jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Mahdi Ghazal | Michel Daher Mansour | Corentin Scholaert | Thomas Dargent | Yannick Coffinier | Sébastien Pecqueur | Fabien Alibart
Source: arXiv (Cornell University) (article, 2021-08-30)
Field: Materials Science — Polymers and Plastics

Bio-inspired adaptive sensing through electropolymerization of organic\n electrochemical transistors Organic Electrochemical Transistors are considered today as a key technology\nto interact with biological medium through their intrinsic ionic-electronic\ncoupling. In this paper, we show how this coupling can be finely tuned (in\noperando) post-microfabrication via electropolymerization technique. This\nstrategy exploits the concept of adaptive sensing where both transconductance\nand impedance are tunable and can be modified on-demand to match different\nsensing requirements. Material investigation through Raman spectroscopy, atomic\nforce microscopy and scanning electron microscopy reveals that\nelectropolymerization can lead to a fine control of PEDOT microdomains\norganization, which directly affect the iono-electronic properties of OECTs. We\nfurther highlight how volumetric capacitance and effective mobility of\nPEDOT:PSS influence distinctively the transconductance and impedance of OECTs.\nThis approach shows to improve the transconductance by 150% while reducing\ntheir variability by 60% in comparison with standard spin-coated OECTs.\nFinally, we show how to the technique can influence voltage spike rate hardware\nclassificationwith direct interest in bio-signals sorting applications.\n Materials science ; PEDOT:PSS ; Transconductance ; Nanotechnology ; Transistor ; Dielectric spectroscopy ; Capacitance ; Optoelectronics ; Raman spectroscopy ; Microfabrication ; Polystyrene sulfonate ; Electrochemistry ; Electrode ; Voltage ; Layer (electronics) ; Electrical engineering Conducting polymers and applications ; Electrochemical Analysis and Applications ; Analytical Chemistry and Sensors
Authors: Sushovit Adhikari | Cristian L. Cortes | Xiewen Wen | Shobhana Panuganti | David J. Gosztola | Richard D. Schaller | Gary P. Wiederrecht | Stephen K. Gray
Source: Physical Review Applied (article, 2021-02-15)
Field: Chemistry — Spectroscopy

Accelerating Ultrafast Spectroscopy with Compressive Sensing Ultrafast spectroscopy is an important tool for studying photoinduced dynamical processes in atoms, molecules, and nanostructures. Typically, the time to perform these experiments ranges from several minutes to hours depending on the choice of spectroscopic method. It is desirable to reduce this time overhead to not only to shorten time and laboratory resources, but also to make it possible to examine fragile specimens which quickly degrade during long experiments. In this article, we motivate using compressive sensing to significantly shorten data acquisition time by reducing the total number of measurements in ultrafast spectroscopy. We apply this technique to experimental data from ultrafast transient absorption spectroscopy and ultrafast terahertz spectroscopy and show that good estimates can be obtained with as low as 15% of the total measurements, implying a 6-fold reduction in data acquisition time. Ultrashort pulse ; Spectroscopy ; Ultrafast laser spectroscopy ; Data acquisition ; Overhead (engineering) ; Compressed sensing Spectroscopy and Laser Applications ; Spectroscopy and Quantum Chemical Studies ; Quantum optics and atomic interactions
Authors: Kritesh Kumar Gupta | T. Mukhopadhyay | Lintu Roy | S. Dey
Source: Materials Advances (article, 2021-11-26)
Field: Materials Science — Materials Chemistry

Hybrid machine-learning-assisted quantification of the compound internal and external uncertainties of graphene: towards inclusive analysis and design With the aim of developing an inclusive paradigm, we have systematically quantified the uncertainties associated with internal and external parameters individually, and their compound effect on the mechanical properties of graphene. Graphene ; Nanotechnology ; Computer science ; Materials science ; Artificial intelligence Graphene research and applications ; Thermal properties of materials ; Machine Learning in Materials Science
Authors: Aleksandr O. Lykhin | Donald G. Truhlar | Laura Gagliardi
Source: Journal of Chemical Theory and Computation (article, 2021-11-18)
Field: Chemistry — Organic Chemistry

