Element Mass Research Articles

Device for calibration of hot air welding machines

Plastics hot air welding techniques involve measuring and maintaining certain values of three physical quantities: temperature, clamping force and the dwell time of the product under load. Technical regulations of the last century do not specify the clamping force value. The value was kept by the mass of the active element of the technology equipment only. The paper considers the newly developed and studied device for calibration of hot air welding machines by clamping force. The device provides calibration of various types of machines with an operating gap of 13 mm and more. The calibration device itself was calibrated by the method of loading with standard weights using a special device. The functioning of the controller board adder was also studied, which allowed controlling the clamping force characteristics of hot air welding machines in case of inhomogeneous distribution of force and non-ideal geometric shape of clamping elements. It is shown that the new device allows controlling one of the main characteristics of hot air welding machines of various designs and manufacturers. The device made it possible to periodically control the actual value of the clamping force of the active element of the machine during the technological process realization. If in a specific model of the machine the measured value is the pressure in the pneumatic system instead of the clamping force, then during the initial calibration the clamping force against the pressure in the pneumatic system matrixes is generated, and its stability is then controlled.

Device topology optimization for an inerter-based structural dynamic vibration absorber

A tuned viscous mass damper (TVMD) and a tuned inerter damper (TID) have been proposed as devices that can achieve weight reduction by replacing the mass element of a structural dynamic vibration absorber (DVA) with an inerter. In the TID, the damping element is arranged in parallel with the spring, making its device topology the same as conventional dynamic vibration absorbers. In contrast, in the TVMD the damping element is arranged in parallel with the inerter. This parallel mechanism of inerter and damping element can be realized in a single device, and the member of the building that supports the device can be used as the spring element, making the TVMD highly practical. In fact, TVMDs with a mass effect equivalent to thousands of tons have been commercialized and applied to high-rise buildings in Japan. This paper aims to clarify the effects of the choice of objective functions and damping element arrangement on the seismic response control effectiveness of inerter-based structural DVAs, providing guidelines for structural engineers in selecting suitable devices to achieve desired control effects. The method of investigation considers a model that encompasses both TVMD and TID configurations and formulates a multi-objective optimization problem to simultaneously minimize the displacement amplification factor and floor response acceleration amplification factor. The results of the multi-objective optimization reveal that the TVMD is optimal when the focus is on controlling displacement response, while the TID is optimal when prioritizing the control of floor response acceleration. It was found that the floor response acceleration amplification factor of a structure containing TVMD could be significantly improved by slightly compromising the displacement response amplification factor, leading to the recommendation of adopting the TVMD configuration as an inerter-based structural DVA.

G.O.Joe: A new non‐commercial software tool for the processing of LA‐ICP‐MS trace element data

A common problem of trace element measurements by LA‐ICP‐MS is the existence of interferences that cannot be resolved instrumentally. The software G.O.Joe is developed to calculate trace element mass fractions in solid samples analysed by LA‐ICP‐MS, offering the opportunity to correct for isobaric interference (including mass bias) and abundance sensitivity. Designed as a platform‐independent web application, G.O.Joe is written in the Dart programming language and runs on all web browsers supported by Flutter (i.e., Chrome, Safari, Edge, Firefox) without the need for installation. G.O.Joe is freely accessible from any computer with an internet connection to facilitate immediate data evaluation and the efficient processing of large datasets (> 400 analyses). G.O.Joe features an intuitive user interface that simplifies the selection of peak and background signals, import of instrument settings and reference material compositions to convert the measured raw signals into element mass fractions. Key functions of G.O.Joe are presented by processing the analysis of tungstates and silicates (i.e., scheelite and garnet) including specific correction methods to demonstrate their large effect on interfered masses/isotopes achievable with only little effort. This study introduces G.O.Joe as a simple, time‐efficient and flexible software to significantly improve data quality in various trace element studies utilising LA‐ICP‐MS.

