jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: M. Myronov | Gerard Colston | Jack Davies | Laura Michael
Source: Semiconductor Science and Technology (article, 2022-03-21)
Field: Materials Science — Materials Chemistry

A fast approach to measuring the thickness uniformity of a homoepilayer grown on to any type of silicon wafer Abstract Optical reflection spectroscopy techniques offer a non-destructive and fast method of measuring the thickness of silicon (Si) epilayers, enabling very fast thickness uniformity mapping across the full surface of epiwafers up to 450 mm in diameter. However, their use for undoped or low doped epilayers has traditionally been constrained by a dependence on high levels of substitutional doping in the Si wafer, at values of approximately 5 × 10 19 cm −3 . Whilst the high dopant concentration of this wafer creates the necessary reflectance boundary for optical reflection, their commercial availability is mainly limited to the (001) surface orientation only. Optical reflectance techniques are therefore also limited in use to this orientation. In this article, an approach to measure the thickness of a Si epilayer on any Si wafer, independent of its crystallographic orientation, doping type and value, using Fourier transform infrared reflection spectroscopy is proposed and demonstrated. Because the use of non-destructive optical reflection spectroscopy is already common and well-understood within both industry and academia, this technique could easily be implemented within existing industrial and research fabrication facilities. Furthermore, this approach could be adapted, with further work, to suit other semiconductor materials and other optical reflection techniques. Wafer ; Materials science ; Reflection (computer programming) ; Dopant ; Doping ; Silicon ; Optoelectronics ; Optics ; Spectroscopy ; Fourier transform spectroscopy ; Infrared ; Computer science ; Physics Silicon Nanostructures and Photoluminescence ; Thin-Film Transistor Technologies ; Silicon and Solar Cell Technologies
Authors: Dennis Berends | Patrick Schwager | Kai Gehrke | Martin Vehse | Carsten Agert
Source: Vacuum (article, 2022-06-25)
Field: Materials Science — Materials Chemistry

Effect of asymmetric power distribution in bipolar reactive sputtering on the optoelectronic and microstructure properties of titanium dioxide for solar water splitting Materials science ; Sputtering ; Sputter deposition ; Titanium dioxide ; Thin film ; Partial pressure ; Optoelectronics ; Titanium ; Analytical Chemistry (journal) ; Microstructure ; Oxygen ; Composite material ; Metallurgy ; Nanotechnology ; Chemistry ZnO doping and properties ; Advanced Photocatalysis Techniques ; Copper-based nanomaterials and applications
Authors: Alexander Soldatov | Alexey Remnev | Akira Okada
Source: Applied Sciences (article, 2022-01-26)
Field: Materials Science — Materials Chemistry

Reconditioning of Diamond Coated Tools and Its Impact on Cutting Performance for CFRP Laminates In recent years, CVD diamond-coated tungsten carbide (WC-Co) tools have been widely utilized due to their benefits in the machining of non-ferrous alloys and polymer composite materials, especially carbon-fiber-reinforced plastics (CFRPs). The reconditioning of such coated tools is economically attractive due to their high cost and short tool life. The decoating of the remaining diamond film from the used tools and the subsequent surface preparation by wet chemical pretreatment are essential steps for new CVD diamond film formation. Previously, it was shown that reactive ion beam etching (RIBE) could effectively remove CVD diamond films. However, some degree of WC-Co tool substrate damage is expected due to the high ion energy in RIBE and the chemical activity in wet etching. This study addresses the effects of RIBE decoating and surface pretreatment steps on WC-Co tools with a complex shape in terms of the ion-induced surface damage, geometry alteration, and adhesion of a subsequently re-applied CVD diamond film. Moreover, the cutting performance of the tools subjected to the RIBE decoating and repeated film deposition was studied via CFRP cutting tests. It has been shown that the RIBE decoated and recoated tools had a high level of cutting performance comparable to the new tools. Materials science ; Diamond ; Tungsten carbide ; Chemical vapor deposition ; Composite material ; Carbon fibers ; Composite number ; Nanotechnology Diamond and Carbon-based Materials Research ; Advanced Surface Polishing Techniques ; Advanced machining processes and optimization
Authors: Richard Röß‐Ohlenroth | Marcel Hirrle | Maryana Kraft | Andreas Kalytta‐Mewes | Anton Jesche | Hans‐Albrecht Krug von Nidda | Dirk Volkmer
Source: Zeitschrift für anorganische und allgemeine Chemie (article, 2022-06-17)
Field: Chemistry — Inorganic Chemistry

