasiantuntijoiden osaamisesta sai minut pohtimaan kuvailutyötä vähän enemmän. Kirjoituksen näkökulma painottuu tieteelliseen kirjastoon.
Työväenliikkeen kirjasto – tietoa työstä ja yhteiskunnasta
Authors: Siimes Tuija
Published: December 2023

Työväenliikkeen kirjasto on monitieteinen työväentutkimuksen erikoiskirjasto ja työväenperinteen valtakunnallinen tallentaja yhdessä muiden muistiorganisaatioiden kanssa. Kirjasto kuuluu Helka-kirjastojen yhteenliittymään ja tuottaa aineistoa kansallisiin tiedonhakujärjestelmiin. Edistämme avointa tiedettä ja tutkitun tiedon käyttöä yhteiskunnassa. Kaikille avoin kirjastomme tarjoaa myös osallistavan kohtaamispaikan. Artikkelissa esitellään Työväenliikkeen kirjaston palveluita ja tulevaisuuden näkymiä.
Legitimacy of The CJEU In the Settlement of Trade Mark Disputes of Non-European Union Foreign Companies: A Case Study
Authors: Musthafa Annas Rasid , Putrazta Satriya Aldi , Efendi A’an
Published: December 2023

Protection of Intellectual Property Rights(IPR) in the industrial world is an urgency for companies to maintain popularity in the general public, Especially on the use of trademarks that greatly affect consumer perceptions. One of the problems in trademark protection is the existence of dispute resolution through court under a supranational organization, namely The Court of Justice of The EU(CJEU), which adjudicates foreign companies originating from non-EU countries. The case is a trademark dispute between China Construction Bank Corp from China and Groupement des cartes bancaires from France.The purpose of this study is to determine the authority and legitimacy as well as the application of justice through The CJEU in resolving disputes of foreign companies. This research was a normative legal research method, which applied to statue approach, case study research, and library research. Based on the results of the research, the authority and legitimacy of The CJEU in resolving disputes with foreign companies has been regulated in the Maastricht treaty and the submission of foreign companies is also related to the opposing party which is a company flagged by a member state of the EU. The use of the CJEU in resolving disputes requires parties to maximize all judicial remedies available at the national level first before proceeding to the international level.
A formação interdisciplinar da bibliotecária e educadora Zila da Costa Mamede (1928-1985)
Authors: Araújo Marta Maria de , Marques Tércia Maria Souza de Moura , Praxedes Ana Luiza Medeiros Pires
Published: December 2023

Defende-se, neste artigo, a tese de que a educação desempenha uma função pedagógica no processo formativo do indivíduo. A partir dessa afirmação e, ainda, em consonância com o corpus da pesquisa (entrevistas, cartas etc.), procura-se delinear – à luz dos escritos de Nobert Elias Sobre o tempo e A sociedade dos indivíduos, e observando a contingência da dimensão temporal – as experiências interdisciplinares formativas, o exercício especializado da Biblioteconomia e da docência em suas intersecções institucionais e, igualmente, as redes de sociabilidade da intelectual Zila Mamede no curso de sua vida. Confirmada a proposição à partida, consolida-se a prova da eminência das experiências formativas interdisciplinares, que são interdependentes em relação à sociedade, às redes de sociabilidade do indivíduo e às temporalidades.
Physiological Signals as Predictors of Mental Workload: Evaluating Single Classifier and Ensemble Learning Models
Authors: Izzah Nailul , Sutarto Auditya Purwandini , Hendi Ade , Ainiyah Maslakhatul , Bin Abdul Wahab Muhammad Nubli
Published: December 2023

With a growing emphasis on cognitive processing in occupational tasks and the prevalence of wearable sensing devices, understanding and managing mental workload has broad implications for safety, efficiency, and well-being. This study aims to develop machine learning (ML) models for predicting mental workload using Heart Rate Variability (HRV) as a representation of the Autonomic Nervous System (ANS) physiological signals. A laboratory experiment, involving 34 participants, was conducted to collect datasets. All participants were measured during baseline, two cognitive tests, and recovery, which were further separated into binary classes (rest vs workload). A comprehensive evaluation was conducted on several ML algorithms, including both single (Support Vector Machine/SVM and Naïve Bayes) and ensemble learning (Gradient Boost and AdaBoost) classifiers and incorporating selected features and validation approaches. The findings indicate that most HRV features differ significantly during periods of mental workload compared to rest phases. The SVM classifier with knowledge domain selection and leave-one-out cross-validation technique is the best model (68.385). These findings highlight the potential to predict mental workload through interpretable features and individualized approaches even with a relatively simple model. The study contributes not only to the creation of a new dataset for specific populations (such as Indonesia) but also to the potential implications for maintaining human cognitive capabilities. It represents a further step toward the development of a mental workload recognition system, with the potential to improve decision-making where cognitive readiness is limited and human error is increased.
Repensando a relação entre estado, sociedade e natureza sob o viés da ética levinasiana
Authors: Tiroli Luiz Gustavo , Miranda Lara Caxico Martins , Alves Fernando de Brito
Published: December 2023