Tourmaline Megacryst Reference Materials for High Precision In Situ Boron Isotope and Elemental Measurement by LA‐MC‐ICP‐MS

Tourmaline serves as a vital recorder of geological processes. However, suitable tourmaline reference materials (RMs) for elemental and stable isotopic composition in situ measurements are still limited. In this study, three tourmaline megacrysts (MD‐B66, IM‐B232 and BR‐DG68) were characterised as potential RMs for B isotope measurements by LA‐MC‐ICP‐MS and mass fraction determinations by LA‐ICP‐MS. Over 251 measurements with LA‐MC‐ICP‐MS on ten randomly selected fragments from MD‐B66 consistently yielded B isotope ratios of ‐7.74 ± 0.25‰ (2s), establishing MD‐B66 as a suitably homogeneous primary reference material for high‐precision, in situ microbeam B isotope measurements. Notably, the (long‐term) intermediate precision of 0.25‰ (2s) for in situ B isotope measurements obtained using this reference material is comparable to that reported from solution MC‐ICP‐MS methods in the literature. Two other tourmaline megacrysts, with intermediate precision ranging from ± 0.48‰ to ± 0.61‰ (2s) for δ11B measurement, can be employed as secondary RMs for quality control. The mean δ11B values determined by solution MC‐ICP‐MS for MD‐B66 (‐7.71 ± 0.32‰, n = 12), IM‐B232 (‐13.17 ± 0.62‰, n = 8) and BR‐DG68 (‐13.85 ± 0.32‰, n = 12), with expanded uncertainties at the 95% confidence level, are consistent with those determined by LA‐MC‐ICP‐MS. Among these three new RMs, BR‐DG68 displays relatively homogeneous major and trace element mass fractions. Characterisation using both in situ and wet chemical techniques demonstrated the suitability of BR‐DG68 as the first tourmaline reference material for elemental measurement by LA‐ICP‐MS, which would permit matrix‐matched and therefore more accurate elemental measurement in tourmalines. Unlike electron probe microanalysis with B and Li contents calculated based on stoichiometric assumptions, direct and accurate measurements of the two low atomic number elements, along with other major and trace elements can be achieved by LA‐ICP‐MS with the aid of the newly developed tourmaline reference material BR‐DG68. Overall, current and future studies in geochemistry may benefit from these newly proposed tourmaline RMs, which should lead to significantly improved precision and accuracy for in situ B isotope and elemental measurement.

Generative Design Method for Single-Layer Spatial Grid Structural Joints

Single-layer spatial grid joints are crucial to structural safety, with commonly used welded hollow spherical joints and cast steel joints. However, these traditional joints face limitations, including a rigid design, excessive weight, and susceptibility to stress concentration. As engineering practices advance, these joints struggle to meet modern requirements. This paper introduces a generative method for designing rigid joints in single-layer spatial grid structures, based on Audze space-filling criteria. The method’s mathematical formulation is presented, followed by developing novel joint configurations by exploring various cross-sectional forms, retention mass, and geometric elements, while considering bending moments. A comparative analysis of static properties between the new and traditional joints shows promising results. The generative approach demonstrates significant innovation, producing lightweight, aesthetically pleasing, and structurally efficient joints. Compared to conventional welded hollow spherical joints, the new joints exhibit a 57% reduction in self-weight, a 51% decrease in maximum equivalent stress, and a 24% reduction in maximum displacement. This method enables versatile and optimized joint design for single-layer spatial grid structures, offering enhanced strength, safety, and aesthetic appeal.

Simulated Warming Increases Litter Decomposition and Release Rates of Some Metallic Elements and Recalcitrant Components in Different-Aged Chinese Fir Plantations

With global warming, understanding the effect of elevated temperature on the decomposition of Chinese fir needle litter has significant implications for nutrient cycling, yield, and management of economically important Chinese fir plantations. We conducted simulated warming decomposition experiments in incubators at 25 °C, 30 °C, and 35 °C on Chinese fir needle litter from middle-aged, mature, and overmature stands. Changes in litter mass and concentrations of some metallic elements and recalcitrant components were measured in litter sampled at different decomposition time-steps up to 264 days (d). Warming to 35 °C significantly increased the mass loss rate of needle litter from overmature stands throughout the experiment (except at 72 d). The effect of warming on litter mass loss rate for middle-aged and mature stands was lower and is attributed to higher litter quality in these stands. Compared to 25 °C, warming to 30 °C and 35 °C increased the needle litter decomposition rate across all developmental stages by 17.3% and 48.3%, respectively. Potassium (K), calcium (Ca), and magnesium (Mg) were mostly released during needle litter decomposition in all Chinese fir developmental stages. Lignin, condensed tannins, total phenols, and cellulose were enriched in needle litter, while the release of hemicellulose from near the start of the decomposition experiment was attributed to its lower molecular weight compared with other carbohydrates in litter. Compared with 25 °C, warming to 35 °C increased the release rates from litter of K, Ca, and Mg by 14.7%, 24.6%, and 21.5%, and the release rates of lignin, total phenols, cellulose, and hemicellulose by 7.5%, 8.8%, 10.4%, and 13.7%. Needle litter iron (Fe), aluminum (Al), and sodium (Na) in different development stages and manganese (Mn) in the overmature stands were mostly enriched during the experiment. Warming significantly promoted the enrichment of Fe, Al (except for mature stands), and Na, and reduced the enrichment of Mn. In summary, the sensitivity of needle litter to temperature in overmature stands is higher than that in middle-aged and mature stands, suggesting that forest managers can extend the rotation length of Chinese fir plantations to increase the yield of large-diameter timber, litter decomposition, and ecosystem nutrient return.

