bluuebunny/crossref_metadata_2025 huggingface dataset:
Gaming Language as a Language Variations in Digital Humanities
Authors: Furianto  , Simanjuntak Risa Rumentha
Published: May 2023

This study examined the language used by players in the online game Valorant. Gaming language develops massively as a digital way of living. In digital humanities, variation in virtual communication needs to be considered an essential milestone in language development. This study investigated in specific the use of slang, which identified a particular community. There were two goals of this study first, to determine the slang words used by players during the game, and second to examine the function of these slang words. Data for this study were collected during one month of the consecutive game, including screenshots and recording of sessions. Results showed four categories of slang words used by Valorant players, with acronyms and clippings used more frequently (42,50% for each category) than other slang words. Players used these slang words to convey emotional and tactical messages. These functions were identified, including disapproval, criticism, support, and praises. It was concluded that the new slang words showed language used in gaming as a phenomenon in digital humanities. Implications for future research were also discussed for further development of digital culture and digital humanities.
Semantic Choices and Patterns in YouTube Commentaries as Digital Language Variation
Authors: Nuraudia Azhari Olivia , Simanjuntak Risa Rumentha
Published: May 2023

Various forms of language use in social media characterize digital culture as part of digital humanities. It is fundamental to be able to get some knowledge of knowing the behavior of people using digital platforms, because nowadays people communicate via digital. Digital communication is a valid text that does not happen suddenly because it can be considered as something that is passive. This paper is important so that the reader can get knowledge about choices and patterns in digital communication. This paper investigated the variety of digital language as social phenomenon in YouTube commentaries. The goals of such investigation were to reveal the semantic choices and the pattern of these choices as online communicative events. Applying qualitative and diachronic approach the research used YouTube comments on a YouTube channel discussing about family vacation throughout 3 years of period, from 2019-2022. Using Halliday’s theory about semantic choice, the paper revealed three groups of semantic choices, which were semantic choice for identifying logical fallacy, semantic choice for identifying statement of feeling and semantic choice for identifying ridiculous behavior. There is also a recurring pattern that can be identified following the results of the analysis. In conclusion, digital language could be used in comparison to in person communication as important and valid development of language in digital humanities.
Digital Prototyping of Candi Kidal Relief on Interior Accessories
Authors: Wijaya Ida Bagus Ananta , Pramono Andi , Maulana Fairuz Iqbal
Published: May 2023

Candi Kidal is one of the most important cultural heritages especially in Malang Raya. Candi Kidal is a relic of Singasari Kingdom that has uniqueness in its relief characteristics, namely the emblem of medallion ornaments and Garudeya reliefs. In fact, not everyone, especially the people of Malang Raya, knows the uniqueness of the relief of Candi Kidal. There are many ways to preserve cultural heritage, one of which is to apply this relief ornament on interior accessories products. In the process of making a product, it is necessary to make a prototype product manufacturing process to find out the advantages and disadvantages of the design. The research method used in making designs is with design thinking. The main purpose of choosing this method is to find out the initial problem, create ideas, and make prototypes. In the manufacturing process it is done by visually optimizing the design with 3D software and is made with precision with 3D printing. The results of this research are a study of the process of making prototypes of interior accessories products with Malang locality, namely ornaments from Kidal Temple.
Mobile App Design to Help College Students Cope Mental Health Crisis During the Covid-19 Pandemic
Authors: Danny Rika Godelava , Huda Miranti Nurul , Kusumawati Yudhistira Ayu , Radhitanti Asri
Published: May 2023

The speed of transmission of the COVID-19 makes the spread of the virus difficult to control so that the number of Indonesians infected with the virus continues to increase every month. This pandemic is an event beyond prediction that makes the government issue policies in the education sector where the learning process ranging from Early Childhood Education level to Higher Education becomes online learning at home. These limitations of daily activities and communication provide an impact on people's social lives, namely the occurrence of mental health crises. Students as part of the youth order in society also feel the crisis of mental health caused by the COVID-19 pandemic. The purpose of this study was to find out the mental health of students during the COVID-19 pandemic and provide solutions in the form of mobile app that provide personal discussions with psychologists, sharing forums, and mental health education. It is hoped that this research can help overcome mental health problems during the COVID-19 pandemic and prevent them from unwanted things. The research method used in this research is the design thinking method that consists of empathize, define, ideate, prototype, and test.
Cyber Extension Content and Interactivity Online Social Media Agricultural Ministry During Covid 19
Authors: Rizkiansyah Mariko , Ariestyani Arleen , Yunus Ulani
Published: May 2023

This study aims to explain the pattern of content and interactivity on YouTube and Instagram accounts of the ministry of agriculture during the COVID-19 pandemic. McMillan's interactivity model and cyber extension concept used to support for the analysis from content social media side. This research uses the virtual ethnographic method of Nasrullah based on the development of Hine's virtual ethnography method. The object of the research is content in the social media agricultural ministry from March to July 2021. For data analyzing, researchers use Creswell’s technique with six steps. The study results show that the content of the two social media focuses on information regarding Covid19 pandemic but does not discuss many agricultural production strategies during the pandemic. There are less information and socialization from ministry to solve the solution of farmer that some mention in the comments. In addition, the lack of interactivity on social media is caused by the ministry's passiveness in engaging in user interaction in the comment’s column. The conclusion, social media agricultural ministry must active to respond the comment in the chat column or dialogue with farmer, therefore farmers will be able to increase the productivity of their plants during or after Covid19.
Japan and Indonesia Comparative Study: Changes in Communication and Impact on the Level of Social Presence of University Student Organizations Before and During the Pandemic
Authors: Juneza Christy Immanuel , Putri Sekar Mantradianing Roosdianto , Novella Utari , Kakkimoto Koki , Ueno Yumi , Fujiyama Ichiro
Published: May 2023

