bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Pumice Sand as Fine Aggregate on Tensile Strength of Precast Concrete
Authors: Majid Abdullah Abd. , Gaus Abdul , Sultan Mufti Amir
Published: December 2021

In this study, a cylinder with a size of 15 cm x 30 cm totaling 10 pieces for the splitting tensile test. 5 pieces cylinder were used for the normal splitting tensile test and the other 5 pieces cylinder were used for the joint splitting tensile test were used. Two tests have been carried out, namely the normal splitting tensile strength (control) and the joint splitting tensile strength. In testing the tensile strength of the test object, the applied tool to provide the load is the Compression Testing Machine. The splitting tensile strength test was carried out on 10 test objects in the form of concrete cylinders with an age of 28 days. 5 test objects were used in the normal splitting tensile strength (control). Meanwhile, the other 5 test objects were used in the joint splitting tensile strength. The test objects were given the load gradually until the test objects experienced cracks or reaching maximum load.
An Analysis the Service Level of Ternate – Bitung Ferry Route
Authors: Hakim Raudha , Hasan Masnur
Published: December 2021

Data analysis in this study was carried out using the Importance Performance Analysis (IPA) analysis method. Importance Performance Analysis (IPA) is used to map the relationship between service (importance) and performance (performance) of each service attribute according to the assessment/perception of passengers on the Ternate – Bitung Ferry. The level of service of the Ternate-Bitung Sea transportation mode using the Importance Performance Analysis (IPA) method is obtained by variables that have high importance/expectations, but performance/reality is quite good. Services that are considered good include: Information services and Ferry Rates, Convenience of seating on the Ferry, Lighting at night, Availability of departure/arrival schedules, Appropriate/not rate rates. While the variables that are considered less important by passengers, but whose performance is good so that passengers think that the performance is excessive, namely: Strict action by officers for those who violate, Places for storing goods, Availability of compass/GPS navigation tools, Availability of life jackets/life jackets, Availability of first aid kits, Availability of radio equipment, Availability of distress signals.
Mass wear application of cooperated elements for evaluation of friction pair components condition
Authors: Matuszewski Maciej , Słomion Małgorzata , Mazurkiewicz Adam , Wojciechowski Andrzej
Published: December 2021

In this study, the influence of the geometrical surface structure shape on wear process of friction pairs elements with conformal contact was analyzed. Characteristics of the machine elements surface layer were described with special distinction of importance of the surface structure directivity and isotropy in terms of the surface layer transformation. This work presents the results of experimental tests in which the following input factors were used: specimen and counter-specimen ridge angle of intersection (0°; 30°; 45°; 60°; 90°) and specimen and counter-specimen clamp (1.0; 1.5; 2.0 MPa). The changes of the surface layer were recorded as a function of a specimen mass changes. Based on the conducted research, it was found that the ridge angle of intersection on the specimen and counter-specimen has a significant impact on the wear process intensity. The changes were uttermost for 0° angle and slightest for 9°. It was also found that the observed changes have a larger gradient for higher specimen load values. Thus, the significance of the geometrical surface structure directivity influence on the friction pair elements wear process intensity was confirmed.
Risk analysis during exploitation of mobile scenes
Authors: Wilczarska Joanna , Sokołowski Michał , Kovtun Igor , Petrashchuk Svitlana
Published: December 2021

This article discusses the risk of exploitation the mobile scene. The types of such scenes were characterized. Building and traffic regulations for mobile scenes are cited. The selected scene construct and the risks related to its safe operation were characterized.
Functioning of public transport systems in the conditions of the COVID-19 pandemic on the example of a selected urbanized area
Authors: Kuliś Ewa , Landowski Bogdan , Povareho Aleksandr
Published: December 2021

For the unit performing the transport task, it is important to have tools that enable the analysis and forecasting of the system status and facilitate making decisions regarding the control of the process. During the epidemic, many legal solutions were imposed, which forced changes in the process of using public transport. The following article describes the changes and their impact on the situation in Poland.
Recent advances of silicon wafer cutting technology for photovoltaic industry
Authors: Chen Changyong , Sun Meng , Chen Xiaoqing , Wang Yi , Jiang Zhouhua , Zhou Jianan
Published: December 2021

Using ultra-fine wire saw to cut solar grade silicon wafer is a very precise technology. In the past 20 years, researchers have done a lot of research and made great progress. The cutting method of silicon rod has developed from single line cutting to multi line simultaneous cutting, which greatly improves the production efficiency and the yield of silicon rod. However, the problems of high cutting loss, low cutting efficiency, and large surface damage of silicon wafer need to be solved; The surface of wire saw line has developed from smooth surface to coated diamond abrasive, which greatly improves the service life of wire saw line; The method of coated diamond abrasive on the surface of wire saw line has developed from resin consolidation to electroplating consolidation, which greatly improves the service life of wire saw line it improves the firmness of the coating; The arrangement of wire saw wire has developed from single wire to multi wire stranding, which makes the wire saw wire can cut large-size silicon rod; The minimum thickness of silicon wafer that can be cut is about 100–140 µm according to the perspective of stress analysis, while the excetive value should be located by more research.
Clinical value of serology for the diagnosis of strongyloidiasis in travelers and migrants: A 4-year retrospective study using the Bordier IVD®Strongyloides rattiELISA assay
Authors: Autier Brice , Boukthir Sarrah , Degeilh Brigitte , Belaz Sorya , Dupuis Anne , Chevrier Sylviane , Gangneux Jean-Pierre , Robert-Gangneux Florence
Published: December 2021