Развитие подходов к расчету параметров напряженно-деформированного состояния массива пород по результатам измерений деформаций на торце скважины

To ensure safe conditions for mining of mineral deposits, information on the stress-strain state of the rock masses is necessary. There are a few methods to obtain this type of information. One of them, which has found wide application at mining enterprises, consists in using the characteristic of elastic restoration of the shape and dimensions of the rock mass element when its connection with the main mass is forcedly broken (the doorstopper method). For its correct realization, a mathematical tool is required that allows the transition from stresses at the borehole bottom to stresses in the rock mass without the use of empirical coefficients. The paper presents the results of developing a mathematical tool to calculate the stresses acting inside the rock mass and determined based on the doorstopper method. The possibility of using empirical coefficients (the concentration coefficient and the axial stress influence coefficient) obtained during long-term in-situ and laboratory studies for the transition from stresses at the borehole bottom (flat stress state) to stresses inside the rock mass (volumetric stress state) is shown. An approach for calculating the components of the stress tensor in the bottomhole plane of three mutually perpendicular boreholes through the deformation values of a four-sensor socket is proposed. The approach for transition from the directions and magnitudes of stresses on the measurement plane to the direction and magnitude of the main stresses inside the rock mass is given.

A new basic air shower observable sensitive to the cosmic-ray elemental mass

Abstract Based on a Monte Carlo simulation study of vertical extensive air showers (EAS) at the KASCADE location we introduce a new simple observable η ρ(45;310) (in short η ρ ) - the ratio between two lateral electron densities of an EAS measured at two well-defined radial distances indicated by the characteristic radial feature of the local age parameter (LAP). Our analyses of simulated data generated by the Group I nuclei with cosmic-ray elemental masses, A actual = 1, 4, 12, 16, 24, 32, 40, 56, observed a double correlation of η ρ with, (i) the lateral shower age s av, and (ii) A actual of the EAS initiating primary particle. Applying the first correlation to a new set of simulated showers initiated by the Group II nuclei with A actual = 7, 14, 20, 28, 40, 52, the average difference between the lateral shower age s av obtained directly from the conventional LAP approach and the estimated one s est is found to be close to 0. The second correlation involving η ρ with A actual applied to the set of such showers estimates the average atomic mass 〈 ln A est 〉 of their shower initiating primaries, utilizing the η ρ s. Results of the work revealed that the method of estimating the lateral shower age is almost high-energy interaction model-independent. A certain level of model dependence is albeit found in the case of 〈 ln A est 〉 estimation.

Design optimization via genetic algorithms of acessible Ferris Wheels

In Brazil, systematic studies related to the design of amusement park equipment are still incipient. Essential normative references for these projects, such as NBR 15926-2 and ISO 17842-1 which deals with design and installation safety requirements, are often not effectively applied, increasing the risk of structural failures and neglecting stability and operational safety evaluation. Consequently, most of these equipment are imported, lacking national designs. The aim of this paper is to perform a preliminary analysis of the structural design of an accessible flexible Ferris wheel, evaluating safety coefficients through a parametric study of its geometry, including actions related to its operation, loading, and wind action. The structure modeling is conducted via Finite Element Method (FEM) using Ansys Mechanical APDL software using beam and mass elements. A routine implemented through MATLAB software communicates the input parameters and the modeled structure via FEM, allowing an easy alteration of the geometric variables, as well as the rectangular or square steel tube sections standardized by NBR-6591. Finally, a multi-objective optimization is implemented via Genetic Algorithms (GAs) with a fitness function aiming to maximize the safety coefficient and minimizing the mass. Optimal combinations are investigated and compared, proving the efficiency of this design methodology.

