bluuebunny/crossref_metadata_2025 huggingface dataset:
A piezoelectric rotatable magnetic force microscope system in a 10 T cryogen-free superconducting magnet
Authors: Xiang Kui , Hou Yubin , Wang Jihao , Zhang Jing , Feng Qiyuan , Wang Ze , Meng Wenjie , Lu Qingyou , Lu Yalin
Published: September 2022

We constructed a piezoelectric rotatable magnetic force microscope (MFM) that works in a 10 T cryogen-free superconducting magnet. The piezoelectric tube is deformed tangentially and drives a bearing under the inertial drive principle so the MFM head can obtain rotary movement. Due to the novel piezoelectric design, the MFM can be hung underneath the heat sink via a soft spring, and it can be rotated in a cryogen-free superconducting magnet so that the direction of the magnetic field can be changed from 0° to 90° continuously. The system functions in magnetic fields of up to 10 T in any direction relative to the tip–sample geometry. This is the first piezoelectric rotatable MFM ever reported. Using this homemade rotatable MFM, we imaged the structure of magnetic tracks on a commercial videotape. When the magnetic field angle changes from 0° to 90°, the magnetic moments on the tape and probe tip also rotate. A magnetic field strength of 0.8 T parallel to the sample surface is required to fully rotate the magnetic moment of the tip we used, but 0.8 T is not enough to fully rotate the magnetic moment of the sample. The piezoelectric rotatable MFM is expected to be widely used to study the anisotropy of magnetic materials due to its superiority in obtaining the same high field in and out of plane (compared with a vector magnet) as well as in maintaining the same scan area precisely (compared with a mechanical rotatable MFM, especially for atomic-scale scan areas).
Fusion product measurements by nuclear diagnostics in the Joint European Torus deuterium–tritium 2 campaign (invited)
Authors: Nocente M. , Kiptily V. , Tardocchi M. , Bonofiglo P. J. , Craciunescu T. , Molin A. Dal , De La Luna E. , Eriksson J. , Garcia J. , Ghani Z. , Gorini G. , Hägg L. , Kazakov Y. , Lerche E. , Maggi C. F. , Mantica P. , Marcer G. , Maslov M. , Putignano O. , Rigamonti D. , Salewski M. , Sharapov S. , Siren P. , Stancar Z. , Zohar A. , Beaumont P. , Crombe K. , Ericsson G. , Garcia-Munoz M. , Keeling D. , King D. , Kirov K. , Nave M. F. F. , Ongena J. , Patel A. , Perez von Thun C. ,   JET Contributors
Published: September 2022

A new deuterium–tritium experimental, DTE2, campaign has been conducted at the Joint European Torus (JET) between August 2021 and late December 2021. Motivated by significant enhancements in the past decade at JET, such as the ITER-like wall and enhanced auxiliary heating power, the campaign achieved a new fusion energy world record and performed a broad range of fundamental experiments to inform ITER physics scenarios and operations. New capabilities in the area of fusion product measurements by nuclear diagnostics were available as a result of a decade long enhancement program. These have been tested for the first time in DTE2 and a concise overview is provided here. Confined alpha particle measurements by gamma-ray spectroscopy were successfully demonstrated, albeit with limitations at neutron rates higher than some 1017 n/s. High resolution neutron spectroscopy measurements with the magnetic proton recoil instrument were complemented by novel data from a set of synthetic diamond detectors, which enabled studies of the supra-thermal contributions to the neutron emission. In the area of escaping fast ion diagnostics, a lost fast ion detector and a set of Faraday cups made it possible to determine information on the velocity space and poloidal distribution of the lost alpha particles for the first time. This extensive set of data provides unique information for fundamental physics studies and validation of the numerical models, which are key to inform the physics and scenarios of ITER.
Solvent effects on the rheology of fuel cell catalyst ink and the adsorption of ionomers on the particles
Authors: Guo Yuqing , Yang Daozeng , Tang Haifeng , Li Bing , Yang Daijun , Ming Pingwen , Zhang Cunman
Published: September 2022

The solvent affects the morphology of ionomers, agglomeration structure, adsorption of ionomers on carbon or catalyst particles, and rheology in the proton exchange membrane fuel cell (PEMFC) ink, which are all related to the microstructure of catalyst inks. We investigated the link between the morphology of the ionomers or the fractal dimension (df) of graphitized carbon (GC) dispersion and the microstructure of the catalyst ink by solvent to change the morphology of the ionomers or df of GC dispersion. The nuclear magnetic resonance results showed relatively low mobility of the ionomer in ethylene glycol (EG), resulting in a weak interaction between the ionomer and EG. GC in water, EG, and n-propanol (nPA) form transition gels with a network structure by a diffusion-limited aggregation mechanism, with df of 1.76 ± 0.03, 1.95 ± 0.04, and 2.01 ± 0.06, respectively. Moreover, the addition of ionomers reduces the viscosity of inks due to the introduction of steric hindrance and an increase in electrostatic repulsion, transforming the ink from shear-thinning to Newtonian fluids. Further, the interaction between ionomer and particles in GC and graphitized-carbon-supported platinum (Pt/GC) inks is solvent-dependent, and nPA is more favorable than water and EG for ionomer adsorption on GC. These findings provide valuable insight into the internal interactions and microstructure of PEMFC catalyst inks.
ν = 0 quantum Hall state in a cadmium arsenide thin film
Authors: Guo Binghao , Lygo Alexander C. , Dai Xi , Stemmer Susanne
Published: September 2022

