bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal Trajectory for a Hypersonic Cruise Missile with a Nonconvex Control Set
Authors: Shachar Sahar , Ben-Asher Joseph Z. , Diepolder Johannes
Published: February 2025

This paper focuses on the range maximization problem for hypersonic cruise missiles (HCMs). The controls of the HCM under investigation are the angle of attack and the fuel flow of the scramjet engine. When fuel is burned, the angle of attack is strictly restricted under the engine’s limitations. Therefore, a novel control relation is introduced, allowing for a broader range of admissible angle-of-attack values during non-fuel-burning periods. Our analysis primarily examines two methods. The first is based on a vanishing constraint formulation, which implies that the control set is nonconvex and the linear independence constraint qualification is invalid. The second method employs an extended variable time transformation (VTT) approach to reformulate the problem. The advantage of the VTT formulation in terms of convergence to an optimal solution is demonstrated using a simplified problem. Finally, we present a comparison of both formulations for the range maximization problem of the HCM, highlighting the merits of the VTT method.
Combined Long-Term Collision Avoidance and Stochastic Station-Keeping in Geostationary Earth Orbit
Authors: De Vittori Andrea , Pavanello Zeno , Di Lizia Pierluigi , McMahon Jay , Armellin Roberto
Published: February 2025

To limit the spread of space debris, space situational awareness (SSA) delineates guidelines to preserve current space assets. Developing effective collision avoidance maneuver (CAM) strategies is emerging as a global top priority among the considered countermeasures to debris-generating events. Despite most encounters happening over very short time frames, some conjunctions occur over a longer time window, such as in geostationary Earth orbit (GEO), where the involved objects may have small relative velocities. Besides, external perturbations, particularly the geopotential, lunisolar, and solar radiation pressure ones, exert forces on the spacecraft, causing it to deviate from its designated slot and potentially endanger neighboring satellites. This issue is compounded when considering state uncertainty. The presented work, therefore, introduces convex optimization approaches for long-term CAM and tailored stochastic station-leeping (SK) policy regarding longitude and latitude in this regime. The formulation enables continuous CAM and chance-constrained SK, ensuring satellite adherence to an assigned GEO slot with a given probability. Two kinds of chance constraints are devised: the first one does not consider the correlation between longitude and latitude, but the latter does.
Natural Convection Inside Square and Cubic Cavity with Left Wall Partially Heated
Authors: An Bo , Meng Xinyu , Bergadà Josep Maria , Xi Chao , Sang Weimin
Published: February 2025

The numerical model is considered as two- (2-D) and three-dimensional (3-D), respectively, for 2-D and 3-D cases. Four heat parameters associated with the heat source are considered and defined as the heat source position ([Formula: see text]), the heat source projection area ([Formula: see text]), the heat source thickness ([Formula: see text]), and the heat source distribution mode ([Formula: see text]). For both 2-D and 3-D cases, the heat source is positioned along the left wall, which is also defined as the high-temperature boundary. The low-temperature boundary is partially distributed along the right wall, and the rest of the walls are defined as the adiabatic boundary. To describe the coupling effect between density and temperature fields, a coupled double distribution function model of lattice Boltzmann method is employed, indicating that, apart from the density distribution function, the temperature distribution function is considered as well, and the coupling effect is considered through the external force term added in the density distribution function. The numerical model is validated by using the classic natural convection inside a square cavity and followed by the grid convergence test. The numerical results of the 2-D and 3-D cases are compared and it is found that the 2-D results have a good agreement with the 3-D cases. The impact of each heat parameter on the properties of flow and heat transfer is regarded as new findings and revealed in detail. The comprehensive study of the different heat parameters presented in this study is aimed to propose more efficient strategies on heat source distributions for specific practical applications.
The Image of the World in A. P. Platonov’s Short Story Nikita: A Mythopoetic Aspect
Authors: Skuridina S. A. , Kuzminykh E. O. , Bugakova N. B.
Published: February 2025

Purpose. The article analyzes the story Nikita, which is important for the work of A. Platonov. It was originally named The Kind Whale and was included into the cycle Good People.

Results. The authors identify the mythological picture of the world implementation features in the story. It is noted that the writer represents the reality through a perception of a five-year-old boy who gives animation, reason and feelings to visible objects around him, which are perceived by the hero through kinship terms, proper nouns, and other linguistic units mastered by this age. In Nikita's mythological picture of the world there are “his own” things, which are associated with the image of a house and a yard, fenced off from the “stranger” things. Being appointed daily to the role of master by his mother, Nikita must preserve the harmony of his world – to live quietly, that is, in kinship with “his” world, not allowing anyone else and not depriving of life named, and therefore animate, inhabitants. Violation of the maternal covenant has negative consequences: “one’s own” and “someone else’s” change places, instilling fear in Nikita, which he had not experienced before, because he lived in the world of objects and phenomena created and named by him, and therefore, endowed with life.