Synthesis, Thermal Stability and Magnetic Properties of an Interpenetrated Mn(II) Triazolate Coordination Framework Abstract Coordination frameworks and metal‐organic frameworks built from simple triazole ligands such as 1 H ‐1,2,3‐triazole ( H‐ta ) have recently inspired great interest owing to physical phenomena such as electronic conductivity, phase transitions and their magnetic behavior. In line of our endeavors we report on the solvothermal reaction of MnCl 2 ⋅ 4H 2 O with H‐ta ligand in isopropyl alcohol leading to the the novel CFA‐23 (((propan‐2‐yl)oxidanium) + [Mn 6 Cl 5 (ta) 8 ] − ; CFA‐23=Coordination Framework Augsburg University‐23) coordination framework. Single‐crystal X‐ray diffraction (SC‐XRD) reveals that it crystallizes in the tetragonal space group P 4 2 /nnm (134) exhibiting a two‐fold interpenetrated framework with the topologies of a dia net with point (Schläfli) symbol 6 6 . The thermal stability of this compound was investigated using variable temperature X‐ray powder diffraction and thermogravimetric analysis. The magnetic properties of CFA‐23 differ from a similar non‐interpenetrated literature structure of the composition (H[Mn 6 (bta) 8 Cl 5 ] ⋅ (H 2 O) 4 ) built from 1 H ‐1,2,3‐benzotriazole, thus, indicating that sterically induced lattice changes might be an adjustment parameter for magnetic properties in such frameworks. Tetragonal crystal system ; Crystallography ; Metal-organic framework ; Thermogravimetric analysis ; Coordination complex ; Isopropyl ; Thermal stability ; Steric effects ; Crystal structure ; Materials science ; Single crystal ; Chemistry ; Stereochemistry ; Metal ; Physical chemistry ; Organic chemistry ; Adsorption Metal-Organic Frameworks: Synthesis and Applications ; Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes
Authors: Stephanie G. E. Amos | Jérôme Waser
Source: CHIMIA International Journal for Chemistry (article, 2022-04-27)
Field: Chemistry — Organic Chemistry

Radical Alkynylations with EthynylBenziodoXolones: from Photocatalysis to Direct Excitation Ethynylbenziodoxolones (EBXs) have recently emerged as potent reagents for the alkynylation of radicals. Their combination with photocatalysis allows the synthesis of valuable alkynes at room temperature. Herein, we discuss two photomediated strategies for the synthesis of internal alkynes. The first transformation is a 1,2-oxyalkynylation of N- and O-alkenes using 4ClCzIPN as a photocatalyst. The second strategy makes use of EBXs as strong photooxidants allowing the oxidation of a variety of substrates with no need for a photocatalyst. Photocatalysis ; Radical ; Reagent ; Alkynylation ; Chemistry ; Photochemistry ; Excitation ; Nanotechnology ; Catalysis ; Combinatorial chemistry ; Materials science ; Organic chemistry ; Engineering ; Electrical engineering Radical Photochemical Reactions ; Sulfur-Based Synthesis Techniques ; Catalytic C–H Functionalization Methods
Authors: Erez Cohen | Liat Avram | Elena Poverenov
Source: Macromolecular Rapid Communications (article, 2022-09-25)
Field: Materials Science — Biomaterials

