jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: María A. Tapia | Clara Pérez‐Ràfols | Cristina Ariño | Núria Serrano | José Manuel Dı́az-Cruz
Source: Analytical Chemistry (article, 2020-01-17)
Field: Chemistry — Analytical Chemistry

New Approach to Multivariate Standard Addition Based on Multivariate Curve Resolution by Alternating Least-Squares: Application to Voltammetric Data A multivariate version of the classical univariate standard addition method is proposed for the analysis of samples generating overlapping signals in the presence of notorious matrix effects. Unlike previous versions based on multivariate calibration by partial least-squares (PLS), the proposed strategy takes advantage of a self-modeling methodology: multivariate curve resolution by alternating least-squares (MCR-ALS) enhanced with signal shape constraints based on parametric functions. In this way, there is no need for the full multivariate response of a blank solution, and in multianalyte determinations, the standard additions can be made with a solution containing all of the analytes, which constitutes a clear advance as compared to PLS approach. The proposed method has been successfully tested in the voltammetric determination of hydroquinone and catechol in solutions of increasing complexity and appears to be a promising tool in the field of electroanalysis. Multivariate statistics ; Univariate ; Chemistry ; Partial least squares regression ; Blank ; Multivariate analysis ; Calibration ; Least-squares function approximation ; Chemometrics ; Resolution (logic) ; Analytical Chemistry (journal) ; Statistics ; Chromatography ; Artificial intelligence ; Computer science ; Mathematics Spectroscopy and Chemometric Analyses ; Water Quality Monitoring and Analysis ; Advanced Chemical Sensor Technologies
Authors: Lucía Trilla‐Fuertes | Angelo Gámez‐Pozo | Jorge M. Arevalillo | Rocío López‐Vacas | Elena López‐Camacho | Guillermo Prado-Vázquez | Andrea Zapater‐Moros | Mariana Díaz‐Almirón | María Ferrer-Gómez | Hilario Navarro | Paolo Nanni | Pilar Zamora | Enrique Espinosa | Paloma Maı́n | Juan Ángel Fresno Vara
Source: PLoS ONE (article, 2020-06-11)
Field: Chemistry — Spectroscopy

Bayesian networks established functional differences between breast cancer subtypes Breast cancer is a heterogeneous disease. In clinical practice, tumors are classified as hormonal receptor positive, Her2 positive and triple negative tumors. In previous works, our group defined a new hormonal receptor positive subgroup, the TN-like subtype, which had a prognosis and a molecular profile more similar to triple negative tumors. In this study, proteomics and Bayesian networks were used to characterize protein relationships in 96 breast tumor samples. Components obtained by these methods had a clear functional structure. The analysis of these components suggested differences in processes such as mitochondrial function or extracellular matrix between breast cancer subtypes, including our new defined subtype TN-like. In addition, one of the components, mainly related with extracellular matrix processes, had prognostic value in this cohort. Functional approaches allow to build hypotheses about regulatory mechanisms and to establish new relationships among proteins in the breast cancer context. Breast cancer ; Context (archaeology) ; Biology ; Oncology ; Proteomics ; Cancer ; Bioinformatics ; Triple-negative breast cancer ; Computational biology ; Internal medicine ; Medicine ; Genetics ; Gene Advanced Proteomics Techniques and Applications ; Bioinformatics and Genomic Networks ; Gene expression and cancer classification
Authors: Yuhua Li | Fengjie Wang | Ye Sun | Yingxu Wang
Source: Sensors (article, 2020-02-23)
Field: Chemistry — Analytical Chemistry