Os ensejos pela aplicação de um efetivo desenvolvimento sustentável abrem espaços para discussões éticas, econômicas, sociais e ambientais. Diante da significativa degeneração ambiental e dos graves problemas de exclusão social, faz-se necessário reconfigurar a relação entre Estado, mercado e natureza. A partir dos estudos de Lévinas (d. n. 1906) sobre a ética, a pesquisa aborda o reconhecimento do Outro humano e do Outro natureza como premissa para a construção de um contrato natural em que o Eu homem reconheça-se como parte do meio ambiente e não o seu dominador. Utilizando o método dedutivo crítico e a pesquisa bibliográfica, o estudo objetiva demonstrar que há no atual sistema capitalista mecanismo eficaz para responder a essa necessidade de reconfiguração. Concluiu-se que a Economia Solidária é modelo econômico que atende às premissas de sustentabilidade sob o viés da ética da alteridade, mas que ainda há necessidade de se positivar um regime jurídico próprio para essa forma de organização.
LA POLÍTICA SEXUAL PATRIARCAL EN LAS AUTORAS DE NARRATIVA PARAGUAYAS
Authors: Iglesias Aparicio Pilar
Published: December 2023

Las escritoras de narrativa paraguayas merecen ocupar un lugar importante en la literatura feminista latinoamericana contemporánea, por incorporar algunas de sus características fundamentales (Martínez, 2003), al abordar con frecuencia en sus obras temáticas relacionadas con las diferentes formas de discriminación y violencia ejercida contra las mujeres y las niñas, y mostrar su capacidad de resistencia y empoderamiento. Este trabajo analiza, desde la perspectiva de la crítica literaria feminista, varias novelas y relatos de escritoras paraguayas, que visibilizan y denuncian la política sexual patriarcal, como construcción socio-cultural que sustenta la profunda desigualdad entre mujeres y hombres, y la violencia sexual contra mujeres y niñas que de ella se deriva.
DELMIRA AGUSTINI: MUJER Y POETA
Authors: Carrasco Canelo María Dolores
Published: December 2023

La figura de Delmira Agustini (1886-1914) ejemplifica un caso de feminidad que se resiste a los cánones establecidos por una sociedad patriarcal, como es la uruguaya, en un momento convulso artísticamente, como es el Modernismo. Delmira se encuentra en la dualidad de mujer y poeta en los márgenes de lo establecido, canalizando su obra a través de su trayectoria vital y de la reinterpretación del propio Modernismo.
ANTHROPOGENIC CENTERS AS INDICATORS OF THE ECOLOGICAL STATE OF THE ENVIRONMENT
Authors: Denysyk Grigoriy , Voyna Inna , Denysyk Bohdan
Published: December 2023

At the beginning of the XXI century. the landscape and ecologically destabilized environment of any region, including Ukraine, is characterized by abnormally rapid changes in the structural organization of geocomponents and landscape complexes and the relationships between them. As a result, new phenomena arise in the reaction of these natural structures to external, mainly anthropogenic, influences, which lead to unpredictable trends in the development of the environment. In such conditions, various anthropogenic centers are actively developing, among which the role and importance of recreational ones is also increasing.

As previous studies show, anthropogenic centers are the most real indicators of the current ecological state of the environment. Knowledge of the processes and phenomena that develop in recreational centers and geoecotones is relevant and promising. On the one hand, they reveal the causes and mechanisms of existing trends of recreational transformations at the local level, and on the other, taking into account their indicator value, they open the way to managing the state of recreational landscapes and, partially, the environment in general

In the conditions of today's unstable environment, anthropogenic centers and processes in them are gaining widespread development, as a manifestation of new landscape, energy, substance and informational connections. The goal is to investigate the formation process and substantiate the significance of anthropogenic centers as indicators of environmental development. In the research process, a constructive landscape approach, the principles of complexity and natural-anthropogenic coexistence were applied; methods - retrospective, natural analogies, modeling, GIS technologies. By the anthropogenic center we understand the territory within which, under the influence of human activity, processes develop that lead to a change in the structural organization of geocomponents and landscape complexes. It is shown that the diversity of anthropogenic centers and the processes that develop in them depend not only on the type of economic activity, but also on the mosaic of landscape complexes on the basis of which anthropogenic centers are formed. On the example of the model region - Middle Pobuzhzhia, the process of formation and structure of recreational centers - recreational centers in the coastal zone of the South Bug River and residential centers in forest landscapes were studied. Taking into account the indicator value of processes developing in anthropogenic centers, the possibilities of using these peculiar landscape structures in the development of regional projects of rational nature management are considered. It is noted that in the future it is necessary to intensify the research of anthropogenic centers and their processes, center boundaries and paradynamic relationships with the environment.

Keywords: anthropogenic landscape, anthropogenic center, processes, indicators, structure, environment, rational nature management.
Ecological consciousness in the works of writers of small peoples of Russia (on the example of Yu. Rytheu, E. Aipina, Yu. Shestalov)
Authors: Cheng Shuangting
Published: December 2023

