Pair Of Elements Research Articles

Multivalent Redox Reversible Conversion-Enhanced Electrochemiluminescence Strategy for Progesterone Detection.

The performance of electrochemiluminescence (ECL) sensing platforms, especially the sensitivity, relies on an efficient signal enhancement mechanism and presents a critical challenge in developing novel strategies simultaneously. In this work, we reported a multivalent redox reversible conversion-enhanced ECL strategy based on the redox reactions of two pairs of multivalent metal elements on the electrode surface. TiO2-loaded Eu(OH)3 (Eu(OH)3@TiO2) was introduced as a dual-enhanced coreactant accelerator to catalyze the oxidation process of tripropylamine (TPrA), thus improving the reaction rate at the sensing interface and the ECL strength of the luminophore. Moreover, gadolinium hydroxide (Gd(OH)3) served as the ECL emitter for the sensing platform. The stable luminescence property of Gd(OH)3 was observed, laying the foundation for its application in ECL sensing. To construct the immunosensor, a heptapeptide affinity ligand (HWRGWVC, HGC) was introduced to oriented immobilize antibodies. HGC effectively maintained the biological activity, thus improving the incubation efficiency and detection performance of the immunosensor. In this study, a competitive ECL immunoassay model was designed for the sensitive detection of progesterone (P4). The competitive immunosensor exhibited a broad range of 0.001-200 ng·mL-1 and a low detection limit of 0.38 pg·mL-1. The competitive sensing model based on the dual-enhanced strategy is expected to offer a prospective approach to precise detection.

Output Characteristics of Carbon Nanotube Thermoelectric Generator with Slitted Kirigami Structure

The objective of our research is to improve the power generation of a thermoelectric generator (TEG) using a single-walled carbon nanotube (SWCNT) sheet by applying the out-of-plane deformation of a slitted kirigami structure. In order to obtain a large amount of power from a TEG using a thin-film thermoelectric (TE) element such as a SWCNT sheet, it is necessary to generate a large temperature difference in the in-plane direction of the thin-film TE element. However, it is difficult to realize a large temperature difference when the thin-film TE element is in contact with a heat source due to the need for a layer with high heat insulation. In this research, we proposed and fabricated a TEG with the out-of-plane deformation of a kirigami structure with slits using a p-n patterned SWCNT sheet as the thin-film TE material and evaluated the open circuit voltage with respect to the out-of-plane deformation and the number of TE elements. As a result, the output performance of SWCNT TEG was clarified when the out-of-plane deformation and the number of TE element pairs were varied.

Intersection density of transitive groups with small cyclic point stabilizers

For a permutation group G acting on a set V, a subset F of G is said to be an intersecting set if for every pair of elements g,h∈F there exists v∈V such that g(v)=h(v). The intersection densityρ(G) of a transitive permutation group G is the maximum value of the quotient |F|/|Gv| where Gv is a stabilizer of a point v∈V and F runs over all intersecting sets in G. If Gv is a largest intersecting set in G then G is said to have the Erdős-Ko-Rado (EKR)-property. This paper is devoted to the study of transitive permutation groups, with point stabilizers of prime order with a special emphasis given to orders 2 and 3, which do not have the EKR-property. Among others, constructions of an infinite family of transitive permutation groups having point stabilizer of order 3 with intersection density 4/3 and of infinite families of transitive permutation groups having point stabilizer of order 3 with arbitrarily large intersection density are given.

Strongly dense representations of surface groups

Abstract The notion of a strongly dense subgroup was introduced by Breuillard, Green, Guralnick and Tao: a subgroup Γ of a semi-simple $\mathbb{Q}$ algebraic group $\mathcal{G}$ is called strongly dense if every pair of non-commuting elements generate a Zariski dense subgroup. Amongst other things, Breuillard et al. prove that there exist strongly dense free subgroups in $\mathcal{G}({\mathbb{R}})$ and ask whether or not a Zariski dense subgroup of $\mathcal{G}(\mathbb{R})$ always contains a strongly dense free subgroup. In this paper, we answer this for many surface subgroups of $\textrm{SL}(3,\mathbb{R})$ .

EXTENSIVE GENETIC INTERACTIONS (EPISTASIS) LINKED TO ALCOHOL USE DISORDER IN A HIGH-RISK POPULATION.