Graphene and topological insulators can feature a unique quantum Hall state with a filling factor of ν = 0 that supplies a wealth of information about the nature of the underlying electronic states. Here, we report on the observation of a ν = 0 Hall state in magnetotransport experiments on a 20-nm-thin, (001)-oriented cadmium arsenide film that is tuned by a gate voltage. While cadmium arsenide is a topological semimetal as a bulk material, thin films can host topological insulator phases. At high magnetic fields, we observe a highly resistive ν = 0 Hall state that we attribute to a widening gap between two zeroth Landau levels as the magnetic field is increased. We discuss possible scenarios that could give rise to the lifting of the degeneracy of zeroth Landau levels. Our results are most consistent with a scenario of hybridization of the topological surface states induced by quantum confinement.
Measurement and simulation of small cryogenic neon pellet Ne-I 640 nm photon efficiency during ablation in DIII-D plasma
Authors: Hollmann E. M. , Naitlho N. , Yuan S. , Samulyak R. , Parks P. , Shiraki D. , Herfindal J. , Marini C.
Published: September 2022

Small (∼1 mm) neon pellet fragments are fired into DIII-D H-mode plasmas, and resulting trajectory-averaged photon efficiencies (neutral neon ionization events for every photon emitted) of S/XB≈85 are estimated for Ne-I 640 nm by dividing the estimated initial pellet fragment mass by the measured number of emitted Ne-I photons. The experiments are modeled by running the Lagrangian particle (LP) fluid/magneto-hydrodynamic pellet code to estimate axial ablation plume neon density profiles and temperature profiles at each pellet position. These solutions are then fed into the PrismSPECT collisional-radiative code, which calculates resulting neon charge states and photon emission rates, giving a profile-average of S/XB≈109. The burnthrough plasma minor radius predicted by LP (ρ≈0.63) is reasonably close to the experimental observation ρ≈0.6. The modeling indicates that local S/XB is not constant along the pellet trajectory but tends to increase with increasing ablation rate. Non-equilibrium kinetics are predicted to be very important, while line trapping is predicted to be relatively unimportant (for Ne-I 640 nm S/XB).
Shear-layer dynamics at the interface of parallel Couette flows
Authors: Kalluri Manohar Teja , Narasimhamurthy Vagesh D.
Published: September 2022

This article aims to make a detailed analysis of co-flowing plane Couette flows. Particularly, the variation of flow quantities from the turbulent to non-turbulent region is studied. While the enstrophy exhibits a sharp jump, the other quantities (e.g., mean velocity, Reynolds normal stress, and kinetic energy) show a continuous variation across the interface. The budget analysis of Reynolds normal stresses reveals that the terms playing a key role in turbulence transportation vary depending on the Reynolds normal stress under study. The terms production, diffusion, and redistribution play an important role in streamwise Reynolds stress (u′u′¯). In the spanwise Reynolds stress (v′v′¯), the diffusion terms play a significant role. In the wall-normal Reynolds stress (w′w′¯), only the redistribution term is significant. The influence of one flow over another in the co-flow state was observed through the additional mean velocity and Reynolds normal stress found in the system compared to a standard plane Couette flow (pCf). Comparing the co-flow system with a conventional pCf system, the former exhibits greater vorticity, vortex stretching, and kinetic energy. A detailed analysis on the geometry and topology of flow structures was studied using flow invariants.
A compact coaxial relativistic klystron amplifier with three cascaded single-gap bunching cavities for efficient output
Authors: Yang Fuxiang , Dang Fangchao , Ge Xingjun , He Juntao , Ju Jinchuan , Zhang Xiaoping
Published: September 2022

A compact coaxial relativistic klystron amplifier (RKA) with three cascaded bunching cavities is investigated to obtain high efficiency output in this paper. When the injection power and drift tube length are both decreased for the compactness of the initial coaxial RKA, the conversion efficiency of this device decreases to only 20%, which is mainly due to the insufficient modulation of intense relativistic electron beam (IREB). To solve this issue, three cascaded bunching cavities are designed to strengthen the modulation of IREB, and each bunching cavity is designed to a non-uniform single-gap cavity with a high external quality factor. Moreover, a specific drift tube length is chosen for minimizing the TEM mode leakage between every two adjacent cavities. With these methods, the self-oscillation between input and three cascaded bunching cavities can be successfully suppressed without loading any reflectors. The proposed three cascaded single-gap bunching cavities are further examined in a Ku-band coaxial RKA, and the output efficiency of this device increases to 44%, which is more than twice that of the initial coaxial RKA. Furthermore, the injection power and axial length of the propagating IREB in the improved coaxial RKA are reduced to only 5 kW and 10 wavelengths, respectively.
Experimental base flow modification on a swept wing using plasma forcing
Authors: Peng K. , Arkesteijn J. P. W. , Avallone F. , Kotsonis M.
Published: September 2022