Strongyloides stercoralisserology is a sensitive method for strongyloidiasis diagnosis, but it is prone to cross-reactions with other helminthiases. This four-year retrospective study aimed at estimating the performance of the Bordier IVD®Strongyloides rattiELISA assay in a non-endemic country (France). The study included all patients tested for strongyloidiasis in our center between 2015 and 2019, by both serology and stool examination. Cases were defined using an algorithm considering serological results, microscopic examination of stools, and other biological, clinical or epidemiological data. The study included 805 stools from 341 patients (70% migrants, 20% travelers, 10% without travel to a highly endemic area). Thirty patients (8.8%) had positive serology, 9 had microscopically proven strongyloidiasis, and 11 and 10 were classified as probable and possible strongyloidiasis, respectively. Performances of microscopy and serology were compared, considering proven and probable strongyloidiasis as true infections. The sensitivity, specificity, positive predictive value and negative predictive value of serology were 100%, 97%, 67% and 100%, respectively, and those of microscopic examination of stools were 45% (p < 0.01), 100% (p < 0.01), 100% (p = 0.079) and 96% (p < 0.001), respectively. Eosinophilia did not help in discriminating true-positive from false-positive results. Overall, these results underline the high value of theS. stercoralisserologic assay, compared to stool examination. The systematic use of this technique for screening purposes in travelers or migrants, or before onset of immunosuppressive therapy, could help to improve patient management and epidemiological knowledge.
Photo-Excited Silicon-Based Spatial Terahertz Modulators
Authors: He Yu-Lian , Wang Yuan-Sheng , Wen Qi-Ye
Published: December 2021

The increasing development of terahertz (THz) technology has led to various potential applications in THz imaging, spectroscopy and communications. These devices capable of actively manipulating the amplitude, phase and frequency of THz waves are thus gaining numerous interests. All-optical silicon-based spatial terahertz modulators (STMs), as a simple, cost-effective, and reconfigurable technique, are standing the focus of research. Beginning with a fundamental concept of THz radiation, this paper systematically summarized the modulation mechanism and theoretical model for this kind of STM, reviewed the recent advancements in THz functional devices implemented by this optical method and yet, discussed the performance-improved measures with an emphasis on the reflection reduction. Despite that, there has been considerable progress in realizing high-performance STMs, and novel design is urgent to realize higher modulation rate and more functionality.
Low-voltage driven graphene-loaded metal wire grating device in total internal reflection geometry for broadband THz modulation
Authors: Liu Xudong , Chen Hao , Li Teng , Sun Yiwen
Published: December 2021

Terahertz modulators with capability of both intensity and phase are essential for THz imaging and communication systems. The low-voltage driven THz modulation technique is crucial for integrating the modulators with electronics components. There is still a lack of broadband devices able to achieve both amplitude and phase modulation with low voltage, due to the underlying physics behind existing approaches. Here, we demonstrate a graphene-loaded metal wire grating THz modulator in the total internal reflection geometry to achieve intensity modulation of 80% and phase modulation of 70 degree within 3 volts gate voltage. Quite different from using the strategy of metamaterials based on the electromagnetic resonance effects, our design has performed a broadband modulation for over 1 THz bandwidth.
Problematische und pathologische Bindungsphänomene im Zusammenhang mit internetbezogenen Störungen
Authors: Dieris-Hirche Jan , Linny Geisler Birte , Bottel Laura , Theodor te Wildt Bert
Published: December 2021

Ziel Das systematische Review untersucht, ob problematische und pathologische Bindungsphänomene bei der Entwicklung internetbezogener Störungen von Bedeutung sind.

Methodik Im Rahmen einer systematischen Literaturrecherche zum Thema Bindung und internetbezogene Störungen in PubMed und PsychINFO wurden klinische und subklinische Studienergebnisse seit 2010 gesichtet, bewertet und in eine Übersicht gebracht.

Ergebnisse Aus 917 in die Vorauswahl aufgenommenen Studien wurden 40 Studien mit 33 389 Teilnehmenden im Alter zwischen 8 und 80 Jahren in das Review eingeschlossen und kritisch bewertet. Sie dokumentieren, dass Bindungsstörungen bei der internetbezogenen Störung allgemein sowie bei 3 spezifischen Varianten – Computerspiel-Typ, Online-Sex-Typ und Sozialer-Netzwerk-Typ – eine Rolle spielen.

