Search

Nuclear level density is calculated with the combinatorial method based on the relativistic density functional theory including pairing correlations. The Strutinsky method is adopted to smooth the total state density in order to refine the prediction at low excitation energy. The impacts of pairing correlations and moments of inertia on the nuclear level density are discussed in detail. Taking Cd112 as an example, it is demonstrated that the nuclear level density based on the relativistic density functional PC-PK1 can reproduce the experimental data at the same level as or even better than the previous approaches.

We present a versatile and model based procedure for estimating a density in a deconvolution setting where the error density is assumed to be singular enough.We assess the quality of our estimator by establishing non-asymptotic risk bounds for the L¹ loss. We specify them when the density is piecewise constant on a finite number of (unknown) pieces, when it is unimodal, and when it is concave/convex. [ABSTRACT FROM AUTHOR]

Metallic glasses are often considered to exhibit remarkable corrosion resistance. However, the respective roles of chemical composition and amorphous structure remain unclear. In this work, we take Ir-Ni-Ta alloy system as a model system and utilize combinatorial fabrication and high-throughput characterizations to reveal the correlations between alloy composition and corrosion current density and corrosion potential. The results indicate strong correlations of corrosion current density with metal-metal bond strength and metal-oxygen bond strength, suggesting that the corrosion of the Ir-Ni-Ta metallic glasses is primarily controlled by chemical composition. However, an amorphous structure can facilitate the formation of denser passive film, and thus superimpose a positive influence on alloys that inherently exhibit corrosion resistance. Our findings would help the designing metallic glasses of superior corrosion resistance. • Combinatorial approach was used to understand the corrosion resistance of Ir-Ni-Ta metallic glasses. • The corrosion resistance of the Ir-Ni-Ta MGs is primarily governed by chemistry. • Amorphous structure can superimpose a positive influence on metallic glasses that inherently exhibit corrosion resistance. [ABSTRACT FROM AUTHOR]

Due to the excellent charge mobility and tunable composition engineering, halide materials are being considered as new resistive switching (RS) memory materials. However, conventional halide materials‐based RS memory devices primarily comprise lead‐based compounds and solution‐based processes, implying that researching new compositions for eco‐friendly RS memory one‐by‐one synthesis would be extremely time consuming. This study reports the fabrication of an eco‐friendly RS memory composition using a combinatorial physical vapor deposition (PVD) technique. The fabricated films are classified into three device types: RS memory, write‐only‐read‐many, and insulator device type, based on the mole fraction of bismuth sulfide (Bi2S3). The 0.75BiI3–0.25Bi2S3 mixture devices exhibit reliable and stable RS memory characteristics with an electroforming‐free process. Additionally, the study of cohesive, formation, and migration energies via first‐principles simulations demonstrate that the type of device changes because of their inability to develop and migrate their anion vacancies, implying that the amorphous nature of the device cannot retard the movement of iodine vacancies. This study is the first to investigate a new composition of eco‐friendly halide materials‐based RS memory via the combinatorial PVD method. These findings will serve as a powerful tool for investigating new compositions of eco‐friendly RS memory. [ABSTRACT FROM AUTHOR]

In this study, we searched for Tiâ€"Niâ€"Hf high formable shape memory alloys (HFSMAs) using combinatorial methods. By adding Hf to Tiâ€"Ni SMAs, the potential is that Tiâ€"Ni SMAs become metallic glasses. For efficient material search, the glass transition temperature was evaluated through combinatorial measurement of electrical resistance during crystallization. From the results, we searched for Tiâ€"Niâ€"Hf HFSMAs, which undergo glass transition in the amorphous state. Ni-rich Tiâ€"Niâ€"Hf thin-film amorphous alloys with more than 10 at% Hf content became thin film metallic glasses, whereas Ni-poor samples did not. Further, we evaluated the effect of annealing temperature on the martensitic transformation temperature of Tiâ€"Niâ€"Hf SMAs using combinatorial methods. From the results, we measured the reverse transformation start temperature A s at 368â€"404 K, and it varied with the annealing temperature and Hf composition. [ABSTRACT FROM AUTHOR]