This work experimentally investigates plasma actuator (PA) forcing effects on the base flow and developing crossflow (CF) instabilities in a swept wing boundary layer. Spanwise-invariant plasma forcing near the leading edge is configured according to the base flow modification (BFM) strategy. A simplified predictive model is constructed by coupling an experimentally derived plasma body force and a linear stability theory and is used to infer the stability characteristics of the boundary layer subject to BFM. The base flow velocity is measured by stereo particle image velocimetry (PIV) at various PA operating conditions. Similarly, the developing CF instabilities, triggered through discrete roughness elements, are quantified by planar-PIV. The results demonstrate that a PA can reduce the boundary layer CF component, whereas the control authority shows a high dependence on the momentum coefficient. The dissimilar reduction between the streamline-aligned velocity and CF component leads to a local re-orientation of the base flow. Spanwise spectral analysis of the time-averaged flow indicates that stationary CF instabilities can be favorably manipulated whereas the BFM reduction effects depend on the corresponding initial amplitudes of stationary instabilities. An evident spanwise shift in the trajectory of stationary CF vortices is observed, which appears to result from the local alteration of the boundary layer stability due to the PA forcing. Despite the overall reduction in the amplitude of stationary CF instabilities, unsteady disturbances are found to be enhanced by the PA forcing. The current results shed light on the underlying principles of BFM-based PA operation in the context of laminar flow control.
Dynamic analysis for the thresher of a combined harvester subjected to stalk winding
Authors: Wang Guangding , Wang Xiaole , Yuan Huiqun
Published: September 2022

In this paper, the whirl characteristics and instability of the thresher in a combined harvester subjected to stalk winding are investigated. Using the spinning Timoshenko beam assumptions, the governing equations of motion for the thresher-stalk system are obtained via Hamilton’s principle. Considering the elastic end supports, the exact and approximated dimensionless whirl frequency equations are derived. On the basis of the obtained formulas, both whirl characteristics and stability of the thresher-stalk system are investigated numerically, and the validation of the present analysis is conducted by comparing with the results available in the literature. In addition, the effects of mode number, mass ratio, eccentric distance, shear deformation, and slenderness ratio on the critical spinning speed, stability, and instability boundary are deeply discussed. The results show that the whirl characteristics and stability of the thresher-stalk system are strongly dependent on the stalks wound around the thresher.
Socio-ecological gap analysis to forecast species range contractions for conservation
Authors: Harris Nyeema C. , Murphy Asia , Green Aalayna R. , Gámez Siria , Mwamidi Daniel M. , Nunez-Mir Gabriela C.
Published: September 2022

Conservation requires both a needs assessment and prioritization scheme for planning and implementation. Range maps are critical for understanding and conserving biodiversity, but current range maps often omit content, negating important metrics of variation in populations and places. Here, we integrate a myriad of conditions that are spatially explicit across distributions of carnivores to identify gaps in capacity necessary for their conservation. Expanding on traditional gap analyses that focus almost exclusively on quantifying discordance in protected area coverage across a species’ range, our work aggregates threat layers (e.g., drought, human pressures) with resources layers (e.g., protected areas, cultural diversity) to identify gaps in available conservation capacity (ACC) across ranges for 91 African carnivores. Our model indicated that all species have some portion of their range at risk of contraction, with an average of 15 percentage range loss. We found that the ACC differed based on body size and taxonomy. Results deviated from current perceptions of extinction risks for species with an International Union for Conservation of Nature (IUCN) threat status of Least Concern and yielded insights for species categorized as Data Deficient. Our socio-ecological gap analysis presents a geospatial approach to inform decision-making and resource allocation in conservation. Ultimately, our work advances forecasting dynamics of species’ ranges that are increasingly vital in an era of great socio-ecological change to mitigate human–wildlife conflict and promote inclusive carnivore conservation across geographies.
Plurilingual practice in language teacher education
Authors: Potts Diane , Cutrim Schmid Euline
Published: September 2022

Despite decades of research supporting the pedagogic value of learners’ plurilingual resources to their linguistic and academic development, pre-service teachers frequently arrive at university inculcated in ‘target language only’ practices underpinned by monoglossic ideologies. The challenge for teacher education is to productively disrupt quotidian beliefs about language beliefs and prompt reconsideration of future classroom practices. Drawing on the work of the Douglas Fir Group (2016), this paper explores the identities, beliefs and values of two student-teachers as they emerged over the length of an innovative English-German pedagogic project on plurilingualism. The project involved German student-teachers developing a language portrait project for Grade 6 students; student-teachers using project data for undergraduate assignments; and English MA students interviewing young learners about their language portraits via videoconference. The videoconference provided young learners further opportunities to use their plurilingual resources and MA students with data for assignments on identity and investment. Working with DFG’s framework (2016), we examine the interplay of the meso- and macro-dimensions of the larger project’s design and the sometimes contradictory indexing of values and identities within and across activities. Analysis reveals that design choices sometimes unintentionally reinforced linguistic ideologies inconsistent with the project’s objectives, though these conflicts also led student-teachers to unexpected insights. We close with personal reflections on the implications of the first iteration of this design-based research project for the advancement of plurilingual pedagogies in teacher education.
Plurilingual and pluricultural competence
Authors: Strasser Margareta , Reissner Christina
Published: September 2022