Diskussion Wie bei anderen Suchterkrankungen auch ist zu vermuten, dass eine internetbezogene Störung unter anderem auf ein Fehlen früher Halt und Sicherheit gebender Bindungserfahrungen zurückgeht. Zukünftige Forschung sollte sich zudem mit der Frage befassen, inwieweit eine primär exzessive digitale Mediennutzung auf Seiten der Eltern und Kinder gleichsam zur Entwicklung von Bindungsstörungen beitragen könnte.
Mehr als trösten – psychische Betreuung in der Kinderanästhesie
Authors: Bittner Sebastian
Published: December 2021

„Kinder sind keine kleinen Erwachsenen!“ – mit diesen Worten startet traditionell jede Fortbildung zum Thema Anästhesie bei Kindern oder Säuglingen. Doch was genau verbirgt sich dahinter? In diesem Beitrag soll es explizit nicht um die anatomischen Besonderheiten oder die daraus resultierenden Anforderungen an das Equipment gehen. Hier richtet sich der Fokus auf die Besonderheiten in der Entwicklung von Kindern und die Bedeutung für die psychische Betreuung in den verschiedenen Altersstufen. Die Inhalte des Artikels sind nicht rein „pflegerisch“ oder „medizinisch“, sie sind viel mehr (entwicklungs-)psychologisch und somit relevant für alle in der Betreuung tätigen Berufsgruppen.
Genesungsbegleitung: Inanspruchnahme und Nutzenbewertung aus Betroffenenperspektive – Ergebnisse einer Beobachtungsstudie
Authors: Gühne Uta , Richter Daniel , Breilmann Johanna , Täumer Esther , Falkai Peter , Kilian Reinhold , Allgöwer Andreas , Ajayi Klemens , Baumgärtner Jessica , Brieger Peter , Frasch Karel , Heres Stephan , Jäger Markus , Küthmann Andreas , Putzhammer Albert , Schneeweiß Bertram , Schwarz Michael , Becker Thomas , Kösters Markus , Riedel-Heller Steffi G.
Published: December 2021

Ziel der Studie Genesungsbegleitung spielt in der Behandlung schwer psychisch erkrankter Menschen eine zunehmende Rolle. Zur Wirksamkeit liegen internationale Befunde vor. Über Wissen, Nutzung und Nutzenbewertung ist in Deutschland bisher wenig bekannt. Die vorliegende Arbeit geht dieser Frage nach und stellt Ergebnisse aus einer Beobachtungsstudie mit 10 teilnehmenden Zentren in Süddeutschland vor.

Methodik Im Rahmen der beobachtenden Querschnittsstudie mit schwer psychisch erkrankten Menschen (IMPPETUS, N=359) wurden zwischen März und September 2019 soziodemografische sowie krankheits- und behandlungsassoziierte Daten erhoben. Mittels binär logistischer Regression wurde ein möglicher Zusammenhang mit der Nutzung von Genesungsbegleitung analysiert.

Ergebnisse 38% (N=138) der Befragten gaben an, von der Möglichkeit der Genesungsbegleitung zu wissen; 15% (N=55) bejahten deren Nutzung. Eine Nutzung schwankte zwischen 6,5 und 37,5% über die Standorte und war mit dem Haushaltseinkommen verbunden. Deutlich seltener wurde Genesungsbegleitung von Personen mit einem hohen gegenüber Personen mit einem geringen Haushaltseinkommen genutzt (OR=0,20 [95% CI: 0,06–0,68], p=0,01). Von den Nutzenden (N=55) gaben 78% an, diese als hilfreich bzw. äußerst hilfreich wahrgenommen zu haben.

Diskussion Genesungsbegleitung erweist sich nicht nur unter Studienbedingungen hinsichtlich verschiedener Outcomes als wirksam, sondern wird auch unter Routinebedingungen in einer umschriebenen Versorgungsregion von der Mehrheit der Nutzenden als wirksam eingeschätzt. Allerdings müssen Wissen und Nutzung hinsichtlich einer Genesungsbegleitung unter (teil)stationär behandelten Personen als gering verteilt bewertet werden.

Schlussfolgerung Um Genesungsbegleitung stärker in die Praxis zu implementieren, muss wirksamer als bisher über dieses Unterstützungsangebot informiert und ein (über-)regionaler Austausch über erfolgreiche Implementierungserfahrungen angestrengt werden.
The participatory turn in health and medicine: The rise of the civic and the need to ‘give back’ in data-intensive medical research
Authors: Siffels Lotje E. , Sharon Tamar , Hoffman Andrew S.
Published: December 2021

What has been called the “participatory turn” in health and medicine refers to a general shift from paternalistic and hierarchical, to more collaborative and egalitarian relationships between medical experts and patients/research participants; a shift from what the pragmatic sociologists Boltanski and Thévenot (2006) call a “domestic” to a “civic” order of worth. Critical scholarship on the participatory turn tends to emphasize discrepancies between ideals of equality and empowerment, and practices of increased individual responsibility and disempowerment. In this paper, we depart from this critical literature by suspending evaluation about authentic and inauthentic ideals and practices. Instead, we explore the issues and challenges that arise in the process of ensuring that ideal and practice align in what we call a civic-participatory style of doing medical research. Drawing on interviews and observations carried out with medical researchers, coordinators and assessors in a longitudinal cohort study called the Personalized Parkinson’s Project (PPP), we show that for study staff it is often unclear how they can meet the demands of reciprocity towards research participants that are presupposed by civic-participatory ideals. In particular, in the context of a study whose aim is the creation of a comprehensive dataset comprised of clinical, environmental and lifestyle data that study participants generously “give” over a period of 2 years, we observed a persistent concern on the part of study staff regarding what and how to “give back”. As we show, study staff negotiate and resolve this tension through recourse to creative workarounds and innovative ways of giving back, including frequent project and scientific updates, newsletters, the designation of personal assessors and pampering Event Days. The paper makes a contribution to the critical literature on the participatory turn by showing the utility of the orders of worth framework in probing the challenges and workarounds that emerge in settings where an incumbent style of organizing medical research (here, the 'civic') comes to challenge practices hitherto organized according to a wholly different logic (in this case, the 'domestic')—without making assumptions about the (in)authenticity of such ideals and practices. Moreover, we contend that this framework offers new tools for evaluating participatory research projects in the form of “good” or “successful” civic–domestic compromises.
Decoding complex state space trajectories for neural computing
Authors: Schittler Neves Fabio , Timme Marc
Published: December 2021