Conclusion. The opposition “life – death” acquires an additional meaning from A. Platonov, including the opposition “kinship – orphanhood”: the one who is related to the world remains alive, and orphanhood is perceived as detachment from the world, loss of connection with it, which is equal to death.
Linguistic Hedges in Scientific Articles on Humanities
Authors: Boginskaya O. A.
Published: February 2025

Purpose. By using a corpus of 120 Russian scientific articles on humanities the study analyzed linguistic actualizers of hedging as a metadiscourse strategy contributing to the efficient communication between an author and a reader. The novelty of the study is determined by scarcity of metadiscourse studies on articles in Russian, while it is relevant due to the ongoing attempts to re-interpret the nature of academic discourse, which has been considered as an interactional rather than informational space. This approach determines the need to study linguistic tools that help to construct an efficient dialogue with the reader and present research results in a way that is appropriate in the scientific community. The study aims to reveal lexical and lexico-syntactic hedges and determine their frequencies and functions in the corpus of scientific articles on humanities.

Results. It was demonstrated that hedging is an integral part of academic discourse, where it mitigates the categoricalness of author’s claims by de-intensifying features under consideration, shifting the communicative focus to the emotional state or subjective nature of author’s opinions, indicating the non-absolute nature of his statements, or presenting the statements as possible ones.

Conclusion. The analysis revealed hedging to be a crucial component of effective author-reader interaction, mitigating categorical statements and conveying a nuanced understanding of the research issue. Adverbs and verbs were the most prevalent lexical hedges, while introductory constructions played a significant role in the lexico-syntactic category. These findings emphasize the importance of hedging in creating a collaborative academic discourse space.
Word Formation and Borrowing of Person Nominations in Internet Discourse (Based on Speech Usage Data and Internet Language Dictionaries)
Authors: Zhirakovskaya A. A.
Published: February 2025

Purpose. The article presents the results of a structural-semantic analysis of person nominations functioning in Internet discourse. Based on speech and lexicographic sources, the composition of the card index was determined – 145 slang personal nouns. The analysis of speech material was carried out within the framework of the derivational paradigm, which involves the complex use of several methods – morphemic, morphonological, word-formational and semantic.

Results. The analysis of lexical material allowed to establish the main ways of replenishing the lexicon of person nominations. Thus, 35.8 % of units are borrowings, and 64.2 % are Russian derivatives. Almost all borrowings in the card index (50 out of 52 lexemes) are Anglicisms; cases of borrowing from the Japanese language are unique. A third of the units in in the card index (44 words) are neolexemes that is, new phonetic units with new semantics The formation of person nominations on the basis of the Russian language occurs through semantic derivation, affixation, compounding, fusion, and phonetic truncation.

Conclusion. Suffixation turns out to be the most productive way of producing personal nouns (the share of suffixal derivatives is 66 %, 13 different formants form neologisms with the meaning ‘person’ have been identified). The other methods of word formation listed earlier are less relevant in Internet discourse.
The Representation of Jewish Identity in On Sleep by Clearchus of Soli
Authors:   The Russian Christian Academy for the Humanities, Galanin Rustam ,   The Saint Petersburg State University
Published: February 2025

The dialogue On Sleep by Clearchus of Soli is the first extant work depicting a personal meeting between a representative of the Jewish people and an ancient Greek. The character Aristotle is surprised by the deeds and words of a wise Jew. In fr. 6 Wehrli, Aristotle says that the wise Jew was a Hellenic not only in his language, but also in his soul. In fr. 7 Wehrli, we are told about a certain magician whom Aristotle met and who extracts the soul from a sleeping young man with a magic wand, and then returns it back into the body. In a number of fragments of the On Sleep, which were not included in the collection of Clearchus in Werhli, but included in the latest German edition by Tsitsiridis and in the English edition by Dorandi, it is said about certain mysterious people who feed on the sunny air and are not subject to sleep, with whom Aristotle allegedly talked. In our article, we propose the hypothesis that the miracle worker from fr. 7 Wehrli is identical to the wise Jew from fr. 6, and in two fragments from new editions, under sleepless and sunny-air-eating people, one must understand the Jewish ethnic group. In general, the representation of Jewish identity in this work of Clearchus is a vivid example of what can be called an Interpretatio Graeca.
Intaglio with the portrait of Silenus from Galilee and the composition of the “inverted/summary faces” in the Greco-Roman period
Authors:   National Treasures Department of the Israel Antiquities Authority, Tarkhanova Svetlana
Published: February 2025

A Persian-Early Hellenistic glass intaglio with the portrait of Silenus was found in Galilee some years ago. Except for the testimony of the spread of Dionysiac cults in the Syro-Palaestinian region during such an early period, the occasional finding would not bear so much meaning if not for the unique iconographical features of the Silenus’s portrait. When turned upside down, the face of the apathetic, passionless Silenus transforms into the portrait of the evil face, supposedly of a Cyclop Polythemus or satyr's mask (two interchangeable faces). The composition of the “inverted faces” might be considered one of the types of more developed synthetic compositions comprised of several faces or creatures and usually applied on the gems (known as janiform or grylloi/baskania). Many remote parallels were mentioned in these rows of examples. The “inverted faces” (bes or pazuzu) are rarer, but they were still applied to some Persian and Hellenistic coins and gems, which were often interconnected iconographically. Most notable is the Roman red glass gem in the British Museum collection, which is decorated with two “inverted faces”: it is incredibly close by its iconography to the gem under consideration. In addition, a unique Roman ceramic beaker from the Budapest History Museum and the Roman glass flask from the Eretz Israel Museum in Tel Aviv adorned with interchangeable faces were mentioned and interpreted. In my opinion, the composition with “inverted/summary faces” is highly underestimated in the history of Classical art and might be detected in a broader range of samples if only it was taken into consideration (usually, the reversibility of the faces remains unnoticed).
Comparison of Airflow Around the Windward and Leeward Sides of an Aircraft Wing with a Straight Leading Edge
Authors: Alpatskiy N. S. , Pavlenko A. M. , Zanin B. Yu. , Bondarev I. A.
Published: February 2025