Since the late 1990s the notion of a plurilingual and pluricultural competence as elaborated by Coste, Moore and Zarate (1997) has had a strong impact on the didactics of languages. Several plural approaches have been developed which aim at developing competences in several languages and/or cultures (Melo-Pfeifer & Reimann, 2018; Reissner, 2010; Tost Planet, 2010), with intercomprehension didactics being one of them. However, existing frameworks (e.g. the Cadre de référence pour les approches plurielles des langues et des cultures (CARAP)/Framework of reference for pluralistic approaches to languages and cultures (FREPA) (Candelier et al., 2007, 2010), or the Companion volume of the Common European framework of reference for languages (Council of Europe, 2018)) do not adequately describe the specific competences that underly intercomprehensive activities. In our contribution, we will present the framework of reference for intercomprehension (= IC) developed within the European project EVAL-IC (Evaluation des compétences en intercompréhension, Erasmus+). The framework is based on a dynamic and complex competence model, comprising of six levels of competence which can be regrouped into three larger levels (basic, advanced, expert). It provides descriptors for the following intercomprehensive activities: written and oral receptive IC; written and oral interproduction; and written and oral interactive IC as well as a global description of each level. The work carried out might also help to apply or further develop plurilingual and pluricultural approaches in higher education.
Exploring bilingual teaching and learning in a Jewish-Palestinian language café
Authors: Haim Orly , Kedar Yarden
Published: September 2022

The context of this exploratory study is aLanguage Café, a bottom-up initiative in which Jews and Palestinians, residing in the same multilingual neighborhood in Jerusalem, learn Hebrew and Arabic from each other. The study explores the features of the bilingual pedagogy which has evolved in theLanguage Caféand the participants’ perceived teaching and learning experiences. A qualitative research design was applied utilizing several data sources: (a) observations and field notes (b) language learning materials; (c) semi-structured interviews with the project leaders; (d) interviews with the Jewish and Palestinian participants and (e) photos posted on social media. Inductively oriented content analyses revealed a number of themes suggesting that the bilingual pedagogy applied in theLanguage Caféis based on principles ofequality, equity, andbidirectional respectwith regard to the participants’ plurilingual/pluricultural repertoires. The learning process is primarily learner-centered, with a continuousengagementof the participants in interactional activities. Yet, given the unique geopolitical situation, conflictual issues surface. The analyses further reveal that the language learning experience in this context is conducive to the participants’ language and cultural knowledge and to their engagement with the Other group. The participants’ accounts suggest that theLanguage Cafésessions have reduced prejudices and feelings of fear and tension between the two groups. Indeed, theLanguage Caféis perceived as part of the broader geopolitical endeavor to reconfigure the neighborhood within the local municipal binational context where language is used as a means to foster identity affirmation and sociocultural connectivity.
The lectin Discoidin I acts in the cytoplasm to help assemble the contractile machinery
Authors: Nguyen Ly T.S. , Robinson Douglas N.
Published: September 2022

Cellular functions, such as division and migration, require cells to undergo robust shape changes. Through their contractility machinery, cells also sense, respond, and adapt to their physical surroundings. In the cytoplasm, the contractility machinery organizes into higher order assemblies termed contractility kits (CKs). Using Dictyostelium discoideum, we previously identified Discoidin I (DscI), a classic secreted lectin, as a CK component through its physical interactions with the actin crosslinker Cortexillin I (CortI) and the scaffolding protein IQGAP2. Here, we find that DscI ensures robust cytokinesis through regulating intracellular components of the contractile machinery. Specifically, DscI is necessary for normal cytokinesis, cortical tension, membrane–cortex connections, and cortical distribution and mechanoresponsiveness of CortI. The dscI deletion mutants also have complex genetic epistatic relationships with CK components, acting as a genetic suppressor of cortI and iqgap1, but as an enhancer of iqgap2. This work underscores the fact that proteins like DiscI contribute in diverse ways to the activities necessary for optimal cell function.
CaV1.2 channelopathic mutations evoke diverse pathophysiological mechanisms
Authors: Bamgboye Moradeke A. , Herold Kevin G. , Vieira Daiana C.O. , Traficante Maria K. , Rogers Philippa J. , Ben-Johny Manu , Dick Ivy E.
Published: September 2022