In biological neural circuits as well as in bio-inspired information processing systems, trajectories in high-dimensional state-space encode the solutions to computational tasks performed by complex dynamical systems. Due to the high state-space dimensionality and the number of possible encoding trajectories rapidly growing with input signal dimension, decoding these trajectories constitutes a major challenge on its own, in particular, as exponentially growing (space or time) requirements for decoding would render the original computational paradigm inefficient. Here, we suggest an approach to overcome this problem. We propose an efficient decoding scheme for trajectories emerging in spiking neural circuits that exhibit linear scaling with input signal dimensionality. We focus on the dynamics near a sequence of unstable saddle states that naturally emerge in a range of physical systems and provide a novel paradigm for analog computing, for instance, in the form of heteroclinic computing. Identifying simple measures of coordinated activity (synchrony) that are commonly applicable to all trajectories representing the same percept, we design robust readouts whose sizes and time requirements increase only linearly with the system size. These results move the conceptual boundary so far hindering the implementation of heteroclinic computing in hardware and may also catalyze efficient decoding strategies in spiking neural networks in general.
Intermodulation distortions from an array of active nonlinear oscillators
Authors: Thipmaungprom Yanathip , Prawanta Ekkanat , Leelasiriwong Wisit , Thammachoti Panupong , Roongthumskul Yuttana
Published: December 2021

Coupling is critical in nonlinear dynamical systems. It affects the stabilities of individual oscillators as well as the characteristics of their response to external forces. In the auditory system, the mechanical coupling between sensory hair cells has been proposed as a mechanism that enhances the inner ear's sensitivity and frequency discrimination. While extensive studies investigate the effects of coupling on the detection of a sinusoidal signal, the role of coupling underlying the response to a complex tone remains elusive. In this study, we measured the acoustic intermodulation distortions (IMDs) produced by the inner ears of two frog species stimulated simultaneously by two pure tones. The distortion intensity level displayed multiple peaks across stimulus frequencies, in contrast to the generic response from a single nonlinear oscillator. The multiple-peaked pattern was altered upon varying the stimulus intensity or an application of a perturbation tone near the distortion frequency. Numerical results of IMDs from a chain of coupled active nonlinear oscillators driven by two sinusoidal forces reveal the effects of coupling on the variation profile of the distortion amplitude. When the multiple-peaked pattern is observed, the chain's motion at the distortion frequency displays both a progressive wave and a standing wave. The latter arises due to coupling and is responsible for the multiple-peaked pattern. Our results illustrate the significance of mechanical coupling between active hair cells in the generation of auditory distortions, as a mechanism underlying the formation of in vivo standing waves of distortion signals.
Design of a tunable electromagnetic vibration absorber for transient vibration suppression under impulse
Authors: Wang Xi , Xu Zhenyuan , Wang Dida
Published: December 2021

Vibration absorbers usually aim to control the steady-state vibration of harmonic excitation based on the traditional fixed point theory, but few efforts focus on suppressing the transient vibration caused by impulse excitation. In this paper, the excitation is regarded as impulse in modeling, and it can be used for impulse excitation. Thus, the transient vibration absorber is designed to control the transient vibration, and the stiffness of the absorber is a key factor to control the response of the primary system. This paper presents a tunable electromagnetic transient vibration absorber to avoid direct mechanical contact for the absorber. The analytical results of the transient response indicate that the vibration can be attenuated by adjusting the stiffness of the absorber. In order to establish the model of the electromagnetic stiffness, the absorber is divided into three equivalent virtual springs. The circular current loop is equivalent to the rectangular current loop to show the spatial distribution of the magnetic flux density in the air gap. The experimental tests demonstrate that the transient vibration of the primary system can be attenuated by 13% when the current of the coil is 6 A.
Tunable homogeneous kG magnetic field production using permanent magnets
Authors: Pizzey Danielle
Published: December 2021

We present a permanent ring magnet arrangement that can achieve a tunable axial magnetic field from 1.80(5) to 2.67(9) kG. The apparatus has been designed to accommodate a cylindrical atomic vapor cell of length 25 mm and diameter 25 mm to lie within the bore of the ring magnets, providing an alternative route for imaging through atomic vapors in large magnetic fields. The measured axial magnetic field has an rms variation of less than 4% over the length of vapor cell, while the calculated field inhomogeneity is less than 5% radially and 12% longitudinally across a cylindrical volume with diameter 20 mm and length 25 mm. The instrument consists of layered concentric off-the-shelf N42 neodymium–iron–boron axially magnetized ring magnets. The magnets are organized into four cylindrical brass holders, whose relative separation can be manipulated to achieve the desired magnetic field strength. We present magnetic field computations and Marquardt–Levenberg fits to experimental data and demonstrate excellent agreement between theory and experiment.
Thermohydrodynamic investigation for supercritical carbon dioxide high speed tilting pad bearings considering turbulence and real gas effect
Authors: Bi Chunxiao , Han Dongjiang , Wu Yao , Li Yimin , Yang Jinfu
Published: December 2021