Next-generation high frequency, high power density, and high operating temperature electrical machines require superior materials which possess an attractive combination of structural as well as functional properties. Development of such new materials by conventional methods is very slow, expensive, and restricted to a few compositions. Hence, we addressed this challenge by the accelerated assessment of multiple properties of a range of Fe-Co-Ni based material compositions. We utilized the magnetron co-sputtering method to prepare compositionally modulated ternary Fe-Co-Ni thin film alloy (TFA) libraries. The structural, electrical, magnetic, and mechanical properties of these libraries were assessed. The structure and properties were found to vary over a wide range with composition and thin film processing parameters. The Fe-Co-Ni TFA library prepared at a substrate temperature of 500 °C exhibited a good combination of multiple properties. The specific alloy composition Ni54.9Co33.1Fe12 was found to possess an attractive blend of properties. Thus, a rapid property assessment of TFA libraries of a wide range of compositions and processing conditions was successfully used to identify a novel specific composition and processing protocol which exhibited an attractive mix of properties.

Antibacterial activity and mechanical properties of FeCoCr-Ag medium entropy alloys were studied via combinatorial fabrication paired with high-throughput characterizations. It was found that the antibacterial activity and mechanical properties exhibit non-linear dependence on the content of Ag addition. Within the studied alloys, (FeCoCr) _80 Ag _20 possesses an optimized combination of different properties for potential applications as antibacterial coating materials. The underlying mechanism is ascribed to the formation of a dual-phase structure that leads to competition between the role of Ag phase and FeCoCr phase at different Ag content. The results not only demonstrate the power and effectiveness of combinatorial methods in multi-parameter optimization but also indicate the potential of high entropy alloys as antibacterial materials.

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nuclear level density is calculated with the combinatorial method based on the relativistic density functional theory including pairing correlations. The Strutinsky method is adopted to smooth the total state density in order to refine the prediction at low excitation energy. The impacts of pairing correlations and moments of inertia on the nuclear level density are discussed in detail. Taking Cd 112 as an example, it is demonstrated that the nuclear level density based on the relativistic density functional PC-PK1 can reproduce the experimental data at the same level as or even better than the previous approaches. [ABSTRACT FROM AUTHOR]

• The phase stability regime was determined of MoVTeNb mixed oxide catalysts depending on hydrothermal synthesis chemistry and crystallization. • Combinatorial methods yielded novel MoVTeNb oxide-based catalysts with improved catalyst performance alkane oxidation reactions. • New organic synthesis aids and promoter elements could be successfully identified by data mining. • A hydrothermal method with newly identified synthesis aids wasoptimized and scaled up to 40 l autoclaves using the cheapest available chemicals. • The large-scale production of this complex MoVNbTe mixed oxide catalyst is now possible. New MoVTeNb multi-component catalysts (so-called M1 phase) were designed and tested using combinatorial and high-throughput methods. An international team of academic institutes and industrial partners has cooperated to understand the chemistry occurring during the hydrothermal synthesis and crystallization of the M1 phase of the MoVTeNb mixed oxide. With this information, the optimization of this catalyst system could be targeted with the aim of improving catalyst performance for short chain alkane – ethane and propane - oxidation reactions. Beside the elements responsible for the formation of the M1 phase (Mo, V, Te, and Nb) and promoters found to be advantageous in our previous work (Mn, Ni, W and citric acid), the following components were added to the synthesis mixture: Ce, Cu, Co, Cr and ethylene glycol. Contrary to the previous approach in this study, the V/Mo, Te/Mo and Nb/Mo ratios were kept constant. Consequently, the experimental space had nine variables. The discrete levels of variables are established in such a way that the number of the potential experimental points in the multi-dimensional experimental space was in the range of 200 000. Five new generations were designed using an optimization platform consisting of holographic optimization algorithm and artificial neural networks. Altogether 250 catalysts were prepared and tested. A complex objective function was created consisting of two independent catalytic performance characteristics – conversion and product selectivity – as well as the expected production costs and prices of the target product acrylic acid (AA) and export steam. The AA production costs were estimated assuming a recycle scheme for such a future AA plant with standard downstream equipment. The best catalysts in the group of catalysts with low vanadium content gave acrylic acid yields of 58% in the high throughput tests after five generations. On the bases of holographic maps, correlations between the composition of the synthesis mixtures and the yields of AA were visualized allowing to see the cross effect between components. Mn and Co had a positive effect, while Cu and Ce resulted in negative effect on the yield of AA. The analysis of the correlation between conversions vs. product yields allowed figuring out the main reaction routes leading to acrylic acid and CO 2 in a consecutive reaction scheme. Following this successful high throughput development, the hydrothermal method using the newly identified synthesis aids was further optimized and successfully scaled up to 40 l autoclaves using the cheapest available chemicals, the oxides. This now renders possible the large-scale production of that complex MoVNbTe mixed oxide catalyst. [ABSTRACT FROM AUTHOR]