Dipole Moment Calculations Using Multiconfiguration Pair-Density Functional Theory and Hybrid Multiconfiguration Pair-Density Functional Theory The dipole moment is the molecular property that most directly indicates molecular polarity. The accuracy of computed dipole moments depends strongly on the quality of the calculated electron density, and the breakdown of single-reference methods for strongly correlated systems can lead to poor predictions of the dipole moments in those cases. Here, we derive the analytical expression for obtaining the electric dipole moment by multiconfiguration pair-density functional theory (MC-PDFT), and we assess the accuracy of MC-PDFT for predicting dipole moments at equilibrium and nonequilibrium geometries. We show that MC-PDFT dipole moment curves have reasonable behavior even for stretched geometries, and they significantly improve upon the CASSCF results by capturing more electron correlation. The analysis of a dataset consisting of 18 first-row transition-metal diatomics and 6 main-group polyatomic molecules with a multireference character suggests that MC-PDFT and its hybrid extension (HMC-PDFT) perform comparably to CASPT2 and MRCISD+Q methods and have a mean unsigned deviation of 0.2-0.3 D with respect to the best available dipole moment reference values. We explored the dependence of the predicted dipole moments upon the choice of the on-top density functional and active space, and we recommend the tPBE and hybrid tPBE0 on-top choices for the functionals combined with the moderate correlated-participating-orbitals scheme for selecting the active space. With these choices, the mean unsigned deviations (in debyes) of the calculated equilibrium dipole moments from the best estimates are 0.77 for CASSCF, 0.29 for MC-PDFT, 0.24 for HMC-PDFT, 0.28 for CASPT2, and 0.25 for MRCISD+Q. These results are encouraging because the computational cost of MC-PDFT or HMC-PDFT is largely reduced compared to the CASPT2 and MRCISD+Q methods. Dipole ; Moment (physics) ; Density functional theory ; Bond dipole moment ; Electric dipole moment ; Chemistry ; Physics ; Transition dipole moment ; Atomic physics ; Statistical physics ; Computational chemistry ; Quantum mechanics Free Radicals and Antioxidants ; Advanced Chemical Physics Studies ; Spectroscopy and Quantum Chemical Studies
Authors: Arindam Dasgupta | Jie Gao | Xiaodong Yang
Source: npj 2D Materials and Applications (article, 2021-08-20)
Field: Materials Science — Materials Chemistry

Natural van der Waals heterostructure cylindrite with highly anisotropic optical responses Abstract The mechanical exfoliation of naturally occurring layered materials has emerged as an easy and effective method for achieving ultrathin van der Waals (vdW) heterostructures with well-defined lattice orientations of the constituent two-dimensional (2D) material layers. Cylindrite is one such naturally occurring vdW heterostructure, where the superlattice is composed of alternating stacks of SnS 2 -like and PbS-like layers. Although the constituent 2D lattices are isotropic, inhomogeneous strain occurring from local atomic alignment for forcing the commensuration makes the cylindrite superlattice structurally anisotropic. Here, we demonstrate the highly anisotropic optical responses of cylindrite thin flakes induced by the anisotropic crystal structure, including angle-resolved polarized Raman scattering, linear dichroism, and polarization-dependent anisotropic third-harmonic generation. Our results provide a promising approach for identifying various natural vdW heterostructure-based 2D materials with tailored optical properties and can be harnessed for realizing anisotropic optical devices for on-chip photonic circuits and optical information processing. Anisotropy ; Heterojunction ; Superlattice ; van der Waals force ; Materials science ; Isotropy ; Condensed matter physics ; Birefringence ; Optoelectronics ; Raman spectroscopy ; Optics ; Physics 2D Materials and Applications ; MXene and MAX Phase Materials ; Luminescence and Fluorescent Materials
Authors: Roman Szücs | Roland Brown | Claudio Brunelli | James Heaton | Jasna Hradski
Source: International Journal of Molecular Sciences (article, 2021-04-08)
Field: Chemistry — Spectroscopy