Graph Constraint and Collaborative Representation Classifier Steered Discriminative Projection with Applications for the Early Identification of Cucumber Diseases Accurate, rapid and non-destructive disease identification in the early stage of infection is essential to ensure the safe and efficient production of greenhouse cucumbers. Nevertheless, the effectiveness of most existing methods relies on the disease already exhibiting obvious symptoms in the middle to late stages of infection. Therefore, this paper presents an early identification method for cucumber diseases based on the techniques of hyperspectral imaging and machine learning, which consists of two procedures. First, reconstruction fidelity terms and graph constraints are constructed based on the decision criterion of the collaborative representation classifier and the desired spatial distribution of spectral curves (391 to 1044 nm) respectively. The former constrains the same-class and different-class reconstruction residuals while the latter constrains the weighted distances between spectral curves. They are further fused to steer the design of an offline algorithm. The algorithm aims to train a linear discriminative projection to transform the original spectral curves into a low dimensional space, where the projected spectral curves of different diseases own better separation trends. Then, the collaborative representation classifier is utilized to achieve online early diagnosis. Five experiments were performed on the hyperspectral data collected in the early infection stage of cucumber anthracnose and <i>Corynespora cassiicola</i> diseases. Experimental results demonstrated that the proposed method was feasible and effective, providing a maximal identification accuracy of 98.2% and an average online identification time of 0.65 ms. The proposed method has a promising future in practical production due to its high diagnostic accuracy and short diagnosis time. Hyperspectral imaging ; Discriminative model ; Classifier (UML) ; Artificial intelligence ; Pattern recognition (psychology) ; Computer science ; Corynespora cassiicola ; Graph ; Fidelity ; Spectral signature ; Mathematics ; Remote sensing Spectroscopy and Chemometric Analyses ; Smart Agriculture and AI ; Remote Sensing and Land Use
Authors: Jacob Søgaard Larsen | Line Katrine Harder Clemmensen | Anders Stockmarr | Thomas Skov | Anders Larsen | Bjarne Kjær Ersbøll
Source: Journal of Chemometrics (article, 2020-02-05)
Field: Chemistry — Analytical Chemistry

Semi‐supervised covariate shift modelling of spectroscopic data Abstract Utilizing the full potential of spectroscopic calibrations in changing environments typically requires large amounts of maintenance and/or model updates as the presence of new sources of variation makes the calibration insufficient. In this paper, we propose the use of unlabelled data in order to automize such maintenance. We extend the Linear Joint Trained Framework by Ryan and Culp such that the shifts in mean value and covariance structure are modelled explicitly. The extension yields a more flexible framework, and thus we are able to regularize the final calibration in a more desirable manner. The proposed framework is tested on a simulated dataset where we simulate three different realistic scenarios that are either challenging for classic multivariate calibrations or challenging when adding unlabelled data. Furthermore, we test our framework on two real datasets across multiple data splits. We find that our framework not only achieves the same (and in some instances lower) error level as that of the baseline model (NARE), it also yields better calibration models than the Linear Joint Trained Framework. Covariate ; Chemometrics ; Computer science ; Statistics ; Mathematics ; Data mining ; Machine learning Spectroscopy and Chemometric Analyses ; Remote-Sensing Image Classification ; Blind Source Separation Techniques
Authors: Yafang Yin | Alex C. Wiedenhoeft | Lloyd Donaldson
Source: IAWA Journal - KU Leuven/IAWA Journal (article, 2020-11-12)
Field: Chemistry — Organic Chemistry

Advancing Wood Identification – Anatomical and Molecular Techniques Identification (biology) ; Biology ; Evolutionary biology ; Computational biology ; Botany Wood and Agarwood Research ; Biological Stains and Phytochemicals ; Cultural Heritage Materials Analysis
Authors: Éric Lafranche | Sandra Macedo | Pedro Eduardo Ferreira | Carla I. Martins
Source: Journal of Applied Polymer Science (article, 2020-11-19)
Field: Materials Science — Polymers and Plastics

Thin wall injection‐overmoulding of polyamide 6/polypropylene multilayer parts: PA6/PP‐g‐ma interfacial adhesion investigations Abstract This work investigates the interfacial adhesion of PA6/PP‐g‐MA in a thin‐walled multilayer part obtained by injection overmoulding. This process is a good solution to the need of weight reduction for the sustainable and economic growth of food packaging. A rigid plastic food package is a complex multilayer structure obtained from the association of polymers with different properties to achieve good barrier, environment, or thermo‐mechanical performance. The present study aims to obtain a complete understanding of the interfacial adhesion of PA6/PP‐g‐MA interface in a three‐layer PA6/sealant/PP assembly through microscopy analysis, mechanical characterization, and inter‐diffusion models. Optical microscopy, XPS, and AFM analyses showed the presence of a copolymer interphase. This layer is greatly dependent on the holding pressure applied, which revealed to be the key parameter to obtain the best results in terms of failure strength. A better interface wettability improves the inter‐diffusion distance and thus chemical grafting efficiency. Other interface improvements were achieved by the addition of EVA in the PP‐g‐MA layer. The lowest viscosity of the EVA dispersed phase has led to a fully cohesive failure due to an interface diffusion efficiency. The presence of EVA increased more than 80% of the peeling performance of the assemblies. Materials science ; Polypropylene ; Polyamide ; Composite material ; Wetting ; Adhesion ; Polymer ; Polymer blend ; Layer (electronics) ; Copolymer Polymer crystallization and properties ; Material Properties and Processing ; Polymer Foaming and Composites
Authors: Jing Li | Raza Ullah | Jian Jiao | Jihong Sun | Shiyang Bai
Source: Materials Chemistry and Physics (article, 2020-08-21)
Field: Chemistry — Inorganic Chemistry