Combinatorial techniques have anim portant role to com pute the joint reliability importance (J RI) of some coherent system s. We obtain combinatorial formula for calcu lation of the JR I of two com p onents in a generalised version of consecutive type systems consisting of nlinearly ordered comp onents such that system fails if and only if (iff) there are at least m l-overlapping runs of k consecutive failed components (n > m(k --l) + l,l < k). Overlapping runs mean having common elements which is denoted by l: We concentrate on both s-independent & identical components and exchangeable components. Explicit combinatorial formulae are provided for computing the JRI of the above mentioned cases. For both cases, we also compare the results with linear m-consecutive-k-out-of-n:F system (nonoverlapping case when l = 0). In addition, some numerical and illustrative examples are presented. [ABSTRACT FROM AUTHOR]

Combinatorial explosion is a common problem to both predominant methods for solving fault trees: Minimal Cut Set (MCS) approach and Binary Decision Diagram (BDD). High memory consumption impedes the complete solution of very complex fault trees. Only approximated non-conservative solutions are possible in these cases using truncation or other simplification techniques. The paper proposes a new method (CSolv+) for solving complex fault trees, without any possibility of combinatorial explosion. Each individual MCS is immediately discarded after its contribution to the basic events importance measures and the Top gate Upper Bound Probability (TUBP) has been accounted. An estimation of the Top gate Exact Probability (TEP) is also provided. Therefore, running in a computers cluster, CSolv+ will guarantee the complete solution of complex fault trees. It was successfully applied to 40 fault trees from the Aralia fault trees data base, performing the evaluation of the top gate probability, the 1.000 Significant MCSs (SMCS) and the Fussell-Vesely, RRW and RAW importance measures for all basic events. The high complexity fault tree nus9601 was solved with truncation probabilities from 10 −21 to 10 −27 , just to limit the execution time. The solution corresponding to 10 −27 , evaluated 3.530.592.796 MCSs in 3 h and 15 min. [ABSTRACT FROM AUTHOR]

• Reliability of a body sensor network with correlated function dependence is modeled. • Competing failure propagation and failure isolation effects are considered. • Random isolation time is considered. • An analytical and combinatorial reliability analysis approach is proposed. Body sensor networks (BSNs) are playing a crucial role in tackling arising challenges during the COVID-19 pandemic. This work contributes by modeling and analyzing the BSN reliability considering the effects of correlated functional dependence (FDEP) and random isolation time behavior. Particularly, the FDEP exists in BSNs where a relay is utilized to assist the communication between some biosensors and the sink device. When the relay malfunctions, the dependent biosensors may communicate directly with the sink for a limited, uncertain time. These biosensors then become isolated from the rest of the BSN when their remaining power depletes to the level insufficient to support the direct communication. Moreover, multiple biosensors sharing the same relay and a biosensor communicating with the sink via several alternative relays create correlations among different FDEP groups. In addition, the competition in the time domain exists between the local failure of the relay and the propagated failures of dependent biosensors. Both the correlation and competition complicate the reliability modeling and analysis of BSNs. This work proposes a combinatorial and analytical methodology to address both effects in the BSN reliability analysis. The proposed method is demonstrated using a detailed case study and verified using a continuous-time Markov chain method. [ABSTRACT FROM AUTHOR]

In this paper, a new non-linear recursive sequence is firstly introduced. Then, using this sequence, a computational problem involving the convolution of the Legendre polynomial is studied using the basic and combinatorial methods. Finally, we give an interesting identity.

The aim of this paper is to research the structural properties of the Fibonacci polynomials and Fibonacci numbers and obtain some identities. To achieve this purpose, we first introduce a new second-order nonlinear recursive sequence. Then, we obtain our main results by using this new sequence, the properties of the power series, and the combinatorial methods.

In this paper, we first introduce a new second-order non-linear recursive polynomials U h , i ( x ) , and then use these recursive polynomials, the properties of the power series and the combinatorial methods to prove some identities involving the Fubini polynomials, Euler polynomials and Euler numbers.

