bluuebunny/crossref_metadata_2025 huggingface dataset:
Facile in situ synthesis and characterization of Fe@Si/zeolite Na composites with magnetic core–shell structures from natural materials for enhanced curcumin loading capacity
Authors: Nasir Munasir , Faaizatunnisa Nuhaa , Ariesta Muhammad Naufal , Rohmawati Lydia , Nurazizah Rifqi Aulia
Published: April 2024

Curcumin is a natural polyphenol that is used in various traditional medicines. However, its inherent properties, such as its rapid degradation and metabolism, low bioavailability, and short half-life, are serious problems that must be resolved. To this end, a drug carrier incorporating natural magnetic cores in a zeolite framework was developed and applied to the loading of curcumin in ethanol solutions. In this system, curcumin is encapsulated in a zeolite Na (ZNA) magnetic core–shell structure (Fe@Si/ZNA), which can be easily synthesized using an in situ method. Synthesis of Fe3O4 nanoparticles was carried out from natural materials using a co-precipitation method. Analysis of the prepared magnetic core–shell structures and composites was carried out using vibrating-sample magnetometery, Fourier transform infrared spectroscopy, transmission electron microscopy, and x-ray diffraction. The cumulative loading of curcumin in the ZNA composite with 9% nanoparticles was found to reach 90.70% with a relatively long half-life of 32.49 min. Stability tests of curcumin loading in the composite showed that adding magnetic particles to the zeolite framework also increased the stability of the composite structure. Adsorption kinetics and isotherm studies also found that the system follows the pseudo-second-order and Langmuir isotherm models.
Bayesian plasma model selection for Thomson scattering
Authors: Suazo Betancourt Jean Luis , Grauer Samuel J. , Bak Junhwi , Steinberg Adam M. , Walker Mitchell L. R.
Published: April 2024

Laser Thomson scattering (LTS) is a measurement technique that can determine electron velocity distribution functions in plasma systems. However, accurately inferring quantities of interest from an LTS signal requires the selection of a plasma physics submodel, and comprehensive uncertainty quantification (UQ) is needed to interpret the results. Automated model selection, parameter estimation, and UQ are particularly challenging for low-density, low-temperature, potentially non-Maxwellian plasmas like those created in space electric propulsion devices. This paper applies Bayesian inference and model selection to a Raman-calibrated LTS diagnostic in the context of such plasmas. Synthetic data are used to explore the performance of the method across signal-to-noise ratios and model fidelity regimes. Plasmas with Maxwellian and non-Maxwellian velocity distributions are well characterized using priors that span a range of accuracy and specificity. The model selection framework is shown to accurately detect the type of plasmas generating the electron velocity distribution submodel for signal-to-noise ratios greater than around 5. In addition, the Bayesian framework validates the widespread use of 95% confidence intervals from least-squares inversion as a conservative estimate of the uncertainty bounds. However, epistemic posterior correlations between the variables diverge between least-squares and Bayesian estimates as the number of variable parameters increases. This divergence demonstrates the need for Bayesian inference in cases where accurate correlations between electron parameters are necessary. Bayesian model selection is then applied to experimental Thomson scattering data collected in a nanosecond pulsed plasma, generated with a discharge voltage of 5 and 10 kV at a neutral argon background pressure of 7 Torr-Ar. The Bayesian maximum a posteriori estimates of the electron temperature and number density are 1.98 and 2.38 eV and 2.6 × 1018 and 2.72 × 1018 m−3, using the Maxwellian and Druyvesteyn submodels, respectively. Furthermore, for this dataset, the model selection criterion indicates strong support for the Maxwellian distribution at 10 kV discharge voltage and no strong preference between Maxwellian and Druyvesteyn distributions at 5 kV. The logarithmic Bayes’ factors for these cases are −35.76 and 1.07, respectively.
Large electro-opto-mechanical coupling in VO2 neuristors
Authors: Khandelwal Upanya , Sandilya Rama Satya , Rai Rajeev Kumar , Sharma Deepak , Mahapatra Smruti Rekha , Mondal Debasish , Bhat Navakanta , Aetkuri Naga Phani , Avasthi Sushobhan , Chandorkar Saurabh , Nukala Pavan
Published: April 2024

Biological neurons are electro-mechanical systems, where the generation and propagation of an action potential are coupled to the generation and transmission of an acoustic wave. Neuristors, such as VO2, characterized by insulator-metal transition (IMT) and negative differential resistance, can be engineered as self-oscillators, which are good approximations of biological neurons in the domain of electrical signals. In this study, we show that these self-oscillators are coupled electro-opto-mechanical systems, with better energy conversion coefficients than the conventional electro-mechanical or electro-optical materials. This is due to the significant contrast in the material's resistance, optical refractive index, and density across the induced temperature range in a Joule heating driven IMT. We carried out laser interferometry to measure the opto-mechanical response while simultaneously driving the devices electrically into self-oscillations of different kinds. We analyzed films of various thicknesses, engineered device geometry, and performed analytical modeling to decouple the effects of refractive index change vis-à-vis mechanical strain in the interferometry signal. We show that the effective piezoelectric coefficient (d13*) for our neuristor devices is 660 ± 20 pm/V, with a 31% internal energy conversion efficiency, making them viable alternatives to Pb-based piezoelectrics for MEMS applications. Furthermore, we show that the effective electro-optic coefficient (r13*) is ∼22 nm/V, which is much larger than that in thin-film and bulk Pockels materials.
Enhancement of photoexcited carrier lifetime in an InGaAs/GaAsP wire-on-well quantum structure investigated by excitation-power-dependent photoluminescence measurements
Authors: Komaba Shintaro , Taketa Nana , Asami Meita , Sugiyama Masakazu , Ikari Tetsuo , Fukuyama Atsuhiko
Published: April 2024