The presented work shows the results of an experimental study of the structure of the flow separation over the wing of a small-sized aircraft with a leading edge and fuselage on the leeward and windward sides. Visualization images of the wall flow were obtained, followed by an analysis of these photographs and a comparison of the flow results on both sides. The flow structure studies were conducted at the critical angle of attack for the model used. Additionally, the study examined the influence of changes in the angle of sideslip and the deflection of control surfaces (elevons).
İşletme Disiplininde Endüstri 4.0: Türkiye’de Hazırlanmış Lisansüstü Tez Çalışmaları Üzerine Bir Derleme
Authors: Kılıç Cumali
Published: February 2025

Endüstri 4.0 dönüşümünü anlamak ve bu alandaki bilgi birikimine katkıda bulunmak amacıyla Türkiye’deki lisansüstü tezlerin derlenmesi bu çalışmanın temelini oluşturmaktadır. Çalışmada, Türkiye Yüksek Öğretim Kurumu (YÖK) Ulusal Tez Merkezi’nde bulunan işletme alanındaki Endüstri 4.0 konulu lisansüstü tezlerin temel bilgileri, metodolojik yaklaşımları ve öne çıkan özelliklerinin detaylı bir analizi ortaya koyulmuştur. Bu bibliyografik derleme, akademik çevrelerde Endüstri 4.0’ın işletme disiplinindeki evrimini anlamak isteyen araştırmacılara kapsamlı bir rehberlik sunmakta ve Endüstri 4.0’ın işletme alanındaki tez çalışmalarındaki genel eğilimleri daha derinlemesine anlamak adına önemli bir kaynak oluşturmaktadır. Ayrıca, Endüstri 4.0’ın işletme stratejileri, operasyonel süreçler ve yönetim yaklaşımları üzerindeki etkilerini belirleyerek, gelecekteki çalışmalara yön verecek kritik çıkarımlarda bulunmayı hedeflemekte ve benzer konulardaki çalışmaların kapsamlı bir analizini sunarak bu alandaki mevcut bilgi birikimini sistemli bir şekilde sunmayı amaçlamaktadır.
Bitcoin Fiyatlarının Gri Tahmin ile Modellenmesi
Authors: Yurtoğlu Yasemin
Published: February 2025

Tarihin başlangıcından itibaren sürekli evrim geçiren para, insanlık tarafından geliştirilen en önemli araçlardan biridir. Para, insanların gelecekteki ve anlık ihtiyaçlarını karşılamak için belirlenen bir değeri temsil eder. Para kavramı, dönemin koşullarına ve imkânlarına göre farklı şekillerde ortaya çıkar. Kripto paraların temelleri 1980'lerde atılmış olup, 2008 yılında Satoshi Nakamoto tarafından Bitcoin'in tanıtılmasıyla hayatımıza girmiştir. Geleneksel paralara alternatif olarak ortaya çıkan kripto paralar, teknolojik bir yenilik olup her geçen gün daha da popüler hale gelmektedir. Bitcoin, merkezi bir otorite tarafından yönetilmeyen ilk kripto paradır ve popülerliği ve başarısı diğer alternatif kripto paraların oluşmasına yol açmıştır. Julong Deng tarafından 1982 yılında geliştirilen “Gri Sistem Teorisi”, belirsiz sistemlerin davranışlarını tahmin etmek için kullanılan bir yöntem olup GM (1,1) modeli en sıklıkla kullanılan gri modeldir. Bu çalışma, Bitcoin'in fiyatlarını GM (1,1) modeli kullanarak tahmin etmeyi amaçlamaktadır. Araştırma sonucunda, modelin gelecek dönem tahminleri için uygun olduğu ve başarılı tahminler yaptığı belirlenmiştir
An Empirical Investigation on the Relationship between Fiscal Transparency and Institutional Quality
Authors: Tekdemir Nazmiye , Yeşil Eda
Published: February 2025

Fiscal transparency, a cornerstone of effective public financial management, encompasses the reliability, comprehensiveness, timeliness, and accountability of reporting on public finances. The quality of institutional structures plays a pivotal role in fostering and sustaining fiscal transparency. Analysing data from 57 countries over the 2008–2021 period using ordered probit analysis, this study reveals significant impacts of political stability, absence of violence, regulatory quality, rule of law, corruption control, and government effectiveness on fiscal transparency. In economies with lower transparency levels, variables such as voice and accountability, government effectiveness, and rule of law have limited positive effects, whereas their influence strengthens in economies with higher transparency. Interestingly, while political stability and corruption control positively affect low-transparency economies, their impact turns negative in highly transparent countries. Strengthening the rule of law, improving regulatory quality, fostering accountability, and enhancing anti-corruption measures are essential for narrowing disparities in transparency and promoting sustainable, credible public financial management.
Advancements in Nanoscale Chemical Analysis using Tip-Enhanced Raman Spectroscopy
Authors: Bienz Siiri , Xu Chengcheng , Xia Yuanzhi , Dutta Anushree , Zenobi Renato , Kumar Naresh
Published: February 2025

