jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Jeroen van Roy | Niels Wouters | Bart De Ketelaere | Wouter Saeys
Source: Journal of Spectral Imaging (article, 2018-03-06)
Field: Chemistry — Analytical Chemistry

Semi-supervised learning of hyperspectral image segmentation applied to vine tomatoes and table grapes Author Summary: Nowadays, quality inspection of fruit and vegetables is typically accomplished through visual inspection. Automation of this inspection is desirable to make it more objective. For this, hyperspectral imaging has been identified as a promising technique. When the field of view includes multiple objects, hypercubes should be segmented to assign individual pixels to different objects. Unsupervised and supervised methods have been proposed. While the latter are labour intensive as they require masking of the training images, the former are too computationally intensive for in-line use and may provide different results for different hypercubes. Therefore, a semi-supervised method is proposed to train a computationally efficient segmentation algorithm with minimal human interaction. As a first step, an unsupervised classification model is used to cluster spectra in similar groups. In the second step, a pixel selection algorithm applied to the output of the unsupervised classification is used to build a supervised model which is fast enough for in-line use. To evaluate this approach, it is applied to hypercubes of vine tomatoes and table grapes. After first derivative spectral preprocessing to remove intensity variation due to curvature and gloss effects, the unsupervised models segmented 86.11% of the vine tomato images correctly. Considering overall accuracy, sensitivity, specificity and time needed to segment one hypercube, partial least squares discriminant analysis (PLS-DA) was found to be the best choice for in-line use, when using one training image. By adding a second image, the segmentation results improved considerably, yielding an overall accuracy of 96.95% for segmentation of vine tomatoes and 98.52% for segmentation of table grapes, demonstrating the added value of the learning phase in the algorithm. Artificial intelligence ; Hyperspectral imaging ; Computer science ; Pattern recognition (psychology) ; Segmentation ; Preprocessor ; Pixel ; Computer vision Spectroscopy and Chemometric Analyses ; Advanced Chemical Sensor Technologies
Authors: Weimin Ge | Sun Mingyue | Xiaofeng Wang
Source: Mathematical Problems in Engineering (article, 2018-09-20)
Field: Chemistry — Analytical Chemistry

An Incremental Two-Dimensional Principal Component Analysis for Object Recognition Two-dimensional principal component analysis algorithm (2DPCA) can be performed in the batch mode and can not meet the real-time requirements of the video stream. To overcome these limitations, the incremental learning of the candid covariance-free incremental PCA (CCIPCA) is innovated to the existing 2DPCA, and the called incremental 2DPCA (I2DPCA) is firstly presented to incrementally compute the principal components of a sequence of samples directly on the 2D image matrices without estimating the covariance matrices. Therefore, the I2DPCA can improve the feature extraction speed and reduce the required memory. However, the variations between the column direction, generally neglected, are also useful for the high-accuracy object recognition. Thus, another incremental sequential row-column 2DPCA algorithm (IRC2DPCA), based on the proposed I2DPCA algorithm, is also proposed. The IRC2DPCA can compress the image matrices in the row and column direction, and the feature matrices extracted by the IRC2DPCA are with less dimensions than the I2DPCA. The substantial experimental results show that the IRC2DPCA, compared with the other three algorithms, can improve the convergence rates and the recognition rates, compress the dimensions of the feature matrices, and reduce the feature extraction time and the classification time. Principal component analysis ; Pattern recognition (psychology) ; Feature (linguistics) ; Feature extraction ; Column (typography) ; Covariance ; Computer science ; Artificial intelligence ; Covariance matrix ; Convergence (economics) ; Object (grammar) ; Image (mathematics) ; Sequence (biology) ; Algorithm ; Mathematics ; Statistics ; Frame (networking) Spectroscopy and Chemometric Analyses ; Face and Expression Recognition ; Advanced Chemical Sensor Technologies
Authors: Олег Градов | P. A. Nasirov | А.А. Гончарова | V. K. Fischenko | Arthur G. Jablokov
Source: Morphologia (article, 2018-06-25)
Field: Chemistry — Spectroscopy

