bluuebunny/crossref_metadata_2025 huggingface dataset:
No-tillage promotes C accumulation in soil and a slight increase in yield stability and profitability of rice in subtropical lowland ecosystems
Authors: Carlos Filipe Selau , Camargo Flávio A. O. , Marcolin Elio , Veloso Murilo G. , Schimitt Fernandes Rodrigo , Bayer Cimélio
Published: June 2022

Context The effects of no-tillage (NT) on soil organic C (SOC) and rice yield in lowland soils are poorly understood in subtropical ecosystems. Aims In a long-term (24 years) field experiment, we assessed the effect of NT on SOC stocks in labile (>53 μm, particulate) and stable (<53 μm, mineral associated) fractions of soil organic matter (SOM), grain yield, between-season stability, and gross margin compared to conventional tillage (CT) and pre-germinated tillage (PG) systems in a lowland Gleysol in southern Brazil. Methods Soil from eight different layers down to 40 cm under each tillage system was sampled in a field experiment, and additional soil samples were obtained from an adjacent area under native grassland (NG) as reference for SOC stocks. Key results While the PG and CT systems maintained similar SOC stocks as the NG soil, NT increased SOC stocks at an annual rate of 0.41 Mg ha−1 in relation to the traditional CT soil. Rice grain yield increased twice over the 24-year period, amounting to 12 Mg ha−1 in the last crop season. Despite lower yield in NT system in most crop seasons, a slight effect on yield stability and profitability (<10%) in favour of NT, compared with CT and PG systems, was observed. Conclusions Based on our findings, NT promotes C accumulation in subtropical paddy rice soils. Implications There is a beneficial effect of NT on rice yield stability and profitability in the long term.
Metatranscriptomics captures dynamic shifts in mycorrhizal coordination in boreal forests
Authors: Law Simon R. , Serrano Alonso R. , Daguerre Yohann , Sundh John , Schneider Andreas N. , Stangl Zsofia R. , Castro David , Grabherr Manfred , Näsholm Torgny , Street Nathaniel R. , Hurry Vaughan
Published: June 2022

Carbon storage and cycling in boreal forests—the largest terrestrial carbon store—is moderated by complex interactions between trees and soil microorganisms. However, existing methods limit our ability to predict how changes in environmental conditions will alter these associations and the essential ecosystem services they provide. To address this, we developed a metatranscriptomic approach to analyze the impact of nutrient enrichment on Norway spruce fine roots and the community structure, function, and tree–microbe coordination of over 350 root-associated fungal species. In response to altered nutrient status, host trees redefined their relationship with the fungal community by reducing sugar efflux carriers and enhancing defense processes. This resulted in a profound restructuring of the fungal community and a collapse in functional coordination between the tree and the dominant Basidiomycete species, and an increase in functional coordination with versatile Ascomycete species. As such, there was a functional shift in community dominance from Basidiomycetes species, with important roles in enzymatically cycling recalcitrant carbon, to Ascomycete species that have melanized cell walls that are highly resistant to degradation. These changes were accompanied by prominent shifts in transcriptional coordination between over 60 predicted fungal effectors, with more than 5,000 Norway spruce transcripts, providing mechanistic insight into the complex molecular dialogue coordinating host trees and their fungal partners. The host–microbe dynamics captured by this study functionally inform how these complex and sensitive biological relationships may mediate the carbon storage potential of boreal soils under changing nutrient conditions.
Self-consistent dispersal puts tight constraints on the spatiotemporal organization of species-rich metacommunities
Authors: Denk Jonas , Hallatschek Oskar
Published: June 2022

Biodiversity is often attributed to a dynamic equilibrium between the immigration and extinction of species. This equilibrium forms a common basis for studying ecosystem assembly from a static reservoir of migrants—the mainland. Yet, natural ecosystems often consist of many coupled communities (i.e., metacommunities), and migration occurs between these communities. The pool of migrants then depends on what is sustained in the ecosystem, which, in turn, depends on the dynamic migrant pool. This chicken-and-egg problem of survival and dispersal is poorly understood in communities of many competing species, except for the neutral case—the “unified neutral theory of biodiversity.” Employing spatiotemporal simulations and mean-field analyses, we show that self-consistent dispersal puts rather tight constraints on the dynamic migration–extinction equilibrium. When the number of species is large, species are pushed to the edge of their global extinction, even when competition is weak. As a consequence, the overall diversity is highly sensitive to perturbations in demographic parameters, including growth and dispersal rates. When dispersal is short range, the resulting spatiotemporal abundance patterns follow broad scale-free distributions that correspond to a directed percolation phase transition. The qualitative agreement of our results for short-range and long-range dispersal suggests that this self-organization process is a general property of species-rich metacommunities. Our study shows that self-sustaining metacommunities are highly sensitive to environmental change and provides insights into how biodiversity can be rescued and maintained.
Single-cell analyses highlight the proinflammatory contribution of C1q-high monocytes to Behçet’s disease
Authors: Zheng Wenjie , Wang Xiaoman , Liu Jinjing , Yu Xin , Li Lu , Wang Heping , Yu Jijun , Pei Xiaoya , Li Chaoran , Wang Zhimian , Zhang Menghao , Zeng Xiaofeng , Zhang Fengchun , Wang Chenfei , Chen Hua , Chen Hou-Zao
Published: June 2022