Ion exchange of cations from different groups with ammonium-modified clinoptilolite and selectivity for methane and nitrogen Clinoptilolite ; Chemistry ; Adsorption ; Endothermic process ; Ion exchange ; Sorption ; Enthalpy ; Selectivity ; Inorganic chemistry ; Cationic polymerization ; Alkali metal ; Kinetics ; Diffusion ; Desorption ; Ion ; Physical chemistry ; Zeolite ; Thermodynamics ; Catalysis ; Organic chemistry Zeolite Catalysis and Synthesis ; Adsorption and biosorption for pollutant removal ; Clay minerals and soil interactions
Authors: Debraj Modak | Abhijit Kundu | Moumita Mukherjee
Source: Semiconductor Science and Technology (article, 2020-05-06)
Field: Materials Science — Materials Chemistry

Multiple-graphene layer based <i> p <sup>++</sup> –n–n <sup>−</sup> –n <sup>++</sup> </i> device on Si/3C-SiC (100) substrate: a highly sensitive visible photo-sensor Abstract The current paper reports the prospects of a multiple-graphene-layer (MGL) based vertically doped p ++ –n–n – –n ++ avalanche photo-sensor in visible wavelength region (300 nm–800 nm). High carrier mobility, intrinsic optical and mechanical properties in graphene at room temperature, have made this material promising for various novel applications. The authors have used an indigenously developed and experimentally verified quantum-corrected field maximum classical drift-diffusion (QCFMCDD) mathematical model for studying the optical characteristics of MGL based p ++ –n–n – –n ++ avalanche photo-diode sensor. The validity of the simulator is established through a comparative study between the experimental and analytical observations under similar operating (structural/electrical/thermal) conditions. Additionally, the superiority of the QCFMCDD model over the conventional classical drift-diffusion model is established through this comprehensive study. The analysis reveals that the opto-electrical properties of the device-under-test improve significantly as a result of the incorporation of MGL in the low doped active region. The authors have compared the results with those of a Si/4H-SiC super-lattice avalanche photo-sensor at 500 nm wavelength of incident radiation. It is observed that graphene outperforms its Si/4H-SiC counterpart in terms of photo-responsivity (0.820 A W −1 vs. 0.650 A W −1 ) and quantum efficiency (84% vs. 62%) for optical irradiation with visible laser source. The opto-electrical performance of the 3 × 3 array type graphene photo-sensor is further analyzed and compared with those of its single array counterpart. The photo-responsivity as well as quantum efficiency increases by at least 30% in the case of the 3 × 3 photo-sensor array. In comparison to available photo detectors, reported so far in published literature, the designed photo-sensor shows overall performance betterment in the visible wavelength region. To the best of authors’ knowledge, this is the first report on MGL based 3 × 3 array type ultra fast highly sensitive visible avalanche diode photo-sensor. Substrate (aquarium) ; Layer (electronics) ; Physics ; Materials science ; Analytical Chemistry (journal) ; Chemistry ; Nanotechnology Graphene research and applications ; Thin-Film Transistor Technologies ; Silicon Nanostructures and Photoluminescence
Authors: Emanuel Bahn | Leidy Hoyos | V. S. Kuznetsov | Irene Calvo‐Almazán | Mohamed Zbiri | Michael Marek Koza | Thomas C. Hansen | Paul F. Henry | Alain Lapp | Stéphanie Pouget | Mónica Mesa | Peter Fouquet
Source: Carbon (article, 2020-05-20)
Field: Materials Science — Materials Chemistry

Ultra-fast diffusion of hydrogen in a novel mesoporous N-doped carbon Materials science ; Mesoporous material ; Graphite ; Hydrogen ; Diffusion ; Carbon fibers ; Neutron diffraction ; Sorption ; Isothermal process ; Neutron scattering ; Doping ; Chemical engineering ; Adsorption ; Scattering ; Composite material ; Physical chemistry ; Crystallography ; Chemistry ; Catalysis ; Organic chemistry ; Thermodynamics ; Crystal structure Hydrogen Storage and Materials ; Ammonia Synthesis and Nitrogen Reduction ; Zeolite Catalysis and Synthesis
Authors: E. A. Haggag | Mohamed Bakry Masod | Ahmed M.A. Abdelsamad | mostafa mohamed | Mohamed A. Ebiad
Source: Egyptian Journal of Chemistry (article, 2020-12-20)
Field: Chemistry — Inorganic Chemistry