On-chip lens-less holographic trichoscopy / trichometry technologies: microinterferometric, Fourier spectral and correlographic techniques for clinical trichology. The novel principle of trichomorphological analysis is provided. This principle, which may be interpreted as a transition between trichoscopy and trichometry, was developed using methods and techniques, explicated from the lens-less holographic microscopy, lens-lens tomography and filtering / decomposition of microscopic images based on orthogonal transformations, such as the FFTW-library-assisted DFT using Bluestein's FFT algorithm (expresses the Chirp Z-transform as a convolution and implements it efficiently using FFT/IFFT), Rader's FFT algorithm (from MIT Lincoln Laboratory) and Cooley–Tukey FFT algorithm (corresponding to different factorizations and / or different memory-access patterns). It is possible, that such methods can be applicable not only for clinical diagnostics, but also for some specialized trichological investigations, including fast and strong determination of different descriptors for ethnomedicine, gender and hormonal or endocrinology-relevant differences, prenatal and neonatal trichology, bio-archaeometric analysis, including palaeotrichology, and criminological trichomorphology, analysis of efficiency of some pharmaceutical and toxicological agents and events (including microelement status) for different psychosomatic cases, etc. The principal schemes of the laser holographic trichometry setups also may be based on a principles of the combined reflection and transmission lens-less microscopes, on-chip differential interference contrast microscopy, lensless wide-field fluorescent imaging on a chip, off-axis holography and lensless incoherent holography, ulttaviolet microscopy, including deep-UV spectral range. Holography ; Fast Fourier transform ; Optics ; Lens (geology) ; Computer science ; Microscopy ; Fourier transform ; Artificial intelligence ; Materials science ; Physics ; Algorithm Molecular Spectroscopy and Structure
Authors: Adib J. Samin | David A. Andersson | Edward F. Holby | Blas P. Uberuaga
Source: Electrochemistry Communications (article, 2018-09-25)
Field: Materials Science — Materials Chemistry

On the role of electro-migration in the evolution of radiation damage in nanostructured ionic materials Grain boundary ; Ionic bonding ; Nanocrystalline material ; Radiation resistance ; Materials science ; Crystallographic defect ; Radiation damage ; Chemical physics ; Irradiation ; Sink (geography) ; Diffusion ; Radiation tolerance ; Grain size ; Ceramic ; Charge carrier ; Nanotechnology ; Ion ; Chemistry ; Metallurgy ; Crystallography ; Optoelectronics ; Microstructure ; Thermodynamics ; Physics ; Nuclear physics Nuclear materials and radiation effects ; Electronic and Structural Properties of Oxides ; Semiconductor materials and devices
Authors: Chih-Yuan S. Chang | Igor Lubomirsky | Sangtae Kim
Source: Physical Chemistry Chemical Physics (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

Applicability of a linear diffusion model to determination of the height of the potential barrier at the grain boundaries of Fe-doped SrTiO<sub>3</sub> The potential barrier formed at the grain boundaries in Fe-doped SrTiO3 is reported to be one of the main reasons of the exceptionally large grain boundary resistivity of the material. Of particular interest is thus how to accurately quantify the potential barrier height, Ψgb, in such electronic conductors. This study aims to expand the applicability of a linear diffusion model (namely I-V model) to electronic conductors. The I-V model has previously proven its success in accurate determination of Ψgb in popular ionic conductors. By employing 1 mol% Fe-doped SrTiO3 as a model material, the current-voltage characteristics of the grain boundary investigated demonstrate the power law behavior predicted by the I-V model, verifying the applicability of this model. The Ψgb estimated from the I-V model at different temperatures are compared with those from the resistivity ratio of the grain boundary to the bulk. The resistivity ratio has been exclusively used to determine Ψgb in various conductors over several decades and yet has limitations in its accuracy. The Ψgb determined by the I-V model are found to be substantially lower than those from the resistivity ratio; such discrepancy implies that the potential barrier only partially contributes to the high grain boundary resistivity of a lightly doped electron-hole conducting SrTiO3. Doping ; Diffusion ; Grain boundary ; Materials science ; Conductor ; Condensed matter physics ; Grain boundary diffusion coefficient ; Diffusion barrier ; Mineralogy ; Analytical Chemistry (journal) ; Chemistry ; Thermodynamics ; Nanotechnology ; Composite material ; Physics ; Microstructure Electronic and Structural Properties of Oxides ; Magnetic and transport properties of perovskites and related materials ; Semiconductor materials and devices
Authors: Sandhya Gullipilli | Ravichandra Babu Rupakula
Source: Separation Science and Technology (article, 2018-12-24)
Field: Chemistry — Organic Chemistry