Behçet’s disease (BD) is a chronic vasculitis characterized by systemic immune aberrations. However, a comprehensive understanding of immune disturbances in BD and how they contribute to BD pathogenesis is lacking. Here, we performed single-cell and bulk RNA sequencing to profile peripheral blood mononuclear cells (PBMCs) and isolated monocytes from BD patients and healthy donors. We observed prominent expansion and transcriptional changes in monocytes in PBMCs from BD patients. Deciphering the monocyte heterogeneity revealed the accumulation of C1q-high (C1qhi) monocytes in BD. Pseudotime inference indicated that BD monocytes markedly shifted their differentiation toward inflammation-accompanied and C1qhimonocyte–ended trajectory. Further experiments showed that C1qhimonocytes enhanced phagocytosis and proinflammatory cytokine secretion, and multiplatform analyses revealed the significant clinical relevance of this subtype. Mechanistically, C1qhimonocytes were induced by activated interferon-γ (IFN-γ) signaling in BD patients and were decreased by tofacitinib treatment. Our study illustrates the BD immune landscape and the unrecognized contribution of C1qhimonocytes to BD hyperinflammation, showing their potential as therapeutic targets and clinical assessment indexes.
Diachronic developments in fricative + nasal sequences
Authors: Chirkova Katia , Handel Zev
Published: June 2022

Through comparison of regular sound correspondences in three closely related Tibeto-Burman (TB) languages, Ersu, Lizu, and Duoxu (collectively “ELD”), informed by external comparison with other TB languages and recent phonetic analyses of the production of voiceless nasals, we reconstruct *fricative-nasal sequences in their common ancestor, Proto-ELD.

In the development of these historic clusters, two pathways of change can be recognized. Their difference lies in the divergent relative phasing of velic and oral gestures in the original fricative-nasal sequences:

(i)

fricative weakening (from a tight cluster): *FN > N̥ > h̃ > x

(ii)

fricative strengthening (from a loose cluster): *F-n > *F-t > t > k or *F‑n > s

The different reflexes observed in Ersu, Lizu, and Duoxu represent different points along these two developmental pathways. These reconstructions and pathways of development have implications for our understanding of both universal (phonetic) and language-specific aspects of change in fricative-nasal sequences. The first pathway makes it possible to explore the process of nasal devoicing beyond voiceless nasals so as to enrich our understanding of nasal devoicing in natural languages. The co-existence of two opposite pathways of change, on the other hand, provides insights into the morphological and syllabic structure of words with contiguous fricative-nasal sequences in ELD languages at different points in time – insights that may be valuable in examining the history of other languages and language families beyond the ELD cluster.
Associations between physical activity, motor skills, executive functions and early numeracy in preschoolers
Authors: Vanhala Anssi , Haapala Eero A. , Sääkslahti Arja , Hakkarainen Airi , Widlund Anna , Aunio Pirjo
Published: June 2022

We investigated direct and indirect cross‐sectional associations of physical activity, fundamental motor skills, executive functions, and early numeracy in preschoolers. The participants were 214 preschoolers aged three to five years. Time spent in moderate and vigorous physical activity was measured by hip‐worn accelerometers and fundamental motor skills using the tasks assessing locomotor, object control, and stability skills. Inhibition/switching and working memory/updating, as components of executive functions, were assessed by computerised tests and a standardised test was used to assess early numeracy. Path analyses were used to examine direct and indirect associations between the constructs. Our results showed that stability skills were indirectly positively associated with early numeracy through inhibition/switching (β = 0.07, p < 0.05, 95% CI [0.02, 0.14]) and locomotor skills through working memory/updating (β = 0.13, p = 0.001, 95% CI [0.06, 0.20]). Vigorous physical activity was positively associated with early numeracy through locomotor skills and working memory/updating (β = 0.04, p = 0.01, 95% CI [0.01, 0.07]) and negatively associated with early numeracy through inhibition/switching (β = −0.06, p < 0.05, 95% CI [−0.11, −0.02]).
Generalized Aubry–André–Harper Models in Optical Superlattices
Authors: Li Yi , Zhang Jia-Hui , Mei Feng , Ma Jie , Xiao Liantuan , Jia Suotang
Published: June 2022

Ultracold atoms trapped in optical superlattices provide a simple platform for realizing the seminal Aubry–André–Harper (AAH) model. However, this model ignores the periodic modulations on the nearest-neighbor hoppings. We establish a generalized AAH model by which an optical superlattice system can be approximately described when V
1 ≫ V
2, with periodic modulations on both on-site energies and nearest-neighbor hoppings. This model supports much richer topological properties absent in the standard AAH model. Specifically, by calculating the Chern numbers and topological edge states, we show that the generalized AAH model possesses multifarious topological phases and topological phase transitions, unlike the standard AAH model supporting only a single topological phase. Our findings can uncover more opportunities for using optical superlattices to study topological and localization physics.
Microscopic Magnetic Origin of Rhombohedral Distortion in NiO
Authors: He Guangmeng , Zhang Huimin , Ni Jinyang , Liu Boyu , Xu Changsong , Xiang Hongjun
Published: June 2022

