jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zara S. Mir | Matthew Jamieson | Nicholas Greenall | Paul W. Seakins | Mark A. Blitz | Daniel Stone
Source:  (preprint, 2022-02-07)
Field: Chemistry — Spectroscopy

Identification, monitoring, and reaction kinetics of reactive trace species using time-resolved mid-infrared quantum cascade laser absorption spectroscopy: Development, characterisation, and initial results for the Criegee intermediate CH <sub>2</sub> OO Abstract. The chemistry and reaction kinetics of reactive species dominate changes to the composition of complex chemical systems, including Earth’s atmosphere. Laboratory experiments to identify reactive species and their reaction products, and to monitor their reaction kinetics and product yields, are key to our understanding of complex systems. In this work we describe the development and characterisation of an experiment using laser flash photolysis coupled with time-resolved mid-infrared (mid-IR) quantum cascade laser (QCL) absorption spectroscopy, with initial results reported for measurements of the infrared spectrum, kinetics, and product yields for the reaction of the CH2OO Criegee intermediate with SO2. The instrument presented has high spectral (&lt; 0.004 cm−1) and temporal (&lt; 5 µs) resolution, and is able to monitor kinetics with a dynamic range to at least 20,000 s−1. Results obtained at 298 K and pressures between 20 and 100 Torr gave a rate coefficient for the reaction of CH2OO with SO2 of (3.83 ± 0.63) × 10−11 cm3 s−1, which compares well to the current IUPAC recommendation of × 10−11 cm3 s−1. A limit of detection of 4.0 × 10−5, in absorbance terms, can be achieved, which equates to a limit of detection of ~2 × 1011 cm−3 for CH2OO, monitored at 1285.7 cm−1, based on the detection pathlength of (218 ± 20) cm. Initial results, directly monitoring SO3 at 1388.7 cm−1, demonstrate that SO3 is the reaction product for CH2OO + SO2. The use of mid-IR QCL absorption spectroscopy offers significant advantages over alternative techniques commonly used to determine reaction kinetics, such as laser-induced fluorescence (LIF) or ultraviolet absorption spectroscopy owing to the greater number of species to which IR measurements can be applied. There are also significant advantages over alternative IR techniques, such as step-scan FT-IR, owing to the coherence and increased intensity and spectral resolution of the QCL source, and in terms of cost. The instrument described in this work has potential applications in atmospheric chemistry, astrochemistry, combustion chemistry, and in the monitoring of trace species in industrial processes and medical diagnostics. Chemistry ; Spectroscopy ; Infrared spectroscopy ; Flash photolysis ; Quantum cascade laser ; Kinetics ; Absorbance ; Analytical Chemistry (journal) ; Chemical kinetics ; Absorption spectroscopy ; Infrared ; Detection limit ; Photodissociation ; Absorption (acoustics) ; Reaction rate constant ; Photochemistry ; Cascade ; Materials science ; Optics ; Organic chemistry Spectroscopy and Laser Applications ; Atmospheric Ozone and Climate ; Atmospheric chemistry and aerosols
Authors: Medtronic | Ajay S. Panwar | Jasdeep Shangari | Kim Lu | Dylan Smith
Source:  (article, 2022-06-01)
Field: Materials Science — Materials Chemistry

INTERMETALLIC MICROSTRUCTURAL AND MECHANICAL RESPONSE OF NITI (NITINOL) SHAPE MEMORY ALLOY WITH LASER WELDING TO VARIOUS MATERIALS In this ever-changing and evolving world, the demand for material goods is ever increasing. Certain metals and materials have become highly sought-after. The demand for new alloys for various commercial and medical applications increases every day [1]. To address the new age industry demands, focusing on longevity, versatility, extreme load case scenarios, and commercial viability, scientists have to develop new manufacturing techniques and methods. This will enable them to create and mass-produce various new metal alloys that can meet the demands for the designs of new products and replace traditional elements, such as carbon steel or aluminum, in existing products with an ever-increasing workload. This paper will focus on the discovery, development, evolution, manufacturing, uses, and commercial viability of Nitinol (NiTi) and what impact it has had due to its unique properties across many industries. Super-elastic Nitinol has become a familiar and wellknown engineering material in the medical industry over the last couple of decades. While the greater flexibility of the alloy drives many of the applications, there are many lesser-known advantages of Nitinol in medical devices. [1, 2, 3] Flexibility (engineering) ; Nickel titanium ; Materials science ; Shape-memory alloy ; Welding ; Manufacturing engineering ; Alloy ; Intermetallic ; Mechanical engineering ; Computer science ; Metallurgy ; Engineering Shape Memory Alloy Transformations
Authors: Nicolas Foos | Mahmoud Rizk | Max Nanao
Source: Acta Crystallographica Section D Structural Biology (article, 2022-05-09)
Field: Materials Science — Materials Chemistry