The first pathogenic mutation in CaV1.2 was identified in 2004 and was shown to cause a severe multisystem disorder known as Timothy syndrome (TS). The mutation was localized to the distal S6 region of the channel, a region known to play a major role in channel activation. TS patients suffer from life-threatening cardiac symptoms as well as significant neurodevelopmental deficits, including autism spectrum disorder (ASD). Since this discovery, the number and variety of mutations identified in CaV1.2 have grown tremendously, and the distal S6 regions remain a frequent locus for many of these mutations. While the majority of patients harboring these mutations exhibit cardiac symptoms that can be well explained by known pathogenic mechanisms, the same cannot be said for the ASD or neurodevelopmental phenotypes seen in some patients, indicating a gap in our understanding of the pathogenesis of CaV1.2 channelopathies. Here, we use whole-cell patch clamp, quantitative Ca2+ imaging, and single channel recordings to expand the known mechanisms underlying the pathogenesis of CaV1.2 channelopathies. Specifically, we find that mutations within the S6 region can exert independent and separable effects on activation, voltage-dependent inactivation (VDI), and Ca2+-dependent inactivation (CDI). Moreover, the mechanisms underlying the CDI effects of these mutations are varied and include altered channel opening and possible disruption of CDI transduction. Overall, these results provide a structure–function framework to conceptualize the role of S6 mutations in pathophysiology and offer insight into the biophysical defects associated with distinct clinical manifestations.
Measuring Charge Distribution of Molecular Cations by an Atomic Coulomb Probe Microscope
Authors: Yu Xitao , Hu Xiaoqing , Zhou Jiaqi , Zhang Xinyu , Zhao Xinning , Jia Shaokui , Xue Xiaorui , Ren Dianxiang , Li Xiaokai , Wu Yong , Ren Xueguang , Luo Sizuo , Ding Dajun
Published: September 2022

Imaging the charge distributions and structures of molecules and clusters will promote the understanding of the dynamics of the quantum system. Here, we report a method by using an Ar atom as a tip to probe the charge distributions of benzene (Bz) cations in gas phase. Remarkably, the measured charge distributions of Bz+ (δ
H = 0.204, δ
C = −0.037) and Bz2+ (δ
H = 0.248, δ
C = 0.0853) agree well with the calculated Mulliken distributions, and the structures of Bz2 is reconstructed by using the measured charge distributions. The structures of two Bz2 isomers (T-shaped and PD isomers) can be resolved from the measured inter-molecular potential V(R) between two Bz ions, and the structures of Bz dimer agree well with the theoretical predictions.
Influence of plasma density on the cross sections of radiative recombination to configuration-averaged excited nitrogen and oxygen atoms and ions
Authors: Ribière Maxime
Published: September 2022

Radiative recombination cross sections of all the charge states of nitrogen and oxygen ions are calculated in the central field and Hartree–Fock–Slater approximations. The recombining ions are considered on their ground states, to form recombined ions on different configuration-averaged excited states. The ion potential energies are calculated assuming electro-neutrality in a Wigner–Seitz cell containing bound and free electrons, and the effect of plasma density on the cross sections is investigated by varying the cell radius. When the plasma density increases up to 1020 cm−3, the bound and free wave functions are distorted which significantly impact the cross sections. These deviations from the free atom case are all the more significant as the ion charge state of the recombining ion is low and as the excitation energy of the recombined ion is high. Also, calculations of the radiative recombination rates allow for quantifying the impact of plasma density at different temperatures. It is shown, for temperatures greater than 1 (Ry), that the rates at low and high plasma densities are closed. Nevertheless, for temperatures lighter than 1 (Ry) the influence of plasma density on the rates is significant. In addition, transition probabilities between the bound levels of all the charge states of N and O are calculated, and the influence of plasma density on these probabilities is analyzed. These cross sections and rates may be used as entrance parameters in collisional-radiative models for fully ionized plasma simulations in the framework of studies concerning for example, switches in Marx generator and laser-induced plasmas in air.
Fault diagnosis of planetary gears based on intrinsic feature extraction and deep transfer learning
Authors: Li Huan , Lv Yong , Yuan Rui , Dang Zhang , Cai Zhixin , An Bingnan
Published: September 2022

The planetary gearbox is a key transmission apparatus used to change speed and torque. The planetary gear is one of the most failure-prone components in a planetary gearbox. Due to the complexity of working environments, collected vibration signals contain a lot of noise and interference; fault characteristic frequencies are usually submerged or even lost. Thus, feature extraction from the vibration signal is beneficial to subsequent fault diagnosis. As a fault identification approach that has been increasingly popular in the field of fault diagnosis, deep learning requires a large number of samples to train the model. Insufficient samples lead to low diagnostic accuracy for deep learning models. This paper proposes a novel fault diagnosis approach for planetary gears based on intrinsic feature extraction and deep transfer learning. The original vibration signals are decomposed into a series of band-limited intrinsic mode functions (BLIMFs) by variational mode decomposition. BLIMF with the most apparent fault characteristics is selected to generate two-dimensional time-frequency maps by continuous wavelet transform. The preprocessed time-frequency maps are adopted as the input of the pretrained VGG16 model. The bottom layers are frozen, and the top layers are fine-tuned to achieve fault diagnosis for planetary gears. Applications to planetary gear datasets verify the superiority of the proposed method.
Fabrication of magnetic helical microribbons made of nickel thin films sandwiched between silicon nitride layers for microswimming applications
Authors: Shojaeian Milad , Caldag Hakan Osman , Bozkurt Ayhan , Yesilyurt Serhat
Published: September 2022