Structure Driven Prediction of Chromatographic Retention Times: Applications to Pharmaceutical Analysis Pharmaceutical drug development relies heavily on the use of Reversed-Phase Liquid Chromatography methods. These methods are used to characterize active pharmaceutical ingredients and drug products by separating the main component from related substances such as process related impurities or main component degradation products. The results presented here indicate that retention models based on Quantitative Structure Retention Relationships can be used for de-risking methods used in pharmaceutical analysis and for the identification of optimal conditions for separation of known sample constituents from postulated/hypothetical components. The prediction of retention times for hypothetical components in established methods is highly valuable as these compounds are not usually readily available for analysis. Here we discuss the development and optimization of retention models, selection of the most relevant structural molecular descriptors, regression model building and validation. We also present a practical example applied to chromatographic method development and discuss the accuracy of these models on selection of optimal separation parameters. Retention time ; Chromatography ; Active ingredient ; Component (thermodynamics) ; Pharmaceutical formulation ; Chemistry ; Drug development ; Biochemical engineering ; Biological system ; Computer science ; Drug ; Bioinformatics Analytical Chemistry and Chromatography ; Computational Drug Discovery Methods ; Chromatography in Natural Products
Authors: Sai Xu | Huazhong Lu | Xu Wang | Christopher Ference | Xin Liang | Guangjun Qiu
Source: HortScience (article, 2021-10-21)
Field: Chemistry — Analytical Chemistry

Nondestructive Detection of Internal Flavor in ‘Shatian’ Pomelo Fruit Based on Visible/Near Infrared Spectroscopy Visible/near-infrared (VIS/NIR) spectroscopy is a powerful tool for rapid, nondestructive fruit quality detection. This technology has been widely applied for quality detection of small thin-peel fruit, although less so for large thick-peel fruit because of the low signal-to-noise ratio of the spectral signal, resulting in a reduction of accuracy. More modeling work should be focused on solving this problem. This research explored a method of spectroscopy for the total soluble solid (TSS) content and acidity detection of ‘Shatian’ pomelo, which are two major parameters of fruit internal flavor. VIS/NIR spectral signal detection of 100 pomelo samples during storage was performed. Detection based on raw data, signal jitter, and scattered light noise removal, feature extraction, and deep learning were performed and combined with modeling detection to achieve an accurate step-by-step detection. Our results showed that 600 W is the optimal light intensity for detecting the internal flavor of pomelo. The TSS content of pomelo is optimally detected using Savitzky-Golay (SG) + multiplicative scatter correction (MSC) + genetic algorithm (GA) + principal component analysis (PCA) + convolutional neural network (CNN) + partial least squares regression (PLSR); however, acidity of pomelo is optimally detected using SG + MSC + GA + PLSR. With the optimal detection method, the coefficient of determination and root mean squared error (RMSE) of the validation set for TSS detection are 0.72 and 0.49, respectively; and for acidity detection are 0.55 and 0.10, respectively. Even though the accuracy is not high, the data are still acceptable and helpful in nondestructive quality grading of large quantities postharvest fruit. Therefore, our results demonstrated that VIS/NIR was feasible for detecting the TSS content and acidity of postharvest pomelo, and for providing a possible method for the nondestructive internal quality detection of other large thick-peel fruit. Partial least squares regression ; Near-infrared spectroscopy ; Mean squared error ; Mathematics ; Detection limit ; Spectroscopy ; Analytical Chemistry (journal) ; Biological system ; Computer science ; Materials science ; Pattern recognition (psychology) ; Chemistry ; Artificial intelligence ; Chromatography ; Optics ; Statistics ; Physics Spectroscopy and Chemometric Analyses ; Advanced Chemical Sensor Technologies ; Water Quality Monitoring and Analysis
Authors: D. Goll | Felix Trauter | Ralf B. Loeffler | Thomas Groß | Gerhard Schneider
Source: Micromachines (article, 2021-08-31)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Additive Manufacturing of Textured FePrCuB Permanent Magnets Permanent magnets based on FePrCuB were realized on a laboratory scale through additive manufacturing (laser powder bed fusion, L-PBF) and book mold casting (reference). A well-adjusted two-stage heat treatment of the as-cast/as-printed FePrCuB alloys produces hard magnetic properties without the need for subsequent powder metallurgical processing. This resulted in a coercivity of 0.67 T, remanence of 0.67 T and maximum energy density of 69.8 kJ/m<sup>3</sup> for the printed parts. While the annealed book-mold-cast FePrCuB alloys are easy-plane permanent magnets (BMC magnet), the printed magnets are characterized by a distinct, predominantly directional microstructure that originated from the AM process and was further refined during heat treatment. Due to the higher degree of texturing, the L-PBF magnet has a 26% higher remanence compared to the identically annealed BMC magnet of the same composition. Magnet ; Remanence ; Coercivity ; Materials science ; Microstructure ; Mold ; Neodymium magnet ; Metallurgy ; Casting ; Composite material ; Mechanical engineering ; Magnetic field ; Magnetization ; Condensed matter physics ; Engineering ; Physics Magnetic Properties of Alloys ; Metallurgical and Alloy Processes ; Magnetic properties of thin films
Authors: Liang Zhao | Mahyuddin K. M. Nasution | Maboud Hekmatifar | Roozbeh Sabetvand | Pavel Kamenskov | Davood Toghraie | As’ad Alizadeh | Teimour Ghahari Iran
Source: Scientific Reports (article, 2021-10-12)
Field: Materials Science — Materials Chemistry