Alcohol use disorder (AUD) is known to have a significant genetic component, yet there remains a substantial gap between its heritability and findings from genome-wide association studies. One potential factor contributing to this gap may be genetic interactions, or epistasis, a largely unexplored aspect in the context of AUD. The aim of this study was to investigate the role of epistasis in AUD susceptibility and severity among American Indians, a population that exhibits the highest rates of AUD among all ethnic groups in the U.S. We began by identifying genes previously linked to alcohol dependence and AUD, then expanded this gene set through biological networks, ultimately comprising 3,736 genes and regulatory elements. The final gene set was mapped to over 476K variants in an American Indian cohort of 742 individuals. We performed a pairwise genetic interaction association analysis on the variant set, followed by a bi-clustering procedure to group the interacting SNP pairs into interacting intervals. A total of 114 interacting pairs of genes and regulatory elements were identified to be significantly associated with AUD severity. These genes were enriched for immune system, cell adhesion, neuronal, and disease pathways. Their expressions were particularly enriched in midbrain GABAergic neurons. Our study represents the first large-scale genetic interaction study of AUD in any population. Our findings suggest that epistasis may significantly contribute to the development and progression of AUD.

Energy efficiency in materials testing by reactive power – part 1: power recirculating method in wear testing

Abstract Reactive power is related to the type of power that does not consume energy but stores it. In the design of test machines, the utilization of this physical phenomenon would be very beneficial. Reactive power allows for the combination of power amplification with energy savings, making it an ideal principle for conducting long-term tests that involve high loads and prolonged energy consumption. This concept is illustrated in this work focusing test machines used in rotary testing procedures. Drive element pairs, which serve as component test objects, are primarily exposed to wear stress. These stressed element pairs are consequently integral parts of a tribological system. The underlying principles of power amplification and power feedback are explained from the perspectives of drive technology, systematic design, methodical design, and mechatronics.

DNA duplication-mediated activation of a two-component regulatory system serves as a bet-hedging strategy for Burkholderia thailandensis.

Transposable elements naturally accumulate within genomes in all kingdoms of life. When present in the same orientation, a pair of homologous elements can act as substrates for DNA recombination reactions that can duplicate and delete intervening sequences - giving rise to genetically heterogenous populations. We showed here that Burkholderia thailandensis strain E264 uses this mechanism to amplify genes encoding a two-component regulatory system and an archaic chaperone usher pilus, priming the cells for rapid biofilm formation. The formation of a small subpopulation of biofilm-ready bacteria serves as a bet- hedging strategy, ensuring overall population survival should conditions change rapidly from those in which planktonic growth is optimal to those in which adherence and biofilm formation is required.

Ranking approaches for similarity-based web element location

Context:GUI-based tests for web applications are frequently broken by fragility, i.e. regression tests fail due to changing properties of the web elements. The most influential factor for fragility are the locators used in the scripts, i.e. the means of identifying the elements of the GUI. Objective:We extend a state-of-the-art Multi-Locator solution that considers 14 locators from the DOM model of a web application, and identifies overlapping nodes in the DOM tree (VON-Similo). We augment the approach with standard Machine Learning and Learning to Rank (LTR) approaches to aid the location of web elements. Method:We document an experiment with a ground truth of 1163 web element pairs, taken from different releases of 40 web applications, to compare the robustness of the algorithms to locator weight change, and the performance of LTR approaches in terms of MeanRank and PctAtN. Results:Using LTR algorithms, we obtain a maximum probability of finding the correct target at the first position of 88.4% (lowest 82.57%), and among the first three positions of 94.79% (lowest 91.86%). The best mean rank of the correct candidate is 1.57. Conclusion:The similarity-based approach proved to be highly dependable in the context of web application testing, where a low percentage of matching errors can still be accepted.

