bluuebunny/crossref_metadata_2025 huggingface dataset:
The developmental basis for scaling of mammalian tooth size
Authors: Christensen Mona M. , Hallikas Outi , Das Roy Rishi , Väänänen Vilma , Stenberg Otto E. , Häkkinen Teemu J. , François Jean-Christophe , Asher Robert J. , Klein Ophir D. , Holzenberger Martin , Jernvall Jukka
Published: June 2023

When evolution leads to differences in body size, organs generally scale along. A well-known example of the tight relationship between organ and body size is the scaling of mammalian molar teeth. To investigate how teeth scale during development and evolution, we compared molar development from initiation through final size in the mouse and the rat. Whereas the linear dimensions of the rat molars are twice that of the mouse molars, their shapes are largely the same. Here, we focus on the first lower molars that are considered the most reliable dental proxy for size-related patterns due to their low within-species variability. We found that scaling of the molars starts early, and that the rat molar is patterned equally as fast but in a larger size than the mouse molar. Using transcriptomics, we discovered that a known regulator of body size, insulin-like growth factor 1 (
Igf1
), is more highly expressed in the rat molars compared to the mouse molars. Ex vivo and in vivo mouse models demonstrated that modulation of the IGF pathway reproduces several aspects of the observed scaling process. Furthermore, analysis of IGF1-treated mouse molars and computational modeling indicate that IGF signaling scales teeth by simultaneously enhancing growth and by inhibiting the cusp-patterning program, thereby providing a relatively simple mechanism for scaling teeth during development and evolution. Finally, comparative data from shrews to elephants suggest that this scaling mechanism regulates the minimum tooth size possible, as well as the patterning potential of large teeth.
MBD2a–NuRD binds to the methylated γ-globin gene promoter and uniquely forms a complex required for silencing of HbF expression
Authors: Shang Shengzhe , Li Xia , Azzo Alexander , Truong Tin , Dozmorov Mikhail , Lyons Charles , Manna Asit K. , Williams David C. , Ginder Gordon D.
Published: June 2023

During human development, there is a switch in the erythroid compartment at birth that results in silencing of expression of fetal hemoglobin (HbF). Reversal of this silencing has been shown to be effective in overcoming the pathophysiologic defect in sickle cell anemia. Among the many transcription factors and epigenetic effectors that are known to mediate HbF silencing, two of the most potent are BCL11A and MBD2–NuRD. In this report, we present direct evidence that MBD2–NuRD occupies the γ-globin gene promoter in adult erythroid cells and positions a nucleosome there that results in a closed chromatin conformation that prevents binding of the transcriptional activator, NF-Y. We show that the specific isoform, MBD2a, is required for the formation and stable occupancy of this repressor complex that includes BCL11A, MBD2a–NuRD, and the arginine methyltransferase, PRMT5. The methyl cytosine binding preference and the arginine-rich (GR) domain of MBD2a are required for high affinity binding to methylated γ-globin gene proximal promoter DNA sequences. Mutation of the methyl cytosine–binding domain (MBD) of MBD2 results in a variable but consistent loss of γ-globin gene silencing, in support of the importance of promoter methylation. The GR domain of MBD2a is also required for recruitment of PRMT5, which in turn results in placement of the repressive chromatin mark H3K8me2s at the promoter. These findings support a unified model that integrates the respective roles of BCL11A, MBD2a–NuRD, PRMT5, and DNA methylation in HbF silencing.
The metabolic rate of the biosphere and its components
Authors: Hoehler Tori M. , Mankel Dylan J. , Girguis Peter R. , McCollom Thomas M. , Kiang Nancy Y. , Jørgensen Bo Barker
Published: June 2023

We assessed the relationship between rates of biological energy utilization and the biomass sustained by that energy utilization, at both the organism and biosphere level. We compiled a dataset comprising >10,000 basal, field, and maximum metabolic rate measurements made on >2,900 individual species, and, in parallel, we quantified rates of energy utilization, on a biomass-normalized basis, by the global biosphere and by its major marine and terrestrial components. The organism-level data, which are dominated by animal species, have a geometric mean among basal metabolic rates of 0.012 W (g C)
−1
and an overall range of more than six orders of magnitude. The biosphere as a whole uses energy at an average rate of 0.005 W (g C)
−1
but exhibits a five order of magnitude range among its components, from 0.00002 W (g C)
−1
for global marine subsurface sediments to 2.3 W (g C)
−1
for global marine primary producers. While the average is set primarily by plants and microorganisms, and by the impact of humanity upon those populations, the extremes reflect systems populated almost exclusively by microbes. Mass-normalized energy utilization rates correlate strongly with rates of biomass carbon turnover. Based on our estimates of energy utilization rates in the biosphere, this correlation predicts global mean biomass carbon turnover rates of ~2.3 y
−1
for terrestrial soil biota, ~8.5 y
−1
for marine water column biota, and ~1.0 y
−1
and ~0.01 y
−1
for marine sediment biota in the 0 to 0.1 m and >0.1 m depth intervals, respectively.
The Epuyén Outbreak of Hantavirus Pulmonary Syndrome, Argentina, 2018–2019
Authors: Blond Olivier
Published: June 2023

In the context of an emerging zoonotic disease, sources of knowledge are multidisciplinary. Considering this requires not only a medical approach but also the study of the Andean hantavirus clade, its animal host,
Oligoryzomys longicaudatus
, and the environmental conditions that favour its spread before infecting humans.