The improvement of mechanical properties of conventional concretes using carbon nanoparticles using molecular dynamics simulation In the present study, the improvement of mechanical properties of conventional concretes using carbon nanoparticles is investigated. More precisely, carbon nanotubes are added to a pristine concrete matrix, and the mechanical properties of the resulting structure are investigated using the molecular dynamics (MD) method. Some parameters such as the mechanical behavior of the concrete matrix structure, the validation of the computational method, and the mechanical behavior of the concrete matrix structure with carbon nanotube are also examined. Also, physical quantities such as a stress-strain diagram, Poisson's coefficient, Young's modulus, and final strength are calculated and reported for atomic samples under external tension. From a numerical point of view, the quantities of Young's modulus and final strength are converged to 35 GPa and 35.38 MPa after the completion of computer simulations. This indicates the appropriate effect of carbon nanotubes in improving the mechanical behavior of concrete and the efficiency of molecular dynamics method in expressing the mechanical behavior of atomic structures such as concrete, carbon nanotubes and composite structures derived from raw materials is expressed that can be considered in industrial and construction cases. Carbon nanotube ; Materials science ; Molecular dynamics ; Modulus ; Composite material ; Carbon fibers ; Poisson's ratio ; Matrix (chemical analysis) ; Young's modulus ; Tension (geology) ; Composite number ; Ultimate tensile strength ; Poisson distribution ; Computational chemistry ; Chemistry ; Mathematics Carbon Nanotubes in Composites ; Fire effects on concrete materials ; Boron and Carbon Nanomaterials Research
Authors: Michele Panzitta | Niccolò Calamassi | Cristina Sabatini | Marzia Grassi | Chiara Spagnoli | Vittoria Vizzini | Elisa Ricchiuto | A Venturini | Andrea Brogi | Judit Brassier Font | Lino Pontello | Giorgio Bruno | Paola Minghetti | Maurizio Ricci
Source: International Journal of Pharmaceutics (article, 2021-04-05)
Field: Chemistry — Analytical Chemistry

Spectrophotometry and pharmaceutical PAT/RTRT: Practical challenges and regulatory landscape from development to product lifecycle European Pharmacopoeia includes dedicated chapters for Raman, NIR and Chemometrics, as well as there is a lot of Academia research on the matter. Despite that, the word innovation is often associated to such tools and there is a still slow implementation at industry. The paper is the outcome of the Associazione Farmaceutici dell'Industria (AFI) Study Group on Process Innovation and Product Lifecycle; the aim is to describe some case studies referring to practical approaches in pharmaceutical industry, in order to depict challenges and opportunities for the implementation of spectroscopic techniques. Case studies include: feasibility and pre-screening evaluations, chemometric model development approaches, way for the method maintenance during commercial manufacturing, challenges for implementation on existing equipment and on sterile processes. Case studies refer to oral solid products, liquid products and sterile Active Pharmaceutical Ingradient (API) manufacturing. There are already successful and robust spectroscopic applications in pharmaceutical industry and the technology is mature: this is the outcome of a strong applied research performed at pharmaceutical production departments. It is necessary to acknowledge efforts done by industry as Research for strengthening the cooperation with Academia, so that advantage of process innovation might reach the patients in a fastest way. Pharmaceutical industry ; Pharmacopoeia ; Process (computing) ; Product lifecycle ; Pharmaceutical manufacturing ; Product (mathematics) ; New product development ; Process management ; Process analytical technology ; Business ; Computer science ; Risk analysis (engineering) ; Manufacturing engineering ; Biochemical engineering ; Work in process ; Engineering ; Marketing ; Medicine ; Pharmacology Spectroscopy and Chemometric Analyses ; Spectroscopy Techniques in Biomedical and Chemical Research ; Pesticide Residue Analysis and Safety
Authors: Murong Zhou | Yi Kong | Xiaobin Wang | Wen Li | Si Chen | Li Wang | Chengbin Wang | Qian Zhang
Source: BioMed Research International (article, 2021-01-01)
Field: Chemistry — Spectroscopy