A global heat balance method for supercritical carbon dioxide (S-CO2) high speed tilting pad bearings was developed, in which the real gas effect, variable thermodynamic properties, and turbulence effect were considered. The bearing characteristics can be obtained by the partial derivative method embracing dynamic variations of complete variables. Then thermohydrodynamic lubrication mechanisms for S-CO2 bearings are studied, and results indicate that the real gas effect of thermal compressibility is significant. The influence of the thermal effect on the static and dynamic characteristics of bearings is caused by changes in density, specific heat, and thermal expansion coefficient rather than viscosity, which is totally different from oil bearings. In general, the influence of thermohydrodynamic lubrication on static characteristics of S-CO2 tilting pad bearings is more obvious than that on dynamic coefficients. For example, the maximum deviation of damping coefficients of a bearing with parameters in this research at a certain speed range is 8%, and that of the load capacity at the corresponding speed is 10.7%. However, the influence of the thermal effect on dynamic coefficients is varied at different rotating speeds.
Oscillatory spreading and inertia in power grids
Authors: Molnar Samantha , Bradley Elizabeth , Gruchalla Kenny
Published: December 2021

The increase in variable renewable generators (VRGs) in power systems has altered the dynamics from a historical experience. VRGs introduce new sources of power oscillations, and the stabilizing response provided by synchronous generators (SGs, e.g., natural gas, coal, etc.), which help avoid some power fluctuations, will lessen as VRGs replace SGs. These changes have led to the need for new methods and metrics to quickly assess the likely oscillatory behavior for a particular network without performing computationally expensive simulations. This work studies the impact of a critical dynamical parameter—the inertia value—on the rest of a power system’s oscillatory response to representative VRG perturbations. We use a known localization metric in a novel way to quantify the number of nodes responding to a perturbation and the magnitude of those responses. This metric allows us to relate the spread and severity of a system’s power oscillations with inertia. We find that as inertia increases, the system response to node perturbations transitions from localized (only a few close nodes respond) to delocalized (many nodes across the network respond). We introduce a heuristic computed from the network Laplacian to relate this oscillatory transition to the network structure. We show that our heuristic accurately describes the spread of oscillations for a realistic power-system test case. Using a heuristic to determine the likely oscillatory behavior of a system given a set of parameters has wide applicability in power systems, and it could decrease the computational workload of planning and operation.
Dynamics of exciton–polariton emission in CuI
Authors: Krüger Evgeny , Bar Michael S. , Blaurock Steffen , Trefflich Lukas , Hildebrandt Ron , Müller Andreas , Herrfurth Oliver , Benndorf Gabriele , von Wenckstern Holger , Krautscheid Harald , Grundmann Marius , Sturm Chris
Published: December 2021

We report on temperature-dependent (10 K – 250 K) spectral and dynamical properties of free exciton–polariton and bound exciton emission in copper iodide (CuI) bulk single crystals analyzed by means of time-resolved photoluminescence spectroscopy. The characteristic line shape of the polariton emission at low temperatures is interpreted in terms of the “k-linear term effect” on the degenerate Z1,2 excitons in CuI. For free exciton–polaritons, an increase in the decay time with increasing temperature up to 360 ps at 160 K is observed. For bound exciton emission, decay times between 180 ps and 380 ps are observed at low temperatures, revealing the expected EB3/2 dependence of radiative lifetime on the localization energy. Based on the observed rise times of bound excitons at low temperatures, a defect density of shallow acceptors of 1 × 1017 cm−3 was estimated, in agreement with measured room temperature free hole density.
An advanced optical–electrochemical nanopore measurement system for single-molecule analysis
Authors: Liu Shao-Chuang , Xie Bao-Kang , Zhong Cheng-Bing , Wang Jia , Ying Yi-Lun , Long Yi-Tao
Published: December 2021

Nanopore measurement has advanced in single-molecule analysis by providing a transient time and confined space window that only allows one interested molecule to exist. By optimization and integration of the electrical and optical analysis strategies in this transient window, the acquisition of comprehensive information could be achieved to resolve the intrinsic properties and heterogeneity of a single molecule. In this work, we present a roadmap to build a unified optical and electrochemical synchronous measurement platform for the research of a single molecule. We design a low-cost ultralow-current amplifier with low noise and high-bandwidth to measure the ionic current events as a single molecule translocates through a nanopore and combine a multi-functional optical system to implement the acquisition of the fluorescence, scattering spectrum, and photocurrent intensity of single molecule events in a nanopore confined space. Our system is a unified and unique platform for the protein nanopore, the solid-state nanopore, and the glass capillary nanopore, which has advantages in the comprehensive research of nanopore single-molecule techniques.
Orientation and actual growth mechanism of ZnO nanorods through hydrothermal method on gold seed layer
Authors: Iqbal Younas , Mustafa Mohd Kamarulzaki , Wang Jianli , Wang Chao
Published: December 2021