The source of lithium in connate fluids: Evidence from the geothermal reservoir at Soultz-sous-Forêts, Upper Rhine Graben, France

Geothermal brines in the Upper Rhine Graben have been used as a spa or for salt production since Roman times. Heat and power are generated in geothermal power plants since 2007. Recently, their elevated Li-content has additionally attracted economic interest. This increased interest is in contrast with our understanding of the geological-hydrothermal evolution. We use petrology, major and trace element mineral chemistry and mass balance calculation from drill cores that intersect granitic geothermal reservoir rocks at Soultz-sous-Forêts between Strasbourg and Karlsruhe to shed light on fluid-rock interaction in a reservoir that is actively used for heat and power generation. The alkali feldspar and the two-mica granite in the reservoir have a typical plagioclase, K-feldspar, quartz, biotite and muscovite assemblage with some accessories of titanite, apatite and zircon. Two hydrothermal alteration events are distinguished: (1) albitization of the feldspars; (2) distal replacement of feldspars by sericite and calcite, of biotite by chlorite and titanite; and proximal to hydrothermal veins replacement of the feldspars by sericite and kaolinite. Event 2 feldspar alteration quantitatively releases Pb and Ba to the fluid, whereas Rb, Cs, Sr and Zn show different behaviour depending on whole-rock and mineral composition. Event 2 biotite-chlorite alteration releases Li, Rb, Cs, Sr, Ba, Zn and Pb to the fluid. Mass balance calculation indicates that Si, Fe, Ca, K, Rb, Sr, Zn and Pb contents of the Soultz-sous-Forêts geothermal brine may be explained by fluid-rock interaction in the reservoir. However, the reservoir rock volume that needs to be leached in order to reach recent brine composition varies by several orders of magnitude between the different elements. Many of the elements may be leached during hydrothermal alteration, however in particular Li and Cs require unrealistic fluid-rock ratios of >1/300. These considerations indicate that Na, Ca, Li, Cs and Ba need an additional external source. Based on this, we propose a model where Middle Triassic bittern brines already enriched in Li, Rb, and Cs reacted with the reservoir rocks during hydrothermal event 2 and subsequently mixed with Jurassic-Cretaceous marine water that dissolved evaporites during downward migration. This agrees with Jurassic-Cretaceous illite ages from various sites in the Black Forest and indicates a complex ∼150 m.y. hydrothermal evolution for the brines. There is likely no single source of Li, and it is likely derived from complex fluid-rock interaction with the sedimentary (evaporite) and, less importantly, the crystalline strata of the Upper Rhine Graben. Critical for Li-resource development is the complex hydrothermal history of connate fluids that interacted with sedimentary strata and the preservation in deep-seated reservoirs.

The impact of baryons on the internal structure of dark matter haloes from dwarf galaxies to superclusters in the redshift range 0 < z < 7

ABSTRACT We investigate the redshift evolution of the concentration–mass relationship of dark matter haloes in state-of-the-art cosmological hydrodynamic simulations and their dark-matter-only (DMO) counterparts. By combining the IllustrisTNG suite and the novel MillenniumTNG simulation, our analysis encompasses a wide range of box size ($50{-}740 \: \rm cMpc$) and mass resolution ($8.5 \times 10^4 {-} 3.1 \times 10^7 \: \rm {\rm M}_{\odot }$ per baryonic mass element). This enables us to study the impact of baryons on the concentration–mass relationship in the redshift interval $0\lt z\lt 7$ over an unprecedented halo mass range, extending from dwarf galaxies to superclusters ($\sim 10^{9.5}{-}10^{15.5} \, \rm {\rm M}_{\odot }$). We find that the presence of baryons increases the steepness of the concentration–mass relationship at higher redshift, and demonstrate that this is driven by adiabatic contraction of the profile, due to gas accretion at early times, which promotes star formation in the inner regions of haloes. At lower redshift, when the effects of feedback start to become important, baryons decrease the concentration of haloes below the mass scale $\sim 10^{11.5} \, \rm {\rm M}_{\odot }$. Through a rigorous information criterion test, we show that broken power-law models accurately represent the redshift evolution of the concentration–mass relationship, and of the relative difference in the total mass of haloes induced by the presence of baryons. We provide the best-fitting parameters of our empirical formulae, enabling their application to models that mimic baryonic effects in DMO simulations over six decades in halo mass in the redshift range $0\lt z\lt 7$.

