bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving dynamic collision frequencies: Impacts on dynamic structure factors and stopping powers in warm dense matter
Authors: Hentschel Thomas W. , Kononov Alina , Olmstead Alexandra , Cangi Attila , Baczewski Andrew D. , Hansen Stephanie B.
Published: June 2023

Simulations and diagnostics of high-energy-density plasmas and warm dense matter rely on models of material response properties, both static and dynamic (frequency-dependent). Here, we systematically investigate variations in dynamic electron–ion collision frequencies ν(ω) in warm dense matter using data from a self-consistent-field average-atom model. We show that including the full quantum density of states, strong collisions, and inelastic collisions lead to significant changes in ν(ω). These changes result in red shifts and broadening of the plasmon peak in the dynamic structure factor, an effect observable in x-ray Thomson scattering spectra, and modify stopping powers around the Bragg peak. These changes improve the agreement of computationally efficient average-atom models with first-principles time-dependent density functional theory in warm dense aluminum, carbon, and deuterium.
Chemically aware unitary coupled cluster with ab initio calculations on an ion trap quantum computer: A refrigerant chemicals’ application
Authors: Khan I. T. , Tudorovskaya M. , Kirsopp J. J. M. , Muñoz Ramo D. , Warrier P. , Papanastasiou D. K. , Singh R.
Published: June 2023

Circuit depth reduction is of critical importance for quantum chemistry simulations on current and near term quantum computers. This issue is tackled by introducing a chemically aware strategy for the unitary coupled cluster ansatz. The objective is to use the chemical description of a system to aid in the synthesis of a quantum circuit. We combine this approach with two flavors of symmetry verification for the reduction of experimental noise. These methods enable the use of Quantinuum’s System Model H1 ion trap quantum computer for a 6-qubit quantum subspace expansion calculation. We present (i) calculations to obtain methane’s optical spectra; (ii) an atmospheric gas reaction simulation involving [CH3⋅—H—OH]‡. Using our chemically aware unitary coupled cluster state-preparation strategy in tandem with state of the art symmetry verification methods, we improve device yield for CH4 at 6 qubits. This is demonstrated by a 90% improvement in two-qubit gate count and a reduction in relative error to 0.2% for electronic energy calculated on System Model H1.
Evolution of the age-included nearest pair distribution in disperse multiphase flows
Authors: Zhang Duan Z. , Wang Min , Balachandar S.
Published: June 2023

The age of the nearest particle pair is introduced as the difference between the current time and the most recent time when the nearest particle pair was formed. The evolution equation for the age-included nearest pair distribution function is derived. With the assumption of random destruction of the nearest particle pairs, the evolution equation predicts the exponential probability distribution of the ages of the nearest particle pairs. Particle-resolved numerical simulations with moving particles are performed to verify this prediction. The equation is then used to derive the evolution equation for the particle–fluid–particle (PFP) stress, which is known to be related to hyperbolicity of the two-fluid equations. It is found that the relaxation time of the age probability distribution is also the relaxation time for the PFP stress. Guided by the closure terms in the PFP stress evolution equation, we study kinematics of the nearest particle pairs in the particle-resolved simulations for flows caused by sedimentation of the particles with initially isotropic and homogeneous particle distributions. At the steady states, the particle Reynolds numbers are around 20. Anisotropy and inhomogeneity of particle distributions are seen to develop in these flows. The mean distances to the nearest particles and evolution of the distribution of the Voronoi cell volumes are studied. We also found the PFP stress is closely related to the changes in these inter-particle scale quantities.
A wave appropriate discontinuity sensor approach for compressible flows
Authors: Chamarthi Amareshwara Sainadh , Hoffmann Natan , Frankel Steven
Published: June 2023

In this work, we propose a novel selective discontinuity sensor approach for numerical simulations of the compressible Navier–Stokes equations. Since transformation to characteristic space is already a common approach to reduce high-frequency oscillations during interpolation to cell interfaces, we exploit the characteristic wave structure of the Euler equations to selectively treat the various waves that the equations comprise. The approach uses the Ducros shock sensing criterion to detect and limit oscillations due to shocks while applying a different criterion to detect and limit oscillations due to contact discontinuities. Furthermore, the method is general in the sense that it can be applied to any method that employs characteristic transformation and shock sensors. However, in the present work, we focus on the gradient-based reconstruction family of schemes. A series of inviscid and viscous test cases containing various types of discontinuities are carried out. The proposed method is shown to markedly reduce high-frequency oscillations that arise due to improper treatment of the various discontinuities; i.e., applying the Ducros shock sensor in a flow where a strong contact discontinuity is present. Moreover, the proposed method is shown to predict similar volume-averaged kinetic energy and enstrophy profiles for the Taylor–Green vortex simulation compared to the base Ducros sensor, indicating that it does not introduce unnecessary numerical dissipation when there are no contact discontinuities in the flow.
Matrix of orthogonalized atomic orbital coefficients representation for radicals and ions
Authors: Llenga Stiv , Gryn’ova Ganna
Published: June 2023