Numerous investigations have been conducted to explore the structural phase transition in antiferromagnetic 3d transition metal monoxides accompanied by appearance of magnetic phase transition. However, how the spins induce distortion in the high symmetric structure has not yet been fully understood. In this study, the monoxide NiO is used as an example to investigate what lowers the structural symmetry. By comparing two different magnetic structures, our results reveal that the spin–lattice coupling is responsible for such a structural distortion. Then, a spin–lattice model, including the strain component, is constructed to simulate the transition procedure. Moreover, the results from the first-principles calculations are used to compare with our model results. Both first-principles calculations and model simulations clarify the structural phase transition caused by a unique magnetic arrangement.
On Bayesian data assimilation for PDEs with ill-posed forward problems
Authors: Lanthaler S , Mishra S , Weber F
Published: June 2022

We study Bayesian data assimilation (filtering) for time-evolution Partial differential equations (PDEs), for which the underlying forward problem may be very unstable or ill-posed. Such PDEs, which include the Navier–Stokes equations of fluid dynamics, are characterized by a high sensitivity of solutions to perturbations of the initial data, a lack of rigorous global well-posedness results as well as possible non-convergence of numerical approximations. Under very mild and readily verifiable general hypotheses on the forward solution operator of such PDEs, we prove that the posterior measure expressing the solution of the Bayesian filtering problem is stable with respect to perturbations of the noisy measurements, and we provide quantitative estimates on the convergence of approximate Bayesian filtering distributions computed from numerical approximations. For the Navier–Stokes equations, our results imply uniform stability of the filtering problem even at arbitrarily small viscosity, when the underlying forward problem may become ill-posed, as well as the compactness of numerical approximants in a suitable metric on time-parametrized probability measures.
Experimental and numerical study of gas flow through microchannel with 90° bends
Authors: Singh H S , Subbarao P M V , Dhanekar S
Published: June 2022

A microchannel with a 90° bend is one of the essential components of a complex microchannel in microdevices. Therefore, a fundamental understanding of flow through a microchannel with bends is required. This paper investigates gaseous flow experimentally and numerically through a microchannel with bends in the slip regime. A microdevice with 20 microchannels of dimensions 393.96 × 1.03 × 25 200 µm3 with double 90° bends has been fabricated using standard silicon microfabrication processes. These channels have a common inlet and outlet plenum, and nitrogen gas is used as the working fluid. The mass flow rate through the microchannel is measured for various pressure ratios ranging between 1.30 and 1.55 at different outlet Knudsen numbers in the slip regime. Three-dimensional simulations are performed for rarefied isothermal flow using Ansys fluent 18.1 with slip boundary conditions on the top and bottom walls. The slip effect is quantified by comparing the measured data of the mass flow rates with the corresponding no-slip boundary conditions. To the authors’ best knowledge, experimental data in the slip regime covering the Knudsen number range 0.0662–0.0805 have not been reported previously. The gas flow was modelled numerically using the first-order model with an appropriate slip coefficient (C
1 = 1.15), and the equivalent straight length per bend in the slip regime was also calculated.
High-precision and long-range optical fiber Fabry–Perot interferometer for high temperature measurement
Authors: Zhao Na , Lin Qijing , Zhang Fuzheng , Zhang Zhongkai , Yao Kun , Zhao Libo , Tian Bian , Yang Ping , Jiang Zhuangde
Published: June 2022

To solve the problem of near-field measurement of aeroengines a novel large-range high-precision Fabry–Perot interferometer (FPI) is developed, which is verified by a high-temperature experiment. Based on the principle of FPI wavelength drift and frequency spectrum drift, a double-beam-interference FPI is designed. Through an analysis of the optical path difference between the two beams, the conclusion that the spectrum drifts to the long-wave direction with the increase of temperature is obtained. Moreover, through frequency spectrum analysis, the measurement error caused by the distortion of the spectrum is avoided, and it is found that the increase in temperature will cause the change in frequency spectrum. The temperature sensitivity of the glass-type FPI is only 0.0011 nm °C−1. A ceramic material with a higher thermal expansion coefficient is selected as the collimating tube to make the sensitivity of the temperature sensor as high as 0.691 nm °C−1 from normal temperature to 100 °C. To meet the needs of a wide range of measurements from room temperature to 1000 °C the frequency drift method is utilized. A field experiment is carried out on the ceramic FPI at the tail spray of the aeroengine simulation platform. The temperature response test from normal temperature to 1000 °C is completed, and the accuracy of the sensor reached 0.043%. In this study, the principle, design, production, and testing of optical fiber sensors are carried out. The developed optical fiber sensor has significance for high temperature monitoring.
Charge transport mechanisms in free-standing devices with electrospun electrodes
Authors: Ciobotaru Iulia Corina , Polosan Silviu , Enculescu Monica , Nitescu Andrei , Enculescu Ionut , Beregoi Mihaela , Ciobotaru Constantin Claudiu
Published: June 2022