Single-support serial isomorphous replacement phasing The use of single isomorphous replacement (SIR) has become less widespread due to difficulties in sample preparation and the identification of isomorphous native and derivative data sets. Non-isomorphism becomes even more problematic in serial experiments, because it adds natural inter-crystal non-isomorphism to heavy-atom-soaking-induced non-isomorphism. Here, a method that can successfully address these issues (and indeed can benefit from differences in heavy-atom occupancy) and additionally significantly simplifies the SIR experiment is presented. A single heavy-atom soak into a microcrystalline slurry is performed, followed by automated serial data collection of partial data sets. This produces a set of data collections with a gradient of heavy-atom occupancies, which are reflected in differential merging statistics. These differences can be exploited by an optimized genetic algorithm to segregate the pool of data sets into `native' and `derivative' groups, which can then be used to successfully determine phases experimentally by SIR. Isomorphism (crystallography) ; Microcrystalline ; Atom (system on chip) ; Set (abstract data type) ; Identification (biology) ; Computer science ; Phaser ; Crystallography ; Derivative (finance) ; Algorithm ; Data mining ; Mathematics ; Crystal structure ; Chemistry ; Physics ; Biology ; Optics Enzyme Structure and Function ; Crystallization and Solubility Studies ; Machine Learning in Materials Science
Authors: K R Harisankar | Sriharsha Sripathi | K. A. Padmanabhan
Source: Letters on Materials (article, 2022-03-01)
Field: Materials Science — Materials Chemistry