Chemical (molecular, quantum) machine learning relies on representing molecules in unique and informative ways. Here, we present the matrix of orthogonalized atomic orbital coefficients (MAOC) as a quantum-inspired molecular and atomic representation containing both structural (composition and geometry) and electronic (charge and spin multiplicity) information. MAOC is based on a cost-effective localization scheme that represents localized orbitals via a predefined set of atomic orbitals. The latter can be constructed from such small atom-centered basis sets as pcseg-0 and STO-3G in conjunction with guess (non-optimized) electronic configuration of the molecule. Importantly, MAOC is suitable for representing monatomic, molecular, and periodic systems and can distinguish compounds with identical compositions and geometries but distinct charges and spin multiplicities. Using principal component analysis, we constructed a more compact but equally powerful version of MAOC—PCX-MAOC. To test the performance of full and reduced MAOC and several other representations (CM, SOAP, SLATM, and SPAHM), we used a kernel ridge regression machine learning model to predict frontier molecular orbital energy levels and ground state single-point energies for chemically diverse neutral and charged, closed- and open-shell molecules from an extended QM7b dataset, as well as two new datasets, N-HPC-1 (N-heteropolycycles) and REDOX (nitroxyl and phenoxyl radicals, carbonyl, and cyano compounds). MAOC affords accuracy that is either similar or superior to other representations for a range of chemical properties and systems.
Textured BiScO3-PbTiO3 piezoelectric ceramics with both high electromechanical coupling factor and high curie temperature
Authors: Wang Mingwen , Yang Shuai , Wu Jie , Li Jinglei , Qiao Liao , Liu Xuechen , Wang Chao , Feng Xinya , Li Chunchun , Li Fei
Published: June 2023

High-temperature piezoelectric devices require piezoelectric ceramics with high Curie temperatures and high-temperature stability of piezoelectric properties to avoid the depolarization of piezoelectric ceramics during application. However, piezoelectric materials with high Curie temperatures usually have restrained piezoelectric properties. Crystallographic orientation via texture engineering is a practicable way to improve piezoelectric performance. Here, we propose a sintering-aid-assisted template grain growth strategy to texture BiScO3-PbTiO3 ceramics to overcome the low orientation issue that challenges the texturing of BS-PT for decades. By judiciously selecting B2O3-CuO as sintering aids, we fabricated highly ⟨001⟩-textured 0.43BS-0.57PT ceramics with Logtering factors >99.0% that possess high piezoelectric coefficients d33 of 474–612 pC/N while maintaining relatively high Curie temperatures of 370–402 °C. Importantly, this work addresses a long-standing issue presented in BS-PT ceramics, i.e., the low electromechanical coupling property of BS-PT ceramics (k33 < 0.70) by improving the electromechanical coupling factor k33 to 81.2%. The newly designed textured BS-PT ceramics are thought to be promising candidates for the design of high-temperature piezoelectric transducers and actuators.
The Ndc80-Cdt1-Ska1 complex is a central processive kinetochore–microtubule coupling unit
Authors: Rahi Amit , Chakraborty Manas , Agarwal Shivangi , Vosberg Kristen M. , Agarwal Shivani , Wang Annie Y. , McKenney Richard J. , Varma Dileep
Published: June 2023

It is known that microtubule-binding proteins including the Ska1 complex and the DNA replication licensing factor, Cdt1, enable the kinetochore-localized Ndc80 complex to form robust kinetochore-microtubule attachments. However, it is not clear how the Ndc80 complex is stably coupled to dynamic spindle microtubule plus-ends. Here, we have developed a conditional auxin-inducible degron approach to reveal a function for Cdt1 in chromosome segregation and kinetochore–microtubule interactions that is separable from its role in DNA replication licensing. Further, we demonstrate that a direct interaction between Cdt1 and Ska1 is required for recruiting Cdt1 to kinetochores and spindle microtubules. Cdt1 phosphorylation by Cdk1 kinase is critical for Ska1 binding, kinetochore–microtubule attachments, and mitotic progression. Furthermore, we show that Cdt1 synergizes with Ndc80 and Ska1 for microtubule binding, including forming a diffusive, tripartite Ndc80-Cdt1-Ska1 complex that can processively track dynamic microtubule plus-ends in vitro. Taken together, our data identify the Ndc80-Cdt1-Ska1 complex as a central molecular unit that can promote processive bidirectional tip-tracking of microtubules by kinetochores.
Design principles for selective polarization of PAR proteins by cortical flows
Authors: Illukkumbura Rukshala , Hirani Nisha , Borrego-Pinto Joana , Bland Tom , Ng KangBo , Hubatsch Lars , McQuade Jessica , Endres Robert G. , Goehring Nathan W.
Published: June 2023

Clustering of membrane-associated molecules is thought to promote interactions with the actomyosin cortex, enabling size-dependent transport by actin flows. Consistent with this model, in the Caenorhabditis elegans zygote, efficient anterior segregation of the polarity protein PAR-3 requires oligomerization. However, through direct assessment of local coupling between motion of PAR proteins and the underlying cortex, we find no links between PAR-3 oligomer size and the degree of coupling. Indeed, both anterior and posterior PAR proteins experience similar advection velocities, at least over short distances. Consequently, differential cortex engagement cannot account for selectivity of PAR protein segregation by cortical flows. Combining experiment and theory, we demonstrate that a key determinant of differential segregation of PAR proteins by cortical flow is the stability of membrane association, which is enhanced by clustering and enables transport across cellular length scales. Thus, modulation of membrane binding dynamics allows cells to achieve selective transport by cortical flows despite widespread coupling between membrane-associated molecules and the cell cortex.
Dirac equation from stereographic projection of the momentum sphere
Authors: Marrocco Michele
Published: June 2023