A wire-on-well (WoW) structure was fabricated using InGaAs/GaAs/GaAsP superlattice device growth technology. This structure modifies the local concentration of carriers in the quantum well and lengthens the carrier lifetime to increase carrier transport efficiency. However, the reason for this remains unclear. Therefore, we investigated the detailed carrier transition properties using photoluminescence (PL) and photoreflectance measurements. Regarding the PL spectra at 4 K, two characteristic peaks at 1.39 and 1.34 eV were observed. Both transitions are attributed to the recombination between the first quantum level of the electron (e1) and that of the heavy hole (hh1). We also discussed the carrier distribution in the WoW structure and found that the maximum carrier existing probabilities for e1 and hh1 are located at different positions. The less overlapping of the wavefunctions causes low transition probability and results in the observed long carrier lifetime. An additional prominent result in the WoW structure is the blue shift attributed to the 1.34 eV PL peak induced by increasing laser excitation power. We found that the blue shift occurred by the screening of the electric field caused by the compressive strain, as in the case of the quantum-confined Stark effect.
Direct measurement of the wakefield excited by a high-power microwave pulse in plasma
Authors: Cao Y. , Maksimov V. , Haim A. , Leopold J. G. , Kostinskiy A. , Bliokh Y. P. , Hadas Y. , Krasik Ya. E.
Published: April 2024

An experimental method to measure the electric fields existing in a plasma wake produced by a ∼0.24 GW, ∼0.5 ns, 9.5 GHz microwave pulse traversing a plasma-filled waveguide is presented. The intensity of the second harmonic of a 30 fs 800 nm laser generated inside a gas-filled dielectric tube placed inside the waveguide is used to characterize the wakefield parameters. Three distinct decaying oscillations of the plasma wakefield, with peak amplitude of ∼20 kV/cm, were observed. The experimental results were confirmed by 3D large-scale plasma particle-in-cell simulations.
Design methodology of adjustable magnetic system for electron devices
Authors: Zhang Cheng , Cai Jinchi , Yin Pengcheng , Su Zixuan , Zhang Xinke , Zeng Lin , Zhang Zhen , Huan Zhonghui , Xu Jin , Yue Lingna , Yin Hairong , Xu Yong , Zhao Guoqing , Wang Wenxiang , Wei Yanyu
Published: April 2024

A novel design methodology based on a current-tunable magnetic focusing system that can flexibly switch between Brillouin and immersive flow focusing modes is presented in this paper. Such a magnetic system, which comprises cascaded solenoid coils and pole pieces, could be used in beam optics systems of vacuum tubes, particle accelerators, and free-electron lasers. Although the profile of this magnetic system is not brand new, the novel way proposed in this paper to establish and manipulate such a system to fit versatile purposes has never been reported in the literature to the best of the authors' knowledge. The specific structure of the magnetic system should be optimized, starting from the immersive flow focusing mode together with the electron gun design, which will be determined on successful optimization. According to our analysis, such systems could be transformed into the Brillouin bunching mode by simply adjusting the coil currents without modifying the hardware. To verify such an approach, single-beam and multi-beam optical systems are demonstrated in this paper. Moreover, the beam radius in such systems could also be conveniently adjusted via a similar technique.
Memory and scission effects of polymers on the flow regime of polyethylene oxide solutions in continuous abrupt contraction–expansion microchannels with different cavity lengths
Authors: Yin Guangzhou , Nakamura Yuta , Suzuki Hiroshi , Lequeux François , Hidema Ruri
Published: April 2024

This study experimentally observes the flow regimes of polyethylene oxide solutions in continuous, abrupt contraction–expansion microchannels. In dilute solutions (0.5 × 10−3–1.5 × 10−3 wt. %), the effects of flow rate, concentration, and cavity length on flow characteristics in the contraction and expansion parts of each cavity are analyzed, including quantified calculations of normalized vortex lengths and extension rates. The results indicate that polymer memory and scission affect the flow transitions. Memory effects enhance vortex growth and scission weakens flow, and these effects occur continuously within the channel. Increased flow rates and cavity lengths intensify polymer scission, accelerating the transitions from elastic instability to corner vortex, lip vortex, and then to steady vortex-free flows in the contraction parts and from steady vortex-free flows to lip and corner vortices in the expansion parts. The flow-regime transitions for concentrations from 0.01 to 0.4 wt. % for dilute and unentangled semi-dilute solutions at various flow rates are summarized in the Reynolds and Weissenberg number spaces. Polymer chains tend to become entangled in higher-concentration solutions, rendering the solution rigid and inducing complex flow regimes.
Passive control of the condensing flows in the three-dimensional steam turbine blade using a suction technique
Authors: Hosseini Seyed Ali , Ghodrati Mohammad , Lakzian Esmail , Kim Heuy Dong
Published: April 2024