Helical swimming is adopted by microswimming robots since it is an efficient mechanism and commonly observed among microorganisms swimming at low Reynolds numbers. However, manufacturing of micro-helices made of sub-micron magnetic thin layers is neither straightforward nor well-established, advanced materials and methods are necessary to obtain such structures as reported in the literature. In this paper, a topological patterning method utilizing basic microfabrication methods is presented for the self-assembly of magnetic micro-helices made of a sandwiched nickel thin film (50–150 nm) between two silicon nitride layers. Strain mismatch between the thin films and the geometric anisotropy introduced by the slanted patterns on the top nitride layer result in self-rolled-up helical microribbons. Moreover, inspired by the actual release process during the wet-etching of the microribbon from the substrate, moving boundary conditions are incorporated in a numerical model to simulate the self-rolling of trilayer ribbons. The simulation results are compared and validated by experimental data within 7% error for all cases, including the geometries that do not result in a helical shape. The swimming performance of the magnetized micro-helix is demonstrated inside a capillary glass tube experimentally and cross-validated with a numerical model.
Two-stage superconductivity in the Hatsugai–Kohomoto-BCS model
Authors: Li Yu , Mishra Vivek , Zhou Yi , Zhang Fu-Chun
Published: September 2022

Superconductivity in strongly correlated electrons can emerge out from a normal state that is beyond the Landau’s Fermi liquid paradigm, often dubbed as ‘non-Fermi liquid’. While the theory for non-Fermi liquid is still not yet conclusive, a recent study on the exactly-solvable Hatsugai–Kohomoto (HK) model has suggested a non-Fermi liquid ground state whose Green’s function resembles the Yang–Rice–Zhang ansatz for cuprates (2020 Phillips et al Nat. Phys.
16 1175). Similar to the effect of on-site Coulomb repulsion in the Hubbard model, the repulsive interaction in the HK model divides the momentum space into three parts: empty, single-occupied and double-occupied regions, that are separated from each other by two distinct Fermi surfaces. In the presence of an additional Bardeen–Cooper–Schrieffer-type pairing interaction of a moderate strength, we show that the system exhibits a ‘two-stage superconductivity’ feature as temperature decreases: a first-order superconducting transition occurs at a temperature T
c that is followed by a sudden increase of the superconducting order parameter at a lower temperature

T

c

′

<

T

c

. At the first stage,

T

c

′

<
T
<

T

c

, the pairing function arises and the entropy is released only in the vicinity of the two Fermi surfaces; while at the second stage,

T
<

T

c

′

, the pairing function becomes significant and the entropy is further released in deep (single-occupied) region in the Fermi sea. The phase transitions are analyzed within the Ginzburg–Landau theory. Our work sheds new light on unconventional superconductivity in strongly correlated electrons.
Electronic viscous boundary layer in gated graphene
Authors: Cosme P , Santos J S , Terças H
Published: September 2022

We investigate the boundary layer problem in viscous electronic flows in gated graphene. Recent experiments on graphene hydrodynamics indicate the emergence of non-Poiseuille behavior, a feature that we reproduce with direct numerical simulations of gated graphene electrons. In fact, the velocity profile displays a maximum value close to the boundary and then decreases as it approaches the bulk. By taking into account the compressibility of the electron fluid, that arises from the dependence of effective hydrodynamic mass on the number density, we derive a generalized Blasius equation governing the transverse velocity profile, in excellent agreement with the simulation results. Evidence of a non-monotonic profile and further deviations with respect to incompressible (classical) hydrodynamics may shed some light on the subject of non-topological edge currents in graphene.
Assessing HD-EEG functional connectivity states using a human brain computational model
Authors: Tabbal Judie , Kabbara Aya , Yochum Maxime , Khalil Mohamad , Hassan Mahmoud , Benquet Pascal
Published: September 2022

Objective. Electro/Magnetoencephalography (EEG/MEG) source-space network analysis is increasingly recognized as a powerful tool for tracking fast electrophysiological brain dynamics. However, an objective and quantitative evaluation of pipeline steps is challenging due to the lack of realistic ‘controlled’ data. Here, our aim is two-folded: (a) provide a quantitative assessment of the advantages and limitations of the analyzed techniques and (b) introduce (and share) a complete framework that can be used to optimize the entire pipeline of EEG/MEG source connectivity. Approach. We used a human brain computational model containing both physiologically based cellular GABAergic and Glutamatergic circuits coupled through Diffusion Tensor Imaging, to generate high-density EEG recordings. We designed a scenario of successive gamma-band oscillations in distinct cortical areas to emulate a virtual picture-naming task. We identified fast time-varying network states and quantified the performance of the key steps involved in the pipeline: (a) inverse models to reconstruct cortical-level sources, (b) functional connectivity measures to compute statistical interdependency between regional signals, and (c) dimensionality reduction methods to derive dominant brain network states (BNS). Main results. Using a systematic evaluation of the different decomposition techniques, results show significant variability among tested algorithms in terms of spatial and temporal accuracy. We outlined the spatial precision, the temporal sensitivity, and the global accuracy of the extracted BNS relative to each method. Our findings suggest a good performance of weighted minimum norm estimate/ Phase Locking Value combination to elucidate the appropriate functional networks and ICA techniques to derive relevant dynamic BNS. Significance. We suggest using such brain models to go further in the evaluation of the different steps and parameters involved in the EEG/MEG source-space network analysis. This can reduce the empirical selection of inverse model, connectivity measure, and dimensionality reduction method as some of the methods can have a considerable impact on the results and interpretation.
Quantification and characterization of household waste in Dumai Timur District, Dumai City, Riau, Indonesia as a measure towards circular economy.
Authors: Hidayat Fauzan , Martono Dwi Nowo , Hamzah Udi Syahnoedi
Published: September 2022