The Dirac equation is commonly demonstrated under stringent hypotheses and after considerable math work made in relativistic quantum mechanics and quantum field theory. Here, a purely geometric approach free from hypotheses is suggested. The suggestion draws inspiration from the technique of stereographic projection that was developed before the quantum era to solve gyroscopic problems of classical mechanics. The projected variable is the generalized (or canonical) momentum vector. Its undetermined geometric orientations define a sphere in the momentum space and the projection onto the equatorial plane generates the Pauli matrices as soon as the conventional stereographic matrix is introduced. The associated eigenvalue problem results in the Dirac equation and the eigenvector (bispinor) has components that are related to geometric elements of the momentum space. The procedure has the advantage of revealing the correct form of the Dirac matrices without the mathematical effort that characterizes the presentation of the equation in traditional approaches. The other remarkable advantage is that, unlike the common reduction to the case of free space, the spatial inhomogeneity due to interaction potentials is included in the demonstration from the very beginning. The whole suggestion has an interdisciplinary character (relativity, complex analysis, rotation of rigid bodies, Pauli matrices) and can be useful in teaching the equation to students who lack in sufficient knowledge of quantum mechanics. Students equipped with more advanced education can benefit from the purely geometric perspective of this work if used to complement their studies about the equation.
Systematic solitary waves from their linear limits in two-component Bose–Einstein condensates with unequal dispersion coefficients
Authors: Wang Wenlong
Published: June 2023

We systematically construct vector solitary waves in harmonically trapped one-dimensional two-component Bose–Einstein condensates with unequal dispersion coefficients by a numerical continuation in chemical potentials from the respective analytic low-density linear limits to the high-density nonlinear Thomas-Fermi regime. The main feature of the linear states herein is that the component with the larger quantum number has instead a smaller linear eigenenergy, enabled by suitable unequal dispersion coefficients, leading to new series of solutions compared with the states similarly obtained in the equal dispersion setting. Particularly, the lowest-lying series gives the well-known dark-anti-dark waves, and the second series yields the dark-multi-dark states, and the following series become progressively more complex in their wave structures. The Bogoliubov-de Gennes spectra analysis shows that most of these states bear unstable modes, but they can be long-lived and remarkably all of them can be fully stabilized in suitable parameter regimes.
Probing the incoherent admixture of low and high-spin states of Co in (LaPr)CoO3 perovskite: focus on structural phase transitions
Authors: Tiwari P , Singha A D , Atkar S A , Datta A , Thota S
Published: June 2023

We report the mixed valence and intermediate spin-state (IS) transitions in Pr substituted LaCoO3 perovskites in the form of bulk and nanostructures. Various compositions (x) of La1−x
Pr
x
CoO3 (0 ⩽ x⩽ 0.9) were synthesized using the sol–gel process under moderate heat treatment conditions (600 °C). The structural analysis of these compounds reveals a phase crossover from the monoclinic phase (space group, s.g.: I2/a) to an orthorhombic one (s.g.: Pbnm), and a rhombohedral phase (s.g.: R-3c) to an orthorhombic one (s.g.: Pnma) in the bulk and nanostructures, respectively, for the composition range 0 ⩽ x⩽ 0.6. Such a structural transformation remarkably reduces the Jahn–Teller distortion factor ΔJT: 0.374 → 0.0016 signifying the dominant role of the IS state (S
Avg = 1) of trivalent Co ions in the investigated system. Magnetization measurements reveal the ferromagnetic (FM) nature of bulk LaCoO3 along with a weak antiferromagnetic (AFM) component coexisting with an FM component. This coexistence results in a weak loop-asymmetry (zero-field exchange-bias effect ∼134 Oe) at low temperatures. Here the FM ordering occurs due to the double-exchange interaction (J
EX
/k
B∼ 11.25 K) between the tetravalent and trivalent Co ions. Significant decrease in the ordering temperatures was noticed in the nanostructures (T
C ∼ 50 K) as compared to the bulk counterpart (∼90 K) due to the finite size/surface effects in the pristine compound. However, the incorporation of Pr leads to the development of a strong AFM component (J
EX/k
B ∼ 18.2 K) and enhances the ordering temperatures (∼145 K for x = 0.9) with negligible FM correlations in both bulk and nanostructures of LaPrCoO3 due to the dominant super-exchange interaction: Co3+/4+‒O‒Co3+/4+. Further evidence of the incoherent mixture of low-spin (LS) and high-spin (HS) states comes from the M–H measurements which yields a saturation magnetization of M
S ∼ 275 emu mol−1 (under the limit of 1/H → 0) consistent with the theoretical value of 279 emu mol−1 corresponding to the spin admixture: 65% LS + 10% IS of trivalent Co along with 25% of LS Co4+ in the bulk pristine compound. A similar analysis yields: Co3+ [30% LS + 20% IS] + Co4+ [50% of LS] for the nanostructures of LaCoO3, yet the Pr substitution decreases the spin admixture configuration. The Kubelka–Munk analysis of the optical absorbance results in a significant decrease in the optical energy band gap (E
g:1.86 → 1.80 eV) with the incorporation of Pr in LaCoO3 which corroborates the above results.
Ultra-sensitive voltage-controlled skyrmion-based spintronic diode
Authors: Rodrigues Davi R , Tomasello Riccardo , Siracusano Giulio , Carpentieri Mario , Finocchio Giovanni
Published: June 2023