This research studies how changes in higher education’s methodologies from face to face to computer mediated communication during the COVID-19 pandemic impacted the quality of communication amongst students in university student organizations in Japan and Indonesia. With how immense the COVID-19 pandemic’s ramifications in the realm of education, countless studies have covered its impact on a variety of angles and from numerous perspectives, but the same could not be said about university student organizations, thus is why the topic is of value to examine further to better understand it and for future references. In search for the answers, qualitative research method is used, with data collected through focus group discussions held with members from two student organizations, one of Japan’s Wakayama University, another of Indonesia’s Bina Nusantara University which results are then compared with relevant studies and analyzed. This study established the importance of media’s richness and level of social presence within current available selection of discussion methods whilst taking into account whether issues in need of discussion is routine or non-routine in nature, the level of familiarity of each other’s way of communication, and differences in context cultures amongst participants.
New Digital Culture Metaverse Preparation Digital Society for Virtual Ecosystem
Authors: Limano Ferric
Published: May 2023

The advancement of digital culture in human life presents a new life that can be lived virtually. The phenomenon of metaverse becomes a new concept to combine the physical and digital worlds in society. The development of this metaverse will present many new opportunities in the future, especially in virtual work. The characteristics of this metaverse result in automation, telework, and also management algorithms, this can have the effect of replacing the work done by humans. It will also appear new job in the metaverse world certainly requires new skills in society, this requires the preparation of an integrated and digital-based educational role. This research is descriptive of skill development and education in the virtual metaverse world, with a qualitative method based on an analysis of the six pillars of the virtual ecosystem (avatar, content creation, virtual economy, social acceptability, security and privacy, trust and accountability). The result of this research is a future job in virtual ecosystem sustainability scheme, by linking the sustainability design dimension – virtual ecosystem – future job and skills need for society. Indonesian people need to adapt to advances in digital technology with academic development that is ready with digital technology
Effect of cooling rate on morphology and distribution of Fe phase in solidification structure of Cu-20Fe alloy
Authors: Guo Junli , Hu Qiang , Zou Jin , Lu Deping
Published: May 2023

Cu–Fe alloys are high-strength and high-conductivity copper-based materials with great potential. The solidified structures comprise of an Fe phase and Cu matrix, and the solidification structure significantly affects the properties of the alloys. The cooling rate during solidification affects the Fe phase morphologies, sizes, and distribution uniformity in Cu–Fe alloys, making it an essential control parameter. The solidification process of a Cu-20Fe alloy were analyzed at cooling rates from 0.3–13.0 °C/s using a confocal scanning laser microscope (CLSM). The secondary dendrite arm spacing (SDAS) and fractal dimension (D) were used to quantitatively characterize the solidification morphology. The uniformity (U) was used to describe the distribution uniformity of the Fe phase in the solidification structure. The results indicate that the morphology and distribution uniformity of the Fe phase were significantly affected by the cooling rate. The relationship between SDAS (λ2) and cooling rate (C) gave the expression: λ2 = 12.05 · C−0.39. The cooling rate during solidification changed the morphology of the dendrites and the overall solidification structure, likely because of the solute diffusion and temperature gradient in front of the solid–liquid interface being affected. In addition, the distribution uniformity of the Fe phase in the solidification structure significantly changed with the solidification time. There was a linear relationship between uniformity and SDAS: U = 82.50−1.03 × λ2. The morphology and distribution uniformity of the Fe phase in the solidification structure of Cu-Fe alloys can be controlled by adjusting the cooling conditions during solidification. This could allow for the enhancement of the functional properties of the alloy and possibly lead to further applications.
Quelques éléments de physique autour des nanopores biologiques
Authors: Molcrette Bastien , Chazot-Franguiadakis Léa , Auger Thomas , Montel Fabien
Published: May 2023

Les nanopores biologiques sont d’étonnantes machines moléculaires. Ils remplissent une grande variété de fonctions, allant du tri des biomolécules à la transmission des signaux dans nos neurones et au repliement des protéines nouvellement produites.

Le membre le plus surprenant de ce club est le pore nucléaire. Il régule le flux de molécules entre le noyau et l’intérieur de la cellule. Ses performances, mesurées par son efficacité énergétique, sa directionnalité ou sa sélectivité, n’ont pas d’équivalent dans les systèmes artificiels. Nous verrons que la compréhension de son fonctionnement permet d’appréhender des phénomènes physiques nouveaux et d’imaginer des systèmes de filtration sélectifs, ainsi que des pompes moléculaires.
Les plasmas froids et le Vivant, de nouvelles avancées
Authors: Douat Claire , Dufour Thierry , Santos Sousa João
Published: May 2023

Depuis le début des années 2000, des avancées technologiques majeures ont permis l'émergence de plasmas froids à pression atmosphérique ayant de faibles valeurs de courant et des températures proches de la température ambiante.