Dumai City, located in Riau Province is the second largest city in Indonesia and is also currently facing problems with solid waste management as the population continues to grow. Dumai Timur District is the most populated district in Dumai City with 68.980 people. The Municipal Solid Waste (MSW) in Dumai Timur District- particularly the plastic waste, paper, and metal; is expected to have some economic potential if seen from the Circular Economy (CE) perspective. Therefore, this study is conducted to quantify and characterize the MSW generated in Dumai Timur District and to analyze the economic potential of inorganic solid waste. The number of solid waste sample was determined by SNI-19-3964-1994 method and carried out using simple random sampling. The results showed that the estimated total household waste generated in Dumai Timur District is 7.772.735,76 kg/year or approximately 0,31 kg/person/day waste generated on average. The three largest waste composition consisted of organic waste, plastic and paper that represents 68,02%; 12,26%; and 8,08 respectively. The economic potential value was estimated up to Rp 871.605.708,42.5.
Ethanol to high-octane hydrocarbons using HZSM-5 as catalyst
Authors: Taco-Vasquez Sebastian , Salinas Miguel , Murillo Herman , Oñate William
Published: September 2022

Dehydration and oligomerization of ethanol to hydrocarbons was studied using a packed-bed reactor over HZSM-5 (SiO2/Al2O3=280 mol/mol) zeolite as catalyst. Nine experiments were performed at different temperature and weight hourly space velocity (WHSV) conditions. The experiments were conducted in three levels for both variables (T: 300, 350, and 410 °C) and (WHSV: 1.3, 3.7, and 7.9 h–1). For all the experiments, ethanol was dehydrated to ethylene; however, oligomerization only occurred at WHSV=1.3 h-1, where the yields to liquid hydrocarbons were 15, 25, and 10% at 300, 350, and 410 °C, respectively. The liquid hydrocarbon products were analyzed by copper metal corrosion, gum content, octane number, Reid vapor pressure, gas chromatography, and fractional distillation. The octane number was about 95 in all cases, higher than Ecuador premium gasoline octane number (92). These laboratory-scale findings provide good insights on the ethanol-to-gasoline approach that could be scaled up to the industry.
Heat transfer optimization in a horizontal helical-shaped ground heat exchanger through response surface methodology
Authors: Malacas J D , Certeza L V R , Alfonso B A , Clerigo M H , Tiangco G A , Valencia C P
Published: September 2022

Various combinations of objective functions and design variables have been considered in several optimization studies of ground heat exchangers (GHEs). In this study, the optimum values of the coil pitch and coil diameter of a helical-shaped GHE were determined to maximize its convection heat transfer rate. Central composite design was used to determine the coil pitch and coil diameter dimensions to be used in GHE modeling. Nine models were generated in Fusion360 which were then exported to ANSYS Fluent for CFD simulation. Then, a second-order model of the convective heat transfer rate per unit length as a function of the coil pitch and coil diameter was generated using the response surface methodology. For the design space considered (coil pitch: 600 to 1200 mm; coil diameter: 600 to 1200mm), the highest heat transfer rate was achieved at a coil diameter of 600mm and at a coil pitch of 1200mm. Furthermore, this study showed that if both the coil pitch and coil diameter are considered simultaneously in the optimization of the heat transfer rate of a helical-shaped GHE, then coil pitch would have a directly proportional relationship with the heat transfer rate, while coil diameter would have an inversely proportional relationship.
Strengthening the biogas sector of Ethiopia through international collaboration: the case of the Digital Global Biogas Cooperation (DiBiCoo)
Authors: Bogale Wondwossen , Misikir Maya F. , Sewnet Bruck , van Laere Ann-Kathrin , Sagala Saut , Ma Chuan , Hilbert Jorge Antonio , Mohammed Mutala , Salie Yaseen
Published: September 2022

Even though biogas technology was introduced in Ethiopia in 1957, the technology is still in its infancy stage with more than 98 % of biogas plants installed in Ethiopia at a small- scale level and used for cooking and lighting applications. The Digital Global Biogas Cooperation (DiBiCoo) project facilitates collaboration between European biogas industries and stakeholders from emerging and developing markets through the development and application of innovative digital and non-digital support tools, knowledge transfer and capacity building. The Digital Global Biogas Cooperation helped the Ethiopian biogas sector through capacity building trainings, creating a digital biogas and gasification matchmaking platform to link companies with local biogas actors in the country, and assisting demo case projects up to prefeasibility study stage. Furthermore, it provided practical exposure through virtual and in person biogas plant tour in several countries, and generating several documents related to the Ethiopian biogas sector including an assessment on biogas potential, financial options and a legal frame work to assist the sector. Based on this collaboration, more than 30 stakeholders participated in 11 web seminars, 2 capacity-building trainings, 3 days business model development training in Biogas and more than 10 virtual study tours. One demo case and three- follower cases prefeasibility studies were supported. Thus, the Digital Global Biogas Cooperation is providing much needed support to the biogas sector of Ethiopia.
Lateral gap analysis for Heterogeneous traffic
Authors: Siddharth Chogule  , Kanimozhee S , Madhu K A
Published: September 2022