Natural assemblages of the earliest Triassic conodont Hindeodus parvus from the Shangsi section, Sichuan province, Southwest China

The morphology and number of elements in the Early Triassic conodont apparatus of the genus Hindeodus, particularly Hindeodus parvus (Kozur and Pjatakova, 1976), still remain controversial. In order to shed light on the apparatus composition of this iconic genus, here we report two well-preserved conodont natural assemblages of Hindeodus from the base of Member I of the Feixianguan Formation (Induan, lower Griesbachian, in age) at Shangsi section, Sichuan Province, Southwest China. These two natural assemblages preserve direct evidence of the number, morphology, and arrangement of elements in the apparatus of Hindeodus, and in particular H. parvus. The apparatus of H. parvus consists of six morphotype elements with S, M, and P positions, showing the typical ozarkodinid 15-element arrangement. The S1-S4 array comprises a set of nine ramiform elements: a crown-shaped alate element without a ‘posterior’ process situated at the S0 position, two inner pairs of digyrate elements positioned at the S1–2 positions, and two outer pairs of bipennate elements located at the S3 and S4 locations. A pair of dolabrate elements occupy the M position outside the S array. The paired P1 and P2 positions are occupied by carminiscaphate and angulate elements, respectively. The 15-element apparatus architecture for the genus, resembles the well-known template of ozarkodinid model, further indicating the conservative architecture of the apparatus in Order Ozarkodinida spanning more than 250 million years.

Mechano-chemical competition in driven complex concentrated alloys

Mechanically driven complex concentrated alloys can be formed by three or more types of elemental powders mixing into a solid solution through severe plastic deformation at temperatures much lower than the melting point of each element. While competition between the thermal and mechanical driving forces during forced mixing of binary systems with positive enthalpy of mixing is relatively well understood, the physics of mechanically driven mixing of multiple elements with negative mixing enthalpies remained unclear. In this work, we combined mechanical alloying (MA), X-ray diffraction (XRD), and kinetic Monte Carlo (kMC) simulations to systematically study the interplay between the chemical pairing potential and the mechanical strength of elemental pairs during the formation process of mechanically driven complex concentrated alloys. We demonstrate that the chemical and mechanical forces play a competing role in the mixing of ternary complex concentrated alloys with negative mixing enthalpies. The chemical driving force favors a chemically ordered atomic structure, while the mechanical force encourages a random atomic arrangement. We reveal the energetic basis of this competition as the gain and loss in mixing enthalpy and configurational entropy. Following this fundamental understanding, three types of mixing mechanisms and their corresponding steady-state phases are defined. We show that the molar content of the element with the lowest average mixing enthalpy governs the mixing mechanisms and thus determines the energetic stabilization of the steady-state phases. A theoretical phase prediction map is provided for alloy design. We synthesized a nanocrystalline equiatomic NiCoCr coating under the guidelines of the map, which presents exceptional mechanical properties achieved by the mechano-chemical mixing.

Determination of Minor and Trace Elements in Breast Milk of Lactating Mothers in Early Lactation from Tehran, Iran Using Neutron Activation Analysis Method.

This study aimed to evaluate the concentrations of both essential and non-essential elements in the breast milk of lactating mothers from Tehran, Iran, during the colostrum period. Neutron activation analysis (NAA) was used to measure the element concentrations. Additionally, the study assessed how these element concentrations were influenced by maternal factors such as age and economic status. Breast milk samples were collected from 95 lactating mothers, aged 18 to 41, during the early lactation phase, specifically within the colostrum period (2-7 days postpartum). The colostrum milk samples were freeze-dried, powdered, and irradiated at the Tehran Research Reactor for neutron activation analysis (NAA). This method was used to measure the concentrations of essential elements-calcium (Ca), potassium (K), sodium (Na), chlorine (Cl), and iodine (I)-as well as non-essential elements-aluminum (Al), bromine (Br), and rubidium (Rb). Descriptive statistics, including mean, median, maximum, minimum, and standard deviation, were calculated for each element. Statistical analyses, such as Pearson's correlation, were performed to assess relationships between the concentrations of various elements. Additionally, t-tests and p-values were employed to evaluate differences in element levels across maternal age groups (17-34 years vs. 35-45 years) and economic status (high/middle vs. low). The mean concentrations of the elements in dry breast milk powder samples were: Al = 6.9mg/kg, Br = 11.9mg/kg, Ca = 2.757mg/g, Cl = 7.836mg/g, I = 1.22mg/kg, K = 5.853mg/g, Na = 4.932mg/g, and Rb = 3.69mg/kg. Significant correlations were found between element pairs, such as Na-Cl, Br-Cl, Na-Br, Rb-K, and I-Cl. Maternal age significantly influenced bromine concentrations, with older mothers showing 22% higher Br levels (p = 0.038), while calcium levels were 15% lower but not statistically significant (p = 0.20). Maternal economic status significantly impacted calcium and potassium concentrations, with higher levels observed in mothers from better economic conditions (p = 0.02 and p = 0.025, respectively). This study highlights the elemental composition of breast milk samples of lactating mothers in Tehran and shows that maternal factors, such as age and economic status, can significantly influence the concentrations of specific elements in breast milk.