Dans cet article, nous exposons dans un premier temps les principales sources de plasma froid utilisées avec succès dans les applications biomédicales, en insistant notamment sur les propriétés physico-chimiques recherchées.

Dans un second temps, nous proposons un état de l'art des dernières avancées médicales (en particulier en cancérologie et en dermatologie), ainsi qu'en agriculture.
Körperliches Training und Frakturprävention.
Trainingsinhaltliche Empfehlungen zur Verbesserung der
Knochenfestigkeit
Authors: Willert Sebastian , von Stengel Simon , Kohl Matthias , Jakob Franz , Kerschan-Schindl Katharina , Lange Uwe , Peters Stefan , Thomasius Friederike , Kemmler Wolfgang
Published: May 2023

„Trainingsinhalte“ sind „konkrete Maßnahmen zur
Realisierung des/der geplanten Trainingsziel(e)s“. Im Bereich
der Forschung am Knochen bietet sich eine Einteilung der Trainingsinhalte (oder
Belastungstypen) in mechanisch lokale wie axiale Belastung, Muskelzugsbelastung,
Belastungsverteilung sowie einen systemisch übergreifenden
„Knochenfaktor“, die endokrine Komponente an. Crosssektionale
Studien mit Sportlerkollektiven sowie longitudinale Untersuchungen mit
untrainierten, älteren Kollektiven zeigen dabei, dass sich
Trainingsinhalte mit hohem osteoanabolem Potenzial durch hohe axiale Belastung,
hohe Muskelzugsbelastung, ungewöhnliche Belastungsverteilung und
günstiges hormonelles Milieu auszeichnen. Ein günstiges
hormonelles Milieu, also eine belastungsinduzierte erhöhte Konzentration
anaboler Substanzen, kann dabei permissiv für die Effekte mechanischer
Knochenfaktoren sein. Hohe axiale Trainingsreize kollidieren indes
häufig mit dem körperlichen Status älterer Menschen. Ein
dynamisches Krafttraining, idealerweise an Kraftgeräten, bietet die
Möglichkeit auch intensive Methodenvarianten sicher und schmerzfrei zu
applizieren. Insbesondere das Vehikel „Wassergymnastik“ bietet
sich für besonders vulnerable Gruppen als Trainingsoption zur
eigenverantwortlichen Osteoporosetherapie/Frakturprophylaxe an.
Rehabilitationssport und Funktionstraining können dabei als geeignete
Vehikel zur Umsetzung dienen.
SARS-CoV-2 Infection in Children with Cancer: Experience from a Tertiary Care Center in North India
Authors: Roy Pritam Singha , Randhawa Manjinder Singh , Nallasamy Karthi , Singh Mini P. , Peyam Srinivasan , Chhabra Prashant , Senguttuvan Gnanamani , Muhammed Safal , Dhankar Mukesh , Jain Richa , Bansal Deepak , Trehan Amita
Published: May 2023

Introduction Children with cancer are immunocompromised due to the disease per se or anticancer therapy. Children are believed to be at a lower risk of severe coronavirus disease 2019 (COVID-19) disease.

Objective This study analyzed the outcome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children with cancer.

Materials and Methods A retrospective analysis was performed on patients (≤ 14 years) with cancer attending the pediatric oncology services of our institute who tested positive for the SARS-CoV-2 infection and those who had COVID-19 disease between August 2020 and May 2021. Real-time reverse transcriptase-polymerase chain reaction performed on the nasopharyngeal swab identified the SARS-CoV-2 infection. The primary endpoints were clinical recovery, interruption of cancer treatment, and associated morbidity and mortality.

Results Sixty-six (5.7%) of 1,146 tests were positive for the SARS-CoV-2 infection. Fifty-two (79%) and 14 (21%) patients had hematolymphoid and solid malignancies. Thirty-two (48.5%) patients were asymptomatic. A mild-moderate, severe, or critical disease was observed in 75% (18/24), 12.5% (3/24), and 12.5% (3/24) of the symptomatic patients. The “all-cause” mortality was 7.6% (5/66), with only one (1.5%) death attributable to COVID-19. Two (3%) patients required ventilation. Two (3%) patients had a delay in cancer diagnosis secondary to COVID-19 infection. Thirty-eight (57.6%) had a disruption in anticancer treatment.

Conclusion Children with cancer do not appear to be at an increased risk of severe illness due to SARS-CoV-2 infection. Our findings substantiate continuing the delivery of nonintensive anticancer treatment unless sick. However, SARS-CoV-2 infection interrupted anticancer therapy in a considerable proportion of children.
Surgical Management of Large (≥3 cm) Trigeminal Schwannomas: Functional Outcomes and Approach Selection in Multicompartmental Schwannomas
Authors: Dwarakanath Srinivas , Deora Harsh , Mehta Sarthak , Shukla Dhaval , A. Arivazhagan , Rao KVLN , Somanna Sampath
Published: May 2023

Introduction Trigeminal schwannoma surgery has shown a remarkable improvement in functional recovery and tumor resection. In the era of radiosurgery, these outcomes need to be characterized for tumors which are outside the realm of being treated with radiosurgery. We present a series of trigeminal schwannomas larger than 3 cm, surgical approaches used, and outcomes with an emphasis on functional recovery in a high-volume center with radiosurgery facilities.