In this study, the hydrothermal method was employed to synthesize an oriented ZnO nanorod array on an annealed gold seed layer coated on a glass substrate from different precursor concentrations. Zinc nitrate hexahydrate and hexamethylenetetramine were used as starting materials for ZnO nanorod growth. The effect of gold seed layer roughness on the orientation of ZnO nanorods is presented. The morphology of the nanorods shows that oriented ZnO nanorods were obtained after deposition on the annealed gold seed layer. Energy dispersive x-ray spectroscopy was used to identify the elemental composition and identify the elements present in the samples. The XRD pattern shows that the nanorods have a good crystalline structure, with dominant (002) peaks for all concentrations, which reflects that the c-axis of the elongated nanorods is oriented normal to the substrate. The proposed growth mechanism for the growth of ZnO nanorods is presented.
Conduction channel configuration controlled digital and analog response in TiO2-based inorganic memristive artificial synapses
Authors: Simanjuntak Firman Mangasa , Hsu Chun-Ling , Abbey Thomas , Chang Lung-Yu , Rajasekaran Sailesh , Prodromakis Themis , Tseng Tseung-Yuen
Published: December 2021

The operating current regime is found to play a key role in determining the synaptic characteristic of memristor devices. A conduction channel that is formed using high current compliance prior to the synaptic operation results in digital behavior; the high current stimulus forms a complete conductive filament connecting the cathode and anode, and the high electric field promotes abrupt redox reactions during potentiation and depression pulsing schemes. Conversely, the conduction can be reconfigured to produce a filamentary-homogeneous hybrid channel by utilizing the low current stimulus, and this configuration enables the occurrence of analog behavior. The capabilities of memristors showing programmable digital-to-analog or analog-to-digital transformation open a wide range of applications in electronics. We propose a conduction mechanism to explain this phenomenon.
Electron-scale temperature gradients in kinetic equilibrium: MMS observations and Vlasov–Maxwell solutions
Authors: Shuster J. R. , Bessho N. , Wang S. , Ng J.
Published: December 2021

For an ideal gas, the notion of thermodynamic equilibrium requires that the system's temperature be spatially uniform. We demonstrate that for a collisionless plasma, kinetic equilibrium can be achieved even in the presence of a temperature gradient. Motivated by recent Magnetospheric Multiscale (MMS) magnetopause observations of thin current layers exhibiting electron-scale temperature gradients, here we present an exact solution to the Vlasov–Maxwell system that accounts for the observed electron temperature gradient and reproduces much of the plasma's spatial variation along one dimension. The current layer in the Vlasov–Maxwell model is self-consistently supported by a prominent crescent-shaped electron velocity distribution that naturally arises due to the temperature transition, which agrees with the electron distribution structures measured by MMS during two asymmetric current layers encountered at the magnetopause.
Uncovering the cell fate decision in lysis–lysogeny transition and stem cell development via Markov state modeling
Authors: Li Xiaoguang , Li Tongkai , Li Chunhe , Li Tiejun
Published: December 2021

Understanding the behavior of a complex gene regulatory network is a fundamental but challenging task in systems biology. How to reduce the large number of degrees of freedom of a specific network and identify its main biological pathway is the key issue. In this paper, we utilized the transition path theory (TPT) and Markov state modeling (MSM) framework to numerically study two typical cell fate decision processes: the lysis–lysogeny transition and stem cell development. The application of TPT to the lysis–lysogeny decision-making system reveals that the competitions of CI and Cro dimer binding play the major role in determining the cell fates. We also quantified the transition rates from the lysogeny to lysis state under different conditions. The overall computational results are consistent with biological intuitions but with more detailed information. For the stem cell developmental system, we applied the MSM to reduce the original dynamics to a moderate-size Markov chain. Further spectral analysis showed that the reduced system exhibits nine metastable states, which correspond to the refinement of the five known typical cell types in development. We further investigated the dominant transition pathways corresponding to the cell differentiation, reprogramming, and trans-differentiation. A similar approach can be applied to study other biological systems.
Isochronal superpositioning of the caged dynamics, the α, and the Johari–Goldstein β relaxations in metallic glasses
Authors: Ren N. N. , Guan P. F. , Ngai K. L.
Published: December 2021

The superposition of the frequency dispersions of the structural α relaxation determined at different combinations of temperature T and pressure P while maintaining its relaxation time τα(T, P) constant (i.e., isochronal superpositioning) has been well established in molecular and polymeric glass-formers. Not known is whether the frequency dispersion or time dependence of the faster processes including the caged molecule dynamics and the Johari–Goldstein (JG) β relaxation possesses the same property. Experimental investigation of this issue is hindered by the lack of an instrument that can cover all three processes. Herein, we report the results from the study of the problem utilizing molecular dynamics simulations of two different glass-forming metallic alloys. The mean square displacement 〈Δr2t〉, the non-Gaussian parameter α2t, and the self-intermediate scattering function Fsq,t at various combinations of T and P were obtained over broad time range covering the three processes. Isochronal superpositioning of 〈Δr2t〉, α2t, and Fsq,t was observed over the entire time range, verifying that the property holds not only for the α relaxation but also for the caged dynamics and the JG β relaxation. Moreover, we successfully performed density ρ scaling of the time τα2,maxT,P at the peak of α2t and the diffusion coefficient D(T, P) to show both are functions of ργ/T with the same γ. It follows that the JG β relaxation time τβ(T, P) is also a function of ργ/T since τα2,maxT,P corresponds to τβ(T, P).
Chemomechanical equilibrium at the interface between a simple elastic solid and its liquid phase
Authors: Sprik Michiel
Published: December 2021