Tip-enhanced Raman spectroscopy (TERS) has established itself as a powerful tool in nanoscale chemical analysis, providing unprecedented spatial resolution with high molecular sensitivity and chemical specificity. TERS employs localized surface plasmon resonance at the apex of a sharp scanning probe microscopy tip to overcome the diffraction limit inherent in conventional Raman spectroscopy, achieving spatial resolutions down to the nanometer scale. In this article, we highlight major advancements in TERS over the past five years from our laboratory at ETH Zurich in the following key areas: heterogeneous catalysis, photovoltaic materials, biological membranes, and on-surface molecular assembly. Our recent studies demonstrate the unique capabilities of TERS for in situmonitoring of catalytic reactions, nanoscale mapping of phase behavior in biomembranes, and precise characterization of photovoltaic interfaces. Through these applications, we highlight the potential of TERS for addressing critical challenges across the chemical, biological, and materials sciences. This review serves as a guide for researchers aiming to harness TERS for label-free, non-destructive nanoanalysis to advance understanding of complex molecular materials and processes through ultrahigh sensitivity, specificity, and spatial resolution.
Life Detection Beyond Earth: Laser-Based Mass Spectrometry for Organics Detection on Solar System Objects
Authors: Riedo Andreas , Boeren Nikita J. , Keresztes Schmidt Peter , Tulej Marek , Wurz Peter
Published: February 2025

The detection and identification of the building blocks of life, from amino acids to more complex molecules such as certain lipids, is a crucial but highly challenging task for current and future space exploration missions in our Solar System. To date, Gas Chromatography Mass Spectrometry has been the main technology applied. Although it has shown excellent performance in laboratory research, it has not yet been able to provide a conclusive answer regarding the presence or absence of a signature of life, extinct or extant, in space exploration. In this contribution we present the current measurement capabilities of our space prototype laser-based mass spectrometer for organics detection. The developed mass spectrometer currently allows the detection and identification of small organic molecules, such as amino acids and nucleobases, at sample concentrations at the level of femtomole mm-2, using the same measurement protocol. The latter is highly relevant to space exploration, since with the instrumentation in use so far only one class of organics can be measured with one instrument configuration.
УРОЖАЙНОСТЬ ОЗИМОЙ ПШЕНИЦЫ ПРИ РАЗЛИЧНОМ УРОВНЕ ОБЕСПЕЧЕННОСТИ ПОЧВ ФОСФАТАМИ
Authors: Кадирова Г.А. , Хайитов М.А.
Published: February 2025

В данной статье рассматривается влияние различных условий фосфатного обеспечения на урожайность и коэффициент использования из удобрений озимой пшеницы сорта Алексееич в условиях орошаемого земледелия на светлых и лугово-сероземных почвах. Установлено, что надежное увеличение урожая наблюдается при очень низком уровне фосфатного обеспечения (0-15 мг/кг) при соотношении и норме минеральных удобрений 1:0,8:0,6 и N210P170K126; при низком обеспечении - 1:0,7:0,5 и N180P125K90; а при среднем обеспечении - 1:0,6:0,4 и N150P90K60, что с увеличением нормы минеральных удобрений коэффициент использования удобрений уменьшается.
КИЗИКСКИЙ СТАТЕР ИЗ МЕОТСКОГО ПОСЕЛЕНИЯ МАРЬЯНСКОЕ 1 В НИЖНЕМ ПРИКУБАНЬЕ
Authors: Абрамзон М.Г. , Плеханов Ю.В. , Зубавичус Е.Я. , Сапрыкина И.А.
Published: February 2025

При археологических раскопках меотского поселения Марьянское 1 (Красноармейский район Краснодарского края) в 2024 г. найден статер Кизика с ти пом Силена, заглядывающего в амфору (ср. Baldwin Brett, 1955. No. 1507). Статер да тируется 460‒400 гг. до н. э. Редкая находка свидетельствует о вовлечении меотских сельских поселений Нижней Кубани в масштабные поставки зерна по р. Кубань на Боспор, откуда оно экспортировалось, прежде всего, в Афины. В меотские же по селения поступал греческий импорт, шедший через Фанагорию и далее по водному пути в глубинные районы Прикубанья.

The paper publishes a rare numismatic find. In 2024, during archaeological excavations at the Maeotian settlement of Maryanskoye 1 (Krasnodar Territory, 285 КСИА. Вып. 276. 2024 г. Krasnoarmeyskiy district), a Cyzicenestater was discovered It bears an image of Silenus peering into an amphora (cf. Baldwin Brett, 1955. No. 1507). The stater dates back to 460‒400 BC. A rare find indicates the involvement of the Lower Kuban Maeotian rural settlements into large-scale grain trade along the Kuban River to Bosporus, from where it was exported, first of all, to Athens. In return, the Maeotian settlements received Greek goods that passed via Phanagoria and further along this waterway to the inland areas of the Kuban region.
ПРЕДВАРИТЕЛЬНЫЕ РЕЗУЛЬТАТЫ КОМПЛЕКСНОГО АНАЛИЗА КОЛЛЕКТИВНОГО ПОГРЕБЕНИЯ 631 АНТИЧНОГО НЕКРОПОЛЯ ВОЛНА 1
Authors: Сударев Н.И. , Шведчикова Т.Ю. , Мимоход Р.А. , Сапрыкина И.А.
Published: February 2025