A great amount of thermodynamic losses and mechanical damages in industrial equipment occur due to the condensation phenomenon and two-phase flows in such equipment. In this study, supercooled vapor suction has been passively used in the 3D (three-dimensional) steam turbine stationary blade. Supercooled vapor suction is one of the techniques used in turbines for resisting corrosion and erosion. For the supercooled flow suction, the design is as follows: an embedded channel inside the turbine blade in the nucleation zone, which has the utmost non-equilibrium mode; furthermore, the impacts of the location and surface of the channels devised in the turbine blade for supercooled vapor suction on the following parameters have been investigated: the two-phase flow, the suction ratio, condensation losses, erosion ratio, the average droplet growth, and kinetic energy. Based on the results, in the optimal case (case F), the condensation losses, erosion ratio, average droplet radius, and kinetic energy decrease by 3%, 24%, 6.5%, and 2%, respectively; also, the suction ratio is 3.6%. The present research reveals that the supercooled vapor suction, due to a decrease in the surface necessary for the condensation, decreases turbine blade corrosion and erosion. This fact can provide the turbine designers with beneficial information.
The monocyte cell surface is a unique site of autoantigen generation in rheumatoid arthritis
Authors: Thomas Mekha A. , Naik Pooja , Wang Hong , Giles Jon T. , Girgis Alexander A. , Kim Seok-Young , Johnson Tory P. , Curran Ashley M. , Crawford Jonathan D. , Jahanbani Shaghayegh , Bingham Clifton O. , Robinson William H. , Na Chan Hyun , Darrah Erika
Published: April 2024

Although anti-citrullinated protein autoantibodies (ACPAs) are a hallmark serological feature of rheumatoid arthritis (RA), the mechanisms and cellular sources behind the generation of the RA citrullinome remain incompletely defined. Peptidylarginine deiminase IV (PAD4), one of the key enzymatic drivers of citrullination in the RA joint, is expressed by granulocytes and monocytes; however, the subcellular localization and contribution of monocyte-derived PAD4 to the generation of citrullinated autoantigens remain underexplored. In this study, we demonstrate that PAD4 displays a widespread cellular distribution in monocytes, including expression on the cell surface. Surface PAD4 was enzymatically active and capable of citrullinating extracellular fibrinogen and endogenous surface proteins in a calcium dose–dependent manner. Fibrinogen citrullinated by monocyte-surface PAD4 could be specifically recognized over native fibrinogen by a panel of eight human monoclonal ACPAs. Several unique PAD4 substrates were identified on the monocyte surface via mass spectrometry, with citrullination of the CD11b and CD18 components of the Mac-1 integrin complex being the most abundant. Citrullinated Mac-1 was found to be a target of ACPAs in 25% of RA patients, and Mac-1 ACPAs were significantly associated with HLA-DRB1 shared epitope alleles, higher C-reactive protein and IL-6 levels, and more erosive joint damage. Our findings implicate the monocyte cell surface as a unique and consequential site of extracellular and cell surface autoantigen generation in RA.
Collective behavior from surprise minimization
Authors: Heins Conor , Millidge Beren , Da Costa Lancelot , Mann Richard P. , Friston Karl J. , Couzin Iain D.
Published: April 2024

Collective motion is ubiquitous in nature; groups of animals, such as fish, birds, and ungulates appear to move as a whole, exhibiting a rich behavioral repertoire that ranges from directed movement to milling to disordered swarming. Typically, such macroscopic patterns arise from decentralized, local interactions among constituent components (e.g., individual fish in a school). Preeminent models of this process describe individuals as self-propelled particles, subject to self-generated motion and “social forces” such as short-range repulsion and long-range attraction or alignment. However, organisms are not particles; they are probabilistic decision-makers. Here, we introduce an approach to modeling collective behavior based on active inference. This cognitive framework casts behavior as the consequence of a single imperative: to minimize surprise. We demonstrate that many empirically observed collective phenomena, including cohesion, milling, and directed motion, emerge naturally when considering behavior as driven by active Bayesian inference—without explicitly building behavioral rules or goals into individual agents. Furthermore, we show that active inference can recover and generalize the classical notion of social forces as agents attempt to suppress prediction errors that conflict with their expectations. By exploring the parameter space of the belief-based model, we reveal nontrivial relationships between the individual beliefs and group properties like polarization and the tendency to visit different collective states. We also explore how individual beliefs about uncertainty determine collective decision-making accuracy. Finally, we show how agents can update their generative model over time, resulting in groups that are collectively more sensitive to external fluctuations and encode information more robustly.
C-type inactivation and proton modulation mechanisms of the TASK3 channel
Authors: Lin Huajian , Li Junnan , Zhang Qiansen , Yang Huaiyu , Chen Shanshuang
Published: April 2024

The TWIK-related acid-sensitive K
+
channel 3 (TASK3) belongs to the two-pore domain (K2P) potassium channel family, which regulates cell excitability by mediating a constitutive “leak” potassium efflux in the nervous system. Extracellular acidification inhibits TASK3 channel, but the molecular mechanism by which channel inactivation is coupled to pH decrease remains unclear. Here, we report the cryo-electron microscopy structures of human TASK3 at neutral and acidic pH. Structural comparison revealed selectivity filter (SF) rearrangements upon acidification, characteristic of C-type inactivation, but with a unique structural basis. The extracellular mouth of the SF was prominently dilated and simultaneously blocked by a hydrophobic gate. His98 protonation shifted the conformational equilibrium between the conductive and C-type inactivated SF toward the latter by engaging a cation–π interaction with Trp78, consistent with molecular dynamics simulations and electrophysiological experiments. Our work illustrated how TASK3 is gated in response to extracellular pH change and implies how physiological stimuli might directly modulate the C-type gating of K2P channels.
MCP-1 and MIP-2 levels during Echinococcus granulosus infections in mice
Authors: Theodorides Y. , Frydas S. , Rallis T. , Adamama-Moraitou K. , Papazahariadou R. , Batzios C. , Conti P.
Published: April 2024