In this paper, firstly, we introduced a second order non-linear recursive sequence, then we use this sequence and the combinatorial methods to perform a deep study on the computational problem concerning one kind sums, which includes the Chebyshev polynomials. This makes it possible to simplify a class of complex computations involving the second type Chebyshev polynomials into a very simple problem. Finally, we give a new and interesting identity for it.

Mechanotransduction in neural cells involves multiple signaling pathways that are not fully understood. Differences in lineage and maturation state are suggested causes for conflicting reports on neural cell mechanosensitivity. To optimize matrices for use in stem cell therapy treatments transplanting human induced pluripotent stem cell derived neural stem cells (hNSC) into lesions after spinal cord injury, the effects of Young's Modulus changes on hNSC behavior must be understood. The present study utilizes polyethylene glycol hydrogels containing a continuous gradient in Young's modulus to examine changes in the Young's Modulus of the culture substrate on hNSC neurite extension and neural differentiation. Changes in the Young's Modulus of the polyethylene glycol hydrogels was found to affect neurite extension and cellular organization on the matrices. hNSC cultured on 907 Pa hydrogels were found to extend longer neurites than hNSC cultured on other tested Young's Moduli hydrogels. The gene expression of β tubulin III and microtubule-associated protein 2 in hNSC was affected by changes in the Young's Modulus of the hydrogel. The combinatory method approach used in the present study demonstrates that hNSC are mechanosensitive and the matrix Young's Modulus should be a design consideration for hNSC transplant applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 824-833, 2017. [ABSTRACT FROM AUTHOR]

(1−x)BaTiO 3 -xBaSnO 3 (BT-xBS, 0≤x≤0.20) perovskite thin films were deposited on Pt/Ti/Si substrates with uniaxial graded composition by using a dual-target combinatorial sputtering technique. These films were highly (101)-oriented and showed strong composition dependence in their electromechanical properties. The maximum value of the relative dielectric constant was 925 at around x=0.028, where the transverse piezoelectric coefficient | e 31, f | also peaked at about 1.5–1.9 C/m 2 . This | e 31, f | value is higher than those of epitaxial BaTiO 3 thin films. Our results indicate that BT-xBS is a promising substitute of lead-based perovskites for applications in piezoelectric MEMS devices. [ABSTRACT FROM AUTHOR]

• High-throughput combinatorial approach to map mechanical, electrical properties of Al-C. • Carbon addition leads to increased hardness, but reduced electrical conductivity. • Mechanical properties of freestanding Al-C thin films are measured and analyzed. • Al-C films exhibit exceptional strength and stability while retaining ductility. • Yield drop is observed and attributed to formation of the cottrell atmosphere. Aluminum (Al) is one of the most widely used structural material in various technologically relevant applications due to its light weight and formability. However, these advantages have been overshadowed by its relatively poor mechanical properties. In this paper, we report theexceptional mechanical properties of aluminum-carbon (Al-C) thin films deposited by multiple source co-sputtering. In the first set of experiments, a high-throughput combinatorial approach was taken to investigate mechanical and electrical properties of a blanket of Al-C thin film deposited with a compositional gradient. Hardness increased along with carbon addition, but at the cost of reduced electrical conductivity. These measurements allowed rapid screening of Al-C films and showed that regions with ∼ 6at% carbon possess a good balance of mechanical and electrical properties (2.8 GPa and 142 Ω·nm). Micro-tensile experiments of freestanding Al, Al-C 6.4at%, and Al-C 10.3at% films were conducted to acquire tensile properties and understand the strengthening mechanism. Al-C films with 6.4at% and 10.3at% carbon both exhibited significantly increased yield stress over 300 MPa while retaining ductility. Unexpectedly, an upper yield followed by a fall in the stress was observed, which resembles the mechanical behavior of low-carbon steel. The unusual mechanical behavior of Al-C is attributed to formation of the Cottrell atmosphere. We also demonstrated that C impurities suppress stress-induced grain growth, which leads to improved microstructural stability during deformation. This paper demonstrates that carbon addition by co-sputter deposition is a viable approach for improving the strength and microstructural stability of Al thin films without loss in ductility. [ABSTRACT FROM AUTHOR]