Applying diffusion coupled deformation theory, we investigate how the elastic properties of a solid body are modified when forced to keep its chemical potential aligned with that of its melt. The theory is implemented at the classical level of continuum mechanics, treating materials as simple continua defined by uniform constitutive relations. A phase boundary is a sharp dividing surface separating two continua in mechanical and chemical equilibrium. We closely follow the continuum theory of the swelling of elastomers (gels) but now applied to a simple two phase one-component system. The liquid is modeled by a local free energy density defining a chemical potential and hydrostatic pressure as usual. The model is extended to a solid by adding a non-linear shear elastic energy term with an effective modulus depending on density. Imposing chemomechanical equilibrium with the liquid reservoir reduces the bulk modulus of the solid to zero. The shear modulus remains finite. The stability of the hyper-compressible solid is investigated in a thought experiment. A mechanical load is applied to a rectangular bar under the constraint of fixed lateral dimensions. The linear elastic modulus for axial loading is evaluated and found to be larger than zero, implying that the bar, despite the zero bulk modulus, can support a weight placed on its upper surface. The weight is stabilized by the induced shear stress. The density dependence of the shear modulus is found to be a second order effect reducing the density of the stressed solid (chemostriction).
Most probable transitions from metastable to oscillatory regimes in a carbon cycle system
Authors: Wei Wei , Hu Jianyu , Chen Jianyu , Duan Jinqiao
Published: December 2021

Global climate changes are related to the ocean’s store of carbon. We study a carbonate system of the upper ocean, which has metastable and oscillatory regimes, under small random fluctuations. We calculate the most probable transition path via a geometric minimum action method in the context of the large deviation theory. By examining the most probable transition paths from metastable to oscillatory regimes for various external carbon input rates, we find two different transition patterns, which gives us an early warning sign for the dramatic change in the carbonate state of the ocean.
Thermal conductivity of single-walled carbon nanotubes under torsional deformation
Authors: Nagaya Hayato , Cho JunHee , Hori Takuma
Published: December 2021

Molecular dynamics simulations were performed to evaluate the thermal conductivity of torsional single-walled carbon nanotubes (CNTs). We found that torsional deformation decreases the thermal conductivity of an isolated CNT as well as that of bundled ones, while tensile strain has no effect. A large decrease in thermal conductivity was observed when the torsion angle exceeded a certain threshold. In addition, the decrement in thermal conductivity of the isolated CNT was larger than that of the bundled ones. To gain a better understanding of the thermal conductivity reduction, the cross section and the energy spectrum of the torsional CNTs were also investigated. The eccentricity of the cross section of CNTs was strongly correlated with the thermal conductivity reduction. The energy spectrum suggested that the reduction in phonon relaxation time caused by torsional deformation leads to a decrement in thermal conductivity.
Asymmetric vortex pair induces secondary traveling wave vibration of a flexible cylinder from still water to incoming flow
Authors: Wang Zhicheng , Li Ang , Wu Baiheng , Fan Dixia , Triantafyllou Michael S. , Tang Dawei
Published: December 2021

As one of the fundamental problems in fluid mechanics, the flow-induced vibration of a flexible cylinder helps shed light on various complex fluid–structure interaction phenomena, such as the coupling effect of the cross-flow and in-line motions in the relationship between external fluid forces and vortical wake patterns. This paper devised a non-uniform in-flow condition (partially uniform flow and partially still water) for flexible cylinders in experimental and numerical conditions. Consistently, a new phenomenon is observed in different scale experiments and simulations where secondary traveling wave vibration of the flexible cylinder is excited from the still water part to the uniform inflow part due to the positive external fluid energy input in the still water. Furthermore, the detailed flow visualization on the vortical wake patterns around the vibrating flexible cylinders reveals that the external fluid force sources in the still water are due to the existence of the attached vortex pair with an uneven strength, which has been observed before in the still rigid cylinder in the oscillatory flow or the rigid cylinder oscillating in the still water at Keulegan–Carpenter number from 4 to 7.
Data-driven modeling of S → S1 excitation energy in the BODIPY chemical space: High-throughput computation, quantum machine learning, and inverse design
Authors: Gupta Amit , Chakraborty Sabyasachi , Ghosh Debashree , Ramakrishnan Raghunathan
Published: December 2021

Derivatives of BODIPY are popular fluorophores due to their synthetic feasibility, structural rigidity, high quantum yield, and tunable spectroscopic properties. While the characteristic absorption maximum of BODIPY is at 2.5 eV, combinations of functional groups and substitution sites can shift the peak position by ±1 eV. Time-dependent long-range corrected hybrid density functional methods can model the lowest excitation energies offering a semi-quantitative precision of ±0.3 eV. Alas, the chemical space of BODIPYs stemming from combinatorial introduction of—even a few dozen—substituents is too large for brute-force high-throughput modeling. To navigate this vast space, we select 77 412 molecules and train a kernel-based quantum machine learning model providing <2% hold-out error. Further reuse of the results presented here to navigate the entire BODIPY universe comprising over 253 giga (253 × 109) molecules is demonstrated by inverse-designing candidates with desired target excitation energies.
Effects of interfacial properties on conversion efficiency of Bi2Te3-based segmented thermoelectric devices
Authors: Yan Zipeng , Song Kun , Xu Liang , Tan Xiaojian , Hu Haoyang , Sun Peng , Liu Guoqiang , Pan Chunrong , Jiang Jun
Published: December 2021