Ten BALB/c mice were infected with the cestode Echinococcus granulosus. After the infection, serum was collected at different periods of time and monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2) were determined. The level of MCP-1 increased from 290±12 pg ml-1 (mean±SD) at day 20 post infection (p.i.), to a maximum of 820±23 pg ml-1 on day 60 p.i., then decreased to 460±12.6 pg ml-1 on day 130 p.i. A second peak was observed at day 150 p.i. In addition, MIP-2 was detectable in serum as late as day 100 p.i. The highest level (100±11 pg ml-1) was observed on day 130 p.i., and decreased thereafter. Serum from noninfected animals (controls) contained no detectable levels of either MCP-1 or MIP-2. However, MCP-1 and MIP-2 appear to be implicated in E. granulosus infections, but their exact role during the disease is under determination.
Protein A immunocapture assay detecting antibodies to fluke cysteine proteinases for immunodiagnosis of human paragonimiasis and fascioliasis
Authors: Ikeda T.
Published: April 2024

Enzyme-linked immunosorbent assays (ELISAs) which detect specific antibodies to fluke cysteine proteinases have provided good sensitivity and specificity for the immunodiagnosis of trematode diseases. To detect specific antibodies without the need for purified proteinase antigens, an immunocapture assay using Protein A was applied for the immunodiagnosis of paragonimiasis and fascioliasis. ELISA plate wells were coated with Protein A, incubated with diluted patient sera, then incubated with a preparation containing fluke cysteine proteinases, excretory–secretory (ES) products of adult Paragonimuswestermani or Fasciola sp. The activity of fluke cysteine proteinases bound on the wells was measured by adding fluorogenic peptidyl substrate, Z-Phe-Arg-MCA or Boc-Val-Leu-Lys-MCA. This assay detected specific immunoglobulin G to cysteine proteinases of P. westermani and Fasciola sp. by measuring proteinase activity on the plate wells. Patient sera showed significant high values of proteinase activity when the wells were treated with the respective homologous ES products, whereas the sera had low values after treatment with the heterologous ES products. The sera of patients with other parasitoses and uninfected healthy individuals also showed low values after treatment with the above fluke ES products. Thus, Protein A immunocapture assay, which detected IgG specific for fluke cysteine proteinases, provided a high sensitivity and specificity for immunodiagnosis of paragonimiasis and fascioliasis.
Prevalence and viability of eggs of Toxocara spp. and Toxascaris leonina in public parks in eastern Spain
Authors: Ruiz de Ybxkáñez M.R. , Garijo M.M. , Alonso F.D.
Published: April 2024

To demonstrate the prevalence of Toxocara spp. and Toxascarisleonina eggs in parks in Murcia city, eastern Spain, a total 644 soil samples were examined from nine parks. More than 67% of parks and 1.24% of soil samples were contamined and the mean egg density per sample was 16.7±20 eggs per 100 g of soil. Over 97% of eggs identified were viable. Only one sample was positive for Toxascaris leonina. The present findings suggest that shady conditions are important for the occurrence and viability of Toxocara spp. and Toxascarisleonina eggs in soil as there were significantly more positive samples in shaded and moist areas compared with open and dry habitats.
Prevalence of species of Toxocara in dogs, cats and red foxes from the Poznan region, Poland
Authors: Luty T.
Published: April 2024

The prevalence of toxocariasis was evaluated for 445 dogs, 105 cats and 92 foxes from the Poznan region during 1997–1998. Forty one cats were infected (39%), 140 dogs (32%) and 15 red foxes (16%). Toxocara canis was found most frequently in puppies up to 3 months old (58%) and T. cati in kittens 4–6 months old (64%). Toxocariasis was much more prevalent amongst adult foxes (14%) than adult dogs (3%). In contrast to cats, female dogs and foxes were less infected than males. The present study suggests that cats may constitute an underestimated risk of transmission of Toxocara spp. to humans and the progressive synatropization of red foxes may also increase the sources of environmental contamination with Toxocara eggs.
Cone-beam consistency conditions for planar trajectories with parallel and perpendicular detectors
Authors: Nguyen Hung , Clackdoyle Rolf , Desbat Laurent
Published: April 2024

Cone-beam (CB) projections provide a first-order model for x-ray imaging with an area detector. CB consistency conditions (CBCCs), also known as range conditions for the 3D divergent x-ray transform, are equations that express the redundant information in a collection of CB projections. For applications purposes, CBCCs are most suitably expressed in terms of detector coordinates. CBCCs are only known for a few geometrical configurations, which depend on the source and detector trajectories. Here we only consider source trajectories that lie in a plane, and detector orientations that are parallel to the trajectory plane, or perpendicular to it. The parallel detector is stationary, but the vertical detector rotates around the center of the circular trajectory. We unify and generalize the existing known CBCCs for planar trajectories, by creating an intermediate geometry consisting of a parallel, rotating detector, and we develop new CBCCs for this geometry. Our main result is a theorem on CBCCs for a perpendicular detector, which must necessarily move in response to movement of the source. We also provide a theorem for the more difficult situation of a perpendicular detector but without the restriction that the target object be on one side or the other of the trajectory plane. We present a simple numerical simulations for a toy calibration problem to provide an example application of the new CBCCs.
Experimental investigation of some photon interaction parameters of popular restorative dental materials with a non-destructive technique
Authors: Kalecik Sedanur , Yılmaz Demet , Gürol Ali , Özdoğan Alper , Kurucu Yakup
Published: April 2024