Method All consecutive cases of trigeminal schwannoma from January 2012 to May 2021 which were more than 3 cm in size and underwent microsurgery were included in this series. The surgical approach, neurological outcomes, and extent of resection were defined objectively with pre/postoperative magnetic resonance imaging.

Results A total of 83 such cases (>3 cm) were found, with cranial nerve symptoms (5th most common) being the commonest. Twenty three percent cases had blindness due to secondary optic atrophy and eighteen percent had long tract motor symptoms signifying the tumor burden in our series. Radiological gross total excision was achieved in 75.9% cases.

Conclusion Large-volume schwannomas present with cranial nerve involvement and may need extensive skull base approaches. Functional outcomes need to be prioritized and can be achieved albeit with lesser gross resection rates. Hearing and facial preservation in addition to relief of trigeminal symptoms should be the goal of resection with minimal additional morbidity.
Deformation diagrams of amorphous polyimide (kapton H) in the state of moderate and deep cooling: Experiment and theory
Authors: Natsik V. D. , Rusakova H. V. , Lubenets S. V. , Lototskaya V. A. , Yakovenko L. F.
Published: May 2023

A comprehensive experimental and theoretical study of the regularities of active deformation at a constant rate of an amorphous polymer at room temperature and the influence of moderate and deep cooling on them was performed. The samples of amorphous aromatic polyimide (an analogue of kapton H) that are randomly cut fragments of the industrially produced thermoplastic film with a thickness of 25 μm were the object of the experimental study. The σ–ε diagrams of the tensile test, where σ and ε=ε˙t are the tensile stress and the relative strain, respectively, were recorded for 32 samples at three rates ε˙ = 7⋅10–5, 7⋅10–4, 6⋅10–3 s–1 under three temperatures T = 293, 77, and 4.2 K. In the state of deep cooling at T = 4.2 K, several samples were deformed as brittle glassy bodies – rupture after short elastic deformation. But the majority of the samples at all values of the experimental parameters (T,ε˙) had the rheological properties of rubber-like highly elastic materials (elastomers) with traditional tensile test diagrams: initial stage I of linear elastic deformation σI=Meε with Young’s modulus Me=Me(T); stage III of linear highly elastic deformation σIII=σfe+Mheε with modulus Mhe=Mhe(T) and conditional limit of elasticity σfe=σfe(T,ε˙); intermediate stage II of the relaxation type σII(ε;T,ε˙) with a nonlinear stress-strain dependence. The σ–ɛ diagrams of the individual samples with sufficiently high accuracy coincide with the graph of the function σ(ε;T,ε˙) which is the solution of the previously derived nonlinear rheological equation (V. D. Natsik and H. V. Rusakova, Fiz. Nizk. Temp.48, 281 (2022) [Low Temp. Phys.48, 253 (2022)]; Fiz. Nyzk. Temp.49, 246 (2023) [Low Temp. Phys.49, 228 (2023)]). In its derivation, a molecular-kinetic model was used: an amorphous polymer is considered as a set of statistically independent kinetic units, namely, molecular segments, and the elementary act of deformation is caused by thermomechanical activation of nonlinear excitations of these segments called elastons. The elaston mechanism of transformation of the deformation diagrams of amorphous polyimide samples under their moderate and deep cooling is discussed in detail: the transition between deformation states of warm and frozen elastomer, low-temperature effects of structural-deformation glass transition and deformation melting. Comparing the results of experiments and theory made it possible to obtain the empirical estimates for the macromechanical characteristics of the studied samples and the microparameters of elaston excitations. A significant and unsystematic (random) scatter of the macro- and micromechanical characteristics of the samples was revealed, which indicates a significant and random heterogeneity of the macro- and microstructure of the polyimide film from which they were made.
Thermal conductivity measurement system for molecules-based compounds available in a wide temperature region
Authors: Zhang Luming , Nomoto Tetsuya , Yamashita Satoshi , Akutsu Hiroki , Krivchikov Alexander I. , Nakazawa Yasuhiro
Published: May 2023

The construction of a thermal conductivity measurement system designed for tiny molecules-based compounds is reported. We introduce complementary usage of chip-type RuO2 thermometers and E-type thermocouples in the sample part by using thin (ϕ 13μm) constantan and chromel wires. Two pairs of the constantan and chromel wires are used as lead wires for the four-terminal measurement of the resistance of RuO2 thermometers in the low-temperature region below about 20 K. Also, in the higher temperature region above 10 K up to room temperature with the overlapping range of 10-20 K, they are used as thermocouples for detecting temperature differences from that of the heat sink. We also compare a kind of resolution parameter of several sensors as a function of temperature to discuss the rational reason to select suitable sensors depending on the temperature region. Using the constructed apparatus, we report temperature dependences of the thermal conductivity of deuterated κ-(d8:BEDT-TTF)2Cu[N(CN)2]Br in a wide temperature range between 2 and 250 K. The result provides convincing evidence for the validity of the newly developed system for the thermal measurements of molecular crystals.
Thermal conductivity of the AsxS100–x glass system at low temperatures
Authors: Baloh Pavlo , Tkáč Vladimír , Tarasenko Róbert , Orendáč Martin , Orendáčová Alžbeta , Mitsa Oleksandr , Mitsa Vladimir , Holomb Roman , Feher Alexander
Published: May 2023