We have designed a passive spintronic diode based on a single skyrmion stabilized in a magnetic tunnel junction and studied its dynamics induced by voltage-controlled magnetic anisotropy (VCMA) and Dzyaloshinskii–Moriya interaction (VDMI). We have demonstrated that the sensitivity (rectified output voltage over input microwave power) with realistic physical parameters and geometry can be larger than 10 kV W−1 which is one order of magnitude larger than diodes employing a uniform ferromagnetic state. Our numerical and analytical results on the VCMA and VDMI-driven resonant excitation of skyrmions beyond the linear regime reveal a frequency dependence on the amplitude and no efficient parametric resonance. Skyrmions with a smaller radius produced higher sensitivities, demonstrating the efficient scalability of skyrmion-based spintronic diodes. These results pave the way for designing passive ultra-sensitive and energy efficient skyrmion-based microwave detectors.
Evaluation of cardiovascular and cerebrovascular control mechanisms in postural orthostatic tachycardia syndrome via conditional transfer entropy: the impact of the respiratory signal type
Authors: Gelpi Francesca , Bari Vlasta , Cairo Beatrice , De Maria Beatrice , Wells Rachel , Baumert Mathias , Porta Alberto
Published: June 2023

Objective. Closed loop cardiovascular (CV) and cerebrovascular (CBV) variability interactions are assessed via transfer entropy (TE) from systolic arterial pressure (SAP) to heart period (HP) and vice versa and from mean arterial pressure (MAP) to mean cerebral blood velocity (MCBv) and vice versa. This analysis is exploited to assess the efficiency of baroreflex and cerebral autoregulation. This study aims at characterizing CV and CBV controls in postural orthostatic tachycardiac syndrome (POTS) subjects experiencing exaggerated sympathetic response during orthostatic challenge via unconditional TE and TE conditioned on respiratory activity (R). Approach. In 18 healthy controls (age: 28 ± 13 yrs; 5 males, 13 females) and 15 POTS individuals (age: 29 ± 11 yrs; 3 males, 12 females) we acquired beat-to-beat variability of HP, SAP, MAP and MCBv and two R signals, namely respiratory chest movement (RCM) and capnogram (CAP). Recordings were made at sitting rest and during active standing (STAND). TE was computed via vector autoregressive approach. Main results. We found that: (i) when assessing CV interactions, the increase of the TE from SAP to HP during STAND, indicating baroreflex activation, is detected solely when conditioning on RCM; (ii) when assessing CBV interactions, the impact of R on the TE computation is negligible; (iii) POTS shows baroreflex impairment during STAND; (iv) POTS exhibits a normal CBV response to STAND. Significance. TE is useful for detecting the impairment of specific regulatory mechanisms in POTS. Moreover, using different R signals highlights the sensitivity of CV and CBV controls to specific R aspects.
Magnetic nozzle performance in a cluster of helicon plasma thrusters
Authors: Di Fede Simone , Manente Marco , João Comunian Paolo , Magarotto Mirko
Published: June 2023

A numerical study of the plasma dynamics in a Helicon Plasma Thrusters’ (HPT) cluster is presented. For the first time in the literature, the three-dimensional (3D) plasma dynamics occurring in the plume of a HPTs’ cluster is analyzed. The physical investigation relies on ProPic, a 3D particle-in-cell (PIC) code specifically designed to simulate the plasma dynamics in magnetic nozzles and in a non-axi-symmetric domain. The code has been validated against experiments reported in the literature and cross-validated with Starfish, an open-source two-dimensional PIC software. The physical investigation has revealed an interesting mutual influence between the thrusters that constitute the cluster. Three significant phenomena that affect the cluster’s performance have been identified. The first phenomenon is related to the effect that clustering has on the shape of the magnetic field lines and, in turn, on the divergence angle of the plume. The second phenomenon is related to electron currents flowing among different thrusters, which affect the potential drop across the plume. The third phenomenon is related to the effect that neighboring thrusters have on the plasma potential map and, in turn, on the expansion of the ions.
Quartic autocatalysis on horizontal surfaces with an asymmetric concentration: water-based ternary-hybrid nanofluid carrying titania, copper, and alumina nanoparticles
Authors: Saranya S , Duraihem Faisal Z , I L Animasaun , Al-Mdallal Qasem M
Published: June 2023