Dental restorative materials are widely used to restore esthetics and function in prosthetic treatments. In this paper, reflection coefficients and effective atomic numbers of some restorative materials (Polyetheretherketone (PEEK), feldspathic porcelain (veneering porcelain on cobalt–chromium alloy as metal framework), lithium disilicate glass-ceramic, zircon core (veneering porcelain on yttria-stabilized tetragonal zirconia polycrystal), monolithic zirconia, and zirconia-reinforced lithium silicate glass ceramic) were measured by using 59.54 keV energy gamma rays emitted from an Am-241 radioactive source. The scattering peaks of the restorative materials were detected using an HPGe detector. The gamma radiation absorption parameters of these materials (MAC, LAC, MFP, and HVL) were also investigated using a ULEGe detector for 59.54 keV photons. It is observed that the largest MAC value is Monolithic zirconia. The material with the highest reflection parameter was found to be PEEK. Of the dental restorative materials investigated, PEEK has the lowest effective atomic number value of 21.650 and Monolithic zirconia has the highest effective atomic number value of 37.841. Effective atomic numbers can be used in non-destructive analysis and medical imaging, as is well known. In addition, the calibration curve obtained can be used in the qualitative analysis of different restorative and implant materials.
Excitation of symmetry-protected vertical modes through arrays of coaxial sub-λ apertures for THz applications
Authors: Dhibi Abdelhak , Boublouh Souhaila , Belkhir Abderrahmane , Mezeghrane Abdelaziz , Alabiad Abdullah , Lucas Grosjean , Bernal Maria-Pilar , Courjal Nadège , Hoblos Ayman , baida Fadi I
Published: April 2024

We numerically study the excitation of a Symmetry-Protected Vertical Mode (SPVM) within a specific periodic structure of coaxial apertures made in gold. The geometrical parameters are chosen to operate in the THz domain. Contrarily to classical SP modes that correspond to a mode propagating in the direction of periodicity of the structure, here the SP mode consists on the Transverse Electro Magnetic (TEM) guided mode that propagates vertically inside the coaxial aperture along the metal thickness. This feature makes the spectral properties of the excited mode less-sensitive to the spatial extension of the grating allowing thus the design of less-cumbersome devices. We demonstrate that the spectrally localized resonance corresponding to this mode is particularly sensitive to mechanical perturbation (acoustic wave for instance) of the geometry, enabling the design of highly efficient THz modulators operating at λ ≈ 300 μm with a sensitivity as great as 12.4 μm/◦ of the tilt angle of its metal core.
Detailed analysis of the relativistic configuration of Bardeen anisotropic spheres in modified f(G) gravity
Authors: Malik Adnan , Almas Ayesha , Naz Tayyaba , Manzoor Rubab , Bhatti M Z
Published: April 2024

The aim of this work is to investigate anisotropic compact objects within the framework of f(G) modified theory of gravity. For our present work, we utilize Krori–Barua metrics, i.e., λ(r) = Xr
2 + Y and β(r) = Zr
2. We use some matching conditions of spherically symmetric spacetime with Bardeen’s model as an exterior geometry. Further, we establish some expressions of energy density and pressure components to analyze the stellar configuration of Bardeen compact stars by assuming viable f(G) models. We examine the energy conditions for different stellar structures to verify the viability of our considered models. Moreover, we also investigate some other physical features, such as equilibrium condition, equation of state parameters, adiabatic index, stability analysis, mass function, surface redshift, and compactness factor, respectively. It is worthwhile to mention here for the current study that our stellar structure in the background of Bardeen's model is more viable and stable.
Whole device modeling of the fuze sheared-flow-stabilized Z pinch
Authors: Datta I.A.M. , Meier E.T. , Shumlak U.
Published: April 2024

The FuZE sheared-flow-stabilized Z pinch at Zap Energy is simulated using whole-device modeling employing an axisymmetric resistive magnetohydrodynamic formulation implemented within the discontinuous Galerkin WARPXM framework. Simulations show formation of Z pinches with densities of approximately 1022 m−3 and total DD fusion neutron rate of 107 per µs for approximately 2 µs. Simulation-derived synthetic diagnostics show peak currents and voltages within 10% and total yield within approximately 30% of experiment for similar plasma mass. The simulations provide insight into the plasma dynamics in the experiment and enable a predictive capability for exploring design changes on devices built at Zap Energy.
Behavioral patterns of children during emergency evacuations: a comparative analysis of experimental observations and simulation results
Authors: Chen Liang , Qiao Chen , Zhang Jian , Xie Chuan-Zhi (Thomas) , Tang Tie-Qiao , Chen Yanyan
Published: April 2024