Also, thanks to a multi-cultural and multi-ethnic context, the containment of this outbreak was achieved through selective respiratory isolation and the cooperation of the local actors involved.

Following a transdisciplinary approach, an actor-oriented analysis and their interaction provide a better understanding of the process that led to this successful containment. It also gives important clues for the control of zoonotic outbreaks, with human-to-human transmission.

Information

© The Author 2023
Convergence analysis of critical point regularization with non-convex regularizers
Authors: Obmann Daniel , Haltmeier Markus
Published: June 2023

One of the key assumptions in the stability and convergence analysis of variational regularization is the ability of finding global minimizers. However, such an assumption is often not feasible when the regularizer is a black box or non-convex making the search for global minimizers of the involved Tikhonov functional a challenging task. This is in particular the case for the emerging class of learned regularizers defined by neural networks. Instead, standard minimization schemes are applied which typically only guarantee that a critical point is found. To address this issue, in this paper we study stability and convergence properties of critical points of Tikhonov functionals with a possible non-convex regularizer. To this end, we introduce the concept of relative sub-differentiability and study its basic properties. Based on this concept, we develop a convergence analysis assuming relative sub-differentiability of the regularizer. The rationale behind the proposed concept is that critical points of the Tikhonov functional are also relative critical points and that for the latter a convergence theory can be developed. For the case where the noise level tends to zero, we derive a limiting problem representing first-order optimality conditions of a related restricted optimization problem. Besides this, we also give a comparison with classical methods and show that the class of ReLU-networks are appropriate choices for the regularization functional. Finally, we provide numerical simulations that support our theoretical findings and the need for the sort of analysis that we provide in this paper.
A statistical framework for domain shape estimation in Stokes flows
Authors: Borggaard Jeff , Glatt-Holtz Nathan E , Krometis Justin
Published: June 2023

We develop and implement a Bayesian approach for the estimation of the shape of a two dimensional annular domain enclosing a Stokes flow from sparse and noisy observations of the enclosed fluid. Our setup includes the case of direct observations of the flow field as well as the measurement of concentrations of a solute passively advected by and diffusing within the flow. Adopting a statistical approach provides estimates of uncertainty in the shape due both to the non-invertibility of the forward map and to error in the measurements. When the shape represents a design problem of attempting to match desired target outcomes, this ‘uncertainty’ can be interpreted as identifying remaining degrees of freedom available to the designer. We demonstrate the viability of our framework on three concrete test problems. These problems illustrate the promise of our framework for applications while providing a collection of test cases for recently developed Markov chain Monte Carlo algorithms designed to resolve infinite-dimensional statistical quantities.
Deep neural network-based reduced-order modeling of ion–surface interactions combined with molecular dynamics simulation
Authors: Kim Byungjo , Bae Jinkyu , Jeong Hyunhak , Hahn Seung Ho , Yoo Suyoung , Nam Sang Ki
Published: June 2023

With the advent of complex and sophisticated architectures in semiconductor device manufacturing, atomic-resolution accuracy and precision are commonly required for industrial plasma processing. This demands a comprehensive understanding of the plasma–material interactions—particularly for forming fine high-aspect ratio (HAR) feature patterns with sufficiently high yield in wafer-level processes. In particular, because the shape distortion in HAR pattern etching is attributed to the deviation of the energetic ion trajectory, the detailed ion–surface interactions need to be thoroughly investigated. In this study, molecular dynamics (MD) simulations were utilized to obtain a fundamental understanding of the collisional nature of accelerated Ar ions on the fluorinated Si surface that may appear on the sidewall of the HAR etched hole. High-fidelity data for ion–surface interaction features representing the energy and angle distributions (EADs) of sputtered atoms for varying degrees of surface F coverage and ion incident angles were obtained via extensive MD simulations. A deep learning-based reduced-order modeling (DL-ROM) framework was developed for efficiently predicting the characteristics of the ion–surface interactions. In the ROM framework, a conditional variational autoencoder (AE) was implemented to obtain regularized latent representations of the distributional data with the condition of the governing factors of the physical system. The proposed ROM framework accurately reproduced the MD simulation results and significantly outperformed various DL-ROMs, such as AE, sparse AE, contractive AE, denoising AE, and variational AE. From the inferred features of the sputtering yield and EADs of sputtered/scattered species, significant insights can be obtained regarding the ion interactions with the fluorinated surface. As the ion incident angle deviated from the glancing-angle range (incident angle >80°), diffuse reflection behavior was observed, which can substantially affect the ion transport in the HAR patterns. Moreover, it was hypothesized that a shift in sputtering characteristics occurs as the surface F coverage varies, based on the inferred EADs. This conjecture was confirmed through detailed MD simulations that demonstrated the fundamental relationship between surface atomic conformations and their sputtering behavior. Combined with additional atomistic-scale investigations, this framework can provide an efficient way to reveal various fundamental plasma–material interactions which are highly demanded for the future development of semiconductor device manufacturing.
Double resonance between corner states in distinct higher-order topological phases
Authors: Medina-Vázquez José A , González-Ramírez Evelyn Y , Murillo-Ramírez José G
Published: June 2023