On a unique constitutive equation for steady state isotropic optimal structural superplastic deformation in all classes of materials Structural Superplasticity in materials has been reported in so many different classes of materials that there is a case to state that this phenomenon is (near)-ubiquitous. Yet, many authors have proposed different rate controlling processes for different superplastic materials. Such an approach goes against Newton’s (Principia, Part 3) axiom that “to the same natural effects we must, so far as possible, assign the same causes”. In contrast, a viewpoint also exists that steady state, isotropic, optimal structural superplastic deformation in different classes of materials can be attributed to a grain-boundary-sliding-rate-controlled process that develops to a mesoscopic scale (defined to be of the order of a grain diameter or more). If this were the case, it should be possible to generate in properly normalized spaces material-independent “universal” curves (2D) and surfaces (3D) for the relationships among the different experimental variables/parameters like stress, strain rate, strain rate sensitivity index, temperature, real activation energy for the rate controlling process and viscosity. In this paper, by a careful analysis of experimental data concerning 175 states of superplastic materials of different classes it is demonstrated that such universal curves and surfaces indeed exist. The existence of such universal curves and surfaces that describe the phenomenology of steady state, isotropic, optimal structural superplastic deformation in different classes of materials in terms of unique equations reinforces the view experimentally arrived at that a unique physical mechanism of deformation is responsible for the near-ubiquitous phenomenon of steady state, isotropic, optimal structural superplasticity. Superplasticity ; Isotropy ; Materials science ; Strain rate ; Mesoscopic physics ; Mechanics ; Grain Boundary Sliding ; Deformation mechanism ; Solid mechanics ; Deformation (meteorology) ; Anisotropy ; Constitutive equation ; State variable ; Classical mechanics ; Thermodynamics ; Metallurgy ; Grain boundary ; Condensed matter physics ; Composite material ; Physics ; Microstructure Microstructure and mechanical properties ; High-Velocity Impact and Material Behavior ; Advanced Surface Polishing Techniques
Authors: Sinuhé Perea‐Puente | Francisco J. Rodríguez‐Fortuño
Source:  (article, 2022-05-24)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Complex wave-vectors in lossy materials: from polarisation-loss locking to bullseye metasurface We investigate the connection between losses of a guided mode and polarisation of the associated evanescent waves in the Poincaré sphere, demonstrating a ``polarization-loss locking'' in analogy to spin-momentum locking. From Fermi's golden rule, we investigate its implications for near-field directional coupling, via the introduction of a complex angular spectrum formalism. The use of complex wave-vector in the spectrum inspired us to investigate a method of achieving improved transmission of light across optically opaque materials by introducing a passive metasurface with a varying transmission phase and amplitude simultaneously. Physics ; Polarization (electrochemistry) ; Lossy compression ; Optics ; Angular momentum ; Opacity ; Amplitude ; Metamaterial ; Classical mechanics ; Computer science Metamaterials and Metasurfaces Applications ; Plasmonic and Surface Plasmon Research ; Orbital Angular Momentum in Optics
Authors: C.R.H. Bahl | Jierong Liang | Marvin Masche | K. Nielsen | Kurt Engelbrecht
Source: AIP Advances (article, 2022-06-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Virgin effect in spheres of LaFeSi-based alloys A virgin phase transition is observed in spherical particles of the industrially relevant magnetocaloric material La(Fe,Mn,Si)13Hy. Upon initial cooling, the phase transition is observed 2–3 K below the heating transition on all subsequent cooling and heating transitions. This virgin transition has been studied using differential scanning calorimetry and vibrating sample magnetometry. Incremental measurements show not only how the phase transition can be carefully approached but also that the initial full transformation requires cooling of about 6 K below the observed phase transformation. No signs of structural damage due to the thermal cycling were observed, neither macroscopically or by scanning electron microscopy. Differential scanning calorimetry ; Materials science ; Phase transition ; Scanning electron microscope ; Magnetic refrigeration ; Magnetometer ; Phase (matter) ; Thermodynamics ; Temperature cycling ; SPHERES ; Transition temperature ; Thermal ; Analytical Chemistry (journal) ; Condensed matter physics ; Composite material ; Chemistry ; Magnetization ; Magnetic field ; Physics Magnetic and transport properties of perovskites and related materials ; Shape Memory Alloy Transformations ; Magnetic Properties of Alloys
Authors: Aleksandar Čabrilo | Nenad Janjić
Source: Advanced Engineering Letters (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

WELDING OF HIGH-HARDNESS ARMOR STEEL Armor steels are difficult to weld due to the high percentage of carbon. The coarse-grained area and the fusion line in the welded joint are sensitive areas due to the high hardness and the possible presence of hydrogen produced during the welding process. Furthermore, multi-purpose armored vehicles made of armored steel are exposed to dynamic loading due to traffic on rough terrain. High hardness in the coarse- grained area of the heat-affected zone and dynamic loading can cause cracks. In the weld metal zone, a crack created during the welding process or due to pores can quickly propagate toward the sensitive fusion line, after which its accelerated growth can occur. Based on the above, achieving a welded joint without porosity or cracks for armor steel is necessary. This paper investigated the welding process of high- hardness armor steel with two regimes. The test aims to achieve an optimal hardness level and a compromise between ballistic requirements and toughness. The test results showed that a high-quality welded joint and an optimal balance between hardness and toughness are achieved with increased heat input. Armour ; Welding ; Materials science ; Toughness ; Heat-affected zone ; Joint (building) ; Metallurgy ; Composite material ; Structural engineering ; Engineering High-Velocity Impact and Material Behavior ; Welding Techniques and Residual Stresses ; Electromagnetic Launch and Propulsion Technology
Authors: TOUFIQUA SIDDIQUA | TOWFIK AZIZ | MAHMUD FARHAD CHOWDHURY | SHAHRIN IMANA TANIA
Source: Fibres and Textiles (article, 2022-11-01)
Field: Materials Science — Polymers and Plastics