On the connectivity of the generating and rank graphs of finite groups

The generating graph encodes how generating pairs are spread among the elements of a group. For more than ten years it has been conjectured that this graph is connected for every finite group. In this paper, we give evidence supporting this conjecture: we prove that it holds for all but a finite number of almost simple groups and give a reduction to groups without non-trivial soluble normal subgroups. Let d(G) be the minimal cardinality of a generating set for G. When d(G)≥3, the generating graph is empty and the conjecture is trivially true. We consider it in the more general setting of the rank graph, which encodes how pairs of elements belonging to generating sets of minimal cardinality spread among the elements of a group. It carries information even when d(G)≥3 and corresponds to the generating graph when d(G)=2. We prove that it is connected whenever d(G)≥3, giving tools and ideas that may be used to address the original conjecture.

Tailoring strength and ductility in novel Ni50Cr20Co15Al10V5 high entropy alloys by cold-rolling followed by aging treatment

In this work, novel Ni50Cr20Co15Al10V5 high entropy alloys were designed and subjected to aging treatment to achieve excellent strength-ductility synergy. The microstructures of the alloys were characterized using X-ray diffraction, electron backscattered diffraction, electron channeling contrast imaging, and transmission electron microscopy methods. The tensile properties and strengthening mechanism were studied and compared to the recrystallized sample. The results indicated that after aging treatment, L12 and BCC precipitates formed at the grain boundaries, enhancing both the yield strength and ultimate tensile strength while maintaining an acceptable elongation of 24.8 %. Dislocation slip dominated the deformation process, and precipitation strengthening contributed significantly to the enhanced yield strength. Molecular dynamics simulations indicated that Ni-Al, Cr-Cr, Cr-V, and Co-V elemental pairs formed the chemical short-range order (SRO) structures, which improved the yield strength of the alloys.

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

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

A new multiphysics finite element method for a quasi-static poroelasticity model

In this paper, we propose a new multiphysics finite element method for a quasi-static poroelasticity model. Firstly, to overcome the displacement locking phenomenon and pressure oscillation, we reformulate the original model into a fluid-fluid coupling problem by introducing new variables-the generalized nonlocal Stokes equations and a diffusion equation, which is a completely new model. Then, we design a fully discrete multiphysics finite element method for the reformulated model-linear finite element pairs for the spatial variables (u,ξ,η) and backward Euler method for time discretization. And we prove that the proposed method is stable without any stabilized term and robust for many parameters and it has the optimal convergence order. Finally, we show some numerical tests to verify the theoretical results.

Pt-Driven Stable and Metastable Ternary Compounds with Tunable Partial Flat Bands in Immiscible Si-Sn System.

A combined machine learning approach and first-principles calculations are employed to efficiently explore energetically favorable ternary compounds involving Pt and an immiscible Si-Sn pair of elements. We predict two stable Pt-Si-Sn ternary compounds (Pt2Si2Sn and Pt8SiSn2) and reproduce the experimentally synthesized Pt5SiSn. The crystal structures of Pt5SiSn and Pt8SiSn2 are composed of a SiPt8 cube and SnPt12 cuboctahedron. Based on these structural motifs, we design a series of Pt-Si-Sn ternary compounds that contain SiPt8 and SnPt12 units and discover some stable and metastable compounds. Partial flat bands near the Fermi level appear in these compounds, and the positions of partial flat bands move upward with increasing the Pt content. The partial flat bands are dominated by Pt atoms. These Pt-Si-Sn ternary compounds provide a platform to study flat band-related properties. Our results open a way to design new compounds in the ternary system.