The temperature dependence of the thermal conductivity k(T) of the AsxS100-x glass system was studied down to 1.8 K in a wide range of various (x = 20, 28.6, 40, 45, and 50) compositions. Universal glass anomalies in k(T) were revealed. The temperature dependence k(T) ∼ T2 onset at the lowest temperatures and plateau below 15 K were detected. The plateau formation is sample quality sensitive and composition-dependent. It was experimentally found that even with a slow cooling rate, several samples were cracked. Depending on the sample damage, the additional internal scattering process leads to the k(T) plateau suppression. The observed k(T) temperature dependence is similar to the glassy ceramics-like behavior.
Radiation-induced phenomena in thermally treated Kr matrices
Authors: Savchenko E. , Khyzhniy I. , Uyutnov S. , Bludov M. , Bondybey V.
Published: May 2023

The effect of thermal treatment on relaxation phenomena in Kr matrices irradiated with a low-energy electron beam has been studied. The experiments were carried out using measurements of the relaxation emissions of preirradiated Kr samples, which were unannealed and annealed before exposure to an electron beam. Three types of emissions were monitored in a correlated real-time manner: thermally stimulated luminescence, thermally stimulated exoelectron emission, and total yield of particles via pressure measurements. The energy levels of defects were estimated from the thermally stimulated luminescence data of the annealed sample. Two types of electron-hole traps created by electronic excitation were identified: close pairs and distant ones. Additional confirmation of the “excited state” mechanism of defect formation was obtained. Analysis of the correlation of yields and the effect of thermal treatment gave additional arguments in support of the crowdion model of anomalous low-temperature post-desorption from pre-irradiated Kr matrices.
Ultra-low-noise transimpedance amplifier in cryogenic STM for studying novel quantum states by measuring shot noise
Authors: Liang Ying-Xin
Published: May 2023

An ultra-low-noise large-bandwidth transimpedance amplifier (TIA) for cryogenic scanning tunneling microscope (CryoSTM) is proposed. The TIA connected with the tip-sample component in CryoSTM is called as CryoSTM-TIA. Its transimpedance gain is as high as 1 GΩ, and its bandwidth is over 300 kHz, but its equivalent input noise current power spectral density is less than 4 (fA)2/Hz at 100 kHz. The low inherent noise for the CryoSTM-TIA is due to its special design: (1) its pre-amplifier is made of a pair of low-noise cryogenic high electron mobility transistors (HEMTs); (2) the noise generated by one HEMT is eliminated by a large capacitor; (3) the capacitance of the cable connected the gate of the other HEMT to the tip is minimized; (4) thermal noise sources, such as the feedback resistor, are placed in the cryogenic zone. The dc output voltage drift of the CryoSTM-TIA is very low, as 5 μV/°C. The apparatus can be used for measuring the scanning tunneling differential conductance spectra, especially the scanning tunneling shot noise spectra (STSNS) of quantum systems, even if the shot noise is very low. It provides a universal tool to study various novel quantum states by measuring STSNS, such as detecting the Majorana bound states.
Cross Sections for Electron Scattering from Cadmium: Theory and Experiment
Authors: Marinković B. P. , McEachran R. P. , Fursa D. V. , Bray I. , Umer H. , Blanco F. , García G. , Brunger M. J. , Campbell L. , Jones D. B.
Published: May 2023

Results from the application of optical potential, relativistic optical potential, relativistic convergent close-coupling, and binary encounter Bethe models to electron scattering from gas-phase cadmium are presented. In particular, integral cross sections for elastic scattering, summed discrete electronic-state excitation, and ionization scattering processes are reported over an extended incident electron-energy range. Total cross sections are constructed by taking their sum. Measurements are presented for elastic scattering and for excitation to the 51P1 state. The theoretical and experimental results are compared to previous calculations and measurements. Recommended electron cross-section datasets are constructed over an incident electron energy range of 0.01–10 000 eV.
A force-free magnetic field solution in toroidal coordinates
Authors: Marsh Gerald E.
Published: May 2023

While there are no known analytic solutions for force-free fields in toroidal coordinates, with a reasonable boundary condition, it is possible to find a solution for the surface field and, with a restriction on the form of the field, the interior of the torus as well.
NMR spectrum prediction for dynamic molecules by machine learning: A case study of trefoil knot molecule
Authors: Tsitsvero Mikhail , Pirillo Jenny , Hijikata Yuh , Komatsuzaki Tamiki
Published: May 2023