Formation of Robust and Adaptive Biopolymers via Non‐Covalent Supramolecular Interactions Biomass-originated materials are the future's next-tier polymers. This work suggests improving mechanical and barrier properties of nature-sourced polymers using non-covalent supramolecular interactions. Polysaccharide chitosan is modified with amino acids via an esterification pathway using a systematic variation of hydrogen bond and aromatic domains (Degrees of substitution 12-49%). These controlled modifications improve stability due to non-covalent interactions, resulting in biopolymers with tailored thermal (decomposition temperature 232-275 °C), mechanical (Young's modulus 540-2667 MPa), and surface properties (roughness 4-40 nm). Chitosan and natural amino acids that are already manufactured at scale are purposely selected. The facile synthesis, controlled properties, stimuli-responsive potential, and inexhaustible origin of the raw materials provide the presented findings with the potential to become the method for the formation of high-performance biodegradable alternatives to petroleum-based polymers that can be used in packaging, food, agriculture, and medicine. Polymer ; Covalent bond ; Supramolecular chemistry ; Thermal stability ; Materials science ; Non-covalent interactions ; Chitosan ; Hydrogen bond ; Chemical engineering ; Biopolymer ; Organic chemistry ; Polymer chemistry ; Chemistry ; Composite material ; Molecule Nanocomposite Films for Food Packaging ; biodegradable polymer synthesis and properties ; Advanced Sensor and Energy Harvesting Materials
Authors: Andreas Hoffmann | Matthias Uhl | Maximilian U. Ceblin | Felix Rohrbach | Joachim Bansmann | Marcel Mallah | Holger Heuermann | Timo Jacob | Alexander J. C. Kuehne
Source: C – Journal of Carbon Research (article, 2022-06-22)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Atmospheric Pressure Plasma-Jet Treatment of PAN-Nonwovens—Carbonization of Nanofiber Electrodes Carbon nanofibers are produced from dielectric polymer precursors such as polyacrylonitrile (PAN). Carbonized nanofiber nonwovens show high surface area and good electrical conductivity, rendering these fiber materials interesting for application as electrodes in batteries, fuel cells, and supercapacitors. However, thermal processing is slow and costly, which is why new processing techniques have been explored for carbon fiber tows. Alternatives for the conversion of PAN-precursors into carbon fiber nonwovens are scarce. Here, we utilize an atmospheric pressure plasma jet to conduct carbonization of stabilized PAN nanofiber nonwovens. We explore the influence of various processing parameters on the conductivity and degree of carbonization of the converted nanofiber material. The precursor fibers are converted by plasma-jet treatment to carbon fiber nonwovens within seconds, by which they develop a rough surface making subsequent surface activation processes obsolete. The resulting carbon nanofiber nonwovens are applied as supercapacitor electrodes and examined by cyclic voltammetry and impedance spectroscopy. Nonwovens that are carbonized within 60 s show capacitances of up to 5 F g−1. Materials science ; Carbonization ; Nanofiber ; Polyacrylonitrile ; Carbon nanofiber ; Composite material ; Electrode ; Supercapacitor ; Fiber ; Atmospheric-pressure plasma ; Chemical engineering ; Polymer ; Carbon nanotube ; Plasma ; Scanning electron microscope ; Electrochemistry ; Chemistry Supercapacitor Materials and Fabrication ; Fiber-reinforced polymer composites ; Electrospun Nanofibers in Biomedical Applications
Authors: Verónica Almeida‐Marrero | Fleur Bethlehem | Sara Longo | M. Candelaria Bertolino | Tomás Torres⊗ | Jurriaan Huskens | Andrés de la Escosura
Source: Angewandte Chemie (article, 2022-06-02)
Field: Materials Science — Materials Chemistry

Tailored Multivalent Targeting of Siglecs with Photosensitizing Liposome Nanocarriers Abstract The modification of surfaces with multiple ligands allows the formation of platforms for the study of multivalency in diverse processes. Herein we use this approach for the implementation of a photosensitizer (PS)‐nanocarrier system that binds efficiently to siglec‐10, a member of the CD33 family of siglecs (sialic acid (SA)‐binding immunoglobulin‐like lectins). In particular, a zinc phthalocyanine derivative bearing three SA moieties ( PcSA ) has been incorporated in the membrane of small unilamellar vesicles (SUVs), retaining its photophysical properties upon insertion into the SUV's membrane. The interaction of these biohybrid systems with human siglec‐10‐displaying supported lipid bilayers (SLBs) has shown the occurrence of weakly multivalent, superselective interactions between vesicle and SLB. The SLB therefore acts as an excellent cell membrane mimic, while the binding with PS‐loaded SUVs shows the potential for targeting siglec‐expressing cells with photosensitizing nanocarriers. Nanocarriers ; Chemistry ; Liposome ; SIGLEC ; Photosensitizer ; Vesicle ; Biophysics ; Lipid bilayer ; Membrane ; Sialic acid ; Nanotechnology ; Biochemistry ; Drug delivery ; Materials science ; Organic chemistry Porphyrin and Phthalocyanine Chemistry ; Lipid Membrane Structure and Behavior ; Supramolecular Self-Assembly in Materials
Authors: Serena Correnti | Mariaimmacolata Preianò | Pierpaolo Murfone | Annalisa Fregola | Massimo Bitonti | Rocco Savino | Rosa Terracciano
Source: International Journal of Molecular Sciences (article, 2022-09-15)
Field: Chemistry — Spectroscopy