Embedding electronic and optoelectronic devices in common, daily use objects is a fast developing field of research. New architectures are needed for migrating from the classic wafer- based substrates. Novel types of flexible PMMA/Au/Alq3/LiF/Al structures were obtained starting from electrospun polymer fibers. Thus, using an electrospinning process poly (methyl metacrylate) (PMMA) nanofibers were fabricated. A thin Au layer deposition rendered the fiber array conductive, this being further employed as the anode. The next steps consisted of the thermal evaporation of tris(8-hydroxyquinolinato) aluminum (Alq3) and aluminum deposition as the cathode. The Au covered PMMA nanofiber layer had a similar behavior with an indium tin oxide film i.e. low sheet resistance 10.6 Ω/sq and high transparency. The low electrode resistivities allow an electron drift mobility of about 10–6 cm2 V−1 s−1 at a low applied field, similar to the counterpart structures based on thin films. Concerning the relaxation processes in these structures, the Cole–Cole plots exhibit a slightly deformed semicircle, indicating a more complex equivalent circuit for the processes between metal electrodes and the active layer. This equivalent circuit includes reactance equivalent processes at the anode, cathode, in the active layer and most probably originates from the roughness of the metallic electrodes.
Superconducting HfO2-added solution-derived YBa2Cu3O7 nanocomposite films: the effect of colloidal nanocrystal shape and crystallinity on pinning mechanism
Authors: Rijckaert H , Malmivirta M , Banerjee S , Billinge S J L , Huhtinen H , Paturi P , De Buysser K , Van Driessche I
Published: June 2022

Two different types of monoclinic HfO2 nanocrystals were employed in this work to study the effect of nanocrystal shape and crystallinity on the structural defects in the YBa2Cu3O7−δ (YBCO) matrix as it leads to an enhancement of pinning performances of solution-derived YBCO nanocomposite films. In this work the nanorod-like HfO2 nanocrystals obtained from surfactant-controlled synthesis led to short intergrowths surrounding the particles, while spherical HfO2 nanocrystals from the solvent-controlled synthesis led to the formation of long stacking faults in the YBCO matrix. It means that the small difference in crystallinity, lattice parameters, nanocrystal structures, core diameter of preformed nanocrystals in colloidal solutions have a strong influence on the formation of the structural defects around the particles in the YBCO matrix, leading to different pinning performances.
Multi-functional attributes of rare earth double doped SrBi2Nb2O9 ferroelectric system
Authors: Nagamani S , Nitchal Kiran J , Siva Basivi Reddy B , Jyothi N , Vijaya Laksmi G , Sambasiva Rao K
Published: June 2022

The ferroelectric perovskite SrBi2Nb2O9 (SBN) material with a low concentration of double doping at the Bi-site of SBN was studied to understand its influence and usefulness in integrated optoelectronic, soft magnetic memory devices and wear-resistant tribomaterials. The aim of the present study is double doping of SBN with a set of rare earth elements Pr3+/Dy3+ (SBPDN), Pr3+/Gd3+ (SBPGN), Pr3+/Sm3+ (SBPSN), and Pr3+/Y3+ (SBPYN) at the Bi-site of SBN to establish the multifunctional ceramic nature pertaining to diverse applications. XRD with Rietveld refinement analysis acknowledged a single-phase orthorhombic structure with an increase in lattice parameters and unsystematic changes in crystallite size. SEM study indicated that the samples possessed non-uniformly distributed needle-shaped grains. The purity of the material and the detection of functional groups were received from the EDS and FTIR spectroscopy. Structural modifications in SBN have been determined based on a diffuse reflectance spectroscopy (DRS) study and therefore the band gap values decrease from 2.98 eV (SBN) to 2.70 eV (double doping) because of the growth of distortion in the structure and pronounced increase in the density of localized states. Photoluminescence (PL) study on double doped SBN material with an excitation wavelength of 320 nm has yielded a novel red emission at 609 nm, that may be useful for white LEDs. The ferromagnetic signature in the studied materials was confirmed from the room temperature VSM study. Noticed mild wear and a low coefficient of friction in the studied materials of SBPDN and SBPSN compared to other studied ceramic samples from mechanical studies. The simultaneous manifestation of optical, magnetic, and mechanical properties by double-doped SBN ceramics keeps the materials as multi-functional candidates for optoelectronic devices, soft magnetic memory devices, and wear-resistant tribomaterials.
Computational study of the electronic structure of the Srm+Kr (m = 0, 1) van der Waals complexes
Authors: Slama Marwa , Habli Héla , Jellali Soulef , Ben El Hadj Rhouma Mounir
Published: June 2022

A computational study of the electronic structure of the SrKr and Sr+Kr molecular systems is presented in this paper. The theoretical approach is based on the pseudo-potential technique for Sr++Kr interaction and core-valence correlation for the one and two electrons-Sr++Kr interaction. The potential energy surfaces (PESs), spectroscopic parameters, electric dipole moments (EDM), and the vibrational levels’ spacing for all electronic states are calculated. The accuracy of the current spectroscopic results is discussed by comparing them to the available experimental and theoretical data. It is interesting to note that several avoided crossings (ACs) have occurred between the high-lying 2Σ+ excited states. Each curve exhibits ionic and neutral branches in the AC region, yielding the appearance of the ionic character and the illustration of charge transfer.
Stimulation-induced changes at the electrode–tissue interface and their influence on deep brain stimulation
Authors: Evers J , Sridhar K , Liegey J , Brady J , Jahns H , Lowery M
Published: June 2022