Understanding the mechanisms and kinetics of homogeneous (i.e. water-based ternary-hybrid nanofluid) and heterogeneous (i.e. catalyst) reactions is capable of creating a more effective distribution of species and quality of fluids at the outlet. Thus, the present study focuses on analyzing the quartic type homogeneous-heterogeneous reactions in ternary-hybrid nanofluid of copper, alumina, and titania nanoparticles with water at the surface of a stationary/moving flat plate. The leading non-linear partial differential equations were transformed into a set of ordinary differential equations using local similarity transformations. The resultant non-linear ordinary differential equations were numerically solved using MATLAB’s built-in BVP4C tool to explore the impact of pertinent factors. From the design side of view, the Tiwari-Das model for nano-liquid was employed to study the flow-thermal behaviour of the nanofluid. The thermal conductivity formulations were taken from experimental works to incorporate the spherical, platelet and cylindrical-shaped nanoparticles. The proposed concept is comparatively analyzed for Blasius and Sakiadis flows. The homogeneous bulk fluid and heterogeneous catalyst concentrations are observed for small and large nanoparticle volume fractions. The investigation shows that the strength of homogeneous and heterogeneous reactions has the opposite effect on the concentration fields. Strong correlations exist between the heterogeneous catalyst’s diffusivity and the homogeneous bulk fluid’s viscosity. Mass diffusion became more prevalent at the surface as the Schmidt number surged. Conversely, the bulk fluid concentration was highest in areas far from the surface.
Simultaneous detection of CH4 and CO2 through dual modulation off-axis integrated cavity output spectroscopy
Authors: Liu 刘 Yi-Xuan 艺璇 , Wang 王 Zhou-Bing 周兵 , Wei 韦 Xin-Xin 欣欣 , Wang 王 Jing-Jing 静静 , Meng 孟 Xin 鑫 , Mao 毛 Gui-Lin 桂林
Published: June 2023

This study established a novel method for the simultaneous detection of two-component gases. Radio frequency (RF) white noise disturbance laser current and wavelength modulation were simultaneously used to improve the off-axis integrated cavity output spectroscopy technique, and a high-precision dual modulation OA-ICOS (RF-WM-OA-ICOS) system was established. The two laser beams were coupled into one laser beam that was applied incident to the cavity of RF-WM-OA-ICOS system. The second harmonic signals of CH4 and CO2 gas simultaneously appeared in the rising or falling edge of a triangular wave. This method was used to measure CH4 and CO2 with different concentrations. The results indicated that the proposed system has high stability and can accurately and simultaneously measure the concentrations of CH4 and CO2, with an optimal integration time of 220 s. The minimum detection limit was 10 ppb for CH4 and 1.5 ppm for CO2. The corresponding noise equivalent absorption sensitivity values were calculated as 2.67 × 10−13 cm−1⋅Hz−1/2 and 5.18 × 10−11 cm−1⋅Hz−1/2, respectively. The proposed dual-component gas simultaneous detection method can also be used for high-precision simultaneous detection of other gases. Therefore, this study may serve as a reference for developing portable multicomponent gas analyzers.
H i Galaxy Detections in the Zone of Avoidance with FAST
Authors: Feng Chao , Liu Bin , Xi Hong-Wei , Peng Bo
Published: June 2023

The Zone of Avoidance (ZoA) is a region of low galactic latitude that is heavily obscured by the Milky Way. Observations with radio telescopes are basically unaffected by dust extinction and can unveil the structure behind it through the Milky Way. One of the scientific goals of the Five-hundred-meter Aperture Spherical radio Telescope (FAST) is to search for the neutral hydrogen and understand the large-scale physics to explore the origin and evolution of the universe. We take the 15,500 IRAS (the Infrared Astronomical Satellite) galaxies from PSCz (“Point Source Catalog”) survey to reconstruct the density field of the local universe, obtain the distribution of the relative density of galaxies in the ZoA region with a redshift z below 0.07, and the number of detectable galaxies with FAST is estimated by using the neutral hydrogen mass function of the ALFA (Arecibo L-band Feed Array) survey. We conclude that FAST can observe more than 2000 ZoA galaxies within a distance of 300 Mpc

h

70

−
1

, and present preliminary results of the partial GPPS (the FAST Galactic Plane Pulsar Snapshot survey) data, compared with ALFA ZoA (The Arecibo L-band Feed Array Zone of Avoidance), show that FAST has a higher detection sensitivity to search for H i galaxies in the ZoA area.
Standard Model and Prospects
Authors: Iliopoulos J
Published: June 2023

We review the present status of the Standard Model in High Energy Physics, its great successes as well as the questions which are left unanswered. We briefly indicate some theoretical ideas and some crucial experiments which may show the way to obtain a theory Beyond the Standard Model.
Review on dark matter searches
Authors: Cebrián Susana
Published: June 2023

Dark matter particles populating our galactic halo could be directly detected by measuring their scattering off target nuclei or electrons in a suitable detector. As this interaction is expected to occur with very low probability and would generate very small energy deposits, the detection is challenging; the possible identification of distinctive signatures (like an annual modulation in the interaction rates or directionality) to assign a dark matter origin to a possible observation is being considered. Here, the physics case of different dark matter direct detection experiments will be presented and the different and complementary techniques which are being applied or considered will be discussed, summarizing their features and latest results obtained. Special focus will be made on TPC-related projects; experiments using noble liquids have presently a leading role to constrain interaction cross sections of a wide range of dark matter candidates and gaseous detectors are very promising to explore specifically low mass dark matter as well as to measure directionality.
Mathematical model of polylactic acid biodegradation under controlled composting conditions
Authors: Baldera-Moreno Y , Rojas-Palma A , Andler R , Cuesta-Herrera L
Published: June 2023