Revealing the Hidden Diagnostic Clues of Male Infertility from Human Seminal Plasma by Dispersive Solid Phase Extraction and MALDI-TOF MS Seminal plasma (SP) mirrors the local pathophysiology of the male reproductive system and represents a non-invasive fluid for the study of infertility. Matrix-Assisted Laser Desorption/Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF-MS) provides a high-throughput platform to rapidly extrapolate the diagnostic profiles of information-rich patterns. In this study, dispersive solid phase extraction (<i>d</i>-SPE) combined with MALDI-TOF-MS was applied for the first time to the human SP, with the aim of revealing a diagnostic signature for male infertility. Commercially available octadecyl (C<sub>18</sub>)-, octyl (C<sub>8</sub>)-bonded silica sorbents and hexagonal mesoporous silica (HMS) were tested and the robustness of MALDI-TOF peptide profiling was evaluated. Best performances were obtained for C<sub>18</sub>-bonded silica with the highest detection of peaks and the lowest variation of spectral features. To assess the diagnostic potential of the method, C<sub>18</sub>-bonded silica <i>d</i>-SPE and MALDI-TOF-MS were used to generate enriched endogenous peptide profiles of SP from 15 fertile and 15 non-fertile donors. Principal component analysis (PCA) successfully separated fertile from non-fertile men into two different clusters. An array of seven semenogelin-derived peptides was found to distinguish the two groups, with high statistical significance. These findings, while providing a rapid and convenient route to selectively enrich native components of SP peptidome, strongly reinforce the prominent role of semenogelins in male infertility. Solid phase extraction ; Matrix-assisted laser desorption/ionization ; Male infertility ; Infertility ; Principal component analysis ; Chromatography ; Mass spectrometry ; Sample preparation ; Biology ; Chemistry ; Materials science ; Andrology ; Desorption ; Medicine ; Genetics Mass Spectrometry Techniques and Applications ; Hormonal and reproductive studies ; Sperm and Testicular Function
Authors: Roberto Viola | Nicola Liberatore | Sandro Mengali
Source: Sensors (article, 2022-09-22)
Field: Chemistry — Spectroscopy

Additively Manufactured Detection Module with Integrated Tuning Fork for Enhanced Photo-Acoustic Spectroscopy Starting from Quartz-Enhanced Photo-Acoustic Spectroscopy (QEPAS), we have explored the potential of a tightly linked method of gas/vapor sensing, from now on referred to as Tuning-Fork-Enhanced Photo-Acoustic Spectroscopy (TFEPAS). TFEPAS utilizes a non-piezoelectric metal or dielectric tuning fork to transduce the photoacoustic excitation and an optical interferometric readout to measure the amplitude of the tuning fork vibration. In particular, we have devised a solution based on Additive Manufacturing (AM) for the Absorption Detection Module (ADM). The novelty of our solution is that the ADM is entirely built monolithically by Micro-Metal Laser Sintering (MMLS) or other AM techniques to achieve easier and more cost-effective customization, extreme miniaturization of internal volumes, automatic alignment of the tuning fork with the acoustic micro-resonators, and operation at high temperature. This paper reports on preliminary experimental results achieved with ammonia at parts-per-million concentration in nitrogen to demonstrate the feasibility of the proposed solution. Prospectively, the proposed TFEPAS solution appears particularly suited for hyphenation to micro-Gas Chromatography and for the analysis of complex solid and liquid traces samples, including compounds with low volatility such as illicit drugs, explosives, and persistent chemical warfare agents. Tuning fork ; Photoacoustic spectroscopy ; Miniaturization ; Explosive material ; Materials science ; Spectroscopy ; Resonator ; Optoelectronics ; Interferometry ; Laser ; Vibration ; Acoustics ; Optics ; Nanotechnology ; Chemistry ; Physics Spectroscopy and Laser Applications ; Advanced Chemical Sensor Technologies ; Gas Sensing Nanomaterials and Sensors
Authors: Yelizaveta Kulynych | D. O. Oriekhov
Source: Physical review. B./Physical review. B (article, 2022-07-13)
Field: Materials Science — Materials Chemistry

Differential entropy per particle as a probe of van Hove singularities and flat bands In the present paper we derive the general expressions for the differential entropy per particle near van Hove singularities (vHs) in the density of states. The dependence of entropy per particle on chemical potential and temperature demonstrates different behavior depending on the type of vHs, and distinguishes high-order vHs with different divergence exponents and flat bands. In addition, it allows one to test the ``flatness'' of the band in experiment. We compare the analytic predictions with the numerical calculation of the differential entropy for tight-binding models of graphene, the Lieb lattice, and the square-octagon lattice. Our results show that the obtained analytic expressions capture the main features of the differential entropy, thus serving as a good probe for details of the density of states structure. Differential entropy ; Gravitational singularity ; Density of states ; Physics ; Entropy (arrow of time) ; Statistical physics ; Condensed matter physics ; Quantum mechanics ; Joint quantum entropy Graphene research and applications ; Quantum and electron transport phenomena ; Advanced Thermodynamics and Statistical Mechanics
Authors: Akash Chandrabhan Chandekar | Biplab Kumar Debnath
Source: Progress in Computational Fluid Dynamics An International Journal (article, 2022-01-01)
Field: Materials Science — Biomaterials