Adsorption studies of Cr(VI) and Cu(II) metal ions from aqueous solutions by synthesized Ag and Mg co-doped TiO<sub>2</sub> nanoparticles This communication provides the eliminating of heavy metals from water resources using Ag-Mg/TiO2 nanoparticles. The nanoparticles with a size of 15 nm were prepared using sol-gel technique and used for the removal of Cr(VI) and Cu(II) from waste waters. Batch sorption studies were carried out to investigate the adsorption of the above metal ions for a concentration range of 0.1–10 mg/L. The maximum sorption capacity values were found to be 2.42 mg/g for Cr(VI) and 2.03 mg/g for Cu(II) at a concentration of 0.1 ppm. The mechanism of adsorption was also investigated. The results showed that both Freundlich and Dubinin–Radushkevitch isotherms were found to be the best fit for the adsorption of metals. The results from kinetic data reveal that the pseudo-second-order and Reichenberg film diffusion models were found to be well fit for the experimental data. The value of the thermodynamic parameter ΔH° revealed the endothermic adsorption process and negative value of ΔG° shows the feasibility and spontaneity of material–anion interaction. In addition, the method is considered to be simple and cost-effective, and shows excellent adsorption removal properties on heavy metals for industrial applications. Adsorption ; Chemistry ; Sorption ; Endothermic process ; Aqueous solution ; Metal ions in aqueous solution ; Freundlich equation ; Diffusion ; Metal ; Nanoparticle ; Inorganic chemistry ; Nuclear chemistry ; Chemical engineering ; Physical chemistry ; Organic chemistry ; Thermodynamics Nanomaterials for catalytic reactions ; Gas Sensing Nanomaterials and Sensors ; Advanced Nanomaterials in Catalysis
Authors: Kai Liu | Lihui Chen | Liulian Huang | Shan Lin | Shilin Cao | Hongping Wang
Source: BioResources (article, 2018-06-12)
Field: Chemistry — Spectroscopy

Adsorption behaviors of acidic and basic dyes by thiourea-modified nanocomposite aerogels based on nanofibrillated cellulose Inspired by the high adsorption efficiency of aerogels, a thiourea-modified nanocomposite aerogel consisting of nanofibrillated cellulose and chitosan was prepared via a facile method. The prepared novel aerogel was studied by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The adsorptions of the acidic and basic dyes (acid orange 7 and crystal violet) on the aerogel from aqueous solutions were investigated according to the adsorption kinetics and isotherms. The results indicated that a pseudo-second-order kinetic model more accurately described the adsorption process than a pseudo-first-order model, and the adsorption processes of both acid orange 7 and crystal violet on the aerogel were controlled by both inter-facial and intra-particle diffusions simultaneously. The Langmuir isotherm was a better model as compared to Freundlich model for the adsorption of dyes. The aerogel prepared by the facile approach is a promising material for practical applications in acidic and basic dye removal. Aerogel ; Adsorption ; Materials science ; Fourier transform infrared spectroscopy ; Freundlich equation ; Nanocomposite ; Crystal violet ; Chemical engineering ; Langmuir adsorption model ; Thiourea ; Aqueous solution ; Cellulose ; Langmuir ; Organic chemistry ; Chemistry ; Composite material Aerogels and thermal insulation ; Advanced Cellulose Research Studies
Authors: D. Sugak | I.I. Syvorotka | Uliana Yakhnevych | Oleh Buryy | M. Vakiv | S. Ubizskii | Damian Włodarczyk | Yaroslav Zhydachevskyy | A. Pieniążek | R. Jakieła | A. Suchocki
Source: Acta Physica Polonica A (article, 2018-04-01)
Field: Materials Science — Materials Chemistry

Investigation of Co Ions Diffusion in Gd<sub>3</sub>Ga<sub>5</sub>O<sub>12</sub> Single Crystals Spatial changes of properties of Gd3Ga5O12 (GGG) single crystals caused by diffusion of cobalt ions during high-temperature annealing (1200 C, 24 h) in Co3O4 powder are investigated. The registration of these changes was carried out by optical spectrophotometry, microscopy and micro-Raman scattering methods. Changes in structure of near-surface layers of the crystal were investigated by X-ray diffraction technique. It was shown that the additional absorption induced by annealing is related to intra-center optical transitions in Co 2+ ions, which occupy tetrahedral positions in the garnet structure at the distances of 250-500 m from the crystal surface. The dependence of induced absorption with depth has got a non-monotonous character with a maximum at 400 m. A comparison of the results obtained by different methods allows to suppose that the thermal treatment of GGG in the presence of cobalt ions leads to formation of the structurally and chemically non-uniform layer with a width about 500 m. Ion ; Materials science ; Diffusion ; Crystallography ; Physics ; Chemistry ; Thermodynamics Luminescence Properties of Advanced Materials ; Glass properties and applications ; Solid State Laser Technologies
Authors: K.P. Rao | C. Dharmendra | K. Suresh | Y. V. R. K. Prasad | Hajo Dieringa | Norbert Hort
Source: Metals (article, 2018-06-18)
Field: Materials Science — Biomaterials