« L’âme faite à partir des ītyē » : l’essai de reconstruction de la psychologie de Bardesane

Abstract The study of Bardesane’s anthropological teachings comes up against testimonies that are difficult to interpret and reconcile. Information about the “soul made of elements” and allusions to atomistic theory cannot be fitted into a tripartite anthropological scheme that observes the separation of soul and body. This article examines Bardesanite anthropology in relation to cosmology and physics. By highlighting Bardesanism’s peculiarities, namely the theory of qualities-atoms (perde) component of elemental masses (itye), we can reconstruct its teaching on human origin, constitution and destiny.

Analysis of nano-mineral chemistry with single particle ICP-Time-of-Flight-MS; a novel approach to discriminate between geological environments

Studies of indicator minerals and mineral chemistry are widely used in geochemistry and are particularly useful in mineral exploration. Due to the low abundance of indicator mineral grains, large field samples and extensive laboratory processing are required for these studies. However, nano- and submicron-scale mineral particles (NPs, diameter < 1 μm) are highly abundant in geochemical sample media, containing millions to billions of particles per gram of soil or sediment. In this study, we analyze mineral NPs using single particle inductively coupled plasma time-of-flight mass spectrometry (spICP-TOFMS), a recently developed technique for high throughput elemental characterization of NPs. We investigate the limitations of the technique that arise from the working range of the ICP-TOFMS instrument and the analytical uncertainty of measured element masses in single particles. Despite these limitations, spICP-TOFMS can be used to determine accurate element mass ratios in NPs, which we validated through analysis of mineral specimens. Elemental mass ratios obtained from spICP-TOFMS in the mineral specimens were supported by SEM-EDS. We analyzed the mineral chemistry of two pairs of elements, ZrHf and NbTa in geochemical samples (sediments, soils, and mine waste) adjacent to a carbonatite and a lithium‑cesium‑tantalum-type pegmatite. Hundreds to thousands of NPs were detected in only 30–80 min of spICP-TOFMS analysis, indicating that these particle types are highly abundant. Pegmatite-associated samples contained Hf and Ta-rich NPs, compared to carbonatite-associated samples that displayed the chondritic or crustal abundance mass ratios in single particles. Zr:Hf mass ratios measured in NPs by spICP-TOFMS were supported by LA-ICP-MS analysis of zircons from selected samples. Diagnostic nano-mineral compositions including Nb-Ta-Bi-Sb (large grains of which are rarely found) were abundant in pegmatite-associated samples, but virtually absent in carbonatite-associated samples. In this study, we demonstrate that the chemistry of mineral nanoparticles can be used to discriminate between geological environments, and for the first time, we show that spICP-TOFMS is an effective tool for this type of analysis.

Recycling Li-Ion Batteries via the Re-Synthesis Route: Improving the Process Sustainability by Using Lithium Iron Phosphate (LFP) Scraps as Reducing Agents in the Leaching Operation

The development of hydrometallurgical recycling processes for lithium-ion batteries is challenged by the heterogeneity of the electrode powders recovered from end-of-life batteries via physical methods. These electrode materials, known as black mass, vary in composition, containing differing amounts of nickel, manganese, and cobalt (NMC), as well as other chemicals, such as lithium iron phosphate (LFP). This study presents the results of the hydrometallurgical treatment of mixed NMC and LFP black masses aimed at creating flexible recycling processes. This approach leverages the reducing power of LFP to optimize the leach liquor composition for re-synthesizing NMC precursors. In particular, the leaching conditions were optimized based on the LFP content in the solid feed to maximize the extraction of key metals (Ni, Mn, Co, and Li). The leaching solid residue, graphite, was treated and characterized as a secondary raw material for new anode preparation. Iron phosphate was recovered by increasing the pH of the leach liquor, and the NMC precursors were obtained via coprecipitation. This process achieved a recycling rate of 51%, based on the black mass input and the mass of recovered elements in the output products. Additionally, substituting LFP scraps as the reducing agent in place of H2O2 reduced the recycling process’s environmental impact by avoiding 1.7 tons of CO2-equivalent emissions per ton of NMC black mass.