Kinetic studies on the adsorption of uranium on a mesoporous impregnated activated carbon A highly porous phosphorous-containing activated carbon derived from pistachio nutshells (PNS) was synthesis as a potential sorbent for uranium (VI) from sulfate media. The prepared phosphate activated carbon (PAC) was visualized under SEM and TEM which revealed highly porous structure. The extraction of U(VI) from acidic media using PAC has been investigated by a batch method and various parameters such as pH, equilibrium contact time, liquid to solid ratio, and initial U(VI) concentration were examined. Under the stated conditions, the optimum pH for U(VI) adsorption was found to be 3.5. The adsorption capacity of uranium upon PAC under the optimum conditions was found to be 335 mg/g. The experimental results were applied for Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R) isotherm models. The thermodynamic equilibrium constant and the Gibbs free energy were determined (ΔG° from -4.72 to -7.65 kJ/mol) and results indicated the spontaneous nature of the adsorption process. Kinetics data were best described by pseudo second-order model. Adsorption ; Activated carbon ; Mesoporous material ; Uranium ; Kinetic energy ; Carbon fibers ; Chemistry ; Chemical engineering ; Materials science ; Inorganic chemistry ; Catalysis ; Metallurgy ; Composite material ; Organic chemistry ; Composite number Radioactive element chemistry and processing ; Chemical Synthesis and Characterization ; Covalent Organic Framework Applications
Authors: Tuba Tarhan
Source: TURKISH JOURNAL OF CHEMISTRY (article, 2020-08-11)
Field: Chemistry — Organic Chemistry

Synthesis and characterization of hexagonal boron nitride used for comparison of removal of anionic and cationic hazardous azo-dye: kinetics and equilibrium studies The purpose of this study was to compare the adsorption behavior of cationic and anionic dyes onto a hexagonal boron nitride (hBN) nanostructure that was rich in a negative charge. Herein, the hBN nanostructure was synthesized using boric acid as a precursor material. The characteristic peaks of the hBN nanostructure were performed using Fourier transform infrared (FT-IR) and Raman spectroscopies. The morphology and the particle size of hBN nanostructure were determined by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). During the studies, various essential adsorption parameters were investigated, such as the initial dye concentration, pH of the dye solution, adsorbent dose, and contact time. Under optimal conditions, the removal of 42.6% Metanil yellow (MY) and 90% Victoria blue B (VBB) from aqueous solution was performed using a 10-mg hBN nanostructure. Furthermore, the equilibrium studies showed that the Freundlich isotherm model fitted well for the removal of MY. However, the Langmuir isotherm model fitted well for the removal of VBB. Moreover, according to the results obtained from the kinetic studies, while the first-order kinetic model was suited for the adsorption of the MY, the second-order kinetic model was found to well fit for the adsorption of VBB. Pollutant ; Chemistry ; Pollution ; Hazardous waste ; Environmental pollution ; Cationic polymerization ; Wastewater ; Dyeing ; Water pollution ; Effluent ; Pulp and paper industry ; Environmental chemistry ; Waste management ; Environmental engineering ; Organic chemistry ; Environmental science ; Environmental protection Nanomaterials for catalytic reactions ; Advanced Photocatalysis Techniques ; Adsorption and biosorption for pollutant removal
Authors: É. S. Mkrtchyan | E. A. Neskoromnaya | И. В. Буракова | O.A. Ananyeva | N.A. Revyakina | А. В. Бабкин | Т. S. Kuznetsova | D. A. Kurnosov | A. E. Burakov
Source: Advanced Materials & Technologies (article, 2020-01-01)
Field: Chemistry — Inorganic Chemistry