Recent studies have shown that higher-order topologies in photonic systems lead to a robust enhancement of light–matter interactions. Moreover, higher-order topological phases have been extended to systems even without a band gap, as in Dirac semimetals. In this work, we propose a procedure to simultaneously generate two distinctive higher-order topological phases with corner states that allow a double resonant effect. This double resonance effect between the higher-order topological phases, was obtained from the design of a photonic structure with the ability to generate a higher-order topological (HOTI) insulator phase in the first bands and a higher-order Dirac half-metal phase (HODSM). Subsequently, using the corner states in both topological phases, we tuned the frequencies of both corner states such that they were separated in frequency by a second harmonic. This idea allowed us to obtain a double resonance effect with ultra-high overlap factors, and a considerable improvement in the nonlinear conversion efficiency. These results show the possibility of producing a second-harmonic generation with unprecedented conversion efficiencies in topological systems with simultaneous HOTI and HODSM phases. Furthermore, since the corner state in the HODSM phase presents an algebraic 1/r decay, our topological system can be helpful in experiments about the generation of nonlinear Dirac-ligh–matter interactions.
Enhancement of torque density and power density of polymer-based ultrasonic motors via flexible usage of anisotropy in elastic property
Authors: Liu Jinshuo , Wu Jiang , Gao Xing , Ding Zhaochun , Wei Wentao
Published: June 2023

The carbon-fiber-reinforced poly phenylene sulfide (PPS/CF), which exhibits low density, low energy dissipation, and relatively high elastic modulus among polymers, is a promising material as the vibrating body of lightweight ultrasonic motors (USMs). Interestingly, the flexible usage of the anisotropy in PPS/CF’s elastic property (induced by carbon fibers’ reinforcement) offers a new idea to enhance the torque densities and power densities of the polymer-based USMs. As the key issue of flexibly using the anisotropy, this study aims to accomplish the optimal arrangement of the carbon-fibers’ filling direction according to the structure, the vibration mode, and the piezoelectric material’s polarization direction of the PPS/CF-based motor by performing model construction, structural optimization, and experimental verification. Initially, the dynamic model capable of setting PPS/CF’s anisotropically elastic moduli with the changeable filling direction is established to analyze the vibration characteristics. Subsequently, to increase the vibration velocity, the stiffness, and the electromechanical coupling factors, the optimization is carried out for the PPS/CF-based ring-shaped vibrators, where the optimal angle between the filling direction and the vibrator’s bottom surface is estimated as 60°. Finally, a prototype of the PPS/CF-based vibrator 30 mm in diameter and 8.5 mm in height is fabricated to form a rotary motor, whose movement and load characteristics are investigated through experiments. At 250 V voltage and 24.42 kHz frequency, the motor yields the no-load rotation speed, the maximal torque, and the maximal output power of 99.3 r min−1, 29.8 mNm, and 72 mW, respectively. Moreover, its torque density and power density reach respectively 7.1 Nm kg−1 and 17.1 W kg−1, relatively high among the rotary motors with polymer vibrating bodies. This study validates the effectiveness of our idea and also provides a basic approach to design lightweight USMs that employ newly-developed materials with anisotropically elastic properties and good vibration characteristics.
Studies on structural and optical characterization of Na:ZnS nanocomposites
Authors: Naveenkumar K R , Kannappan P , Asokan K , Arul K Thanigai , Dong Chung-Li , Gupta Gaurav , Senthil K , Dhanasekaran R , Anand G Theophil
Published: June 2023

In this work, we report the structural, morphological and optical characterization of pure and sodium (Na) mixed ZnS nanocomposites. The Na:ZnS nanocomposites were synthesized by the co-precipitation method using the Na2SO4. The powder XRD pattern reveals a mixed phase of cubic and hexagonal structure. The crystalline size was found to be ∼6 nm based on the full width at half maximum (FWHM) by using the Debye Scherrer formula. Moreover, the diffraction peaks were shifted towards a higher angle compared to pure ZnS. This can be due to the difference in the ionic radii of Na+ and Zn2+ ions. The SEM images show the spherical shape of nanocomposites. The UV-visible absorption spectra of pure and Na:ZnS show an absorption cut-off wavelength of 278 nm (4.46 eV) compared to bulk band gap of ZnS (3.78 eV). The blue shift can be attributed to the quantum confinement effect. In addition to that, the optical absorption increases with increasing Na concentration. The functional groups are identified by FTIR analysis. The photoluminescence (PL) study reveals the near band edge emission at 468 nm (2.64 eV). The broad and high relative intensity of defect level emission is observed in the lower energy side of the PL spectra. The intensity of luminescence increases with increasing Na concentration due to the radiative recombination process. The Raman spectra show the formation of nanocomposite through change in phonon frequency, structural disorder and width for LO phonon mode. A change of 1.7 cm−1 phonon width suggests the formation of disorder.
Multipole analysis on stationary massive vector and symmetric tensor fields with irreducible Cartesian tensors
Authors: Wu Bofeng
Published: June 2023