This study investigates the behavioral patterns of children during emergency evacuations through a dual approach comprising controlled experimental evacuations within a classroom and computational modeling via a cellular automaton (CA) model. Observations from the experiments reveal several characteristic behaviors among children, including preferences for destinations, the impact of obstacles on their movement, as well as patterns of exit utilization, running and pushing during the evacuation process. Drawing upon these empirical findings, a CA model is developed to encapsulate these observed behaviors. A novel algorithm is introduced within this model to simulate the pushing behavior of children during emergency evacuations. Numerical simulations are conducted to validate the capability of the model to replicate the observed behaviors. The simulation results confirm that the model accurately reproduces the child behavior during evacuations. Furthermore, the results indicate that the total evacuation time is directly influenced by both the proportion of children exhibiting pushing behavior and the strength of the pushing force. These insights advance our understanding of child behavior in emergency situations and have significant implications for enhancing public safety.
Characterisation of plastic scintillator paddles and lightweight MWPCs for the MID subsystem of ALICE 3
Authors: Alfaro Ruben , Alvarado Hernández Mauricio , Bencédi Gyula , Cabanillas Noris Juan Carlos , Díaz Maldonado Marco Antonio , Duarte Galvan Carlos , Fernández Téllez Arturo , Gábor Barnaföldi Gergely , Gera Ádám , Grabsky Varlen , Hamar Gergő , Herrera Corral Gerardo , León Monzón Ildefonso , Martínez García Josué , Martínez Hernandez Mario Iván , Muñoz Méndez Jesús Eduardo , Nagy Richárd , Narcio Laveaga Rafael Ángel , Ortiz Antonio , Rodríguez-Cahuantzi Mario , Rojas Torres Solangel , Szollosova Timea , Patiño Salazar Miguel Enrique , Pazarán García Jared , Regules Medel Hector David , Tejeda Muñoz Guillermo , Vargas Torres Paola , Varga Dezső , Vértesi Róbert , Vasquez Beltran Yael Antonio , Vázquez Villamar Carlos Rafael , Yoval Pozos Irandheny
Published: April 2024

The ALICE collaboration is proposing a completely new
detector, ALICE 3, for operation during the LHC Runs 5 and 6. One of
the ALICE 3 subsystems is the Muon IDentifier detector (MID), which
has to be optimised to be efficient for the reconstruction of
 J/ψ at rest (muons down to p
T ≈ 1.5 GeV/c) for
|η| < 1.3. Given the modest particle flux expected in the MID of
a few Hz/cm2, technologies like plastic scintillator bars
(≈ 1 m length) equipped with wavelength-shifting fibers and
silicon photomultiplier readout, and lightweight Multi-Wire
Proportional Chambers (MWPCs) are under investigation. To this end,
different plastic scintillator paddles and MWPCs were studied at the
CERN T10 test beam facility. This paper reports on the performance
of the scintillator prototypes tested at different beam momenta
(from 0.5 GeV/c up to 6 GeV/c) and positions (horizontal,
vertical, and angular scans). The MWPCs were tested at different
momenta (from 0.5 GeV/c to 10 GeV/c) and beam intensities,
their efficiency and position resolutions were verified beyond the
particle rates expected with the MID in ALICE 3.
Nodes for modes: Nodal honeycomb metamaterial enables a soft robot with multimodal locomotion
Authors: Dikici Yusuf , Daltorio Kathryn , Akkus Ozan
Published: April 2024

Soft-bodied animals, such as worms and snakes, use many muscles in different ways to traverse unstructured environments and inspire tools for accessing confined spaces. They demonstrate versatility of locomotion which is essential for adaptation to changing terrain conditions. However, replicating such versatility in untethered soft-bodied robots with multimodal locomotion capabilities have been challenging due to complex fabrication processes and limitations of soft body structures to accommodate hardware such as actuators, batteries and circuit boards. Here, we present MetaCrawler, a 3D printed metamaterial soft robot designed for multimodal and omnidirectional locomotion. Our design approach facilitated an easy fabrication process through a discrete assembly of a modular nodal honeycomb lattice with soft and hard components. A crucial benefit of the nodal honeycomb architecture is the ability of its hard components, nodes, to accommodate a distributed actuation system, comprising servomotors, control circuits, and batteries. Enabled by this distributed actuation, MetaCrawler achieves five locomotion modes: peristalsis, sidewinding, sideways translation, turn-in-place, and anguilliform. Demonstrations showcase MetaCrawler’s adaptability in confined channel navigation, vertical traversing, and maze exploration. This soft robotic system holds the potential to offer easy-to-fabricate and accessible solutions for multimodal locomotion in applications such as search and rescue, pipeline inspection, and space missions.
Transient Analysis of LBLOCA with Subsequent Loss of Offsite Power and Loss of All AC Power in VVER-1200 Reactor
Authors: Asaduzzaman  , Hassan Mehedi , Hossain Kabir , Alam Shahinoor , Faruk Mohammad Omar , Rumi K M Jalal Uddin
Published: April 2024

The generation III+ VVER-1200 (AES-2006) reactor is equipped with improved safety features with component redundancy compared to the previous models. This paper is concerned with the performance of active and passive safety features during the transient of a major beyond design basis accident (BDBA) scenario of the reactor. The study is done considering large break loss of coolant accident (LB LOCA) with loss of offsite power (LOOP) and LB LOCA with loss of all AC power (LOACP) sources namely station blackout (SBO) using VVER-1200 NPP simulator. It was found that the reactor is capable of mitigating such BDBA scenarios by the effectiveness of the active and passive safety systems. Moreover, LB LOCA with LOACP is observed to be more severe compared to LBLOCA with LOOP. This comparative analysis is compatible with IAEA safety guidelines.
Fuzzy Logic Control Solar-Powered Portable Cooling Box
Authors: Qureshi Md. Jasim Uddin , Islam Ariful , Islam Thohidul
Published: April 2024