The environment suffers constant damage due to the excessive manufacture of non-degradable materials. Since petroleum-derived plastic polymers degrade slowly, it is necessary to promote the use of biodegradable plastics, such as polylactic acid. Polylactic acid is produced from natural and renewable resources, it has suitable physical and chemical properties, and biodegrades under appropriate temperature and humidity conditions, which are achieved in the composting process. Currently, there are models that are based on the measurement of carbon dioxide, and mass loss, among others. However, there are no models that describe the biodegradation of polylactic acid considering the effect of the influencing factors of the composting process. The objective of this work is to model the dynamics of polylactic acid biodegradation under controlled composting conditions, considering the main influencing factors, such as temperature, moisture content, and oxygen. Using mathematical modeling from ordinary differential equations as a methodology, simulations were carried out based on the degradation of dry matter from different substrates. The results aim to predict the dynamics of polylactic acid biodegradation, through a model that integrates the influencing factors of the composting process.
Hydromechanical behavior of unsaturated swelling clays: review
Authors: Olarte M C , Cavalcante A L B
Published: June 2023

Expansive soils are materials composed mainly of active minerals of the smectite family, where montmorillonite is an essential member of that group. These types of soils tend to undergo volumetric changes due to variations in moisture content. Many geotechnical engineering practices, such as dam core design or subgrade compaction, require a thorough evaluation of the response of these soils to determine placement conditions. However, the main problem in evaluating the mechanical response of this type of soil lies in the nonlinear nature, which limits the use of most classical constitutive models that apply the basic rules of elastoplasticity. In this study, an analysis is carried out to understand the hydromechanical behavior of expansive soils in saturated and unsaturated conditions. Direct and indirect physical evidence is presented and discussed to evaluate the hydraulic response of the soil structural elements responsible for these adverse dynamics from a global (expansive phenomena as a whole) and individual (swelling and shrinkage) perspective. Since the response of these soils is hydrostatic dependent, the locus of water movement in porous media is examined, starting from the Richards equation (1931), in order to consider the flow mechanisms in unsaturated media under transient conditions.
Improvement of maintenance and asset management strategy in a maritime terminal under regulatory and physicochemical testing criteria
Authors: Arrieta-Estrella E A , Dueñas-Ramírez L M
Published: June 2023

This work was developed in the gas and oil sector, more specifically in the equipment that make up the Coveñas maritime terminal, one of the main oil terminals in Colombia. This work sought to improve the maintenance strategy and asset management of all terminal equipment through criteria based on international standards such as International Organization for Standardization 14224, which guides the ranking of equipment; also considered were the results of physicochemical tests that were applied to sample materials obtained from the equipment in the field. With this information, a road map was drawn up to establish a maintenance and asset management plan to improve the efficiency of the marine terminal’s operation. The physical variables measured in this equipment and its parts, evidenced the importance of carrying out projects with interdisciplinary approaches, to enhance the achievement of the objectives set. In this specific case, a considerable improvement in maintenance work execution hours was shown.
Obtaining structural parameters of cerium-doped lanthanum cobaltites from X-ray diffraction pattern modeling
Authors: Oviedo Cuéter J M , Sánchez Pacheco L C , Mora Florez C D
Published: June 2023

In this work, structural parameters of lanthanum cobaltites doped with cerium atomic concentration of 1%, 3%, and 5 %, synthesized using the sol-gel method and considering calcination temperature of 900 °C, were estimated from the modeling of the X-ray diffraction patterns of the samples. Modeling of the experimental X-ray diffraction patterns is carried out using the Rietveld refinement method implemented with the Fullprof-Suite program. Estimation of crystallite sizes obtained from diffraction peak modeling, implemented with the X powder program, and using the Scherrer equation and Williamson-Hall plots, considering Lorentzian and Pseudo Voigt line profiles, are also performed. Additionally, the obtained compounds were also characterized by scanning electron microscopy. The identified phase for the samples corresponds to hexagonal perovskite structure and

R

3

¯

c

(# 167) space group, with crystallite size in the range of 38 nm to 56 nm. In general, significant changes in the structural parameters of the samples due to doping with cerium are not evidenced.
Mechanical analysis for personalized implant for neurocranial protection manufactured with Polymethylmethacrylate
Authors: Moncayo-Matute F P , Vázquez-Silva E , Torres-Jara P B , Peña-Tapia P G , Moya-Loayza D P , Abad-Farán G
Published: June 2023

Advances in terms of mathematical simulation techniques have favored the development of successful methodologies for the restoration or restitution of bone structures in the human body. Achievements in materials science and their physical, mechanical and biological characterization have allowed the development of biocompatible composites capable of achieving properties and similarities comparable to those of natural bone. This research aims to evaluate some mechanical properties of a customized cranial implant manufactured from polymethylmethacrylate. With the support of finite element method, the level of neurocranial protection offered by the manufactured implant is assessed.
Local Yang–Baxter correspondences and set-theoretical solutions to the Zamolodchikov tetrahedron equation
Authors: Igonin S , Konstantinou-Rizos S
Published: June 2023

We study tetrahedron maps, which are set-theoretical solutions to the Zamolodchikov tetrahedron equation, and their matrix Lax representations defined by the local Yang–Baxter equation. Sergeev (1998 Lett. Math. Phys.
45 113–9) presented classification results on three-dimensional tetrahedron maps obtained from the local Yang–Baxter equation for a certain class of matrix-functions in the situation when the equation possesses a unique solution which determines a tetrahedron map. In this paper, using correspondences arising from the local Yang–Baxter equation for some simple