The article analyzes the ecological consciousness in the works of writers of the small peoples of the North of Russia. The subjects of the study are the works of Yu. Rytheu, E. Aipina. Yu. Shestalov. Unlike ecological works, ecological consciousness in the works of these writers is more connected with national continuity and cultural heritage. Globalization and modernity have had a huge impact on all spheres of development of national minorities, and they were forced to integrate into the modernization process, whether through active choice or passive acceptance.Modern economic means of industrialization, programming and rationing have an impact on the traditional ways of supporting ethnic minorities. Writers from small nations, as representatives of the advanced intelligentsia of various ethnic groups, were the first to feel this crisis and expressed their concern in their works. This article mainly uses the method of text analysis to analyze ecological consciousness in the work of writers from small peoples. The main contribution of the author is that he offers new methods of studying the literature of small peoples. Ecological consciousness in the works of writers of national minorities differs from other ecological literary works. Ecological consciousness in the works of writers of ethnic minorities is ultimately a matter of survival and sustainability of an ethnic group. At a time when the problem of globalization and modernity is becoming obvious, writers from ethnic minorities use their own literary works to raise this environmental alarm and arouse readers' attention to this problem. The author analyzes the works of writers belonging to small peoples, pointing out the various means and ways in which writers express their ecological knowledge.
Supersonic Wind Tunnel Flow Characterization Using Planar Laser CO2 Rayleigh Scattering
Authors: Aguilera Camilo , Sosa Jonathan , Hyde Evan W. , Miklosovic David S. , Kessler David A.
Published: December 2023

A complementary experimental and computational study was performed to characterize the test section flowfield of a variable-Mach-number supersonic wind tunnel. A planar laser Rayleigh scattering technique using [Formula: see text] nanocrystals was used to capture cross-sectional flow visualizations at various test section streamwise locations. Reynolds-averaged Navier–Stokes simulations of the wind tunnel flow were performed using a [Formula: see text] shear stress transport turbulence model to compare against the flow visualizations. Mach 3.20 and 3.55 flow conditions were investigated in the wind tunnel with an empty test section. The Rayleigh signal profile near the wind tunnel walls was compared against boundary-layer thickness data from shadowgraph visualizations, pitot survey measurements, and numerical simulation predictions to guide the interpretation of the scattering results. A brief discussion regarding the nature and potential source of certain unexpected scattering patterns in the images was provided. The most distinguishable flowfield characteristics observed in the Rayleigh scattering visualizations were the asymmetric thickness of the boundary layers along the test section walls and the appearance of two floor lobes near the flow-path corners. The results of the numerical simulations showed favorable agreement with the experimental data and were used to provide insight into the mechanism that caused the boundary-layer features observed. This study demonstrated the usefulness of [Formula: see text] Rayleigh scattering to obtain flow visualization data of great value to better understand flow quality in supersonic wind tunnels with two-dimensional nozzles.
Wall-Modeled Large-Eddy Simulation of Turbulent Boundary Layer with Spatially Varying Pressure Gradients
Authors: Hayat Imran , Park George Ilhwan
Published: December 2023

Wall-modeled large-eddy simulations of turbulent boundary layers subjected to spatially varying streamwise pressure gradients are conducted to assess the predictive performance of three wall models: ordinary differential equation equilibrium, integral nonequilibrium, and partial differential equation (PDE) nonequilibrium models. The test case is based on experiments conducted by Volino (Journal of Fluid Mechanics, Vol. 897, Aug. 2020, p. A2), where the flow is subjected successively to zero pressure gradient (ZPG), favorable pressure gradient (FPG), recovery ZPG, and adverse pressure gradient (APG) regions. Skin friction is overpredicted in FPG by all the wall models. For equilibrium and integral models, this overprediction is attributed to the strong deviation of mean velocity profiles within FPG from the log law, used explicitly in the equilibrium and implicitly in the integral model. The overprediction is more pronounced for the PDE model, which is attributed to dynamic correction of wall-model eddy viscosity for resolved stresses and a lack of correction for pressure gradient. Potential remedies to mitigate this problem are proposed. Grid refinement improves wall-stress predictions in both FPG and APG but only affects the outer profiles in APG, revealing that accurate wall-flux modeling is more critical for APG. Anisotropic grid analysis shows streamwise grid refinement to be more crucial than spanwise for the convergence of skin-friction, outer velocity, and Reynolds stress profiles.
Experimental Study on Combustion Modes and Oscillations in a Cavity-Based Scramjet Combustor
Authors: Ji Jianheng , Cai Zun , Wang Taiyu , Wang Zhenguo , Sun Mingbo
Published: December 2023

This study conducted experiments to investigate flame behaviors in a cavity-based scramjet combustor operating under Mach 2.92 supersonic inflow. Pressure measurements and flame chemiluminescence observations were combined to study the initial flame formation and combustion mode transitions. In addition, flame luminosity standard deviation and fast Fourier transform power spectral density (PSD) were post-processed to assess the impact of equivalence ratio and aft wall height on combustion modes as well as oscillations. It is indicated that increasing the equivalence ratio leads to a transition from lifted shear-layer mode to ramjet mode. Elevating the cavity aft wall height improves the combustor’s self-ignition capability and promotes the transition from lifted shear-layer mode to ramjet mode as long as flame stabilization is achieved. It is found that increasing the equivalence ratio and aft wall height also results in more intense combustion oscillations; besides, raising the cavity aft wall height could accentuate the predominant frequency of low-frequency oscillations in the combustor. Finally, it is demonstrated that the application of spark plasma effectively suppresses these low-frequency combustion oscillations, which is a promising active control method in the scramjet engine.
Constrained Recalibration of Reynolds-Averaged Navier–Stokes Models
Authors: Bin Yuanwei , Huang George , Kunz Robert , Yang Xiang I. A.
Published: December 2023