There are still some areas in the country that are having difficulties receiving uninterrupted electricity for medical aid like vaccines or insulin that require maintenance at certain temperatures. A combination of renewable energy for electricity and portable cooling boxes for medical aid can be a tremendous solution to this problem. In this research, the temperature inside the portable cooling box is kept at 2–16 °C by Peltier units running on solar power. The temperature sensor indicates the inside box’s temperature and the current sensor indicates how much power is being generated. Depending on the variation in solar radiation, the entire system is powered by direct solar or batteries. All data is processed by the Arduino using a fuzzy inference system (FIS). At the end of the process, the prototype project achieved its goal and thus played an important role in providing healthcare resources to marginalized stakeholders.
Hazard Assessment of Rice Husk Ash Generated from Rice Mills in Bangladesh and Way Forward to Overcome or Adopt the Hazards
Authors: Hossain Mohammad Tanvir , Zaman Musarrat , Sakib Sadman , Mahmud S.M. Ikhtiar
Published: April 2024

Rice husk (RH), an agricultural waste, is abundantly available in Bangladesh, where the major agricultural crop is paddy consisting of 73.94 percent of all crops. Bangladesh produced 37.61 million metric tonnes of paddy in 2020-21, among which the volume of rice husk was 7.52 million metric tonnes. These are mainly used for low-value applications such as fuel in the parboiling of the rice mills, where the burning of rice husk produces more than 5 million metric tonnes of rice husk ash (RHA). The disposal in landfills or open fields causes serious environmental and human health hazards due to the low bulk density of RHA. As silicon dioxide (SiO2) has the highest amount of presence in the rice husk ash, long-term exposure can lead to lung cancer, silicosis, chronic obstructive pulmonary disease, or tuberculosis. This research primarily focuses on the feasible and cost-effective technology to convert the rice husk ash into environment-friendly valuable products namely amorphous silica, crystalline silica, and porous silica, apart from ash’s usage as construction material, pesticide, or soil improvement material.
Sign Language Word Detection Using LRCN
Authors: Sumon Md. Shaheenur Islam , Ali Muttakee Bin , Bari Samiul , Ohi Ipshita Rahman , Islam Mayisha , Rahman Syed Mahfuzur
Published: April 2024

Sign language is the most effective communication for deaf or hard-of-hearing people. Specialized training is required to understand sign language, and as such, people without disabilities around them cannot communicate effectively. The main objective of this study is to develop a mechanism for streamlining the deep learning model for sign language recognition by utilizing the 30 most prevalent words in our everyday lives. The dataset was designed through 30 ASL (American Sign Language) words consisting of custom-processed video sequences, which consist of 5 subjects and 50 sample videos for each class. The CNN model can be applied to video frames to extract spatial properties. Using CNN’s acquired data, the LSTM model may then predict the action being performed in the video. We present and evaluate the results of two separate datasets—the Pose dataset and the Raw video dataset. The dataset was trained with the Long-term Recurrent Convolutional Network (LRCN) approach. Finally, a test accuracy of 92.66% was reached for the raw dataset, while 93.66% for the pose dataset.
Structural and Electrochemical Performance of Sr0.9La0.1WO4Electrolyte Materials for Solid Oxide Fuel Cells
Authors: Afif Ahmed , Bhuiyan Md. Humayun Kabir , Zaini Juliana , Abdalla Abdalla Mohamed , Rahman Seikh Mohammad Habibur , Azad Abul Kalam
Published: April 2024

A possible component of power generation technologies, solid oxide fuel cells (SOFCs) offer a high fuel-to-power conversion efficiency and no negative environmental impact. The solid-state sintering process was used to synthesize the scheelite-structured Sr0.9La0.1WO4(SLW1) electrolyte material, and phase stability and ionic conductivity were evaluated for their technological applicability for SOFC applications. The resulting mixture, which was a single phase in a tetragonal crystal system, produced a scheelite structure of the space group I41/a. Its symmetry, space group, and structural characteristics are confirmed by X-ray diffraction (XRD) at room temperature and the Rietveld analysis that follows. A highly dense crystal structure was revealed by SEM examination. The ionic conductivity of the SLW1 sample is higher than SBW materials and lower than the conventional BCZY perovskite structure. At 900°C in both the wet Ar and dry Ar conditions, the SLW1 sample’s ionic conductivity was 2.41 × 10−5S cm-1and 1.76 × 10−5Scm−1. This scheelite-like compound showed a thick microstructure and substantial conductivity, making it a potential mixed ion-conducting electrolyte for SOFC.
Development and Analysis of Additively Manufactured Non-Pneumatic Tires for Mars Rover
Authors: Faisal Md Fahim , Akbar Naheen Ibn , Zayed Abdul Hasib Hasan
Published: April 2024