Achieving low thermal conductivity and high quality factor in sextuple-doped TiS2

Transition-metal dichalcogenide TiS2 stands out as a sustainable candidate for room- and medium-temperature thermoelectric materials due to its affordability, non-toxicity, eco-friendly nature and use of non-critical elements. However, its light element compositional nature results in a large thermal conductivity, which is the main limitation of the thermoelectric performance of TiS2. Here, we report a multi-element doping strategy by incorporating equivalent (Se, Zr) elements and introducing higher-valence (Nb, Ta) and lower-valence (Y, La) elements in pairs to minimize its lattice thermal conductivity, κlat. The findings indicate a nearly 50 % decrease in κlat across the entire temperature range, attributed to the presence of strong point-defect scattering after multi-element doping. Additionally, we observed a reduced dependency of κlat on temperature in multi-element doped TiS2, as point defects can effectively scatter phonons at room temperature. As a result, the multi-element doped TiS2 attained its highest ZT value of approximately 0.4 at 625 K. Incorporating higher-valence and lower-valence elements in pairs proves to be an effective method for decreasing lattice thermal conductivity without compromising too much of its large Seebeck coefficient.

The acoustic complexity index (ACI): theoretical foundations, applied perspectives and semantics

The acoustic complexity index (ACI) is a commonly used metric in ecoacoustics, demonstrating reliability across diverse environments and ecological conditions. However, this index requires specific procedures to be applied correctly. Based on the Canberra metric, the ACI is an unsupervised metric formulated to extract information from fast Fourier transform (FFT) sonic matrices. The ACI measures contiguous differences in acoustic energy of each frequency bin along temporal steps (ACItf) and a temporal interval along the frequency bins (ACIft). Aggregating data after an FFT with a clumping procedure allows for better scaling of sonic signals before computing the ACI. A filter must be applied to reduce the effects of nonenvironmental signals produced by microphone electrical noise . Due to the singularity of the index for values of 0, ACI requires ad hoc procedures to exclude element pairs for which one of the elements is equal to 0 from the comparisons. The spectral and temporal sonic signatures are vectors obtained from the sequence of ACItf and ACIft values, respectively. The comparison between sonic signatures using the chord distance index returns spectral and temporal sonic dissimilarities, allowing the evaluation of sonic patterns at different temporal and spatial resolutions. Sonic variability, sonic evenness, and the effective number of frequency bins are further derivative metrics that help interpret sonic heterogeneity by distinguishing the temporal and spatial heterogeneity of sonoscapes. Moreover, this paper proposes changing the terminology of ‘acoustic complexity index' to ‘sonic heterogeneity index.'

A stabilized finite volume method based on the rotational pressure correction projection for the time-dependent incompressible MHD equations

This paper presents an efficient numerical scheme for solving the time-dependent incompressible Magnetohydrodynamics (MHD) equations based on the rotational pressure correction projection method within the finite volume framework. Utilizing the lowest equal-order mixed finite element pair (P1−P1−P1) to approximate the velocity, magnetic and pressure fields, our numerical scheme satisfies the discrete inf–sup condition by the pressure projection stabilization. To tackle the coupling inherent in the time-dependent incompressible MHD equations,the rotational pressure correction projection method is introduced to split the original problem into several linear subproblems. The unconditional stability of numerical schemes are provided,optimal error estimates in both L2 and H1-norms of numerical solutions are also presented. Finally, some numerical results are given to verify the established theoretical findings and show the performances of the considered numerical schemes.

Computation of Deformable Interface Two‐Phase Flows: A Semi‐Lagrangian Finite Element Approach

ABSTRACTThis work aims at presenting a new computational approach to study two and three dimensional two‐phase flows and two dimensional coalescence phenomenon using direct numerical simulation. The flows are modeled by the incompressible Navier–Stokes equations, which are approximated by the finite element method. The Galerkin formulation is used to discretize the Navier–Stokes equations in the spatial domain and the semi‐Lagrangian method is used to discretize the material derivative. In order to satisfy the Ladyzhenskaya–Babuška–Brezzi condition, high‐order stable pair of elements are used, with pressure and velocity fields being calculated on different degrees of freedom in the unstructured mesh nodes. The interface is modeled by an unfitted adaptive moving mesh, where interface nodes are tracked in a Lagrangian fashion and moved with the velocity solution of the fluid motion equations. The surface tension is computed using the interface curvature and the gradient of a Heaviside function, and added in the momentum equations as a body force. In order to avoid undesired spurious modes at the interface due to high property ratios, a smooth transition between fluid properties is defined on the interface region. Several benchmark tests have been carried out to validate the proposed approach, and the obtained results have demonstrated agreement with analytical solutions and numerical results reported in the literature. A coalescence model is also proposed based on geometric criteria and results show interesting dynamics.