Resistance to Electrical Corrosion of Au-Cu Alloy Coatings for Electronic Contacts

In order to obtain electronic contacts with good performance, Au-Cu alloy coatings with different gold contents were prepared on copper substrates by direct current electrodeposition and were tested against electrochemical corrosion and arc corrosion. The experimental results showed that the hardness of the Au-Cu alloy was in the range of 115.2 HV~171.6 HV, which meets the requirements of electronic contact materials. The polarization curve (Tafel) test and electrochemical impedance spectroscopy (EIS) test results indicated that the electrochemical corrosion resistance of Au-Cu alloy plating was much better than pure copper. With the rise of gold content in the alloy coatings, the corrosion resistance of the alloy coatings enhanced gradually. Compared with pure copper, the Au-Cu alloy coatings showed more stable contact resistance. After 1000 contacts, the resistivity of the alloy with 75% gold varied from 72 mΩ to 78 mΩ, whereas under the same conditions, the resistivity of copper changed from 14 mΩ to 78 mΩ. Anode-type material transfer occurred after 1000 contacts with a reduction in the total mass of each contact element. The mass loss of Au75Cu25 and Au86Cu14 contact elements was lower than that of pure copper. The Au-Cu alloy coatings displayed excellent arc corrosion resistance when the gold content in the alloy plating was higher than 75%.

Development of Software for Hydrometallurgical Calculation of Metal Extraction

Hydrometallurgy plays a critical role in the metallurgical industry by providing an efficient method for extracting metals from ores and secondary materials using aqueous solutions. This approach is particularly advantageous for processing low-grade and complex ores, as well as secondary resources that cannot be effectively processed by traditional pyrometallurgical methods. The objective of this study is to develop specialized software to automate and optimize the calculations necessary for metal extraction in hydrometallurgical processes. The software integrates a complete computational framework for automating the various stages of the hydrometallurgical process, including ore composition initialization, total element mass calculations, and the determination of metal concentrations in both metal products (matte) and by-products (slag). The methodology involves the design and implementation of a web-based application using Django for the user interface and MySQL for robust data storage. The computational module, written in Python, automates the mathematical operations required to simulate complex chemical reactions and metal extraction processes. This module supports real-time processing and ensures accurate calculations for each stage of metal extraction, including leaching, extraction, re-extraction, sorption, and electrolysis. The software also features detailed tables and dynamic graphs that allow users to analyze the distribution of valuable metals and assess the influence of key operational parameters on extraction efficiency. The results show that the developed software successfully manages large datasets, enhances the precision of hydrometallurgical calculations, and minimizes the risk of human error. The implementation of the software leads to significant improvements in the economic efficiency of production by optimizing metal recovery rates and reducing operational costs. Additionally, it supports comprehensive process control by providing actionable insights into each stage of extraction, thus improving the quality of the final metal product. Overall, the software represents a significant technological advancement in the field, offering a scalable solution for industries aiming to streamline hydrometallurgical processes.

Frequency and amplitude dependence of nuclear displacement and phase delay in mechanical vibrations for determining cellular natural frequency

Cultured cells biochemically respond to mechanical vibrations. However, the mechanisms of sensing mechanical vibrations and transducing biochemical responses remain unclear. A previous study reported that the expression of the alkaline phosphatase gene of osteoblastic cell under mechanical vibrations peaks at 50 Hz, which seems like a resonance curve in the mechanical vibration theory. Since forced displacement excitation is a dynamic mechanical stimulus that differs from other static mechanical stimuli in that an external force is equivalent to inertia, force is apparently exerted on the mass element by considering the equation of motion. In this study, the method for obtaining the change of a nucleus’s relative displacement to an excited dish was refined, and the frequency and acceleration amplitude dependence of the nucleus’s relative displacement and phase delay under mechanical vibrations was demonstrated by regarding a cell model as a vibration system. The change of the relative displacement of a HeLa nucleus to an excited dish decreases with increasing frequency in the 12.5–100 Hz range at 0.5 G and increases with increasing acceleration amplitude in the 0.5–2.0 G range at 50 Hz. Phase reversal occurs between 12.5 Hz and 50 Hz, which suggests the existence of the natural frequency of the cell between 12.5 Hz and 50 Hz. The single actin filament tension estimated from the nucleus’s relative displacement change was 2.3–10 pN and can be a biochemical response of the mechanotransducer. These findings can contribute to clarifying the mechanism of cell mechanotransduction in dynamic mechanical stimuli.