Connected Process Design for Hot Working of a Creep-Resistant Mg–4Al–2Ba–2Ca Alloy (ABaX422) With a view to design connected processing steps for the manufacturing of components, the hot working behavior of the ABaX422 alloy has been characterized for the as-cast and extruded conditions. In the as-cast condition, the alloy has a limited workability, due to the presence of a large volume of intermetallic phases at the grain boundaries, and is not suitable to process at high speeds. A connected processing step has been designed on the basis of the results of the processing map for the as-cast alloy, and this step involves the extrusion of the cast billet to obtain a 12 mm diameter rod product at a billet temperature of 390 °C and at a ram speed of 1 mm s−1. The microstructure of the extruded rod has a finer grain size, with redistributed fine particles of the intermetallic phases. The processing map of the extruded rod exhibited two new domains, and the one in the temperature range 360–420 °C and strain rate range 0.2–10 s−1 is useful for manufacturing at high speeds, while the lower temperature develops a finer grain size in the product to improve the room temperature strength and ductility. The area of the flow instability is also reduced by the extrusion step, widening the workability window. Materials science ; Intermetallic ; Extrusion ; Alloy ; Hot working ; Metallurgy ; Grain size ; Microstructure ; Ductility (Earth science) ; Creep ; Strain rate ; Grain boundary ; Die (integrated circuit) Magnesium Alloys: Properties and Applications ; Aluminum Alloys Composites Properties ; Aluminum Alloy Microstructure Properties
Authors: Katsuya Nagayama | Takeshi Kurihara
Source: Journal of Applied Mathematics and Physics (article, 2018-01-01)
Field: Materials Science — Polymers and Plastics

Numerical Simulation of Skin Formation: The Relationship between Transepidermal Water Loss and Corneum Thickness Skin moisturizing has drawn attention in terms of beauty and anti-aging industries. However, it is difficult to observe the inside of the epidermis and the relationship between the epidermis and water content is not yet clear. Computational simulations can be useful in understanding such mechanisms of skin formation. A particle model was used to simulate three-dimensional skin turnover, and the results reproduced the epidermal skin turnover phenomenon. In this study, a diffusion model is introduced into this simulation model and a moisture diffusion analysis of the epidermis was performed. In particular, transepidermal water loss (TEWL) was modeled by considering diffusion and surface evaporation in the stratum corneum and other layers. The relationship between the moisture content and the keratin detachment was considered, and the exfoliation condition of keratin based on the moisture content was calculated in the model. As a result, it was possible to calculate the intraepidermal water content distribution in the skin using the particle model. It was also possible to reproduce phenomena such as keratin thickening due to increase of TEWL. This phenomenon is consistent with cases of dry skin. In the future, it will be necessary to introduce a change in TEWL according to the thickness of the stratum corneum and the diffusion coefficient. Stratum corneum ; Transepidermal water loss ; Epidermis (zoology) ; Keratin ; Diffusion ; Water content ; Moisture ; Materials science ; Particle (ecology) ; Dermatology ; Chemistry ; Thermodynamics ; Composite material ; Anatomy ; Pathology ; Physics ; Biology ; Medicine ; Geology Textile materials and evaluations ; Advancements in Transdermal Drug Delivery ; Skin Protection and Aging
Authors: José D. Torres | Armando Alvis-Bermúdez | Luis Alberto Gallo‐García | Diofanor Acevedo-Correa | Francisco Javier Castellanos Galeano | Pedro Bouchon-Aguirre
Source: Indian Journal of Science and Technology (article, 2018-02-01)
Field: Chemistry — Organic Chemistry