The conversion efficiency η of a thermoelectric (TE) device can be effectively improved by constructing segmented TE legs, but the specific interfaces between the heterogeneous materials inevitably degrade the performance. Focusing on the Bi2Te3-based two-segmented module, we systematically investigated the influences of the Peltier effect, interfacial electrical resistance Re, and interfacial thermal resistance Rt on the conversion efficiency η. It is found that the Peltier heat can increase the conversion efficiency if the Seebeck coefficient increases along the direction of an electric current. An applicable Re should be kept on the order of magnitudes of 10−5 Ω cm2 for segmented TE devices, since the increased Re significantly decreases η. With a determined Re, η depends on the leg height L rather than the cross-sectional area A. In contrast, η is hardly affected by the variation in the interfacial thermal resistance Rt, while both the input heat flux Qin and output power P decrease with the increasing Rt.
Computational NMR of natural products
Authors: Semenov V. A. , Krivdin L. B.
Published: December 2021

This review generalizes diverse computational NMR studies of different natural products involving true alkaloids (indole, quinolizidine, pyrrolizidine, piperidine, indolizidine, quinoline, isoquinoline, indoloquinoline, and guanidine alkaloids), pseudoalkaloids (terpenes and steroids), quinones, lactones, lactams, flavonoids, and many others. The diverse computational protocols employed in each particular case are thoroughly discussed with a special emphasis on their structural and stereochemical applications.
 The bibliography includes 165 references.
Free recall scaling laws and short-term memory effects in a latching attractor network
Authors: Boboeva Vezha , Pezzotta Alberto , Clopath Claudia
Published: December 2021

Significance

The ability to store and retrieve information is a crucial function of memory in the brain. One well-established paradigm in which this is tested is free recall, in which a number of robust features and biases characterize the statistics of recall. Although these laws are consistently reproduced, the neuronal basis of how they emerge is not clear. In this manuscript, we propose a neural network model with a plausible learning rule that expresses these laws that may provide a mechanistic insight into memory function. In particular, our model reproduces power laws governing the recall capacity, as well as the biases that human subjects use to guide recall, such as the use of temporal and semantic cues.
Evaluation of borinic acids as new, fast hydrogen peroxide–responsive triggers
Authors: Gatin-Fraudet Blaise , Ottenwelter Roxane , Le Saux Thomas , Norsikian Stéphanie , Pucher Mathilde , Lombès Thomas , Baron Aurélie , Durand Philippe , Doisneau Gilles , Bourdreux Yann , Iorga Bogdan I. , Erard Marie , Jullien Ludovic , Guianvarc’h Dominique , Urban Dominique , Vauzeilles Boris
Published: December 2021

Significance

Hydrogen peroxide plays an important role in the fine balance between physiological and pathological processes. To detect this diffusible small molecule, we expanded the scope of organic triggers in developing borinic acids as an alternative and more sensitive trigger than the most conventional boronate-based sensors. We discovered that borinic acid is 10,000-fold more reactive than its boronic counterpart toward H
2
O
2
-mediated oxidation. An accurate determination of oxidation kinetic constants and computational experiments corroborate this higher reactivity. This improvement also proved effective for in-cell detection of exogenously as well as endogenously produced H
2
O
2
. We believe borinic acids represent a new and efficient tool allowing for the development of new devices for a better understanding of H
2
O
2
-mediated signaling processes.
Pedestrian dynamics at the running of the bulls evidence an inaccessible region in the fundamental diagram
Authors: Parisi Daniel R. , Sartorio Alan G. , Colonnello Joaquín R. , Garcimartín Angel , Pugnaloni Luis A. , Zuriguel Iker
Published: December 2021

Significance

A topic of special interest in crowd dynamics that can lead to better infrastructure management is the study of people under high competitiveness. Persons fleeing from real danger is one instance of this scenario, but of course it is difficult to analyze it experimentally. This is why people running with bulls at the San Fermín Festival provides an exceptional annual event where real data of pedestrian dynamics under extreme conditions can be collected. This kind of data is scarce and therefore highly valuable.
Benchmarking the ideal sample thickness in cryo-EM
Authors: Martynowycz Michael W. , Clabbers Max T. B. , Unge Johan , Hattne Johan , Gonen Tamir
Published: December 2021

Significance

A systematic investigation of the effects of sample thickness on electron scattering in electron cryo-microscopy (cryo-EM) was previously not feasible. Here, methods are employed to investigate the effects of increasing sample thickness. Near identical protein crystals are used as samples, and microcrystal electron diffraction data are used to assess the effects of thickness. These experiments were conducted using the three most-common accelerating voltages in cryo-EM, and data were compared using the calculated inelastic mean free path. Structures may be determined using crystals up to twice the inelastic mean free path. No coherent information remains at thicknesses over four times the mean free path. This study provides limits for biological specimen thickness with implications for all cryo-EM methods.