The constants and functions in Reynolds-averaged Navier–Stokes (RANS) turbulence models are coupled. Consequently, modifications of a RANS model often negatively impact its basic calibrations, which is why machine-learned augmentations are often detrimental outside the training dataset. A solution to this is to identify the degrees of freedom that do not affect the basic calibrations and only modify these identified degrees of freedom when recalibrating the baseline model to accommodate a specific application. This approach is colloquially known as the “rubber-band” approach, which we formally call “constrained model recalibration” in this paper. To illustrate the efficacy of the approach, we identify the degrees of freedom in the Spalart–Allmaras model that do not affect the log law calibration. By subsequently interfacing data-based methods with these degrees of freedom, we train models to solve historically challenging flow scenarios, including the round-jet/plane-jet anomaly, airfoil stall, secondary flow separation, and recovery after separation. In addition to good performance inside the training dataset, the trained models yield similar performance as the baseline model outside the training dataset.
Males, adversidades e incomodidades en el escrito senecano sobre la providencia
Authors:   Universidad Panamericana (México, Valencia Constantino Genaro
Published: December 2023

In Seneca’s writing about providence three terms (mala, adversa, incommoda) are employed to build his philosophical arguments on supposed evils that occur to humanity, so that the divinity is liberated from being guilty of the «evils» existing in the world. Although the titles of ancient works are a matter of discussion, the currently edited version of this text goes for a title like «discomforts» based on the oldest codex evidence; however, in the light of Seneca’s own philosophical development and the textual tradition, it is possible to think of other proof in behalf and against each of terminology options. At the end, the Stoic creed allows to outline the most suitable choice to Seneca’s philosophical and discoursal project, which promotes moral perfection.
Critical Race Theory: Counter-Storytelling the Case of ‘Old Frank’ and the Daniel Family Cemetery
Authors: Grafenreed Mark C.
Published: December 2023

The Texas Historical Commission (“THC”), a legislatively enacted agency of the State of Texas, has erected and disseminated nearly 17,000 historical markers across the state’s vast 268,596 square miles and 254 counties with one express purpose: “To protect and preserve the state’s historic and prehistoric resources for the use, education, enjoyment, and economic benefit of present and future generations.” Unfortunately, the histories of both the United States and Texas are under siege. Politically charged and fear driven constituents have fully devoted their collective time, energy, and financial resources to destroying the perceived new boogeyman, Critical Race Theory (“CRT”). Since January 2021, all but six states have considered legislation concerning CRT in public schools. Currently, eighteen states, including Texas, have passed legislation banning CRT to eradicate altogether or offer a redacted historicity. Despite their intent, the THC, through its application and review processes, actively participates in erecting memorials that obscure aspects of Texas history, especially those pertaining to race and racism. Conversely, CRT advocates, through one of its key tenets of counter-storytelling, aim to reveal all history. The specific case of “Old Frank” illuminates the intersectionality between CRT, the State of Texas, and Southern Methodist University’s histories. Located two blocks north of the campus in University Park, Texas, “Old Frank,” a family slave, inaugurated The Daniel Family Cemetery in 1850 and has been buried there with other “unknown” slaves in unmarked graves for nearly two centuries. “Old Frank’s” untold or “undertold” story both illuminate CRT’s necessity and stymies the THC’s ability to fulfill its motto of “Real Places Telling Real Stories.”
NEW MARKER GENES OF TUMOR CELL RESISTANCE TO DOXORUBICIN AND THE DEVELOPMENT OF DRUG CANDIDATES FOR ITS THERAPY
Authors:   Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk, Moralev A.D. , Salomatina O.V. , Zenkova M.A. , Markov A.V. ,   Novosibirsk State University,   N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS
Published: December 2023

Key genes associated with tumor cell resistance to doxorubicin (Dox) were identified. The screening of P-glycoprotein (P-gp) inhibiting activity of 8 amides of soloxolone was carried out. Through molecular docking, we demonstrated the ability of compounds to bind the transmembrane domain of P-gp. Hit compound sg-650 enhanced the intracellular accumulation of Rhodamine 123 and Dox, synergistically increased cytotoxic effects of Dox in vitro.
SEARCH FOR REGULATORY GENES AND SMALL-MOLECULAR INHIBITORS OF THE HIGHLY AGGRESSIVE PHENOTYPE OF GLIOBLASTOMA
Authors:   Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk, Odarenko K.V. , Salomatina O.V. , Salakhutdinov N.F. , Zenkova M.A. , Markov A.V. ,   N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS
Published: December 2023

Four sets of RNA-sequencing data were re-analyzed, and INHBA and VEGFC were found to be novel regulators of the highly aggressive mesenchymal phenotype of glioblastoma; their expression was validated in vitro. In the library of amide derivatives of soloxolone, the compound Jil-46 was identified, which blocked glial‑mesenchymal transition (GMT), inhibited stemness, and induced apoptosis in U87 glioblastoma cells.
Biorefining Twin Transition: Digitalisation for Bio-based Chemicals/Materials - Discovery, Design and Optimisation
Authors: Žula Matej , Grilc Miha , Kostyniuk Andrii , Tofani Giorgio , Jasiukaitytė-Grojzdek Edita , Ročnik Kozmelj Tina , Kumar Chowdari Ramesh , Lavrič Žan , Teržan Janvit , Hočevar Brigita , Jakob Ana , Rakić Emilija , Pomeroy Brett , Cajnko Miša Mojca , A. Vicente Filipa , Marinič Dana , Oberlintner Ana , Novak Uroš , Benedetto Tiz Davide , Huš Matej , Likozar Blaž
Published: December 2023