Nuclear magnetic resonance (NMR) spectroscopy is one of the indispensable techniques in chemistry because it enables us to obtain accurate information on the chemical, electronic, and dynamic properties of molecules. Computational simulation of the NMR spectra requires time-consuming density functional theory (DFT) calculations for an ensemble of molecular conformations. For large flexible molecules, it is considered too high-cost since it requires time-averaging of the instantaneous chemical shifts of each nuclear spin across the conformational space of molecules for NMR timescales. Here, we present a Gaussian process/deep kernel learning-based machine learning (ML) method for enabling us to predict, average in time, and analyze the instantaneous chemical shifts of conformations in the molecular dynamics trajectory. We demonstrate the use of the method by computing the averaged 1H and 13C chemical shifts of each nuclear spin of a trefoil knot molecule consisting of 24 para-connected benzene rings (240 atoms). By training ML model with the chemical shift data obtained from DFT calculations, we predicted chemical shifts for each conformation during dynamics. We were able to observe the merging of the time-averaged chemical shifts of each nuclear spin in a singlet 1H NMR peak and two 13C NMR peaks for the knot molecule, in agreement with experimental measurements. The unique feature of the presented method is the use of the learned low-dimensional deep kernel representation of local spin environments for comparing and analyzing the local chemical environment histories of spins during dynamics. It allowed us to identify two groups of protons in the knot molecule, which implies that the observed singlet 1H NMR peak could be composed of the contributions from protons with two distinct local chemical environments.
Enhanced p-type Ohmic contact performance in FCLEDs by manipulating thermal stress distribution to suppress Ag agglomeration
Authors: Sun Ke , Qian Yinzuo , Lv Zhenxing , Qi Shengli , Zhou Shengjun
Published: May 2023

The implementation of reflective p-type Ohmic contact is an effective way to solve current crowding and improve the optoelectronic performance of flip-chip light-emitting diodes (FCLEDs). Here, we investigate the effects of annealing temperature, annealing time, and N2 flow rate on the formation for Ag/p-GaN Ohmic contact and determine the optimal annealing process parameters. After inserting an indium-tin oxide layer between Ag and p-GaN, the specific contact resistance decreases from 6.66 × 10−3 to 1.86 × 10−3 Ω cm2. In addition, we discover the appearance of a “black line” around the edges of the chips after high-temperature annealing. Finite element analysis and experiments show that the “black line” is related to Ag agglomeration under high temperatures due to stress concentration at the edges of the chips. A strategy for manipulating the stress concentration by adjusting the thickness of the TiW diffusion barrier layer is proposed based on insight obtained by modeling the stress distribution at the edge of the chips. The electrical properties of the fabricated FCLEDs show that the proposed stress manipulation strategy solves the problem of “black line” effectively and maintains the performance of the chips well.
Self-Oscillated Growth Formation of Standing Ultrathin Nanosheets out of Uniform Ge/Si Superlattice Nanowires
Authors: Gan Xin , An Junyang , Wang Junzhuan , Liu Zongguang , Xu Jun , Shi Yi , Chen Kunji , Yu Linwei
Published: May 2023

Self-oscillation is an intriguing and omnipresent phenomenon that governs a broad range of growth dynamics and formation of nanoscale periodic and delicate heterostructures. A self-oscillating growth phenomenon of catalyst droplets, consuming surface-coating a-Si/a-Ge bilayer, is exploited to accomplish a high-frequency alternating growth of ultrathin crystalline Si and Ge (c-Si/c-Ge) nano-slates, with Ge-rich layer thickness of 14–19 nm, embedded within a superlattice nanowire structure, with pre-known position and uniform channel diameter. A subsequent selective etching of the Ge-rich segments leaves a chain of ultrafine standing c-Si nanosheets down to ∼ 6 nm thick, without the use of any expensive high-resolution lithography and growth modulation control. A ternary-phase-competition model has been established to explain the underlying formation mechanism of this nanoscale self-oscillating growth dynamics. It is also suggested that these ultrathin nanosheets could help to produce ultrathin fin-channels for advanced electronics, or provide size-specified trapping sites to capture and position hetero nanoparticle for high-precision labelling or light emission.
Near-Field Radiative Heat Transfer between Disordered Multilayer Systems
Authors: Tian Peng , Ge Wenxuan , Li Songsong , Gao Lei , Jiang Jianhua , Xu Yadong
Published: May 2023

Near-field radiative heat transfer (NFRHT) research is an important research project after a major breakthrough in nanotechnology. Based on the multilayer structure, we find that due to the existence of inherent losses, the decoupling of hyperbolic modes (HMs) after changing the filling ratio leads to suppression of heat flow near the surface mode resonance frequency. It complements the physical landscape of enhancement of near-field radiative heat transfer by HMs and more surface states supported by multiple surfaces. More importantly, considering the difficulty of accurate preparation at the nanoscale, we introduce the disorder factor to describe the magnitude of the random variation of the layer thickness of the multilayer structure and then explore the effect on heat transfer when the layer thickness is slightly different from the exact value expected. We find that the near-field radiative heat flux decreases gradually as the disorder increases because of interlayer energy localization. However, the reduction in heat transfer does not exceed an order of magnitude, although the disorder is already very large. At the same time, the regulation effect of the disorder on NFRHT is close to that of the same degree of filling ratio, which highlights the importance of disordered systems. This work qualitatively describes the effect of disorder on heat transfer and provides instructive data for the fabrication of NFRHT devices.
Methyl and carbon–carbon double bond in anhydride molecules modulated surface charge trap depth of epoxy materials
Authors: Zhao Yushun , Xu Yufan , Teyssèdre Gilbert , Xue Jianyi , Zhao Yanning , Du Bin
Published: May 2023