Objective. During deep brain stimulation (DBS) the electrode–tissue interface (ETI) forms a critical path between device and brain tissue. Although changes in the electrical double layer (EDL) and glial scar can impact stimulation efficacy, the effects of chronic DBS on the ETI have not yet been established. Approach. In this study, we characterised the ETI surrounding chronically implanted DBS electrodes in rats and compared the impedance and histological properties at the electrode interface in animals that received daily stimulation and in those where no stimulation was applied, up to 8 weeks post-surgery. A computational model was developed based on the experimental data, which allowed the dispersive electrical properties of the surrounding encapsulation tissue to be estimated. The model was then used to study the effect of stimulation-induced changes in the ETI on the electric field and neural activation during voltage- and current-controlled stimulation. Main results. Incorporating the observed changes in simulations in silico, we estimated the frequency-dependent dielectric properties of the EDL and surrounding encapsulation tissue. Through simulations we show how stimulation-induced changes in the properties of the ETI influence the electric field and alter neural activation during voltage-controlled stimulation. A substantial increase in the number of stimulated collaterals, and their distance from the electrode, was observed during voltage-controlled stimulation with stimulated ETI properties. In vitro examination of stimulated electrodes confirmed that high frequency stimulation leads to desorption of proteins at the electrode interface, with a concomitant reduction in impedance. Significance. The demonstration of stimulation-induced changes in the ETI has important implications for future DBS systems including closed-loop systems where the applied stimulation may change over time. Understanding these changes is particularly important for systems incorporating simultaneous stimulation and sensing, which interact dynamically with brain networks.
Role of secondary long wavelength fluctuation in nonlinear saturation of the kinetic ballooning mode in tokamak plasmas
Authors: Ren Guangzhi , Li Jiquan , Wei Lai , Wang Zheng-Xiong
Published: June 2022

Nonlinear saturation dynamics of electromagnetic turbulence and associated transport are investigated using a global simulation based on the Landau-fluid model in the finite β tokamak plasmas. The focus is on the kinetic ballooning mode (KBM), while a comparison to the β stabilized ion temperature gradient mode is carried out. Results show that the KBM turbulence creates relatively weaker zonal flows in finite β plasmas. Zonal current could be formed around the low order rational surfaces, but is too narrow and localized to affect the global transport level. It is found that the KBM turbulence is nonlinearly saturated in two sequential stages. The linear KBM instability is first saturated transiently at a low fluctuation level by weak zonal flows. Afterward, robust, linearly stable long wavelength fluctuations are nonlinearly excited and then interact feedback with primary unstable KBM components through the modulation process. As a result, the KBM is finally saturated with a down-shifted wavenumber spectrum. The suppression of turbulent transport by long wavelength fluctuations is identified as mainly resulting from the reduction of KBM turbulence intensity.
The movement characteristics of pedestrians on a single-file track at the uphill and downhill conditions
Authors: Guo Ning , Ding Jian-Xun , Liu Yue-Mei , Ding Zhong-Jun , Zhu Kong-Jin , Chen Jia-Jia , Wu Chao-Yun
Published: June 2022

Ramps, as very common building structures, are widely used in railway stations, subways, shopping malls and other public places. In order to study the movement characteristics of pedestrians both uphill and downhill, we present a group of single-file movement experiments of pedestrians on a ramp with a 9° slope. It is found that in the free flow state, the average speed uphill and downhill is about 1.1 m s−1, while the average speed on the flat surface is about 1.4 m s−1. As the density increases, the critical densities at which the speed of pedestrians begins to decrease going uphill and downhill are both slightly higher than that on the flat surface. We also propose a step-based model considering different step frequencies and step lengths of pedestrians to simulate the movement on the ramp. Compared with the experimental results, it is shown that the model can reproduce the pedestrian’s walking behavior on the ramp well.
Analysis on flexural behavior of fabricated steel keel foamed concrete strip
Authors: Hong Cheng , Zhou Haonan , Liu Kai , Tu Bin , Su Ge
Published: June 2022

The new fabricated steel keel foamed concrete strip wall panel studied in this paper is a new steel-concrete non load-bearing outer wall panel based on the traditional fabricated foamed concrete outer wall panel. The utility model is composed of a built-in crack resistant steel wire mesh, a foamed concrete vertical plate and embedded light steel keels on both sides. When in use, the light steel keels on both sides of the strip wallboard are connected by welding to form a residential enclosure system. In order to study the bending performance of this new wall panel, this paper uses Midas FEA finite element software to carry out three-dimensional modeling of the wall panel, deformation and strain analysis under Z-direction concentrated load, and draw load deflection curve and load strain curve. The results show that under the load, the steel-concrete synergy is obvious and the stress is clear. The light steel keel has a great contribution to the flexural capacity of the wall panel, and the overall flexural performance of the wall panel is excellent.
Research on compressive performance of high-strength concrete confined by high-strength stirrups
Authors: Li Hongyu , Liao Ri , Zhang Lu , Geng Lei , Jiang Zishi , Shi Yajun , Wei Jifen
Published: June 2022