Effect of Deep Fat Frying on the Mass Transfer and Color Changes of Arepa Con Huevo Objectives: To study the effect of deep fat frying on the mass transfer and color changes of ArepaCon Huevo. Methods: The product was prepared as a round plate (diameter: 10 cm and thickness: 2.5 cm). Palm oil was used in a 7 L fryer at 170, 180 °C and 190°C under a ratio of 250 g sample/L oil. Findings: Moisture content decreased as time and temperature increased (p<0.05). Da coefficients in increased order of temperature were: (1.75 ± 0.01, 3.56 ± 0.08 and 5.03 ± 0.06 x10-7) m2 /s, with kc values of (4.26 ± 0.31, 6.31 ± 0.45 y 9.58 ± 0.81) m/s. The activation energy calculated with Arrhenius equation was 63.96 kJ/mol. The rate of oil absorption was higher at low temperatures, with values of (1.28 ± 0.06, 0.77 ± 0.02 and 0.67 ± 0.04 x 10-3) s-1 and an activation energy of 50.66 kJ/mol. Lightness (L*) decreased with increasing factors, varying from 75.02 ± 3.42 (before frying) to 46.82 ± 2.28 at 190 °C. This was attributed to the non-enzymatic browning at high temperatures. Application: Understand mass transfer parameter is important in order to optimize the frying processing of ArepaCon Huevo. Keywords: Arepa con huevo, Deep Fat Frying, Lightness, Moisture, Oil Absorption Lightness ; Browning ; Food science ; Mass transfer ; Absorption (acoustics) ; Arrhenius equation ; Activation energy ; Biology ; Materials science ; Botany ; Horticulture ; Animal science ; Chemistry ; Chromatography ; Physics ; Composite material Edible Oils Quality and Analysis ; Food Chemistry and Fat Analysis ; Coconut Research and Applications
Authors: Marcelo Kobelnik | Leonardo Miziara Barboza Ferreira | Luís Octávio Regasini | Luiz Antônio Dutra | Vanderlan da Silva Bolzani | Clóvis Augusto Ribeiro
Source: Journal of Thermal Analysis and Calorimetry (article, 2018-01-23)
Field: Chemistry — Organic Chemistry

Thermal study of chalcones Thermogravimetry ; Chalcone ; Chemistry ; Activation energy ; Thermal decomposition ; Differential scanning calorimetry ; Kinetic energy ; Oxygen ; Nitrogen ; Thermal analysis ; Nuclear chemistry ; Analytical Chemistry (journal) ; Organic chemistry ; Physical chemistry ; Inorganic chemistry ; Thermal ; Thermodynamics Synthesis and biological activity ; Free Radicals and Antioxidants ; Synthesis of Organic Compounds
Authors: Tingting Zhang | Hai‐Kui Yang | Zichao Yang | Suiyi Tan | Jiabin Jin | Shuwen Liu | Jiajie Zhang
Source: ChemistryOpen (article, 2018-06-01)
Field: Materials Science — Materials Chemistry

Sulfonated Compounds Bind with Prostatic Acid Phosphatase (PAP<sub>248–286</sub>) to Inhibit the Formation of Amyloid Fibrils The peptide segment of prostatic acid phosphatase (PAP<sub>248-286</sub>) aggregates to form SEVI (semen-derived enhancer of virus infection) amyloid fibrils. These are characteristic seminal amyloids that have the ability to promote the effect of HIV infection. In this paper, we explore the binding of sulfonated compounds with PAP<sub>248-286</sub> through an in silico study. Three derivatives of suramin, NF110, NF279, and NF340, are selected. All of these sulfonated molecules bind to PAP<sub>248-286</sub> and alter the conformation of the peptide, even though they have various structures, sizes, and configurations. The compounds bind with PAP<sub>248-286</sub> through multiple interactions, such as hydrogen-bonding interactions, hydrophobic interactions, π-π stacking interactions, and electrostatic interactions. However, NF110, which has an X-shaped configuration, has the highest binding affinity of the three derivatives investigated. We also perform surface plasmon resonance and a Congo red assay to validate the results. The interactions between PAP<sub>248-286</sub> and the sulfonated compounds are proposed to depend on the orientations of the sulfonate groups and the specific configurations of the compounds instead of the number of sulfonate groups. NF110 molecules occupy the exposed binding sites of PAP<sub>248-286</sub>, blocking interactions between the peptides. Therefore, these compounds are important in inhibiting the aggregation of PAP<sub>248-286</sub>. Herein, we provide useful information to develop new efficient microbicides to antagonize seminal amyloid fibrils and to block HIV transmission. Prostatic acid phosphatase ; Amyloid fibril ; Fibril ; Chemistry ; Amyloid (mycology) ; Biochemistry ; Amyloid β ; Acid phosphatase ; Biophysics ; Enzyme ; Medicine ; Biology ; Internal medicine ; Inorganic chemistry ; Disease Enzyme Structure and Function ; Protein Structure and Dynamics ; Carbohydrate Chemistry and Synthesis