Epoxy insulators in gas insulated switchgear and gas insulated transmission lines tend to accumulate surface charges, leading to insulation flashover. Improving the surface trap characteristics of epoxy materials, which can accelerate the surface charge dissipation of epoxy insulators, is a promising method to improve the surface insulation performance. The surface trap characteristics of epoxy materials are strongly influenced by the chemical groups in the acid anhydride molecules. In this work, by quantum chemical calculations and isothermal surface potential decay tests, taking six organic anhydrides that differ only in the methyl and carbon–carbon double bonds, we find the modulation laws of methyl and carbon–carbon double bonds on the charge trap depth within and between molecular chains. The regulation mechanism is revealed from the microscopic perspectives of electron energy structure and electron cloud offset. The changes of surface charge trap depth of epoxy materials are primarily attributed to the changes in the spatial distribution of the electron cloud density between and on the valence bonds caused by the interaction between the electron-donating methyl group and the electron-absorbing carbon–carbon double bond.
Influence of oxygen on solid carbon formation during arcing of eco-friendly SF6-alternative gases
Authors: Zhang Boya , Wang Sunsiqin , Chen Li , Li Xingwen , Tang Nian
Published: May 2023

During the arc breaking process of high-voltage circuit breakers, the eco-friendly SF6-alternative gases will inevitably decompose and generate various decomposition products. In some cases, this will contain solid by-products such as solid carbon, which will have a deterioration effect on the electrical insulation performance of the equipment. It has been found that adding a proper amount of O2 can effectively inhibit the formation of solid carbon. In this paper, based on the improved Gibbs free energy minimization method, a calculation model considering the solid decomposition products was established, and the arc plasma composition of CO2/O2 mixtures with the new eco-friendly gases, such as C4F7N, C5F10O, HFO-1234ze(E) and HFO-1336mzz(E), in local thermodynamic equilibrium state was calculated. The change of decomposition products with the initial O2 ratio is studied, and the criterion expression of inhibiting solid carbon formation is obtained. We also applied the method to the calculation of other SF6-alternative gases containing sulfur atoms such as NSF3 and CF3SO2F. Finally, we showed that solid carbon can be inhibited when a proper molecule formula is satisfied. This work may provide new ideas for further exploring the potential of SF6-alternative gases.
Translocation of an active polymer into a two dimensional circular nano-container
Authors: Rezaie-Dereshgi Amir , Khalilian Hamidreza , Sarabadani Jalal
Published: May 2023

Translocation dynamics of an active semi-flexible polymer through a nano-pore into a rigid two dimensional circular nano-container has been studied by using Langevin dynamics simulations. The results show that the force exponent β, for regime of small nano-container radius, i.e.

R
≪

R

g

, where R
g is the gyration radius of the passive semi-flexible polymer in two dimensional free space, is

β
=
−
1

, while for large values of

R
≫

R

g

the asymptotic value of the force exponent is

β
≈
−
0.93

. The force exponent is defined by the scaling form of the average translocation time

⟨
τ
⟩
∝

F

sp

β

, where F
sp is the self-propelling force. Moreover, using the definition of the turning number (number of net turns of the polymer configuration) for the polymer inside the cavity, it has been found that at the end of translocation process for small value of R and in the strong force limit the polymer configuration is more regular than the case in which the value of R is large or the force is weak.
Novel 3D printed probe for bioimpedance spectroscopic measurement of oral mucosa: design and testing with ex vivo porcine oral tissues
Authors: Emran Shekh , Jokinen Noora , Laitinen Kimmo , Lappalainen Reijo , Myllymaa Sami
Published: May 2023

Three-dimensional (3D) printing has a high potential in various biomedical applications. We hypothesize that 3D printing could be a viable option to construct novel bioimpedance spectroscopic (BIS) sensors suitable for electrochemical characterization of oral mucosal tissues. Previous BIS studies have relied on hand-made probes possessing significant limitations related to their single patient disposable use, large inter-probe differences, and weak reproducibility of measurement. There is also uncertainty related to the effect of varying loading pressure between the probe and biological tissue. Here, we introduce three differently sized rectangular shaped 3D printed probes and test those using a four-terminal measurement principle on various porcine oral tissue samples. We find that constructing a fully 3D printed probe is a challenging task, prone to issues relating to short-circuiting or electrochemical corrosion. However, our final prototype version, constructed with silver-coated copper electrodes, showed favorable characteristics in BIS experiments. All three differently sized probes were able to differentiate between different tissue types with excellent reproducibility. The effect of loading pressure was found to be almost negligible when using small- and medium-sized probes. However, further studies are needed to measure tissues with uneven surfaces, such as palatinum, and to avoid manual or (electro)chemical surface-finishing steps.
Evaluation of stability and antitumor activity of two-dimensional black phosphorus modified with positively charged protein
Authors: Zhao Chong , Lin Jiamin , Cai Yin , Zhong Yuming , Li Yinghua , Zhou Benqing
Published: May 2023

Two-dimensional black phosphorus (2D BP), a novel 2D photoelectric material with excellent near-infrared optical absorption, biocompatibility, and degradability, has shown enormous potential in biomedical field. However, under the action of light, oxygen and water, 2D BP is easily degraded to phosphate and phosphonate. In this work, trastuzumab (Tmab) as a positively charged protein was used to modify 2D BP through electrostatic interaction to form BP-Tmab. The Tmab layer on the surface of 2D BP can effectively protect BP from water, which significantly enhanced the water stability of BP. PEGylated 2D BP (BP-PEG) as a control was also prepared. After 7 days in air-exposed water, the attenuation value of BP-Tmab was only 6.62 ± 2.72% at room temperature, which was much lower than that of naked 2D BP (52.47 ± 2.26%) and BP-PEG (25.84 ± 2.80%) under the same conditions. The result was further confirmed by the temperature changes at different time points under laser irradiation, suggesting that the degradation of BP was effectively reduced by Tmab modification. In addition, BP-Tmab displayed satisfactory biocompatibility and can effectively destroy cancer cells under laser irradiation, showing an excellent photothermal therapy effect.
Contact topology and non-equilibrium thermodynamics
Authors: Entov Michael , Polterovich Leonid
Published: May 2023