Axial compressive test of high-strength concrete prism specimens confined by high-strength stirrups are carried out. The yield strength of stirrups, volumetric stirrup ratio and concrete strength are investigated for the impact of pressure performance. The results show that the confined concrete specimens with high stirrup ratio, high strength, exhibits good ductility. The use of high-strength stirrups is an effective measure to prevent a sudden drop in the falling section of the high-strength concrete stress-strain curve; under the circumstances, the application of high-strength stirrups can reduce the volumetric stirrup ratio.
Application of Digital Twin Technology in Auxiliary Decision-making System for Grid-connected Dispatching of New Energy
Authors: Shen Runjie , Wang Yiying , Ma Ming , Zhou Qiang , Lyu Qingquan , Zhang Jianmei
Published: June 2022

Digital twin is the digital expression of physical entities. With the further development of big data and artificial intelligence technology, many fields are actively promoting the digital transformation of industries. As the key area of Chinese infrastructure to promote clean coal production and efficient green transformation, using the digital twin technology to promote the overall perception of new energy power stations, intelligent decision-making and dynamic prediction has become a new research hotspot. Through the intelligent acquisition in the perception layer, intelligent integration in the data layer and intelligent decision making in the service layer, we can set up a whole set of super short-term forecasting system and dispatching decision support system for new energy power stations, which can improve the operational efficiency. From hindsight to foresight, It’s an innovative imporve to promote the construction of smart power grid and digital power grid by effectively solving the abandon of wind and irradiance, reducing the cost of power generation and ensuring the stable operation of the whole power grid.
Research and Performance Optimization of Visualization of Panoramic Monitoring in Responsive Distribution Network
Authors: Xiao Xiaolong , Yang Jinggang , Su Wei , Shi Mingming , Yang Xiong
Published: June 2022

As the scale of the power grid continues to expand, the number of power grid devices in the national power system is increasing, the structure of the power grid is becoming more and more complex, and the information construction of the distribution network is improving, but the visualization is relatively low in real time. In terms of informationization, the current information presentation and interaction mode cannot adapt to the rapid expansion of power supply scale and daily distribution network operation and maintenance management. In this paper, we study GIS-based grid panoramic visualization display technology and responsive visualization solutions for multiple terminals. These solutions not only improve the monitoring efficiency of the distribution network, but also reduce the time of finding and overhauling when problems occur. It also enables visualization of topological data and timely access to the required information. The experiments in this paper use clustering methods to optimize the visualization elements as well as to optimize the GIS rendering, which effectively improves the visualization efficiency.
Design and Implementation of W-shaped Steel Band Hole Image Recognition System Based on OpenCV-Python
Authors: Chen Xu , yuepin Bai , Qiang Guo
Published: June 2022

The mine Roofbolter is widely used in drilling and supporting of underground roof and side wall, which greatly alleviates the imbalance of driving anchor. However, with the progress of sensor technology, electrical and electronic technology, electro-hydraulic proportional control technology and the continuous improvement of users’ requirements for the safety and efficiency of bolt support, domestic and foreign mining equipment manufacturers have carried out the development of automatic bolt and anchor cable support equipment, especially to improve the performance requirements of control system and develop intelligent visualization technology. At present, the hole location in the process of drilling still needs to be identified and located by human eyes, which is inefficient and the working environment is a great threat to the physical and mental health of personnel, so it is urgent to introduce computer technology and artificial intelligence technology. In this paper, with the help of image recognition technology, machine vision recognition replaces human eye recognition of hole location, and puts forward an image recognition technology of W-shaped steel belt hole recognition system based on OpenCV to assist the scheme, so as to ensure the safety and efficiency of roadway support. This system uses pychar, opencv and python language to realize the recognition and positioning of W-shaped steel strip hole. The scheme has the advantages of small amount of calculation, high accuracy and fast recognition speed. This research conclusion provides a reference for the further spatial positioning analysis of W-shaped steel belt hole, and improves the efficiency of underground support operation and personnel safety.
16th International Engineering and Computing Research Conference (16th EURECA)
Authors: Goh Wei Wei , Nagentrau M , Hamzah N , L Angeline , Kok S H
Published: June 2022

The 16th EURECA 2021 is the outcome of the hard work and dedication of researchers, research groups, academic programmes and effort of academic and non-academic staff from the School of Computer Science and Engineering, Taylor’s University, Malaysia. 16th EURECA Conference was held on 24th November 2021 with the double edge objectives to assist in equipping the undergraduate and post-graduate with necessary research skills as well as providing an outlet channel for the students to creatively and efficiently share their research outcome. Due to travel restrictions during pandemic, the conference was conducted virtually using Zoom as the video conferencing platform throughout the conference period.

With the ever-increasing expectations of graduates to be ready to address a variety of new world challenges, the requirements to equip the graduates, especially those in the field of Engineering, Computing, Science and Technology, with research skills are more pressing. Thus, the aim of the 16th EURECA 2021 conference is to provide the undergraduate Computing and Engineering students an opportunity to experience a research environment. This is expected to prepare them not only for careers in research but also to provide a precursor for them to use the developed research skills in their future endeavors. In addition, the 16th EURECA 2021 also serves as a platform for postgraduate Engineering and Computing students to expand their network with other researchers as well as gaining invaluable feedback with regards to their research project from both academicians and industrial experts.