2
×
2

matrix-functions, we show that there are (non-unique) solutions to the local Yang–Baxter equation which define tetrahedron maps that do not belong to the Sergeev list; this paves the way for a new, wider classification of tetrahedron maps. We present invariants for the derived tetrahedron maps and prove Liouville integrability for some of them. Furthermore, using the approach of solving correspondences arising from the local Yang–Baxter equation, we obtain several new birational tetrahedron maps with Lax representations and invariants, including maps on arbitrary groups, a nine-dimensional map associated with a Darboux transformation for the derivative nonlinear Schrödinger equation, and a nine-dimensional generalisation of the three-dimensional Hirota map.
Seasonal response of coccolithophores and its potential to reconstruct paleomonsoon in the eastern Indonesian seas: an overview
Authors: Yuwono F S , Rendy
Published: June 2023

Coccolithophore is a group of marine calcifying phytoplankton and its living distribution is sensitive to ecological change within the photic zone. Their coccoliths contribute majorly to the marine sediments and have become a reliable proxy in paleoceanography and paleoclimatology. The upper hydrology of the eastern Indonesian seas has been strongly influenced by seasonal climate change, the Australian-Indonesian monsoon. We review and discuss the result of previous studies on the response of living coccolithophore to seasonal change and the significance of their coccoliths as a proxy for reconstructing past dynamic of monsoon in the region. Coccolithophores abundance, species assemblages and coccolith malformation change in respond to the shift of photic environment condition modulated by reversing monsoon with particular responds across the region. Coccoliths variations in the marine sediment core archives from off southwest Sumba, eastern Banda Sea and Halmahera Sea show an insignificant control of glacial-interglacial climate variability to paleoproducitivity. Primary productivity based on the relative abundance of Florisphaera profunda has contributed to reconstruction of the past dynamic of Australian-Indonesian monsoon. However, more extensive and continuous observation of coccolithophores and their relationship with the photic environment in the eastern Indonesian seas is necessary for a better understanding of their response to monsoon dynamics in the present, past and future.
Sedimentary Facies of the Cimanuk River Delta on the North Java Coastal Area and Its Geotechnical Properties
Authors: Soebowo E , Sarah D , Wibawa S
Published: June 2023

Understanding the sedimentary facies and their engineering properties in the Cimanuk river delta is very important to support the regional infrastructure development and the environmental assessment of the north Java coastal area. This research is aimed to characterize the sedimentary facies association and its geotechnical properties of the Cimanuk delta, Indramayu, West Java. Methods included geotechnical boring and Cone Penetration Tests with pore water measurement (CPTu). The results show that the subsurface condition of the Cimanuk delta comprises several sedimentary facies development and boundaries, namely the delta plain, delta front, and prodelta. The delta plain consists of the fluvial channel sands and marsh-lagoon; the delta front consists of beach ridge, and the prodelta is of clay to silt thickening towards the northeast. The fluvial channel consists of fluvial sand and silt, dense and hard with SPT N value of 30 and cone resistance, qc of 2,000-10,000 kPa. The beach ridge comprises beach sand and sandy silt, loose to very dense, with qc value of 500-16,000 kPa and SPT N value of 30. The delta plain sandy silt has a variable consistency from very soft to hard with SPT N value of 1-37, and qc value of 300- 4,900 kPa. The prodelta clay and silt consist of very soft to medium consistency, with qc value of 200- 3,000 kPa and SPT N value of 1-8. The prodelta clay-silts engineering properties are very soft to a soft consistency. When development occurs in the marsh-lagoon and prodelta facies, particular caution must be taken. The vertical, lateral, and spatial sedimentary facies and their geotechnical properties can provide information for spatial planning in the coastal region.
Quaternary Seabed Sediment Characteristics as an indication of VMS-mineral deposits at the South Banda Basin and its surroundings, Indonesia
Authors: Aryanto Noor C.D. , Kurnio H. , Tuakia M.Z. , Tampubolon A. , Pardiarto B. , Widi B.N , Widodo W. , Kusnawan
Published: June 2023

The South Banda back-arc basin is a morphotectonic environment that is part of the South Banda Basin, characterized by a flat morphology with depths ranging from 5000m to 6000m. The purpose of this paper is to analyze and relate morphometric aspects to the Quaternary seabed sediment deposits deposited in an active tectonic basin in the Banda Sea area, including information on the type of sediment and its distribution as well as its relation to volcanic hosted-massive sulfide (VHMS) or volcanogenic massive sulfide (VMS) mineral deposits. The seabed lithofacies in the Banda Arc area were deposited in several morphotectonic environments. The types of deposits that are deposited are pelagic, and hemipelagic deposits including turbidite and volcanic origin deposits. Volcanic deposits consist of gravel, sand, muddy sand, and silt which are classified very poorly to moderately well sorted. The grain composition is volcanic lithic, feldspar, augite, hypersthene, and enstatite which are commonly found in volcanic arcs and troughs. Groups of volcanic grains composed of pyroxene andesite, pumice, and tuffite or siliceous gravel, distributed in the northern and the middle of the volcanic arc area are interpreted to originate from the Banda volcanic complex and the Seram-Gorong islands.
A preliminary magnetic anomaly study of the Nieuwerkerk Seamount, Banda Sea, Indonesia
Authors: Alodia G , Nugroho A B , Nurhidayat  , Kalambo Y , Fadillah A , Pratama A , Wiguna T
Published: June 2023