The multipole expansions for massive vector and symmetric tensor fields in the region outside spatially compact stationary sources are obtained by using the symmetric and trace-free formalism in terms of the irreducible Cartesian tensors, and the closed-form expressions for the source multipole moments are provided. The expansions show a Yukawa-like dependence on the massive parameters of the fields, and the integrals of the stationary source multipole moments are all modulated by a common radial factor. For stationary massive vector field, there are two types of ‘magnetic’ multipole moments, among which one is the generalization of that of the magnetostatic field, and another, being an additional set of multipole moments of the stationary massive vector field, can not be transformed away. As to the stationary massive symmetric tensor field, its multipole expansion is presented when the trace of its spatial part is specified, where besides the counterparts of the mass and spin multipole moments of massless symmetric tensor field, three additional sets of multipole moments also appear. The multipole expansions of the tensor field under two typical cases are discussed, where it is shown that if the spatial part of the tensor field is trace-free, the monopole and dipole moments in the corresponding expansion will vanish.
A probabilistic model for the efficiency of cosmic-ray radio arrays
Authors: Lenok Vladimir , Schröder Frank G.
Published: June 2023

Digital radio detection of cosmic-ray air showers has emerged as an alternative technique
in high-energy astroparticle physics. Estimation of the detection efficiency of cosmic-ray radio
arrays is one of the few remaining challenges regarding this technique. To address this problem,
we developed a new approach to model the efficiency based on the explicit probabilistic treatment
of key elements of the radio technique for air showers: the footprint of the radio signal on
ground, the detection of the signal in an individual antenna, and the detection criterion on the
level of the entire array. The model allows for estimation of sky regions of full efficiency and
can be used to compute the aperture of the array, which is essential to measure the absolute flux
of cosmic rays. We also present a semi-analytical method that we apply to the generic model, to
calculate the efficiency and aperture with high accuracy and reasonable calculation time. The
model in this paper is applied to the Tunka-Rex array as example instrument and validated against
Monte Carlo simulations. The validation shows that the model performs well, in particular, in the
prediction of regions with full efficiency. It can thus be applied to other antenna arrays to
facilitate the measurement of absolute cosmic-ray fluxes and to minimize a selection bias in
cosmic-ray studies.
Gauge invariance on the light-cone: curvature perturbations and radiative degrees of freedom
Authors: Fanizza G. , Marozzi G. , Medeiros M.
Published: June 2023

We derive the expressions on the observed light-cone for some relevant cosmological gauge invariant variables, such as the Mukhanov-Sasaki variable and E- and B- modes of the tensor perturbations. Since the structure of the light-cone does not reflect in a direct way the FLRW symmetries, we develop a formalism which is coordinate independent and classifies the perturbations according to their helicities. Even though we work with linear perturbations, our formalism can be readily extended to non-linear theory and put the basis to study the evolution of cosmological perturbations, since the early- until the late-time Universe, directly along the observed light-cone.
Impact of multiple modes on the evolution of self-interacting axion condensate around rotating black holes
Authors: Omiya Hidetoshi , Takahashi Takuya , Tanaka Takahiro , Yoshino Hirotaka
Published: June 2023

Ultra-light particles, such as axions, form a macroscopic condensate around a highly spinning black hole by the superradiant instability. Due to its macroscopic nature, the condensate opens the possibility of detecting the axion through gravitational wave observations. However, the precise evolution of the condensate must be known for the actual detection. For future observation, we numerically study the influence of the self-interaction, especially interaction between different modes, on the evolution of the condensate in detail. First, we focus on the case when condensate starts with the smallest possible angular quantum number. For this case, we perform the non-linear calculation and show that the dissipation induced by the mode interaction is strong enough to saturate the superradiant instability, even if the secondary cloud starts with quantum fluctuations. Our result indicates that explosive phenomena such as bosenova do not occur in this case. We also show that the condensate settles to a quasi-stationary state mainly composed of two modes, one with the smallest angular quantum number for which the superradiant instability occurs and the other with the adjacent higher angular quantum number. We also study the case when the condensate starts with the dominance of the higher angular quantum number. We show that the dissipation process induced by the mode coupling does not occur for small gravitational coupling. Therefore, bosenova might occur in this case.
Primordial black hole formation in Starobinsky's linear potential model
Authors: Pi Shi , Wang Jianing
Published: June 2023