List of Organizing Committee, Committee Members Secretariat, Event Management and Finance are available in this pdf.
Analysis of fatigue characteristics on camshaft using finite element analysis
Authors: Zamros M I , Ku P X
Published: June 2022

Camshaft plays an important role in the internal combustion engine, where it regulates the opening and closing time of the valves to allow fuel and air mixture to enter the engine and exhaust. The study aims to analyze the fatigue characteristics of the camshaft made from gray cast iron and cast carbon steel. SolidWorks and ANSYS Workbench were used to design and predict the lifespan of the camshaft. The modelled camshaft was used to analyze the fatigue properties. Modal analysis was performed to evaluate the deflections and natural frequency of the camshaft while static structural analysis used to evaluate the total deformation, maximum stress, and safety factor. Appropriate mesh size was used where the component was divided into several discrete parts or finite elements. The camshaft was assigned with boundary conditions such as fixed support and moment. Dunkerley’s approach was used to compare simulated natural frequencies to theoretical values. The resulting S-N curve plots the alternating stress on the camshaft against the number of cycles required to fail. Cast carbon steel was suggested to be the more desirable material since it can withstand 260 MPa of stress for 10 million cycles, whereas gray cast iron can endure only 140 MPa.
Investigation of the Base Oil Properties in Optimizing the Demulsification
Authors: Low C M , Ilia Anisa A N , Chua B L , Abdurahman N H
Published: June 2022

In this research, the correlation of the physical properties from different types of base oil- Group I and Group II base oils - to the demulsification process with variables such as mixing speed (500-1500 rpm), water content (20-80%) and volume of formulated surfactant (1 - 5 ml) were investigated. The water-in-oil emulsion was prepared using a formulated surfactant, and the demulsification was observed via a Bottle Test method. The optimization of demulsification was obtained from the correlation of the respective variables using the Central Composite Design (CCD) for Response Surface Methodology (RSM). Results showed that the Group I base oil emulsions have a lower viscosity and higher density than the Group II base oil, which has higher emulsion stability. The higher demulsification was observed by reducing the mixing speed, increasing the water content, and reducing the volume of the formulated surfactant for both groups of the base oil. The optimum of the water separation w obtained from the Group I base oil was 46.73% at 515 rpm, 76% water content, and 1 ml volume of the formulated surfactant. Meanwhile, 99.29% of water separation was found for the Group II base oil at 520 rpm, with 75% water content and 2 ml volume of the formulated surfactant.
Variations of IMF Cone Angle and IMF Clock Angle to Solar Cycles and Geomagnetic Storms
Authors: Fadiyah A I , Herdiwijaya D
Published: June 2022

Interplanetary magnetic field (IMF) carried by solar wind and rooted at solar corona. Variations of IMF depend on solar surface activities, e.g. sunspots. Moreover, solar magnetic storms are connected by the IMF. IMF parameters, sunspot number, and geomagnetic index for more than 55 years were downloaded from OMNIWeb, which the data were obtained from several spacecraft in geostasionary and L1 Lagrange orbits. Solar cycles are measured in terms of variations in the number of sunspots and their surface areas. Both magnetic events of IMF and sunspots indicate the relation between solar cycles and IMF orientation which is clock angle and cone angle. IMF also interacts with the Earth’s magnetosphere, and it can cause geomagnetic storms. Cone angle and clock angle are derived from IMF components on X-axis, Y-axis, and Z-axis. Their frequency distribution charts on each solar cycle of 20 to 24 and their maxima phase and minima phase are the key points for the analysis. The plot of clock angle to Dst index as a geomagnetic index for each solar cycle was also derived. Based on the analysis, solar cycles are indicated to give an impact on the magnitude of each IMF component. It makes the peak of the charts shifted from the minima phase to the maxima phase. Other than that, the reconnection in magnetopause mostly occurs when the clock angle is between 1400–2520 or when the clock angle directions are southward. But the 23rd solar cycle shows the northward clock angle can also cause extreme geomagnetic storms.
Preliminary Result of Rayleigh Wave Tomography beneath Jailolo Volcanic Complex, North Moluccas, Indonesia using Ambient Noise
Authors: Vita A N , Zulfakriza  , Martha A A , Rohadi S , Heryandoko N , Milkerreit C
Published: June 2022

From November 2015 to February 2016, seismic swarm activity occurred around Jailolo volcano, a long-dormant and few-studied volcano located on Halmahera Island, North Moluccas, Indonesia. We perform seismic ambient noise tomography method to delineate the sub-surface seismic structure beneath Jailolo volcanic complex. We use the vertical seismogram data from 29 temporary short-period seismic stations of 7G Seismic Network from January to March 2017 observation. The 7G Seismic Network was collaborative research between the Indonesian Agency of Meteorology, Climatology, Geophysics (BMKG), Indonesia, and the German Research Centre for Geoscience (GFZ). We cross-correlated vertical components of pair stations to estimate Green’s Rayleigh wave function. More than 350 group velocities were estimated. We measure the dispersion characteristic of Rayleigh wave group velocity by applying the frequency-time analysis (FTAN) technique. We compare Green Function and the dispersion curve by applying different band-pass filters. The Green Function of Rayleigh wave is clearly seen in causal and/or acausal part by applied 0.01-0.5 Hz band-pass filter and then dispersion curve is picked within 2-10 s. The Rayleigh group velocities average is 0.6-0.9 km/s.
A Preliminary Result: Characteristic and Mechanism of Deep earthquake in Java subduction zone
Authors: Rahman A , Afnimar  , Perdana Y H , Vita A N
Published: June 2022