A ceramic combinatorial method to investigate the phase space of e.g. metal oxides by a single sample is reviewed along with its application to cuprate superconductors. The main idea behind this method is to use a large number N of starting materials (micrometer size grains) to generate local reaction centers producing possible compounds at the reaction temperature. Mathematical calculations using also empirical data on the occurrence of compounds in phase systems allow to conclude that in 1 cm 3 of a sample, there are enough grains to populate all local reaction centers in order to obtain in principle what the N starting materials can produce. A variety of characterization technics have been applied to such libraries to identify e.g. cuprate superconductors. Finally the success of the concept will depend on analytical tools allowing for a simultaneous analysis of the composition and physical properties. Here, we have applied for the first time scanning SQUID microscopy to reveal local superconductivity in inhomogeneous ceramic samples. [ABSTRACT FROM AUTHOR]

A combinatorial hydrothermal reaction has been used to prepare pure and additive (Sb, Cu, Nb, Pd, and Ni)-loaded In2O3 hollow spheres for gas sensor applications. The operation of Pd- and Cu-loaded In2O3 sensors at 371 °C leads to selective H2S detection. Selective detection of CO and NH3 was achieved by the Ni-In2O3 sensor at sensing temperatures of 371 and 440 °C, respectively. The gas responses of six different sensors to NH3, H2S, H2, CO and CH4 produced unique gas sensing patterns that can be used for the artificial recognition of these gases.

At the current state of the studies concerning the decipherment of the so–called «Cypro–Minoan», it can be justly claimed that a syllabic writing system was used in Late Bronze Age Cyprus to express probably three different languages. The signs of the syllabary therefore show evident similarities with the signs of the other Aegean Linear writing systems. Many decipherment proposals brought forward in the last few decades have lead to no other certain conclusion. The use of the combinatorial method based on the analysis of the binary frequencies – how often a sign is followed or preceded by each of the other signs – and of the distance between the signs – whether the similarity/difference between the signs at the left/right of two signs reveals any similarity/difference between the signs themselves – could determine whether or not said hypotheses are reliable. Already tested on Linears B and A as well as on the Classical Cypriot Syllabary by C. Consani and M. Federighi, this method is used in this article to identify the glide in the Cm 2. The result obtained from this first test reveals how each sign's phonetic value, at least that of the Cm 2, now seems to be ascertainable. Consequently, Cm 2 could have been an «adaptation writing», as has been demonstrated in respect of Linear B.

Magnetostrictive materials of the Fe-Ni-Cr ternary system for sensitivity enhancement of force sensors were searched by using a combinatorial method. Magnetostrictive materials for force sensors require large magnetostriction, high relative permeability, and high resistivity. This research is an attempt to find composition ranges that satisfy the following requirements: magnetostriction greater than 20×10 -6, relative permeability greater than 4,000, and resistivity over 90 μΩ cm. A novel combinatorial deposition method, known as Combinatorial New Facing Targets Sputtering (Combi-NFTS) method was applied to fabricate libraries of samples with various compositions. Samples for measurement of the relative permeability and resistivity were synthesized with a composition distribution by using Combi-NFTS onto a 108 mm×76 mm glass substrate. After deposition of thin film, each sample is divided into 10 mm×10 mm. The relative permeability and resistivity were measured by using a vibrating sample magnetometer and the four probe method, respectively. Bilayer cantilever samples for evaluation of magnetostriction were fabricated onto a 6 mm×20 mm×0.1 mm Si substrate, whereby deflection of the samples changes when a magnetic field is applied. The laser lever method was used to measure the cantilever deflection. The results indicate that the composition range with an Fe content of 26-36.5 at.%, a Ni content of 61-66 at.%, and a Cr content of 7.5-9.5 at.% satisfy the requirement criteria.

In this work combinatorial approach was applied for synthesis of Ca (0.98+ a ) Eu 0.02 Al 2 Si (1+ b ) O (6+ y ) , ( a =0, 0.5, 1; 0≤ b ≤1; 0≤ y ≤2) compound. Influence of the Ca 2+ to Si 4+ ratio on europium emission was studied. Combinatorial method allows to obtain and analyze multiple compounds simultaneously and turned out to be useful in obtaining new phosphors. It was found that concentration of Si 4+ ions influence intensity of Eu 3+ and Eu 2+ emission, the Ca 2+ concentration has minor impact on spectroscopic properties of the investigated host. [ABSTRACT FROM AUTHOR]