We study the power spectrum of the comoving curvature perturbation ℛ in the
model that glues two linear potentials of different slopes, originally proposed by Starobinsky.
We find that the enhanced power spectrum reaches its maximum at the wavenumber which is π 
times the junction scale. The peak is ∼ 2.61 times larger than the ultraviolet plateau. We
also show that its near-peak behavior can be well approximated by a constant-roll model, once we
define the effective ultra-slow-roll e-folding number appropriately by considering the
contribution from non-single-clock phase only. Such an abrupt transition to non-attractor phase
can leave some interesting characteristic features in the energy spectrum of the scalar-induced
gravitational waves, which are detectable in the space-borne interferometers if the primordial
black holes generated at such a high peak are all the dark matter.
Detecting vector charge with extreme mass ratio inspirals onto Kerr black holes
Authors: Zhang Chao , Guo Hong , Gong Yungui , Wang Bin
Published: June 2023

Extreme mass ratio inspirals (EMRIs) are excellent sources for space-based observatories
to explore the properties of black holes and test no-hair theorems. We consider EMRIs with a
charged compact object inspiralling onto a Kerr black hole in quasi-circular orbits. Using the
Teukolsky and generalized Sasaki-Nakamura formalisms for the gravitational and vector
perturbations about a Kerr black hole, we numerically calculate the energy fluxes for both
gravitational and vector perturbations induced by a charged particle moving in equatorial circular
orbits. With one-year observations of EMRIs, we apply the Fisher information matrix method to
estimate the charge uncertainty detected by space-based gravitational wave detectors such as the
Laser Interferometer Space Antenna, TianQin, and Taiji, and we find that it is possible to detect
vector charges as small as q ∼ 0.0049. The results show that EMRIs composed of a Kerr black
hole with a higher spin a and lighter mass M, and a secondary charged object with more vector
charge give smaller relative error on the charge, thus constrain the charge better. The positive
spin of the Kerr black hole can decrease the charge uncertainty by about one or two orders of magnitude.
On the emergence of gravitational dynamics from tensor networks
Authors: Dai Hua-Yu , Sun Jia-Rui , Sun Yuan
Published: June 2023

Tensor networks are used to describe the ground state wavefunction of the quantum many-body system. Recently, it has been shown that a tensor network can generate the anti-de Sitter (AdS) geometry by using the entanglement renormalization approach, which provides a new way to realize bulk reconstruction in the AdS/conformal field theory correspondence. However, whether the dynamical connections can be found between the tensor network and gravity is an important unsolved problem. In this paper, we give a novel proposal to integrate ideas from tensor networks, entanglement entropy, canonical quantization of quantum gravity and the holographic principle and argue that the gravitational dynamics can be generated from a tensor network if the wave function of the latter satisfies the Wheeler–DeWitt equation.
Observation of electron-scale turbulence suppression under weak magnetic shear with neon seeding in EAST plasma
Authors: Chu Y.Q. , Zhang B.S. , Li P. , Yang X.D. , Liu H.Q. , Jie Y.X. , Wu C.B. , Zhang W.M. , Li K.D. , Zhou T.F. , He L. , Zang Q. , Lian H. , Zhong F.B. , Zhu R.J. , Zhang L. F. , Hanada K.
Published: June 2023

Improved confinement caused by Ne injection is investigated in EAST. The safety factor q profile and electron-scale turbulence are studied with a polarimeter-interferometer system and CO2 laser collective scattering system in a series of Ne injection experiments in EAST. Ne with a suitable injection rate can lead to negative magnetic shear in the plasma core, which promotes electron-scale turbulence suppression. The continuous injection of Ne under the reversed shear condition further reduces the electron-scale turbulence intensity. Core electron temperature increase and confinement improvement are observed. QuaLiKiz is applied to model the influence of an impurity and reversed q on turbulence. The combination of stabilization effects of negative magnetic shear and Ne on turbulence is much stronger than the impurity’s own effect, which could explain the experimentally observed electron temperature (T
e) increase and turbulence suppression. Besides, the relationship between pedestal structure induced by Ne injection and lower hybrid wave (LHW)-driven current deposition is discussed. These results provide a new perspective to improve the confinement in the case of Ne injection, i.e. to adjust the Ne injection to modify the ideal plasma equilibrium.
Burr Formation in drilling of aluminum plates under cutting conditions modelled for manual operation
Authors: Miyake Y , Kondo Y
Published: June 2023

Aluminum alloy is widely used in aircraft structural components. The high cutting force in the conventional machining often causes the burr formation in the machined parts. To overcome the problems, machining method with low cutting force are recommended. In this study, we attempted to mechanize the manual drilling (soft-machining) to establish a new drilling method with a small probability of burr generation. The thrust force in manual drilling is less than one-tenth of that in CNC machining. A total of more than 200 holes were drilled with the same drill at 35 to 110N of applied load. In the drilling of single plate, burr formation is related to the inclination of the drill exit surfaces. Even in the drilling of stacked plates, the soft-machining can drill the through holes at the specified points in all conditions. In the soft-machining, the level of load P[N] becomes an important parameter to minimize the damage generation and it may be a mandatory to adjust the load to the minimum level required for cutting and tool feed. Applying soft machining to robotic drilling may solve vibration problem.
Simulation and research on fracture behavior of vehicle structural alloy materials based on XFEM
Authors: Li Peiyuan , Cai Qiaoyan , Wang Fei , Zhang Tao
Published: June 2023