Comparative Analysis of the Adsorption Kinetics of the Methylene Blue Dye on Graphene Aerogel and Activated Coconut Carbon The comparative adsorption capacity of graphene aerogel and activated coconut carbon in the process of removing the main cationic synthetic dye, methylene blue (MB), from aqueous solutions with an initial concentration of 150 mg/l was investigated. The characteristics of the new material have been determined using scanning electron microscopy, thermogravimetry, and Raman spectroscopy. The values of the adsorption capacity of graphene aerogel – 420 mg/g and activated carbon – 205 mg/g were established. The saturation time in the presence of graphene aerogel was 7 min. The experimental data were processed using kinetic models – pseudo-first and pseudo-second order, Elovich and intraparticle diffusion. According to the results obtained, graphene aerogel is a promising sorption material in the extraction of molecular organic pollutants, namely, synthetic dyes, demonstrating a high efficiency of the target pollutant removal. Aerogel ; Graphene ; Adsorption ; Methylene blue ; Activated carbon ; Sorption ; Chemical engineering ; Aqueous solution ; Thermogravimetry ; Materials science ; Chemistry ; Nuclear chemistry ; Inorganic chemistry ; Organic chemistry ; Nanotechnology ; Photocatalysis Pigment Synthesis and Properties ; Advanced Theoretical and Applied Studies in Material Sciences and Geometry ; Adsorption and biosorption for pollutant removal
Authors: Augustus Newton Ebelegi | Nimibofa Ayawei | A. K. Inengite | Donbebe Wankasi
Source: Journal of Chemistry (article, 2020-12-28)
Field: Materials Science — Polymers and Plastics

Generation-3 Polyamidoamine Dendrimer-Silica Composite: Preparation and Cd(II) Removal Capacity Generation-3 polyamidoamine (PAMAM) dendrimer was implanted on silica to produce a very good adsorbent (G-3 PAMAM-SGA). The composite was characterized and used for the removal of Cd(II) ions from aqueous solution. Kinetic data fit the Lagergren pseudo-second-order model and also follow the intraparticle diffusion kinetic model to an extent, which is an indication that the sorption process is controlled by both mechanisms: intraparticle/film layer and adsorption inside the pores/crevices of the composite. Equilibrium sorption data of Cd(II) on G-3 PAMAM-SGA fit the Freundlich isotherm (R2 = 0.9993) which is indicative of multilayered adsorption that occurred on heterogeneous surfaces. The ΔG° values for all temperatures studied were negative, which indicated a spontaneous and feasible process. The result implies that G-3 PAMAM-SGA is a promising adsorbent for microscale scavenging of Cd(II) ions in aqueous solutions. Chemistry ; Adsorption ; Sorption ; Aqueous solution ; Composite number ; Dendrimer ; Freundlich equation ; Diffusion ; Chemical engineering ; Microscale chemistry ; Nuclear chemistry ; Chromatography ; Polymer chemistry ; Organic chemistry ; Composite material ; Thermodynamics Dendrimers and Hyperbranched Polymers ; Adsorption and biosorption for pollutant removal ; Covalent Organic Framework Applications
Authors: M. Bobeth | Arezoo Dianat | Rafael Gutiérrez | David Werner | Hongliu Yang | Hagen Eckert | Gianaurelio Cuniberti
Source: BMC Materials (article, 2020-10-07)
Field: Materials Science — Biomaterials

Continuum modelling of structure formation of biosilica patterns in diatoms Abstract Formation of regularly structured silica valves of various diatom species is a particularly fascinating phenomenon in biomineralization. Intensive investigations have been devoted to elucidate the formation mechanisms of diatom valve structures. Phase-separation of species-specific organic molecules has been proposed to be involved in pattern formation, where the evolving organic molecule structures serve as template for silica formation. In the present work, using a continuum approach, we investigate the conditions under which silica structures of high regularity can develop within a phase separation model. In relation to previously reported in vitro experiments of silica formation, which revealed the important role of phosphate ions in the self-assembly of organic molecules, we propose a model where phase separation is coupled with a chemical reaction. We analyze the impact of the reaction of phosphate ions with organic molecules on the appearing morphology of the organic template. Two- and three-dimensional simulations of the development of regular stationary patterns are presented. The influence of a confined geometry and an interaction of organic molecules with the walls on pattern formation is also addressed. We expect that our approach will be relevant for experimental studies aiming at inducing structure formation under controlled in vitro conditions. Biomineralization ; Molecule ; Chemical physics ; Organic molecules ; Structure formation ; Diatom ; Crystallization ; Chemistry ; Ion ; Materials science ; Pattern formation ; Phosphate ; Phase (matter) ; Chemical engineering ; Nanotechnology ; Organic chemistry ; Biology ; Ecology ; Physics Diatoms and Algae Research ; Protist diversity and phylogeny ; Paleontology and Stratigraphy of Fossils