LC‐MS/MS‐Based Quantitative Proteomics Analysis of Different Stages of Non‐Small‐Cell Lung Cancer Lung cancer has a higher incidence rate and mortality rate than all other cancers. Early diagnosis and treatment of lung cancer remain a major challenge, and the 5-year survival rate of its patients is only 15%. Basic and clinical research, especially the discovery of biomarkers, is crucial for improving the diagnosis and treatment of lung cancer patients. To identify novel biomarkers for lung cancer, we used the iTRAQ8-plex labeling technology combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to analyze the serum and urine of patients with different stages of lung adenocarcinoma and healthy individuals. A total of 441 proteins were identified in the serum, and 1,161 proteins were identified in the urine. The levels of elongation factor 1-alpha 2, proteasome subunit alpha type, and spermatogenesis-associated protein increased significantly in the serum of patients with lung cancer compared with those in healthy controls. The levels of transmembrane protein 143, cadherin 5, fibronectin 1, and collectin-11 decreased significantly in the serum of patients with metastases compared with those of nonmetastatic lung cancer patients. In the urine of stage III and IV lung cancer patients, the prostate-specific antigen and prostatic acid phosphatase decreased significantly, whereas neutrophil defensin 1 increased significantly. The results of LC-MS/MS were confirmed by enzyme-linked immunosorbent assay (ELISA) for transmembrane protein 143, cadherin 5, fibronectin 1, and collectin-11 in the serum. These proteins may be a potential early diagnosis and metastasis biomarkers for lung adenocarcinoma. Furthermore, the relative content of these markers in the serum and urine could be used to determine the progression of lung adenocarcinoma and achieve accurate staging and diagnosis. Lung cancer ; Medicine ; Adenocarcinoma ; Lung ; Cancer ; Internal medicine ; Metastasis ; Prostate cancer ; Gastroenterology ; Oncology ; Pathology Advanced Proteomics Techniques and Applications ; Ferroptosis and cancer prognosis ; Cancer, Lipids, and Metabolism
Authors: Robin Legner | Melanie Voigt | Carla Servatius | Johannes Klein | Antje Hambitzer | Martin Jaeger
Source: Applied Sciences (article, 2021-02-10)
Field: Chemistry — Analytical Chemistry

A Four-Level Maturity Index for Hot Peppers (Capsicum annum) Using Non-Invasive Automated Mobile Raman Spectroscopy for On-Site Testing A handheld Raman spectrometer was used to determine the ripeness of peppers. Raman spectra were recorded non-invasively on the fruit surface. The spectroscopic data were transformed into a classification scheme referred to as the maturity index which allowed for attribution of the fruit stadium to four levels from immature to fully mature. Hot pepper and tomato ripening includes pectic polysaccharide depolymerization, chlorophyll degradation and carotenoid formation, among others. The latter were followed non-invasively by Raman spectroscopy. Two portable systems and one benchtop system were compared for their applicability and robustness to establish a suitable maturity index. Spectral acquisition, data treatment and multivariate data analysis were automated using a Matlab script on a laptop computer. The automated workflow provided a graphic visualization of the relevant parameters and results on-site in real time. In terms of reliability and applicability, the chemometric model to determine the maturity of fruits was compared to a univariate procedure based on the average intensity and ratio of three characteristic signals. Portable Raman spectrometers in combination with the maturity index or a chemometric model should be suitable to assess the stage of maturing for carotenoid-containing fruits and thus to determine ripeness on-site or during a sorting process in an automated manner. Ripeness ; Ripening ; Raman spectroscopy ; Chemistry ; Mathematics ; Horticulture ; Biological system ; Analytical Chemistry (journal) ; Computer science ; Food science ; Chromatography ; Biology ; Optics ; Physics Spectroscopy and Chemometric Analyses ; Essential Oils and Antimicrobial Activity ; Advanced Chemical Sensor Technologies