В статье публикуются первые результаты комплексного анализа ма териалов из сырцовой гробницы (погребение 631), из которой происходят костя ки 11 индивидов, с богатым погребальным инвентарем. Гробница функционировала в период с 30-х гг. IV в. до н. э. по первую четверть III в. до н. э.; одной из возможных атрибуций этого погребального сооружения является отнесение его к категории семейных усыпальниц. Такая компактная выборка антропологического материала, несмотря на плохую сохранность костей, дает прекрасную возможность провести необходимые аналитические исследования для дифференциации населения, оставившего некрополь Волну 1. Был проведен изотопный анализ соотношений δ13C и δ15N, 87Sr/86Sr костной ткани для 7 индивидов; шесть из которых, судя по полученным результатам, являются представителями автохтонного населения, в том числе самый первый из захороненных. Последняя из погребенных в данной усыпальнице, возможно, является представителем другой группы населения, наиболее близкие параллели которым имеются в материалах из с. Веселого (Адлерский район).

The paper publishes the first results of the integrated analysis of materials from a mud-brick tomb (grave 631) that contained skeletons of 11 individuals with rich grave goods. The tomb functioned from the 30s of IV century BC to the first quarter of the III century BC. One of the possible interpretations of the burial construction is the variant of a family sepulcher. The bones were of poor state of preservations, yet this com pact selection of anthropological materials offers a great opportunity to conduct necessary analytical studies for differentiation of the population that used the Volna 1 necropolis. The study included the stable isotope analysis of the 15N/13C ratio and the 87Sr/86Sr ratio of the bone tissue for 7 individuals. Based on the results obtained, nine buried individuals are local, including the individual that was buried first. The latest individual buried in this 437 КСИА. Вып. 276. 2024 г. sepulcher is a representative of a different population group that shows the closest parallels among the human remains from the village of Veseloe (Adler district).
How does the molar ratio between two anions affect the properties of surface active double salt ionic liquids (DSILs)?
Authors: Rzemieniecki Tomasz , Kaczmarek Damian Krystian , Stachowiak Witold , Marcinkowska Katarzyna , Niemczak Michał
Published: February 2025

The strategy of mixing ionic liquids enables the formation of double salt ionic liquids (DSILs)—liquid systems consisting of three or more ions with tailored, beneficial properties that are crucial for designing new active chemical ingredients. In this study, we utilized this approach to obtain new DSILs containing a common surface active cation with a hexadecyl substituent and two anions derived from commonly used synthetic auxin herbicides—4-chloro-2-methylphenoxyacetic acid (MCPA) and 3,6-dichloro-2-methoxybenzoic acid (dicamba)—at varying molar ratios. Nuclear magnetic resonance analysis revealed significant chemical shift changes (up to 0.256 ppm for the methylene group in MCPA anion) which were linearly or exponentially dependent on the molar ratio of the DSIL counterparts, indicating specific, competitive interactions between the ions. The performed studies of physicochemical properties, including density, refractive index, and phase transition temperatures in most cases indicated a linear dependence of these properties on the molar ratio of the DSIL counterparts. However, combining two surface-inactive anions unexpectedly enhanced surface activity of the analyzed systems. DSILs with molar ratios from 8:2 to 2:8 exhibited nearly 50 % lower critical micelle concentrations than their single-anion counterparts. This increase in surface activity was responsible for an almost twofold increase in the aquatic toxicity toward Chlorella vulgaris.
Synthesis of Chiral δ-Aminoboronic Esters by Enantioselective Hydrogenation of 1,2-Azaborines
Authors: Liu Jiangpeng , Dai Yuping , Robinson Devon , Li Bo , Miqueu Karinne , Liu Shih-Yuan
Published: February 2025

We describe herein an iridium-catalyzed highly diastereo- and enantioselective hydrogenation of 1,2-azaborines ac- cessing δ-aminoboronic esters of potential biological importance. This method represents the first enantioselective hydrogenation of boron-containing heteroarene and features a diverse substitution pattern and wide scope. The synthetic utility of our method was demonstrated by the synthesis of (–)-Phenibut and the formal synthesis of (+)-3-PPP and Fluvirucinine A1.
Chemical Vapor Deposited Si:P Epitaxial Growth for DRAM Bit Contact
Authors: Sahu Protyush , Brown Jay , Borsari Silvia , Hull Jeff
Published: February 2025

Next generation DRAM series will rely on the ability to obtain low resistance contact junctions in very tight spaces and narrow trenches. Current DRAM technology uses a polycrystalline plug, followed by silicidation with Ti metal to obtain a low resistance interface. The upcoming generations of DRAM series requires us to narrow the bit contact (BC) CD down to ~10 nm and further decrease the BC resistance. This requires the use of a highly doped epitaxial plug to obtain low resistance BC. In this paper, we study the growth mechanisms and physics of SiP epitaxy. We explain the process optimizations that were undertaken to obtain an epitaxial plug close to our device specifications. We also explore the fundamental limitations of epitaxial growth, referred in this paper as Epitaxy trilemma. TEM/STEM and fundamental material characterizations showed the fundamental mechanisms behind the growth of SiP epi. Furthermore, we also characterized the effects of post-processing on the structural integrity of the BC.
Realizing the magneto-structural correlation of a highly anisotropic Fe(III) porphyrin complex through ab-initio approaches
Authors: Das Mayurika , Kamilya Sujit , Mandal Subhankar , Meena Sher Singh , Pechousek Jiri , Herchel Radovan , Mondal Abhishake
Published: February 2025