The Nieuwerkerk seamount has been identified in the Banda Sea since the 1930s by Dutch researchers through the Snellius Expedition. However, the physical description of the seamount and its relation to the surrounding seafloor features has not been discussed due to the lack of geophysical data in the area. This study addresses those issues by examining the shipboard magnetic anomalies acquired during the Jalacitra II-2022 “Banda” Expedition. The result indicates two possible magmatic flows, with the reduced-to-equator magnetic anomaly of around -120 nT and -30 nT at the main and secondary summits, respectively. No magnetic anomaly is identified at the ridge east of the seamount, indicating the absence of structure or magmatic rocks. An extreme magnetic anomaly contrast of up to 145 nT is indicated at the southern foot of the seamount, striking ENE-WSW. These magnetic discontinuities are possibly depicting strike-slip faults, which are also found at the three other smaller seamounts southwest of Nieuwerkerk. These preliminary physical descriptions are key to opening up a discussion on the structure and activities of the Nieuwerkerk seamount and its relationship with the surrounding seafloor features.
Geopark as a Participatory Collaborative Management Concept to Manage the Raja Ampat Archipelago
Authors: Septiana A R , Samodra H , Lamatenggo Y N
Published: June 2023

Numerous and multi-level organizations from sub-national to international working in Raja Ampat Regency as the globally important marine areas and world’s class tourism, yet the gap of knowledge and capacities with communities keeps distancing. Raja Ampat Geopark exists as a management agency that coordinates various programs implemented by multi-institutions with various interests within the Regency. Approaching the effective management, Raja Ampat Geopark performs through three stages: 1) mapping relevant stakeholders; 2) designing a participatory collaboration strategy; and 3) encouraging the collaborative works following the strategy where the roles of each stakeholder are clear. Master plan of Raja Ampat Geopark were developed and agreed by 41 related partners of were clustered into 8 interest groups, who are implementing 31 programs consists of 84 activities. This collaborative participatory marine management resulting an increase of documentation and published biodiversity data, of which empowered by the improved capacities of local government and communities in Raja Ampat.
Marine Protected Area management under the impacts of climate change and increased human activities in marine ecosystems: A review for Anambas Islands MPA
Authors: Taufiqurrahman Edwards , Prayitno Hanif Budi , Ibrahim Putri Sapira , Ratnawati Herlina Ika , Maslukah Lilik
Published: June 2023

The Anambas Islands is one of richest marine biodiversity area in western part of Indonesia, especially for species appeared in coral reef ecosystems. However, as in other parts of the world, climate change and increased human activities pose threats to the ecosystem’s sustainability. Efforts to maintain the balance of the ecosystem in Anambas Islands have been conducted by stating the Anambas Islands and its surrounding sea as a Marine Protected Area (MPA). Here, we review the studies featuring Anambas Island MPA in ecosystem resilience of the islands. From this review, we suggest that oceanographic parameters, especially marine biogeochemistry parameters, should be further utilized to provide environmental data to be used for policy development in the MPA management. Further research and development using marine biogeochemical parameter monitoring/assessment should be taken into consideration by relevant stakeholders in order to achieve MPA’s objectives.
Analysing climate change in the coastal zone: the case of Kepulauan Riau, Indonesia
Authors: Safitri Dian Prima , Hakim Abdul , Khairul Muluk M.R. , Putra Fadillah
Published: June 2023

Unsustainable development is our species’ biggest threat to private and public values. The coastal zone most affected by climate change and public value (PV) should be actively engaged with the environmental issues because ecology has provided the most fundamental criticism of PV. However, we still don’t fully comprehend how public value is considered while managing climate change in Kepulauan Riau, Indonesia. This paper challenges Moore’s strategic triangle as a framework for coordinating the process in producing public value, namely: the definition of public value; the authorising environment, and; organizational capacity. The purpose of the paper is to explore the public value considered in reducing the impact of climate change. We identified Moore’s strategic triangle using desk research and secondary sources. Results support the assertion that public value is not created by the public sector alone but also recognized by other sources. This study suggests that government develop and strengthen institutions to handle contemporary environmental issues in order to organize climate change. Lack of ecological literacy can have ramifications for organizational capability.
Determination of Marine Conservation Areas by means of Satellite Imagery and Participatory Planning in Bawean Island, Gresik Regency, East Java
Authors: Firmansyah F , Ariastita P G , Wirawan I , Yusuf M , Koswara A Y , Argarini T O
Published: June 2023

Bawean Island and its marine surrounding hold a lot of potential biotas in its marine ecosystem. To maintain these potential natural resources, it is necessary to make marine conservation efforts, one of which is by means of Bawean marine conservation area determination. This research began with the preparation of image processing to determine the distribution of seagrass and coral reef biota. Furthermore, a groundcheck was carried out to review the condition of the existing ecosystem, the results of which became input for FGD as a form of participatory planning. Categories, types, zones, and subzones of conservation areas are determined based on marine and fisheries regulations. As a result, seagrasses can be found at several points in Bawean waters with a total area of 125.60 ha. The average seagrass closure condition can be considered as moderate, with the most encountered species being Thalassia Hemprichii. Meanwhile, coral reefs distribution is scattered in almost all Bawean marine with a total cover area of 3,037.51 ha. The average live coral reef cover in the observation area reaches 76%, which can be considered as good condition.