Aluminum alloy 7050 has been widely used in the structure of aerospace vehicles because of its excellent comprehensive performance. In this paper, based on the extended finite element method and classical theory, the material parameters in the finite element simulation are calculated, next the metal plate with a central pre-crack is analyzed for static load breaking and fatigue damage under cyclic loading, the observation of different loading levels and the damage characteristics under different preset crack lengths are summarized, the rules are summarized to provide support for follow-up work.
An algebraic transition model for fluid flows
Authors: Rahman M. M. , Li Baojun , Hasan K. , Chen Sheng
Published: June 2023

An algebraic (zero-equation) transition model is developed to capture multiple transition mechanisms. The newly devised algebraic transition model is parameterized using “flow-structure-adaptive” variables and coupled with the truncated Spalart-Allmaras (SA) turbulence model. The intermittency factor γ relies on “local flow information” and is directly linked to the “vorticity-based production” term of the SA model. Splitting γ into lower and higher regimes of the “free-stream turbulence intensity” enhances the model coefficient calibration and predictions of various phenomena (“natural, bypass, separation-induced, wake-induced”, etc.) encountered in transitional flows. Simulations approve that the new formulation provides good correspondence with other transition models, available in the literature.
Design of a Hydro Bicycle for The Junín- Huancayo Region
Authors: Aylas Quispe A , Tovar J C , Calcina A , Moggiano N
Published: June 2023

The objective of this study was the design of a hydraulic bicycle and the assembly of a floating structure, steering and propulsion to be able to navigate. To this end, a variety of studies have been conducted. A study on the selection of the most suitable materials for the marine environment was also conducted, where a detailed analysis of each component of the power transmission was carried out, where the Shigley-McGrawhill mechanical engineering design book of machine elements was also used. The study of the structural part was carried out to ensure the integrity of the user, also a study of the transmission of pedaling power to the propeller and the pontoons to be able to withstand a maximum load of 120 kg and stability to ensure buoyancy.
Floor vibrations and rectification
Authors: Gad E , Nguyen T , Saidi I , Wilson J , Haritos N
Published: June 2023

Excessive floor vibration due to human excitation is a significant serviceability concern in buildings and other long span structures. The use of lightweight materials, nominal furniture and open plan layouts is resulting in lighter floors with lower damping than traditional older floors and hence an increased risk of excessive vibration response. This paper provides insights into walking excitation, floor response and remedial actions for floors with excessive vibrations.
Toward effective utilization of fly ash and multi-binder system with fly ash in concrete
Authors: Tantermsirikul S , Saengsoy W , Kaewmanee K , Julnipitawong P , Samranwanich T
Published: June 2023

This paper describes first the situation of fly ash in various ASEAN countries. Then the development of fly ash utilization in Thailand is discussed, which includes fly ash specification, standards on durability and service life design for fly ash concrete, and in the final, study results of application potential of various off-spec fly ashes are elaborated. Characteristics of fly ash in different ASEAN countries are different and have different problems. Thailand has 2 major sources of fly ash which have significantly different properties, especially CaO content (high and low CaO). Therefore, the standard specification of the Thai fly ashes classifies the fly ashes based on both quality classes (Classes 1, 2, and 3, with class 1 having the highest quality) and CaO content (high and low CaO). The effects of the fly ash were considered in the durability and service life design standard, for example in estimating the diffusion coefficient of chloride, critical chloride content, carbonation coefficient, and sulfate resistance. Lastly, examples of comparative study results on some off-spec fly ashes (high free lime, dumped wet, and high LOI fly ashes) are demonstrated.
The effect of the corrosion inhibition of steel bar and the property of salt adsorption to salt adsorption type epoxy resin
Authors: Shokyu F , Yamauchi T , Furuta M , Takigawa M , Hirayama G
Published: June 2023

Reinforced concrete structures in a salt-damaged environment are deteriorated by salt damage due to the influence of salt. As a repair measure, repair materials with salt adsorption performance and rebar rust prevention performance are used for inorganic materials. However, products with these added to organic materials are used for various purposes, which are used for various applications as repair materials. Unfortunately, there are few examples of its use becoming possible expected that measures against salt damage will be taken in various applications which have developed a “salt-adsorbing epoxy resin repair material” in which a salt-adsorbing agent is added to epoxy resin, which is an organic material. In addition, this research presented the salt adsorption effect and the corrosion inhibition effect on steel bars applied to each repair application.
Properties and durability of concrete added with recycled polypropylene/polyethylene-based food packaging waste material
Authors: Paglia C , Paderi M
Published: June 2023

The plastic waste from food packaging is hard to be recycled. Different material composition of the polymers makes the mixing impossible. Therefore, the possibility of adding selected Polypropylene / Polyethylene - based materials (PP / PE) in concrete for building applications may be a solution to reduce the waste management. In this study, investigations were carried out on the compressive and flexural strength, the elastic modulus, the density, the workability, the porosity and the water permeability. The durability parameters, such as the freeze/thaw resistance and the accelerated carbonation were also measured on concrete specimens with the addition of recycled PP/PE pellets from food packaging. The results showed that as the addition of plastic material slightly decreased and remained around 4 %, the density, workability, and mechanical properties of the concrete were comparable to the original cementitious material. The porosity was variable, while the water permeability as well as the chloride resistance were not significantly affected by the addition of 4 % plastic aggregates and remained within acceptable values. On the other hand, the freeze/thaw resistance, was significantly lowered in concrete with plastic aggregates in form of granulates.
Different orientations of shear wall in a reinforced concrete structure to control drift and deflection
Authors: Zahid Chowdhury Zubayer Bin , Alam Shahriar , Fahik Azmain , Khan Minhaz Imran , Mohammed Tarek Uddin
Published: June 2023