Comparison Study on the Fatigue Damage of a Container Ship Applying Hydroelastic Fatigue Analysis Procedures of LR and BV Classification Societies

&lt;i&gt;Container ships, which have hatch openings, are subject to low natural frequencies and exhibit elastic behavior due to wave loads, a phenomenon referred to as the hydroelastic effect. Classification societies have established hydroelastic fatigue analysis procedures to address the increased fatigue damage caused by this effect. This study compares the fatigue damage increase ratios at the hatch coaming top corners according to the procedures provided by Lloyd's Register (LR) and Bureau Veritas (BV). The weight distribution was adjusted using mass and interpolation elements, and normal mode analysis was conducted to obtain the natural frequencies and mode shapes of the ship, which were then used in frequency-domain hydroelastic motion analysis. The fatigue analysis was performed based on LR and BV procedures, using mode response amplitude operators (RAOs) and hydrodynamic coefficients derived from the hydroelastic motion analysis. Despite the differing methodologies between LR and BV, similar stress RAOs were obtained, with the midship showing a higher fatigue damage increase ratio than the forward and aft ends. For the LR procedure, more modes are needed for greater accuracy at the aft end, and for the BV procedure, further investigation is required to address the unreasonable response of the dynamic stress RAO in the low-frequency region, which is distant from the resonance frequency.&lt;/i&gt;

Proportional distribution pattern and modal principle of tuned viscous mass dampers for multi-degree-of-freedom structures

A tuned viscous mass damper (TVMD) is an inerter-based damper that has been adopted in several high-rise buildings in earthquake-prone Japan recently to protect the structures from seismic-induced vibrations. However, as a TVMD contains a mass element, it adds degrees of freedom to the controlled structure, making the system’s eigenmodes complex. Inspired by the Rayleigh damping matrix, this study proposes a mass-proportionally distributed TVMD (MPD-TVMD) system, which enhances the efficiency of TVMD utilization compared to the previously proposed stiffness-proportionally distributed TVMD (SPD-TVMD) system. It is theoretically proven in this study that when the arrangements of the TVMDs are proportional to the stiffness or mass distribution of the primary structure, the equations of motion of a TVMD controlled shear building can be decomposed into the eigenmodes of the uncontrolled structure. This modal principle allows structural engineers to estimate the response of the controlled structure by understanding the modal characteristics of the uncontrolled system, which is highly beneficial for preliminary design decisions and the retrofitting of existing structures. Furthermore, given that the damping properties at each story level are typically adjusted by the number of dampers installed, it is often unrealistic in practical design to maintain strict proportionality in damper distribution. Through numerical examples, this study demonstrates that TVMD systems with realistic distribution patterns that are slightly different from a strictly proportional distribution can still perform as effectively as strictly proportional systems, providing a comprehensive design basis for the application of inerter-based damper in practical engineering.

Real-time four-dimensional scanning transmission electron microscopy through sparse sampling

Abstract Four-dimensional scanning transmission electron microscopy (4-D STEM) is a state-of-the-art image acquisition mode used to reveal high and low mass elements at atomic resolution. The acquisition of the electron momenta at each real space probe location allows for various analyses to be performed from a single dataset, including virtual imaging, electric field analysis, as well as analytical or iterative extraction of the object induced phase shift. However, the limiting factor in 4-D STEM is the speed of acquisition which is bottlenecked by the read-out speed of the camera, which must capture a convergent beam electron diffraction (CBED) pattern at each probe position in the scan. Recent developments in sparse sampling and image inpainting (a branch of compressive sensing) for STEM have allowed for real-time recovery of sparsely acquired data from fixed monolithic detectors, Further developments in compressive sensing for 4-D STEM have also demonstrated that acquisition speeds can be increased, i.e., live video rate 4-D imaging is now possible. In this work, we demonstrate the first practical implementations of compressive 4-D STEM for real-time inference on two different scanning transmission electron microscopes.