We describe a method, based on contact topology, of showing the existence of semi-infinite trajectories of contact Hamiltonian flows which start on one Legendrian submanifold and asymptotically converge to another Legendrian submanifold. We discuss a mathematical model of non-equilibrium thermodynamics where such trajectories play a role of relaxation processes, and illustrate our results in the case of the Glauber dynamics for the mean field Ising model.
On pulse-to-pulse coupling in low-temperature filamentary plasma-assisted ignition in methane-air flows
Authors: Patel Ravi , van Oijen Jeroen , Nijdam Sander , Dam Nico
Published: May 2023

This work aims to characterize the effects of pulse repetition rate (PRR) and flow speed on dielectric barrier discharge (DBD) plasma pulse-to-pulse coupling and its ability to ignite methane-air flows. Experiments are performed on a homemade DBD flow reactor with 5 mm discharge gap. Pressure and equivalence ratio are kept constant at 700 mbar and 0.6. First, we perform high-speed intensified imaging to visualize pulse-to-pulse plasma behavior and ignition kernel development. In air flows, plasma morphology changes from multiple weak filaments to a few stronger filaments indicating plasma pulse-to-pulse coupling. This leads to plasma energy addition in nearly the same gas volume as the previous discharge. The study performed in methane-air flows highlights the importance of plasma pulse-to-pulse coupling for ignition. We find a critical PRR and a minimum number of pulses required to achieve a strong enough coupling to develop a successful ignition kernel. Ignition probability and kernel growth are also evaluated for various conditions. Finally, plasma pulse-to-pulse coupling is quantified by measuring the plasma parameters such as gas temperature and reduced electric field from an optical emission spectroscopy.
Geometric control of thermoformable knitted textiles using raster images
Authors: Tan Ying Yi , Quek Yu Han , Chia Pei Zhi , Gupta Ujjaval
Published: May 2023

Computer numerical control (CNC) knitting technology offers great potential in the creation of thermoformable textiles that can be shaped and stiffened in response to heat. Our research explores how CNC knitting can be used to design and fabricate textiles with precisely allocated material and microstructure layouts. These layouts pre-program specific deformation mechanism(s) into the textile that bias it to form an intended geometry, forgoing the need for a mould during the thermoforming process. We fabricate these smart textiles by knitting two thermal-reactive yarns with different extents of shrinkage, in a double layered structure akin to a bilayer strip. We develop a computational design-to-fabrication pipeline that translates raster images into machine-knittable instructions. Referencing multi-material additive manufacturing principles and self-actuating textiles, this paper proposes several design strategies of dithered gradients, tessellated patches and origami creases, to convert input pixel data into a material distribution layout. When paired with our assisted thermoforming process, this layout induces specific deformations of the textile, such as uni-/multi-axial curling, periodic buckling and sharp folding. Our prototypes implement these strategies on the micro-, meso- and macroscale, leading to the design and fabrication of an architectural cladding panel (700 × 535 × 110 mm) and a patterned clutch bag (200 × 420 × 65 mm).
Pseudo-Riemann’s quartics in Finsler’s geometry—two-dimensional case
Authors: Itin Yakov
Published: May 2023

Finsler’s geometry usually describes an extension of Riemmann’s geometry into a direction-dependent geometric structure. Historically, the well-known Riemann’s quartic length element example served as the inspiration for this construction. Surprisingly, the covariant Fresnel equation—a fundamental dispersion relation in solid-state electrodynamics—emerges as the exact same quartic expression. As a result, Riemann’s quartic length expression can be regarded of as a mathematical representation of a well-known physical phenomenon. In this study, we offer numerous Riemann’s quartic examples that show Finsler’s geometry, even in the situation of a positive definite Euclidean signature space, is too restrictive for many applications. The strong axioms of Finsler’s geometry are violated in a substantially greater number of distinctive subsets for the spaces having an indefinite (Minkowski) signature. We suggest a weaker characterization of Finsler’s structure based on explicitly calculated two-dimensional examples. In tangential vector space, this concept permits singular subsets. Only open subsets of a manifold’s tangent bundle are required to satisfy the strong axioms of Finsler’s geometry. We demonstrate the distinctive unique subsets of the Riemann’s quartic in two dimensions and briefly discuss their possible physical origins.
Comparison of Two Competing Theories of 3-Flavor Neutrino Oscillations
Authors: Fanchi John R.
Published: May 2023

Neutrino oscillation observations are used to compare two competing theories of 3-flavor neutrino oscillations. The two theories considered here are the standard model of neutrino oscillations, and parametrized Relativistic Quantum Theory (pRQT). pRQT is a manifestly covariant quantum theory with invariant evolution parameter. Recent data and a neutrino mass model from each theory are used to calculate neutrino masses. The models yield significantly different predictions of neutrino masses.