The occurrence of deep-focus earthquakes is unusual and has become one of mysterious seismic phenomena. The behavior of deep earthquake occurrence is still poorly understood. The geodynamical process of a deep earthquake must have a fundamental difference of physical processes from a shallow or intermediate earthquake. There are two main processes of deep earthquake occurrence, water infiltration into the subduction zone (dehydration embrittlement) and transformational faulting of metastable olivine. In Indonesia, the Java subduction zone is known as the deep earthquake source region. We will present preliminary results from the study of characteristic and geodynamical processes of deep earthquake events. We used catalog data from ISC-EHB and mechanism data from global CMT catalog within study area 3° – 13°S and 104,5° – 115°E. The activity of deep earthquakes in Java subduction showed 3 main characteristics i.e the seismicity decreases exponentially in 60 – 300 km depth, lack of earthquake activity due to hole structure in 330 – 500 km and increasing earthquake activity in 500-600 km depth due to transformational faulting of metastable olivine. Earthquakes’ focal mechanism most varies at shallow depth, subsequently, focal mechanism transition occurred from reverse at 60-300 km to normal at >300 km depth.
Simple Forward Calculation Study for Anomaly Response Simulation and Geomagnetic Data Transformation in Karangsambung Area
Authors: Aji W , Wahyudi E J , Simanjuntak S D , Belia S
Published: June 2022

A geomagnetic survey aims to obtain a model related to geological conditions based on the magnetic properties of the rock. Forward modeling techniques can estimate the anomalies that will be observed based on anomalous bodies below the surface. The rectangular prism body forward modeling approach can approximate a complex anomaly body to be a prism group, thus simplifying the computational process of forward modeling. In this research, a program for computing the forward calculation of magnetic data with a rectangular prism approach is arranged. The program is applied to perform forward modeling of the Karangsambung geological conceptual model. Based on the modeling carried out, the magnetic anomaly range in the Karangsambung area was obtained, namely -3200 nT to 2700 nT with the smallest wavelengths based on the simulation results shown in the range of 200 meters. In addition, the forward modeling program is also used to transform geomagnetic data in the Karangsambung area. The transformations applied are the reduction to the poles and the upward continuation transformation by utilizing the equivalent source technique. Based on the transformation result, it can be interpreted that the area of the intrusion rock in Karangsambung is indicated by a magnetic anomaly value of up to 400 nT, While the area of sedimentary rocks, especially the Karangsambung Formation, is shown by a low magnetic anomaly value reaching -400 nT.
Mapping of Peak Ground Acceleration (PGA) Values using the Donovan Model for Sumatran
Authors: Zera Tati , Fauziah Ai Rahmi , Nafian M. , Ramadhani Akbar
Published: June 2022

The island of Sumatra is characterized by three tectonic systems, which are sequentially from west to east consisting of an oblique subduction zone with gentle subduction angles, the Mentawai fault, and the Sumatran large fault zone (Semangko fault). These three tectonic systems have caused high seismic activity and have implications for ground movement (Peak Ground Acceleration). This research calculates the PGA value using the Donovan model based on historical data from 100 years of destructive earthquakes. The results of this calculation are mapped and obtained results that have similarities with the tectonic system, where the west coast is a high-risk area for ground movement. The model gives PGA results in the range 8.5508 – 368.1172 gal with a minimum value of 3.295° N, 95.982° E caused by earthquake 9.1 SR, Andaman Island. The maximum value is at 4.436° S, 101.076° E caused by earthquake 5.2 SR, Bengkulu. In general, this map provides an overview of the risk of land movement on the island of Sumatra and can be used for land movement disaster mitigation efforts.
Petrophysical characterizations and shale distribution analysis of Kissenda reservoir sands, Gabon
Authors: Pradhanitasari N , Fatkhan
Published: June 2022

A gas field in western Gabon is penetrated by an exploration site N field with a major fault dividing the well locations. The upthrown block and the downthrown block have different characterization based on the history of Gabon Basin located in Equatorial West Africa, as part of the salt basin complex. In addition to major fault separating the blocks, four wells are selected in this study to identify each block. Petrophysical properties was undertaken by using wireline logs to generate each well composite. These properties include shale volume, total porosities, water saturation and permeability. The presence of shale in sandstone reservoir can affect the producibility rate of the reservoir. Shale volume and density porosity are cross-plotted using the Thomas-Stieber method to determine the shale distribution of both blocks, including the distribution types of laminar shale, dispersed shale and structural shale. Based on this method, the upthrown block has relatively small grain diameters with mostly laminar-dispersed shale distributions, while in downthrown block the grain diameters are four times larger with more dynamic shale distributions.