While Dhaka, the capital city of Bangladesh, adapts to more and more high-rise buildings and skyscrapers, concerns remain about their design efficiency and ability to withstand shear loads from seismic movements. In this study, several orientations and placements of shear walls in a regular G +15 story reinforced concrete building were assessed to observe the nature of the structure subjected to earthquake seismic loads by adopting the Equivalent Static Analysis. CSi ETABS 2019 was utilized to analyze the story shear, drift, displacement, stiffness, torsional irregularity and compared against eight separate models with different shear wall placements. The significance of this study lies in its contribution to the area of designing earthquake-resistant structures with appropriate shear wall locations following the recent Bangladesh National Building Code 2020 (Seismic criteria as per ASCE 7-05). Results reveal that shear walls placed symmetrically and along the shorter span for the selected structural plan have shown less lateral drift and displacement than structures with other shear wall orientations.
Service life optimization and life cycle assessment of concrete using SCMs as partial replacement of cement
Authors: Zahid Chowdhury Zubayer Bin , Rezwan M M , Redwan-Ul-Islam  , Mohammed Tarek Uddin
Published: June 2023

Developing a concrete mixture with the lowest possible environmental impacts while improving durability performance is crucial for a sustainable environment. In this study, a Base Case Scenario (BCS) and Alternative Case Scenario (ACS) concrete mixtures were developed with identical water-to-cement ratio (w/c) of 0.4, having cement substitution of 0% and 34%, respectively. Supplementary cementitious materials (SCMs) such as silica fume, fly ash, and slag cement were implemented as cement replacing mineral admixture. A simplified life-cycle assessment (LCA) was performed to determine environmental impact reduction factors such as fossil fuel depletion, ecotoxicity, ozone depletion, carcinogenic, and global warming. Then a simulation-based approach was carried out to optimize the durability performance of concrete mixtures using Life365™. As a result, a 24.9% reduction of environmental impacts was observed with a decent service life optimization in ACS compared to the BCS mixture.
Internal hydrophobization of cement-based materials by means of silanes
Authors: Materak K , Wieczorek A , Bednarska D , Koniorczyk M
Published: June 2023

The paper shows the opportunity of application of an organosilicon compound such as triethoxyoctylsilane (OTES) containing long, hydrophobic alkyl sidechains (octyl groups – C8H17) attached to the silicon atoms, as the admixtures for internal hydrophobization of cementitious building materials characterized by a porous internal structure. The study included the cement paste, mortar and concrete with three different hydrophobic admixtures based on triethoxyoctylsilane, but with miscellaneous concentration of the triethoxyoctylsilane in the admixture and different dosage in the fresh mix. The impact of organosilicon hydrophobic admixtures on the mechanical properties such as compressive strength, capillary water absorption of the cement mortar and concrete and the microstructure of cement paste was investigated. The hydrophobic, silicon-based admixtures decrease the capillary water absorption coefficient significantly. Even by 81.1% in case of cement mortar. The mechanical strength of cement mortar is also decreased, by 23.6%. The noticeable changes in the internal structure of pores of cement paste only for one admixture is observed.
Data-driven ultimate condition prediction of UHPC columns subjected lateral confinement using Artificial Neural Network (ANN) approach
Authors: Lee Stein S Y , Hiew Shack Yee , Raman Sudharshan N
Published: June 2023

Despite the superior mechanical properties of Ultra-High Performance Concrete (UHPC) in comparison to conventional concrete, UHPC is still not widely used in the construction industry due to the lack of design standards. This research mainly focuses on using advanced computational tools for the prediction of ultimate stress and its corresponding strain for confined UHPC columns, to facilitate the process of analysis and design, and to support further development of standards. Characteristic parameters of confined UHPC column samples were extracted from available literature as the input, and the corresponding ultimate stress and strain as the output. Artificial Neural Network (ANN) technique was adopted to process the input parameters in order to train and predict the output. In the regression analysis, the trained networks exhibited the coefficients of determination (R2) of 0.995 and 0.964 for the prediction of ultimate stress and corresponding strain respectively. The weights and biases within the best performance ANN from the k-fold cross validation can be extracted to perform mathematical solutions for the prediction in design.
A simplified design solution for shear capacity of post-installed anchors encompassing all failure modes in EC2-4 (2018)
Authors: Ng L T , Looi D T W , Lee J , Ng A L Y
Published: June 2023