Computational analysis of mixing characteristics of port-injected bioCNG with air for different designs of intake manifold The bioCNG with 90% of methane makes a potential renewable alternative of CNG for the application in dual-fuel diesel engine. The bioCNG is to be inducted in the manifold through port injection. The work is aimed to find the optimum port length and port-injector diameter. The objective is to mix bioCNG homogenously with air, before entering the engine. This would create an opportunity for major replacement of diesel to reduce the running cost of the vehicle. The two injector diameters (7 mm and 10 mm) and four port lengths (0 mm, 100 mm, 150 mm and 200 mm) are investigated. The manifold has a diameter of 28.5 mm and the port-injector is inclined at 35 to the manifold axis. The geometries are simulated in ANSYS Workbench 19.2, and post-processed in Tecplot. The results show that the port length of 200 mm with an injector diameter of 7 mm delivered homogeneous mixture in dual-fuel mode. Mixing (physics) ; Computational fluid dynamics ; Port (circuit theory) ; Manifold (fluid mechanics) ; Mechanics ; Environmental science ; Mechanical engineering ; Engineering ; Physics Electrospun Nanofibers in Biomedical Applications ; 3D Printing in Biomedical Research ; biodegradable polymer synthesis and properties
Authors: Zhaolong Cao | Jianfa Chen | Shaozhi Deng | Huanjun Chen
Source: Nanoscale (article, 2022-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

A physical interpretation of coupling chiral metaatoms The physical origins of chiroptical responses from artificial optically active media are significant for developing high-performance circular dichroism (CD) spectroscopic techniques. Here, we present a biorthogonal approach based on temporal coupled-mode theory to unravel the underlying physics of chiral metasurfaces. Equipped with physically meaningful parameters, this approach inherits the intrinsic properties of open optical cavities, including time-reversal symmetry and non-Hermitian Hamiltonians, which are found to be in excellent agreement with numerical results. Remarkably, it identifies that the intrinsic chirality of coupled chiral nanocavities arises from (i) the asymmetric coupling between interlayer cross-polarized resonant modes and (ii) a coherent interference between doubly degenerate states. Based on this formalism, a critical coupling condition capable of achieving zero transmission for circularly polarized light is proposed. Interpretation (philosophy) ; Coupling (piping) ; Theoretical physics ; Chemical physics ; Statistical physics ; Materials science ; Computational chemistry ; Physics ; Computer science ; Chemistry Metamaterials and Metasurfaces Applications ; Random lasers and scattering media ; Liquid Crystal Research Advancements
Authors: Jikai Wang | J. M. Schwarz | Joseph D. Paulsen
Source: Physical Review Research (article, 2022-01-10)
Field: Materials Science — Materials Chemistry

Propagating irreversibility fronts in cyclically sheared suspensions The interface separating a liquid from its vapor phase is diffuse; the composition varies continuously from one phase to the other over a finite length. Recent experiments on dynamic jamming fronts in two dimensions [Waitukaitis et al., Europhys. Lett. 102, 44001 (2013)] identified a diffuse interface between jammed and unjammed disks. In both cases, the thickness of the interface diverges as a critical transition is approached. We investigate the generality of this behavior using a third system: A model of cyclically sheared non-Brownian suspensions. As we sediment the particles toward a boundary, we observe a diffuse traveling front that marks the interface between irreversible and reversible phases. We argue that the front width is linked to a diverging correlation length scale in the bulk, which we probe by studying avalanches near criticality. Our results show how diffuse interfaces may arise generally when an incompressible phase is brought to a critical point. Brownian motion ; Front (military) ; Critical point (mathematics) ; Boundary (topology) ; Compressibility ; Phase transition ; Length scale ; Mechanics ; Phase (matter) ; Jamming ; Physics ; Statistical physics ; Materials science ; Condensed matter physics ; Geometry ; Mathematics ; Mathematical analysis Material Dynamics and Properties ; Micro and Nano Robotics ; Diffusion and Search Dynamics