TRAVELLER CLEARER GAUGE CONSEQUENCE ON YARN QUALITY Traveller clearer is an important part of the ring frame machine because, without it, fiber flying in the traveller cannot be cleaned. As a result, fiber congests travellers which may lead to a rise in end breakage rate as well as declination of quality of yarn. Six ring spun yarns of count 85’s tex were produced by using different traveller clearer settings and Burkina Faso cotton fiber was used as a raw material. Both High Volume Instrument (HVI) along with Advanced Fiber Information System (AFIS) was used for recognizing the fiber properties. The ring-spun yarn was produced from the roving count of 985 tex and spindle speed was kept at 7000 R.P.M. with Twist Per Meter (TPM) 492. Evenness properties, as well as strength of yarns, were measured with Uster Tester-6 and Titan Single Yarn Strength Tester respectively, and end breakage rate was studied. One-way ANOVA test was accomplished for all properties of yarn by using Microsoft Excel 2019. Traveller clearer gauge with 3.10 mm shows the best result among the other samples. Yarn properties such as imperfection index, hairiness, Sh (-), tenacity, and processing performance like end breakage rate express the best values. ANOVA result shows a significant difference for all properties except elongation. Yarn ; Breakage ; Composite material ; Fiber ; Mathematics ; Materials science ; Engineering Textile materials and evaluations ; Mechanical Engineering and Vibrations Research ; Natural Fiber Reinforced Composites
Authors: Giovanni Masciocchi | Johannes W. van der Jagt | Maria‐Andromachi Syskaki | Alessio Lamperti | Niklas Wolff | Andriy Lotnyk | J. Langer | Lorenz Kienle | G. Jakob | Benjamin Borie | Andreas Kehlberger | D. Ravelosona | Mathias Kläui
Source: Applied Physics Letters (preprint, 2022-10-31)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Control of magnetoelastic coupling in Ni/Fe multilayers using He+ ion irradiation This study reports the effects of post-growth He+ irradiation on the magneto-elastic properties of a Ni/Fe multi-layered stack. The progressive intermixing caused by He+ irradiation at the interfaces of the multilayer allows us to tune the saturation magnetostriction value with increasing He+ fluences and even to induce a reversal of the sign of the magnetostrictive effect. Additionally, the critical fluence at which the absolute value of the magnetostriction is dramatically reduced is identified. Therefore, insensitivity to strain of the magnetic stack is nearly reached, as required for many applications. All the above-mentioned effects are attributed to the combination of the negative saturation magnetostriction of sputtered Ni and Fe layers and the positive magnetostriction of the NixFe1−x alloy at the intermixed interfaces, whose contribution is gradually increased with irradiation. Importantly, the irradiation does not alter the layer polycrystalline structure, confirming that post-growth He+ ion irradiation is an excellent tool to tune the magneto-elastic properties of multilayer samples. An alternative class of spintronic devices can be envisioned with a material treatment able to arbitrary change the magnetostriction with ion-induced “magnetic patterning.” Irradiation ; Materials science ; Coupling (piping) ; Control (management) ; Ion ; Condensed matter physics ; Metallurgy ; Physics ; Computer science ; Nuclear physics ; Artificial intelligence ; Quantum mechanics Magnetic Properties and Applications ; Magnetic properties of thin films ; Metallic Glasses and Amorphous Alloys
Authors: Hanshin Lee | Menelaos K. Poutous
Source: Journal of Astronomical Telescopes Instruments and Systems (article, 2022-10-28)
Field: Materials Science — Surfaces, Coatings and Films