Indian traffic mainly composes of heterogeneous traffic with minimum or no lane discipline, due to this there are various vehicular interactions in the traffic stream. Lateral gap is the lateral distance between two vehicles flowing in the traffic stream. In this paper an attempt is made to analyse the safe gap maintained by the various category of vehicles with respect to their traffic characteristics and how the road width is affected by area occupancy. Methodology for collection of microscopic data is elaborated. Variation in lateral gap is observed due to the speed of adjacent moving vehicles, road width, and composition of vehicle. The relation between flow and area occupancy determines the utilisation of road width on the selected stretch.
Application of BIM for Effective Construction Safety Management in High Rise Buildings
Authors: Swaroop Devaiah K. L. , Keshav Vasanth
Published: September 2022

The construction industry has a higher occupational casualty rate than other industries. As a proactive approach to safety management, a good safety management system (SMS) can go a long way to help prevent accidents and occupational hazards. This work proposes the use of BIM 3D with the help of Autodesk Revit for the identification of hazards and risks at the designing stages and for implication and planning of effective safety measures. This is carried out from the inception of the project itself which later can be applied to the construction process based on efficient SMS. The SMS established is based on surveys conducted on 45 personnel in the construction industry. The top 5 important issues found to be associated with site safety were: Exposed Rebars; Laboures and Visitors without ID; CCTV monitoring of site; Signs not secured properly; Access to Fire Engine and personnel in case of fire break out.
Experimental Investigation on Mechanical Behavior of AAC Block Masonry
Authors: Raj Pruthvi , Ravula Mehar Babu
Published: September 2022

Autoclaved Aerated Concrete (AAC) flyash Blocks are light weight bricks, which is rapidly used in high rise buildings. The AAC Blocks are one of the sustainable materials manufactured using industrial waste flyash. The masonry infills made with AAC blocks contribute to light weight of structure, thermal conductivity and faster construction. The AAC block masonry needs to be studied at material level to improve its efficiency. The material level understanding of the behavior of AAC block masonry is lacking in the literatures. In this paper, Experimental investigation is presented to understand the compressive stress-strain behavior of AAC Block masonry and its constituents. The response of AAC block masonry with weak and strong mortar is obtained from compression test.
An Experimental Investigation on Characteristic Properties of Hybrid Fibrous Ferro Cement
Authors: Chandrashekar A R , Praveen Kannam
Published: September 2022

Ferro-Cement is a notably new material such as cord meshes and cement mortar. This fabric turned into developed via P L Nervi, an Italian architect and engineer, in1940. He revived the idea of Ferro-Cement and used it for building fishing boats. Ferro-Cement is skinny and light weight cement composite, with numerous specific houses. The inclusion of fibers to the concrete can amplify the energy homes of the blended and transfigure the frangible cement blended into more consistent and malleable fabric known as FRC. Yet the both substances consists few draw backs. Both the substances unable to be waged where unreasonable tremble, unreasonable bending intensity and excessive effect are to be endured. Accordingly the answer lies within the new compound known as fibrous Ferro-Cement, that's the mixture of fibber bolstered concrete and fibrocement. This new composite has some stepped forward mechanical homes, inclusive of sturdiness, impact resistance and so on. Addition of a couple of kind of fibers to the composite improves the energy houses to even greater quantity. However the inclusion of multiple kind of fiber in to the fibrous Ferro-Cement steers to hybrid fibrous Ferro-Cement, which is having more power, homes than the mono fibrous Ferro-Cement.
Superior dielectric properties of epoxy-based photoresist thin film nanocomposites with carbon-coated Cu@C nanoparticles
Authors: Lapeyronie C , Alfonso M S , Viala B , Tortai J-H
Published: September 2022

The microelectronics community has shown great interest for high-k percolative nanodielectric materials for their applications as integrated capacitors. This work highlights the manufacturing process of high-quality Metal Polymer Nanocomposites (MPCs) thin dielectric films with Cu@C nanoparticles into SU8™ negative photolithographic resist. Four capacitor formulations from 0.8%vol up to 3.0%vol of Cu@C functionalized with an insulating layer of Polystyrene Pyrene-terminated (PyrPS) were produced. These films, with a targeted thickness of 15 μm, were spin-coated onto p-doped silicon wafers. Raman spectroscopy demonstrated the nature of the carbon shell of the nanoparticles and its effectiveness in protecting the core from oxidation, while SEM-EDS highlighted the uniformity of the nanoparticle distribution in the resist. Broadband dielectric spectroscopy measured an enhancement of

ε

r

to 124 with reasonable losses of 0.65 at 5 kHz for the (Cu@C)-PyrPS//SU8 3.0%vol nanocomposite. Through the use of Percolation Theory (PT) it was estimated the percolation threshold

φ

C

in the vicinity of 3.2%vol. Furthermore, no electrical aging or dielectric breakdown was detected at low voltage. All the results show the potential use of Cu@C nanoparticles to achieve a high-quality high-k MPC photoresists for the implementation as integrated capacitors.