A mononuclear pentacoordinate Fe(III)-porphyrin-NCS complex has been synthesized and characterized by single-crystal X-ray diffraction, magnetic, electrochemical, spectroscopic, and theoretical studies. Single crystal X-ray diffraction studies show a planar porphyrin moiety with an axial NCS coordinated to the Fe(III) centre. Electrochemical and spectroelectrochemical studies in solution depict clear changes in the system during oxidation and reduction processes. Mössbauer spectroscopic analysis at different temperatures also supported the observation of a high-spin state of the Fe(III)-porphyrin complex that was further backed by DFT calculations. Attempts to understand the origin of high magnetic anisotropy in the ground state as determined by DC magnetic measurements was undertaken by detailed CASSCF/QD-NEVPT2 calculations.
Features of the crystal structure and influence of long-term exposure in the air atmosphere on electrical transport of HTSC-compounds of system 1-2-3 (review)
Authors: Pashchenko L.O. , Du Junyi , Komisarov A.O. , Nazirov Z.F. , Kotvytska K.A. , Vovk R.V.
Published: February 2025

The problem of the influence of a defect ensemble and long-term exposure in an air atmosphere on various mechanisms of electrical transport of HTSC compounds Re1Ba2Cu3O7-δ (Re = Y or other rare earth ion) is considered. The features of the crystal structure and the influence of structural defects of various morphologies on the electrical conductivity of these compounds in the normal, pseudogap, and superconducting states are discussed. A review of experimental data obtained from studies of the effect of long-term aging in air on various mechanisms of electrical transport of Re1Ba2Cu3O7-δ compounds of various compositions and technological backgrounds is carried out. The effect of long aging on stability of the oxygen subsystem and the electrical resistance of pure and aluminum-doped YBa2Cu3O7-δ single crystals with a given topology of planar defects have been studied. Various theoretical models are discussed on the effect of long-term exposure in an air atmosphere on the electrical conductivity of HTSC compounds of the 1-2-3 system.
Mechanical behavior and mechanisms of superplastic deformation of aluminum alloys exhibiting the effect of structural superplasticity in solid and in solid−liquid states
Authors: Poyda V.P. , Poyda A.V. , Myla D.Ye.
Published: February 2025

The article presents the results of research aimed at summarizing experimental data on the mechanical behavior, structural state and mechanisms of superplastic deformation of aluminum alloys Al-4 wt.% Ge, Al-4.1 wt.% Cu-0,5 wt.% Zr, 1420T, 1933. It is revealed that the initial microstructure of Al-4 wt.% Ge alloy samples is coarse-grained. Initial microstructure of 1420Т and 1933 alloy samples is bimodal. The study of characteristic types of samples microstructure deformed under the optimal conditions showed that the average grain size d av in samples of Al-4.1 wt.% Cu-0.5 wt.% Zr and 1420T alloys increases slightly. It is revealed that in the course of superplastic deformation of Al-4 wt.% Ge and 1933 alloy samples, recrystallization takes place intensively, it leads to an increase in the initial grain sizes. Accumulation of cavities in the samples of all studied alloys during superplastic flow is observed. In the samples of alloys 1420T and 1933 during superplastic deformation, structural changes occur, which are probably associated with local melting of the alloys. The viscous flow of the metastable liquid-solid phase localized at the grain boundaries leads to the formation of fibrous structures in cavities and cracks. The study of the deformation relief of the samples gives grounds for asserting that their superplastic deformation takes place due to the cooperative development of deformation and accommodation mechanisms, namely grain boundary sliding, intragranular dislocation sliding and diffusion creep. The contribution of grain boundary sliding to the overall deformation of the samples was analyzed, as well as the likely influence of liquid phase inclusions on the mechanism of superplastic deformation of samples that exhibit the effect of structural superplasticity in the solid-liquid state.
Impact on QoS with active queue management techniques in AODV routing protocol in MANETs
Authors: Uppe Nanaji , Sagar M. , K. Vara Prasad , Boddeda Ganesh
Published: February 2025

Active Queue Management (AQM) techniques are essential for addressing congestion in Mobile Ad Hoc Networks (MANETs), where the Ad hoc On-Demand Distance Vector (AODV) routing protocol is frequently used. AODV is a reactive routing protocol that establishes routes only when required, making it efficient in highly dynamic network environments. However, its performance can be adversely affected by congestion, resulting in packet loss, increased delays, and reduced throughput, especially in networks with limited resources and high traffic. This paper examines the integration of AQM techniques, specifically Random Early Detection (RED) and Drop Tail, within AODV for better congestion control in MANETs. RED is an AQM technique that anticipates congestion by monitoring the average queue length and selectively drops packets before the buffer overflows. This early packet dropping helps manage congestion and prevents network collapse, leading to more stable and efficient communication. Drop Tail, a simpler technique, drops packets only when the buffer is full, which may lead to bursty packet loss and affect real-time application performance. By incorporating AQM techniques like RED and Drop Tail, AODV can more effectively handle congestion and improve overall Quality of Service (QoS) in MANETs. These techniques contribute to reducing delays, minimizing packet loss, and ensuring more consistent throughput. This study highlights the importance of AQM in enhancing network performance, enabling more efficient communication in mobile ad hoc environments, and ensuring that AODV-based routing can perform well under varying network conditions.
DIREITO E ALTERIDADE EM TEMPOS DE INTELIGÊNCIA ARTIFICIAL
Authors: Pepler Nadieje de Mari
Published: February 2025