Reactive ion plasma etched surface relief gratings for low/medium/high resolution spectroscopy in astronomy We report the fabrication of a binary-phase proof-of-concept astronomical diffraction grating embedded in a quartz substrate via reactive ion plasma etching. This grating operates at the first diffraction order within the 450 to 750 nm wavelength band. It features 1400-nm-deep, 188-nm-wide binary grooves at a 566-nm pitch, or 1767 lines/mm groove density, over a 25.4 × 25.4 mm2 area. A high depth-to-width ratio ( ∼ 8 ∶ 1 in this case) is one of the keys to near-theoretical diffraction efficiency being attained by the fabricated grating (94% at center wavelength and 70% at band edges) over a broad bandpass (>200 nm). This performance is also attributed to high-resolution micro-lithographic electron-beam patterning and anisotropic reactive ion etching process fabrication techniques. These types of binary gratings can potentially be high-throughput alternatives to Volume-Phase Holographic Gratings (VPHGs) for general spectroscopic applications. When scaled to appropriate sizes for astronomy, such gratings can serve as main or cross dispersion elements in low-, medium-, and high-resolution spectrographs not only in ground-based telescopes but also in those subject to challenging environmental conditions such as in space observatories. Grating ; Materials science ; Optics ; Reactive-ion etching ; Diffraction grating ; Diffraction efficiency ; Deep reactive-ion etching ; Optoelectronics ; Etching (microfabrication) ; Physics ; Nanotechnology Optical Coatings and Gratings ; Superconducting and THz Device Technology ; Adaptive optics and wavefront sensing
Authors: Xiaoyu Wang | Joe Finney | Aaron L. Sharpe | Linsey K. Rodenbach | Connie L. Hsueh | Kenji Watanabe | Takashi Taniguchi | M. A. Kastner | Oskar Vafek | David Goldhaber‐Gordon
Source: arXiv (Cornell University) (preprint, 2022-09-17)
Field: Materials Science — Materials Chemistry

Unusual magnetotransport in twisted bilayer graphene from strain-induced open Fermi surfaces Anisotropic hopping in a toy Hofstadter model was recently invoked to explain a rich and surprising Landau spectrum measured in twisted bilayer graphene away from the magic angle. Suspecting that such anisotropy could arise from unintended uniaxial strain, we extend the Bistritzer-MacDonald model to include uniaxial heterostrain. We find that such strain strongly influences band structure, shifting the three otherwise-degenerate van Hove points to different energies. Coupled to a Boltzmann magnetotransport calculation, this reproduces previously-unexplained non-saturating $B^2$ magnetoresistance over broad ranges of density near filling $ν=\pm 2$, and predicts subtler features that had not been noticed in the experimental data. In contrast to these distinctive signatures in longitudinal resistivity, the Hall coefficient is barely influenced by strain, to the extent that it still shows a single sign change on each side of the charge neutrality point -- surprisingly, this sign change no longer occurs at a van Hove point. The theory also predicts a marked rotation of the electrical transport principal axes as a function of filling even for fixed strain and for rigid bands. More careful examination of interaction-induced nematic order versus strain effects in twisted bilayer graphene could thus be in order. Condensed matter physics ; Bilayer graphene ; Graphene ; Strain (injury) ; Fermi Gamma-ray Space Telescope ; Materials science ; Bilayer ; Fermi level ; Physics ; Nanotechnology ; Chemistry ; Quantum mechanics ; Electron Graphene research and applications ; Quantum and electron transport phenomena ; Diamond and Carbon-based Materials Research
Authors: Ming Li | Junru Zhou | Qian Deng | Liufei Lv
Source: Vibroengineering PROCEDIA (article, 2022-11-18)
Field: Materials Science — Materials Chemistry

Vibration and instability of a fluid-conveying nanotube resting on elastic foundation subjected to a magnetic field Using the nonlocal Euler-Bernouli beam model, this paper is carried out to investigate the vibrations and instability of a single-walled carbon nanotube (SWCNT) conveying fluid subjected to a longitudinal magnetic field. The nanobeam with clamped-clamped boundary conditions lies on the Pasternak foundation. Hamilton’s principle is applied to derive the fluid-structure interaction (FSI) governing equation and the corresponding boundary conditions. In the solution part the differential transformation method (DTM) is used to solve the differential equations of motion. The influences of nonlocal parameter, longitudinal magnetic field, Pasternak foundation on the critical divergence velocity of the nanotubes is studied. Instability ; Boundary value problem ; Vibration ; Magnetic field ; Classical mechanics ; Mechanics ; Physics ; Hamilton's principle ; Timoshenko beam theory ; Beam (structure) ; Differential equation ; Equations of motion ; Foundation (evidence) ; Galerkin method ; Euler's formula ; Carbon nanotube ; Mathematical analysis ; Materials science ; Mathematics ; Composite material ; Acoustics ; Nonlinear system Nonlocal and gradient elasticity in micro/nano structures ; Composite Structure Analysis and Optimization ; Thermoelastic and Magnetoelastic Phenomena