Mars rovers are developed using the most sophisticated technology. Competitions such as the University Rover Challenge (URC), European Rover Challenge (ERC), and Anatolian Rover Challenge (ARC) encourage students to become acquainted and experienced with cutting-edge technology. This paper focuses on the development and analysis of a modified version of a non-pneumatic tire (NPT) for the MIST Mars rover “Phoenix 2.0.” Recent studies show that NPT has a good potential to replace conventional tires. To optimize the tire design for the rover, many design aspects are considered. The additive manufacturing process is used to fabricate the tire model to ensure the proper geometrical shape and usage of material. Later, a static structural analysis is conducted to investigate the stress and deformation of the tire that it may experience during rover operation. The developed deformation and stress in this analysis are well protected by the honeycomb structures that are optimized from many design attempts. The result shows a positive indication of meeting the desired criteria that eventually results in the fabrication of the tire and participation in the ARC competition. This research will inspire others to contribute to the advancement of NPT in various circumstances where pneumatic tires perform inadequately.
Characteristics and Comparative Study of Sodium Hydroxide Treated Banana Fiber Reinforced Composite Material
Authors: Moon Mehrab Khan , Saha Showvik , Biswas Anindya , Paul Aranya Aumit
Published: April 2024

Environmental issues have become a worldwide crisis because of the high rate of pollution and changing climate patterns. Due to innovations and discoveries, the need for materials is increasing day by day. Here, composite materials can be substituted for any other mono-clinic materials fulfilling the requirements of those particular materials. However, the maximum composite materials are man-made or artificially fabricated fibers. These are not environmentally friendly and bio-degradable, which creates an environmental hazard. So, scientists are trying to fabricate composite materials from eco-friendly and green resources. The main advantages of natural fibers are their low cost, easy availability, and low density. Besides these acceptable specific properties, ease of separation, increasing energy recovery, carbon-oxide neutrality, and recyclable properties are increasing the popularity of natural fiber. In this study, we have used mainly two types of banana fiber for preparing the composite specimens, especially highlighting the hybrid fiber, which is made by mixing those two types of fiber: “Shobri” and “Champa” banana fibers. These names are renowned locally in Bangladesh. In this study, polyester and MEKP are used as matrix and hardener sequentially. We have accomplished a chemical treatment process. The treating process was accomplished in the alkaline medium with two different molar concentrations of NaOH. These are 1% and 5% solutions of NaOH. After the treatment neutralization process was performed with a 1 gm/L acetic acid solution. In addition, two distinct mechanical tests— the bending and tensile tests—were carried out. The results indicated that the hybrid fiber treated with 1% NaOH had the highest tensile properties; its Young’s modulus was around 625 MPa and its tensile strength was approximately 36.42 MPa. The tensile strength and Young’s modulus of Champa banana fiber treated with 1% and 5% NaOH solutions were the lowest, respectively. Approximate values are 1.82 GPa and 18.3 MPa. The flexural strength of hybrid fiber treated with 1% and 5% NaOH was the highest and lowest in that order. 69.2 MPa and 56.21 MPa, respectively, are their values. Regarding flexural modulus, Champa fiber treated with 5% and 1% NaOH exhibits the highest and lowest values, measuring roughly 4 and 1.82 GPa, respectively.
Effect of Nylon Fiber Reinforcement on Mechanical Behavior of Expanded Perlite/Sodium Silicate Composites
Authors: Takey A.S.M. Aziz Naser , Hossain G.M. Ismail , Sarker Soumik , Arifuzzaman Md
Published: April 2024

In this research, expanded perlite/sodium silicate composites reinforced with nylon fibers were manufactured with varying percentages of nylon fibers without changing the quantity of expanded perlite and sodium silicate solution. The composites were made by compression molding and cured at a temperature of 120 degrees Celsius for 48 hours. The flexural and compression tests were conducted according to the ASTM standards in the universal testing machine. The maximum flexural and compressive properties are found for 1.62 percent nylon fiber reinforcement. The addition of a higher quantity of nylon fiber in the composites deteriorates the compressive and flexural properties. The energy absorption during flexural and compression tests is improved significantly due to nylon fiber reinforcement. The fiber-reinforced composites show the ability to carry a significant amount of load even after crack initiation.
The effects of ZrSi2 on the ablation and insulation performances of low-density carbon-phenolic composites
Authors: Chen Yaxi , Huang Xuechen , Wang Feilong , Jiao Qiming , Fu Yuxin
Published: April 2024

Carbon-phenolic (C-Ph) composites are typical ablative thermal protection materials. Excellent ablation and insulation performance indicate a decreased thickness of the thermal shield. Thus, ZrSi2 particles were introduced to improve the performance of the low-density C-Ph composite. An oxyacetylene flame torch was used to examine the ablation and insulating characteristics. The curing process of the matrix resin was not affected by ZrSi2. The thermal conductivities of the composites with different ZrSi2 contents ranged from 0.219 ∼ 0.254 W K−1·m−1. A continuous but not very compact cover was formed on the ablating surface of the C-Ph composite with 10% ZrSi2, which limited the escape of the charred matrix. The passageways for the gaseous products of the charring phenolic compounds were also not impeded by this cover. The C-Ph composite with 10% ZrSi2 exhibited the lowest linear loss rate (0.0081 mm s−1) and the best heat insulating performance.
Legitimacy without Authority
Authors: Brinkmann Matthias
Published: April 2024

This chapter argues that political legitimacy, understood as the moral permission to exercise power, does not require authority, understood as the moral power to change rights and duties. Two models are contrasted: on the Authority Model, legitimate political institutions are (normally) required to have authority. By contrast, the Transmission Model claims that political institutions merely trigger changes in the rights and duties of subjects without possessing authority. Especially because we can expect political institutions not to possess authority (as philosophical anarchism claims), the Transmission Model is shown to be theoretically and morally preferable. The chapter also answers various objections to the Transmission Model and sketches its theoretical and practical implications.