The article discusses the production of platform chemicals from various biological sources, including glycerol, lignin, cellulose, bio-oils, and sea products. It presents the results of catalytic and downstream processes involved in the conversion of these biomass-derived feedstocks. The experimental approaches are complemented by numerical descriptions, ranging from density functional theory (DFT) calculations to kinetic modellingof the experimental data. This multi-scale modelling approach helps to understand the underlying mechanisms and optimize the production of platform chemicals from renewable resources.
Bridging the Gap Between Academia and Chemical Industry through Entrepreneurship: An Account on the Case of Hydrogen-assisted Catalytic Plastic Waste Valorisation
Authors: Bobbink Felix , Van Muyden Antoine
Published: December 2023

Herein, we provide an account on the multi-faceted approach to scaling up a low-carbon chemical technology that originates from academia. First, we discuss technical considerations that must be met prior to industrialisation of a process. Then, we discuss the non-technical considerations such as financing, regulatory and IP rights that are required to obtain support for the project. We use our experience in plastic waste hydrocracking to reflect on strategies that can aid to improve go-to-market time in the field.
An increase in hydrocarbon reserves of Andylakhskoye gas condensate field (Yakutia) taking into account the specifics of its geological structure
Authors: Rudykh I. V.
Published: December 2023

As a result of the research; a conclusion was made about the high prospects for the growth of gas reserves of Andylakhskoye gas condensate field- located within the Loglor swell of the Vilyui syneclise of the Sakha Republic (Yakutia). An increase in reserves is expected; both due to previously discovered deposits and new; more promising horizons located in the Permian deposits.

It is proposed to set up seismic surveys using the 2D common depth point method within the field and the adjacent; most promising areas to increase investment attractiveness; the rational use of natural resources; and increasing gas reserves of Andylakhskoe gas condensate field. According to the results of the studies carried out in this article; the prospects for the growth of hydrocarbon reserves of Andylakhskoe gas condensate field are estimated by over 10 times of the amount.
МОЛЕКУЛЯРНО-ДИНАМИЧЕСКИЙ АНАЛИЗ ДИСПЕРСИОННОГО УПРОЧНЕНИЯ КОГЕРЕНТНЫМИ ИНТЕРМЕТАЛЛИДНЫМИ ФАЗАМИ В ОЦК ВОЛЬФРАМЕ
Authors: Шарапова Ю.Р. , Казаков А.М. , Семенов А.С. , Семенова М.Н. , Рахматуллина Ж.Г. , Корзникова Е.А.
Published: December 2023

Дисперсионное упрочнение играет важную роль в изменении механических свойств конструкционных материалов. Особенно важно поминать механизм такого упрочнения в материалах, используемых при экстремальных воздействиях. Вольфрам применяется в виде защитного материала в ядерных реакторах, и при облучении в нем накапливаются дефекты и выделяются различные когерентные и некогерентные дисперсные частицы. Изучение взаимодействия дислокаций с выделившимися фазами поможет обеспечить длительную и безопасную работу реактора. В данной работе представлены результаты молекулярно-динамического моделирования взаимодействия краевой дислокации с частицей, содержащей атомы рения с различной стехиометрией, возникающие в реальности в процессе трансмутации вольфрама с ОЦК кристаллической решеткой когерентной основному металлу. Полученные результаты демонстрируют повышение напряжения течения по мере увеличения среднего размера частицы, при этом зависимость от температуры является слабовыраженной. В силу того, что данный вид дефектов является одним из многих (поры, границы зерен, некогерентные частицы), целесообразным представляется продолжение работы в ключе моделирования движения дислокации в поле напряжений, индуцированным рядом вышеупомянутых дефектов. Исследование влияния макроскопических дефектов на динамику движения дислокации в кристалле вольфрама является важным для понимания стабильности кристаллической решетки материала в далеких от равновесия условиях.
БОРСОДЕРЖАЩИЕ ПОКРЫТИЯ, СФОРМИРОВАННЫЕ НА ВЫСОКОЭНТРОПИЙНОМ СПЛАВЕ: СТРУКТУРА, СВОЙСТВА
Authors: Иванов Ю.Ф. , Шугуров В.В. , Ажажа И.И. , Петрикова Е.А. , Толкачев О.С.
Published: December 2023