Post-installed anchors are commonly used for steel-to-concrete connections, attributable to ease of installation as drilling technology advances. Besides, they offer the advantage of minimizing misalignment issues during construction compared to cast-in anchors. The anchor design calculations in EN 1992-4:2018 can be daunting for practicing engineers, given its complexity and state-of-the-art compared to ETAG 001 (2013). In an earlier publication, the authors described a methodology for simplifying the complex empirical equations in EN 1992-4:2018 for designing the tensile capacity of post-installed anchors into a simplified design tool. This work is a sequel to the previous work to develop a simplified design tool for estimating the design shear capacity of post-installed anchors (mechanical and bonded anchors) encompassing all failure modes. The calculation was first automated using a spreadsheet for the characteristic shear resistance of anchors and was verified using Hilti PROFIS Engineering software. The simplified design tool is summarized based on the lowest resistance of the anchor encompassing all failure modes. The design tool is demonstrated for an example of a 125 mm thick C30/37 concrete slab for commonly available anchor sizes of M8, M10, M12, M16, M20, and M24.
Properties of concrete with glass fibre reinforced polymer waste as partial replacement of fine aggregate
Authors: Aziz F N A A , Tan A R , Bakar N B , Nasir N A M
Published: June 2023

The proper disposal of fibre waste products is a significant issue for the GFRP industries; as a result, the reuse and recycling of these waste products require sustainable solutions. Given that FRP materials, especially those created with thermosetting resins, cannot be reprocessed, so the majority of thermosetting FRP waste will be dumped in landfills. Innovative approaches are thus required to manage waste. This study investigates the performance of the FRP waste, known as Glass Fibre Reinforced Polymer (GFRP), that is ground to 0.15mm to 2.36mm in size and used to replace sand at 5%, 10%, 15%, 20%, and 25% by weight of the concrete composite. The experimental work starts with the grinding and sieving process, followed by preparing grade 45 concrete. Then the workability of concrete with GFRP was determined, followed by the compression, and split tensile strengths. The findings showed that adding up to 5% of GFRP waste as a partial replacement for fine aggregate improved the workability and compressive strength of the concrete mix. but decreases when more GFRP waste is added. While the split tensile strength shows increments in line with the increasing amount of GFRP waste replacement. It can be concluded that GFRP waste replacement has the potential to be used in the construction industry, however, the long-term performance must be determined first.
Mechanical properties of blended-rubberized concrete
Authors: Mohd Nasir N A , Bakar N B , Safiee N A , Aziz F N A A , Archnaah N
Published: June 2023

Recently, the disposal of waste tire rubber is no longer a non-common environmental problem, which is due to its non-biodegradable nature. Many works were done with regard to the utilization of crumb rubber from waste tires into concrete. In conjunction to deal with the disposal issues, this effort also preserving the natural sources of aggregate and producing a green sustainable concrete. In this study, the crumb rubber was used in the concrete containing metakaolin and it replaced fine aggregate content at 10% and 15%. The investigations were conducted on the mechanical properties of concrete like compressive strength, split tensile strength, flexural strength and elastic modulus. The result showed reduction in mechanical properties is proportionate with the increment of crumb rubber. The bond between cement paste and rubber particles was found to be a factor affecting its strength. The finding indicated that the strength of blended-rubberized concrete decreased about 13% with increasing crumb rubber content from 10% to 15%. Thus, the study concluded that there was no significant strength reduction for rubberized concrete with increasing crumb rubber content (up to 15%). Furthermore, the compressive strength was complied to the minimum requirement for building structural application (25MPa). Thus, the blended-rubberized concrete has promising potential properties for the construction applications.
Techniques for mass production of large-sized GEM foil by the Korean CMS group for CMS phase-2 upgrade
Authors: Yoon I.
Published: June 2023

This study presents techniques for the mass production of large-sized GEM foils for the
CMS phase-2 upgrade by the Korean CMS group. The foil production facility is designed with a
focus on mass production, including the adoption of the double-mask technique. A polyimide wet
etching technology that uses mono ethanolamine is reported, providing a safer working environment
due to its lower inhalation toxicity compared to ethylene diamine. The study also covers the
denaturation of the etchant over time and the process of retuning. Finally, R&D results on
soldering surface mount resistors with hot air for faster production are discussed.
Spatial profiles of collimated laser Compton-scattering γ-ray beams
Authors: Ari-Izumi Takashi , Gheorghe Ioana , Filipescu Dan , Hashimoto Satoshi , Miyamoto Shuji , Utsunomiya Hiroaki
Published: June 2023

The intensity and energy spatial distributions of collimated laser Compton scattering (LCS) γ-ray beams and of the associated bremsstrahlung beams have been investigated as functions of the electron beam energy, electron beam phase space distribution, laser optics conditions and laser polarization. We show that the beam halo is affected to different extents by variations in the above listed parameters. In the present work, we have used laser Compton scattering simulations performed with the eliLaBr code (https://github.com/dan-mihai-filipescu/eliLaBr) and real LCS and bremsstrahlung γ-ray beams produced at the NewSUBARU synchrotron radiation facility. A 500 μm MiniPIX X-ray camera was used as beamspot monitor in a wide γ-ray beam energy range between 1.73 MeV and 38.1 MeV.