O presente artigo parte da necessidade de compreender as mudanças estruturais que estão em curso a partir do advento da inteligência artificial no sentido de avaliar se essas mesmas inovações proporcionadas pela IA estão a serviço do ser humano, na perspectiva da ética da alteridade, ao definir possibilidades contributivas sem deixar de se ater ao alto risco que a problemática envolve e, ainda, ao mesmo tempo, estabelecer limites éticos ao formular possíveis enfrentamentos típicos da periferia do sistema capitalista, no que tange aos aspectos centralizadores da totalidade detentora do capital tecnológico. Aponta-se, assim, a necessidade de formar uma interface entre o direito e a ética da alteridade de modo a rumar para a análise crítica que estabelece tanto os contornos estruturais dessa nova era da complexidade e da tecnologia como os possíveis impactos diretos para a realidade social, a partir dos pressupostos idealizados pela cyberjustice e suas ramificações tecnológicas. Para atingir os objetivos traçados o estudo será desenvolvido a partir da técnica bibliográfica (indireta e de fontes secundárias) e documental, isto é, presentes em livros históricos, filosóficos, documentos, revistas, artigos e pesquisa eletrônica, referentes ao problema em questão. Os múltiplos campos de conhecimento que englobaram o artigo destacaram um enfoque metodológico jurídico-filosófico-democrático-crítico-transdisciplinar.
Downscaling GRACE Data for Improved Groundwater Forecasting Using Artificial Neural Networks
Authors: Awawdeh Abdel Rahman M. , Yasarer Hakan , Ghaffari Zahra , Yarbrough Lance D.
Published: February 2025

This study introduces a dual-phase approach utilizing Artificial Neural Networks (ANNs) to overcome the challenges of groundwater monitoring at regional scales. Traditional well-based methods provide limited spatial coverage, while GRACE satellite data, despite its value for large-scale hydrological analysis, suffers from low spatial resolution (~300 km), limiting its application for local-scale assessments. Existing downscaling methods such as geographically weighted regression and Random Forests are computationally intensive and often lack adaptability to complex groundwater systems. In this study, Phase 1 refines GRACE data using ANNs to achieve a 4×4 km spatial resolution, addressing the resolution challenge for regional applications. Phase 2 integrates the downscaled GRACE data with groundwater well observations and climatic factors to predict groundwater levels with high accuracy (R² = 0.9885). This dual-phase framework demonstrates significant improvements over existing methods, providing an efficient and scalable solution for groundwater monitoring in hydrologically complex regions. The findings highlight the potential of machine learning to enhance groundwater resource management, particularly in addressing water scarcity and climate variability challenges. Doi: 10.28991/CEJ-2025-011-02-01 Full Text: PDF
The Effect of Additional Baffle Plates on Double-Stage Gravitational Water Vortex Turbine
Authors: Prasetyo Ari , Rovianto Eki , Adika Dimas , Maulana Reza , Septiyanto Muhamad D. , Budiana Eko P. , Hadi Syamsul , Prabowoputra Dandun M.
Published: February 2025

A Gravitational Vortex Water Turbine (GWVT) is an appropriate device to harness the kinetic energy of water to convert it into rotational mechanical energy in low-head. The water flow is directed into a circular basin, which can produce a vortex and can rotate the turbine blades. Turbine performance is influenced by the shape of the blade, so an optimal blade shape is required. Turbine performance is influenced by the shape of the blades, which can rotate optimally. This study aims to determine the effect of adding baffle plates in the blade on the performance of two-stage GWVT using experimental methods. The variation used is the proportion of baffle plate on the runner in the first stage with variations without baffle plate, 25%, 50%, 75%, and 100%. The data taken in the test is the torque and rotation at each additional blade plate. Torque measurement uses a rope brake system, and rotation measurement uses a tachometer. The results of the study showed that the addition of a 50% baffle plate in the first stage can capture the energy of the water vortex more optimally. A baffle plate can increase efficiency by up to 23.15% compared to the blade without the addition of a baffle plate. Doi: 10.28991/CEJ-2025-011-02-011 Full Text: PDF
Modified Asphalt Mixtures Incorporating Pulverized Recycled Rubber and Recycled Asphalt Pavement
Authors: Cubas Marlon , Correa Evelyn , Benavides Wilmer , Suclupe Robert , Arriola Guillermo
Published: February 2025

In the search to achieve eco-friendly techniques that ensure significant improvements in the properties of hot mix asphalt (HMA), recycled materials are being considered with greater application, coming from the pavement itself and also from artificial elements such as rubber. In this sense, the objective was to study the behavior of the mechanical and microstructural properties of HMA by adding pulverized recycled rubber (PRR) and recycled asphalt pavement (RAP), taking into account a control group without any addition and an experimental group with PRR and RAP. The research involved the production of briquettes with the modification of asphalt cement (AC) using doses of 3%, 5%, and 7% of PRR as a replacement by weight of AC. Then, the optimal percentage of PRR was combined with 10%, 20%, and 30% RAP as a partial substitute for the coarse aggregate. It should be noted that in both aspects, the thermogravimetric and microstructural performance of the asphalt mixture was evaluated. Subsequently, the results obtained indicate that the HMA is MAC-1 type, and it was established that the combinations of PRR and RAP significantly influence the physical-mechanical properties of the HMA with 3%PRR+10%RAP. On the other hand, the findings of the PRR thermogravimetric analysis show that the degradation of HMA occurs at 350°C, causing the loss of both mechanical and microstructural properties. However, infrared spectroscopy and scanning electron microscopy revealed that the PRR adheres correctly with the aggregate, improving the morphology and texture of the HMA. Doi: 10.28991/CEJ-2025-011-02-02 Full Text: PDF
A Theoretical Pore Network Model for the Soil–Water Characteristic Curve and Hysteresis in Unsaturated Soils
Authors: Gómez Angela V.
Published: February 2025