Целью работы является анализ результатов, полученных при исследовании структуры, элементного и фазового состава, прочностных и трибологических свойств борсодержащих покрытий, полученных на высокоэнтропийном сплаве комплексным ионно-плазменным методом. В качестве материала подложки использовали сплав CoFeCrMnNi неэквиатомного состава (25,2Co, 15,1Cr, 37,8Fe, 3,4Mn, 16,3Ni; ат. %). Борсодержащие покрытия элементного состава Al–Mg–Ti–B толщиной 1, 3 и 5 мкм формировали методом ионно-плазменного высокочастотного напыления (магнетронное ВЧ-осаждение в условиях ионно-плазменного ассистирования при использовании генератора газовой (аргон) плазмы «ПИНК»). Для осуществления процесса напыления борсодержащего покрытия была использована мишень диаметром 200 мм, изготовленная из смеси двух порошков AlMgB14 + 50 % TiB2. Для интенсификации процесса распыления мишени был применен генератор газовой плазмы «ПИНК», с помощью которого в рабочей вакуумной камере установки создавалась объёмная аргоновая плазма. При подаче ВЧ потенциала на мишень ионы аргона извлекались из плазмы и бомбардировали мишень, производя ее интенсивное распыление. Формирование покрытия на поверхности подложки происходит в результате подачи на нее напряжения смещения 35 В. Температура подложки при напылении покрытия (350-360) °C. Скорость напыления покрытия 0,05 мкм/мин. Исследования структуры и элементного состава борсодержащего покрытия элементного состава Al–Mg–Ti–B, сформированного на образцах высокоэнтропийного сплава состава CoFeCrMnNi комплексным ионно-плазменным методом осуществляли методами электронной дифракционной микроскопии. Установлено, что покрытие имеет аморфно-кристаллическую структуру. Размер областей кристаллического состояния материала (3-5) нм. Твердость покрытия H = 11,0 ГПа; модуль Юнга Е = 185 ГПа; отношение H/Е = 0,059, параметр износа k = 4×10-7 мм3/Н×м; коэффициент трения μ = 0,12. Для подложки без покрытия H = 2,1 ГПа; k = 2,9×10-4 мм3/Н×м; μ = 0,62.
МИКРОСТРУКТУРНЫЕ ИЗМЕНЕНИЯ В СПЛАВЕ Al-3 вес. % Cu В ПРОЦЕССЕ РАВНОКАНАЛЬНОГО УГЛОВОГО ПРЕССОВАНИЯ ПРИ ПОВЫШЕННОЙ ТЕМПЕРАТУРЕ
Authors: Ситдиков О.Ш. , Загитов Р.Р. , Автократова Е.В. , Маркушев М.В.
Published: December 2023

Исследовали изменение микроструктуры крупнозернистого бинарного сплава Al-3 вес. % Cu в процессе равноканального углового (РКУ) прессования при Т=150 °C ≈ 0,5Тпл (где Tпл – температура плавления чистого алюминия). Перед началом деформации в сплаве были получены гомогенные выделения упрочняющей фазы Q(Al2Cu) со средним размером около 16 нм. Как и в условиях низкотемпературной деформации, основной особенностью РКУ прессования данного сплава при 0,5Тпл было развитие на начальной стадии деформации (e=1) полосовых деформационных структур, приводящих к фрагментации исходных зерен. Однако, при дальнейшем РКУ прессовании такие дислокационные структуры трансформировались в характерную для горячей деформации смешанную (суб)зеренную структуру, что сопровождалось измельчением зерен. В результате при e=8 в сплаве формировалась бимодальная микроструктура с долей высокоугловых границ около 50 %, состоящая на 60 % из областей новых зерен размером около 1 мкм и нерекристаллизованных фрагментов исходных зерен, содержащих субзерна. Показано, что в отсутствие дисперсных алюминидов переходных металлов выделения основной упрочняющей фазы Q оказывали существенное влияние на процессы накопления и релаксации энергии деформации. В результате эти выделения контролировали формирование дислокационной структуры, протекание динамического возврата и миграцию границ (суб)зерен, определяя характер и кинетику процессов формирования новой мелкозернистой структуры.
ВЛИЯНИЕ ТЕМПЕРАТУРЫ СВАРКИ ДАВЛЕНИЕМ И ПОСЛЕДУЮЩЕЙ ТЕРМИЧЕСКОЙ ОБРАБОТКИ НА СТРУКТУРУ И СВОЙСТВА ТВЕРДОФАЗНЫХ СОЕДИНЕНИЙ ИЗ НИКЕЛЕВЫХ СПЛАВОВ ЭП975 И ЭК61
Authors: Галиева Э.В. , Классман Е.Ю. , Валитов В.А.
Published: December 2023

Проанализировано влияние температуры сварки давлением (СД) и термической обработки на структуру и свойства твердофазного соединения деформируемых гетерофазных никелевых сплавов в сочетании ЭП975//ЭК61с различным типом упрочняющей фазы. По результатам энерго-дисперсионного анализа установлено, что в процессе СД в вакууме в температурно-скоростных условиях (850-925 °С; 10-4 с-1) проявления низкотемпературной сверхпластичности сплава ЭК61 между соединяемыми сплавами ЭП975 с микродуплексной структурой (6-8 мкм) и ЭК61 с ультрамелкозернистой (≤1 мкм) структурой в результате протекания процессов взаимной диффузии легирующих элементов формируется узкая переходная зона диффузионного взаимодействия. Ее ширина возрастает от 3 мкм до 8 мкм с увеличением температуры СД с 850 до 925 °С. Изучено влияние последующей термической обработки на изменение фазового состава в зоне твердофазного соединения (ТФС) и прочность сварных образцов. Показано, что увеличение температуры СД с 850 до 925 °С, а также последующая термическая обработка приводят к расширению зоны диффузионного взаимодействия до 10-20 мкм. По результатам механических испытаний на растяжение при комнатной температуре установлено, что наибольшая прочность сварных образцов после СД при температуре 850 ºС достигает величины 0,8 от прочности соединяемого сплава ЭК61, а после термической обработки сохраняется на том же уровне.
Chiral arylsulfinylamides: all-in-one reagents for visible light-mediated asymmetric alkene aminoarylations
Authors: Hervieu Cedric , Kirillova Mariia S. , Hu Yawen , Cuesta-Galisteo Sergio , Merino Estíbaliz , Nevado Cristina
Published: December 2023

Two- or one-electron mediated alkene aminoarylations represent straightforward approaches to assemble molecular complexity by the simultaneous formation of two contiguous Csp3-Csp2/Csp3-N stereocenters. While racemic versions have been extensively explored, asymmetric variants, especially those involving open-shell C-centered radical species, are much more limited both in number and scope. In this work, we describe enantioenriched arylsulfinylamides as all-in-one reagents for the efficient asymmetric, intermolecular aminoarylation of alkenes. Under mild photoredox conditions, Nitrogen addition of the arylsulfinylamide onto the double bond followed by 1,4-translocation of the aromatic ring produce the corresponding aminoarylation adducts in a single operation. The sulfinyl group acts here as a traceless chiral auxiliary and is eliminated in situ under the reaction conditions. Optically pure beta, beta-diarylethyl- and aryl-alpha, beta-ethylenediamines, prominent motifs in pharmaceuticals and bioactive natural products, are obtained with excellent levels of regio-, relative and absolute stereocontrol.
Evolution of Complex Chemical Mixtures Reveals Combinatorial Compression and Population Synchronicity
Authors: Matange Kavita , Rajaei Vahab , Capera-Aragonès Pau , Costner John T , Robertson Adelaide , Seoyoung Kim Jennifer , Petrov Anton S , Bowman Jessica C. , Williams Loren Dean , Frenkel Pinter Moran
Published: December 2023

Some of the most interesting open questions about the origins of life and molecular sciences center on chemical evolution and the spontaneous generation of complex and functional chemical species. The processes that generated the spectacular biopolymers that underlay biology demonstrate an untapped, by modern science, creative potential. We have established a robust, facile, and generally applicable platform for observing and analyzing chemical evolution using complex mixtures. While previous studies have characterized the formation of proto-polymers via chemical reactions, we systematically studied the process itself. We report empirical outcomes that were not foreseen or predicted. We have constructed an experimental platform to study the evolution of chemical systems that: (i) undergoes continuous recursive change with transitions to new chemical spaces while not converging throughout the course of the experiment, (ii) demonstrates chemical selection, during which combinatorial explosion is avoided, (iii) maintains synchronicity of molecular sub-populations, and (iv) harvests environmental energy that is stored in chemical energy. We have established some general guidelines for conducting chemical evolution. Our results suggest that chemical evolution can be adapted to produce a broad array of molecules with novel structures and functions.
Pincer-ligated Iridium Complexes with Low-Field Ancillary Ligands: Complexes of (iPrPCP)IrCl2 and Comparison with (iPrPCP)IrHCl
Authors: Parihar Ashish , Emge Thomas J. , Goldman Alan S.
Published: December 2023

Pincer-ligated iridium complexes have been widely developed, and (pincer)Ir(III) complexes, particularly five-coordinate, are central to their chemistry. Such complexes typically bear two formally anionic ligands in addition to the pincer ligand itself. Yet despite the prevalence of halides as anionic ligands in transition metal chemistry there are relatively few examples in which both of these ancillary anionic ligands are halides or even other monodentate low-field anions. We report a study of the fragment (iPrPCP)IrCl2 (iPrPCP = 3-2,6-C6H3(CH2PiPr2)), and adducts thereof. These species are found to be thermodynamically disfavored relative to the corresponding hydridohalides. For example, DFT calculations and experiment indicate that one Ir-Cl bond of (iPrPCP)IrCl2 complexes will undergo reaction with H2 to give the (iPrPCP)IrHCl or an adduct thereof. In the presence of aqueous HCl, (iPrPCP)IrCl2 adds a chloride ion to give an unusual example of an anionic transition metal complex ((iPrPCP)IrCl3–) with a Zundel cation (H5O2+). (iPrPCP)IrCl2 is not stable as a monomer at room temperature but exists in solution as a mixture of clusters which can add various small molecules. DFT calculations indicate that dimerization of (iPrPCP)IrCl2 is more favorable than dimerization of (iPrPCP)IrHCl, in accord with its observed tendency to form clusters.
Enumeration, Nomenclature and Stability Rules of Carbon Nanobelts
Authors: Wang Yang , Zhou Yi , Du Ke
Published: December 2023

With the recent breakthroughs and advances in synthetic chemistry, carbon nanobelts (CNBs) have become an emerging hot spot in chemistry and materials science. Owing to their unique molecular structures, CNBs have intriguing properties with applications in synthetic materials, host–guest chemistry, optoelectronics, and so on. Although a considerable number of CNBs with diverse forms have been synthesized to date, no systematic nomenclature is available yet for this important family of macrocycles. Moreover, little is known about the detailed isomerism of CNBs, which, in fact, exhibits greater complexity than that of carbon nanotubes. The copious variety of CNB isomers, along with the underlying structure–property relationships, bears fundamental relevance to the ongoing design and synthesis of novel nanobelts. In this paper, we propose an elegant approach to systematically enumerate, classify, and name all possible isomers of CNBs. Besides the simplest, standard CNBs defined by chiral indices (n, m), the nonstandard CNBs (n, m, l) involves an additional winding index l. Based on extensive quantum chemical calculations, we present a comprehensive study of the relative isomer stability of CNBs containing up to 30 rings. A simple Hückel-based model with a high predictive power reveals that the relative stability of standard CNBs is governed by the π stabilization and the strain destabilization induced by cylindrical carbon framework, and the former effect prevails the latter. For nonstandard CNBs, a third stability factor, the H...H repulsion in the benzo[c]phenanthrene-like motifs, is shown to be also important and can be incorporated into the simple quantitative model. In general, lower-energy CNB isomers have a larger HOMO–LUMO gap, suggesting that their thermodynamic stability coincides with kinetic stability. The determined most stable CNB isomers can be considered as the optimal targets for future synthesis. These results lay an initial foundation and provide a useful theoretical tool for further research on CNBs and related analogs.
Sustainable Electrosynthesis of Cyclohexanone Oxime through Nitrate Reduction on a Zn-Cu Alloy Catalyst
Authors: Sharp Jonathan , Ciotti Anna , Andrews Hayley , Udayasurian Shaktiswaran , García-Melchor Max , Li Tengfei
Published: December 2023