This study presents a novel approach to modeling the soil–water characteristic curve in unsaturated soils, employing Monte Carlo simulations to capture the complex behavior of the pore network. The primary objective is to develop an alternative method to represent the hysteretic nature of the soil–water characteristic curve, which is critical for understanding unsaturated soil behavior in various engineering applications. The proposed approach conceptualizes soil as a network of interconnected pores, where each pore interacts with its nearest neighbors. Monte Carlo simulations are used to model the pore-filling distribution as a function of pressure differences during drying and wetting cycles. The model effectively reproduces the characteristic hysteresis curves associated with the hydraulic and mechanical processes in unsaturated soils. A key finding is that the simulated soil–water characteristic curve captures the impact of pore-scale interactions and reflects the complex hysteresis effects observed in experimental data. The novelty of this work lies in integrating pore network modeling with Monte Carlo simulations, addressing limitations of traditional models and offering a more accurate representation of unsaturated soil behavior. While the model has not yet undergone experimental validation, it provides valuable insights into the dynamics of soil moisture retention and serves as a foundation for future experimental testing and refinement of soil–water models. Doi: 10.28991/CEJ-2025-011-02-021 Full Text: PDF
Seismic Assessment of First and Second Secant Stiffness for the Masonry Infilled RC Frame
Authors: Galatage Abhijeet A. , Patil Satish B.
Published: February 2025

The seismic resilience of composite concrete frame structures composed with masonry infill walls, is a critical research area due to its impact on structural performance during earthquakes. Most studies on reinforced concrete (RC) frames focus on key seismic response parameters like lateral strength and overall hysteretic behavior under cyclic loading, often analyzing the first and second secant stiffness throughout the seismic loading process. The present study examines the first and second secant stiffness as the structural performance during earthquake. A series of experimental tests are performed on half scaled RC frames filled with autoclaved aerated concrete (AAC) block masonry with external dimensions of 1.5 m x 1.5 m. These frames are subjected to displacements ranging from 2 mm to 6 mm and frequencies between 1 Hz and 7 Hz for simulating earthquake loading conditions. The experimental program aimed to evaluate the resistance of structure to earthquake loading by using dual mode of testing viz. displacement and frequency-controlled loading protocol. During test the RC frame responded elasto-plastically due to minor cracking at block joints and localized yielding at the interface between the frame and the infill at lower frequencies and displacements. Conversely the degradation of both first and second secant stiffness values became more pronounced at higher frequencies. The first secant stiffness decreased by 73.4%, while the second secant stiffness showed increase of 24.6% at a displacement of 4 mm and a frequency of 4 Hz with respect to the previous loading cycle which indicated the complex stress redistribution and temporary stabilization. Doi: 10.28991/CEJ-2025-011-02-05 Full Text: PDF
Flexural Behaviour of Precast Lightweight Concrete Sandwich Slabs With Demountable Bolted Steel Shear Connectors
Authors: Al-Kerwei Rana H. , Osman S. A. , Al-Zand Ahmed W. , Hanoon Ammar N.
Published: February 2025

A concrete slab is a fundamental element and contributes the highest weight in structural buildings. In this paper, a new type of sandwich slab consisting of two layers of lightweight concrete and demountable steel connectors is proposed in a new attempt to reduce the weight of the floors within the structure and apply a simpler and faster approach to connecting the layers of sandwich panels. The structural effects of the proposed connectors on Precast Lightweight Concrete Sandwich Slab (PLCSS) are evaluated experimentally and theoretically in terms of strength, stiffness, degree of composite action, and usability for floor construction. The behaviors of six PLCSS specimens subjected to four-point loads were investigated, studying the effects of varied parameters such as different numbers, arrangements, and shapes of demountable steel connectors (I, V, and X connector shapes) fastened with steel bolts, in addition to one solid concrete slab as a reference specimen. The panels' performance in this structural system was evaluated by measuring the degree of composite action using load, displacement, stress, and neutral axis methods. Based on the experimental results, the slab panels exhibited composite panel behavior until the point of failure. Under flexural loads, the panel behaved similarly to that of a solid one-way slab; crack patterns appeared in one direction. The specimens with IC, VC, and XC showed different load capacity values, ranging from 22.74 kN to 50.55 kN; these values depend on the types of shear connectors and their numbers in the sandwich panels. Using V and X connectors enhances the composite action between layers, increasing the shear demand and making the shear failure more likely. It can be concluded that demountable shear connectors can transfer shear between the two concrete wythes, resulting in a composite panel with structural integrity, a lighter weight, and satisfying ACI specifications for floor applications. Doi: 10.28991/CEJ-2025-011-02-06 Full Text: PDF