Cyclohexanone oxime is an important precursor for Nylon-6 and is typically synthesized via the nucleophilic addition-elimination of hydroxylamine with cyclohexanone. Current technologies for hydroxylamine production are, however, not environment-friendly due to the requirement of harsh reaction conditions. Here we report an electrochemical method for the one-pot synthesis of cyclohexanone oxime under ambient conditions with aqueous nitrate as the nitrogen source. A series of Zn-Cu alloy catalysts are developed to drive the electrochemical reduction of nitrate, where the hydroxylamine intermediate formed in the electroreduction process can undergo a chemical reaction with the cyclohexanone present in the electrolyte to produce the corresponding oxime. The best performance is achieved on a Zn93Cu7 electrocatalyst with a 97% yield and a 27% Faradaic efficiency for cyclohexanone oxime at 100 mA/cm2. By analyzing the catalytic activities/selectivities of the different Zn-Cu alloys and conducting in-depth mechanistic studies via in-situ Raman spectroscopy and theoretical calculations, we demonstrate that the adsorption of nitrogen species plays a central role on catalytic performance. Overall, this work provides an attractive strategy to build the C–N bond in oxime and drive sustainable organic synthesis through electrochemical nitrate reduction, while highlighting the importance of controlling surface adsorption for product selectivity in electrosynthesis.
A critical analysis of chemical and electrochemical oxidation mechanisms in Li-ion batteries
Authors: Spotte-Smith Evan Walter Clark , Vijay Sudarshan , Petrocelli Thea Bee , Rinkel Bernardine L.D. , McCloskey Bryan D. , Persson Kristin A.
Published: December 2023

Electrolyte decomposition limits the lifetime of commercial lithium-ion batteries (LIBs) and slows the adoption of next-generation energy storage technologies. Fundamental understanding of electrolyte degradation is critical to rationally design stable and energy-dense LIBs. To date, most explanations for electrolyte decomposition at LIB positive electrodes rely on ethylene carbonate (EC) being chemically oxidized by evolved singlet oxygen (1O2) or electrochemically oxidized. In this work, we apply density functional theory to assess the feasibility of these mechanisms. We find that electrochemical oxidation is unfavorable at any potential reached during normal LIB operation, and we predict that previously reported reactions between EC and 1O2 are kinetically limited at room temperature. Our calculations suggest an alternative mechanism, in which EC reacts with superoxide (O2^–1) and/or peroxide (O2^–2) anions. This work provides a new perspective on LIB electrolyte decomposition and motivates further studies to understand reactivity at positive electrodes.
Resource Mobilisation, Utilisation and Wellbeing of Social and Solidarity Groups In The Assin Fosu Municipality, Ghana.
Authors: Koomson F. , Buadu C. , Ntiri R. O.
Published: December 2023

Purpose: The study focused on farm-based cooperatives in the Assin Fosu municipality and examined resource mobilisation as well as the factors that determine resource utilisation and the wellbeing of social and solidarity organisations.

Design/Methodology/Approach: 180 respondents from six registered farm-based cooperatives in the Assin Fosu Municipality were chosen for the study using a mixed research design and a multi-stage sample method that included purposive, proportional, and simple random sampling procedures. The Focus Group comprised cooperative chairpersons and was further expanded to include the Municipal Co-operative Officer, who was specifically chosen as a key informant. In addition to narratives drawn from qualitative data, descriptive statistics and logistic regression were used to examine the data.

Research Implications/Limitations: The limitation of this study is the measurement of farm size and income which were based on the mental construct of farmers because most of the cooperative members did not keep records. This tended to distort the reality related to farm size and income which were included in the construct of wellbeing and collective resource mobilisation.

Findings: We discovered that, except for cooperatives based on cocoa, resource mobilisation was low across all the cooperatives. The study found that the mobilisation of resources and the collective purchase of agricultural equipment and supplies, which reduced production costs, were the driving forces behind resource utilisation. The main wellbeing indicators were longer membership durations and group resource mobilisation and utilisation.

Practical Implications: The findings of the study will help contribute to the management of social and solidarity groups in Ghana and broaden the understanding of how this development approach affects livelihoods. It is also hoped that the findings will contribute to the mitigation of the cost of neoliberal policies by providing a path to wellbeing at the micro and informal levels through group resource mobilisation and utilisation.

Social Implications: Social and Solidarity organisations serve as an alternative to economic organisations that are based on neoliberal principles. This is because the latter favours the dominant few in developing economies culminating in widespread poverty, inequalities, and a decline in wellbeing. To maximise wellbeing, cooperatives should intensify resource mobilisation, and utilisation whilst maintaining their membership.

Originality/Value: The novelty of this paper lies in its contribution to the literature on social and solidarity economies. It provides information on the missing link on how farm-based cooperatives mobilise and utilise resources for the wellbeing of their members.