jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Hongfen Zhu | Zhanjunm Xu | Yaodong Jing | Rutian Bi | Wude Yang
Source: Journal of soil science and plant nutrition (article, 2018-01-01)
Field: Chemistry — Analytical Chemistry

Spatial variation and predictions of soil organic matter and total nitrogen based on VNIR reflectance in a basin of Chinese Loess Plateau Taiyuan basin in Chinese Loess Plateau was characterized as the variety of landform, land use fragmentation, low soil organic matter (SOM) and soil total nitrogen (STN) content; therefore, the predictions of soil nutrients in the area were rather difficult. In this study, three soil sampling transects of cropland soil from northwest to southeast in Taiyuan basin were established and the visible-near infrared reflectance (VNIR) of soil samples were measured. The predicting models for SOM and STN based on VNIR were established, and the predicting accuracies were assessed by traditional evaluating index, wavelet transform, and semivariance structure. The traditional evaluating index showed that the partial least square regression (PLSR) and optimum number of latent variables were suitable for SOM prediction. The accuracies were "good" (RPD ranges from 2.30 to 2.40) for calibration and "moderate" (RPD ranges from 1.80 to 1.95) for validation, whereas the model and parameters of STN were "moderate" (RPD ranges from 1.83 to 1.87) for calibration and "acceptable" (RPD ranges from 1.41 to 1.48) for validation procedure. Based on the wavelet transform, the patterns of global wavelet power spectrum for predicted and measured SOM were closer than that of STN, and their difference in local wavelet spectra could present the predicting errors in the scale and location domain. The nugget effect indicated that the stochastic variability weakened, and the spatial structure of predicted SOM and STN enhanced. The range of predicted SOM and STN were greater than those of measured. Therefore, the predicting models based on independent dataset using PLSR could be used for the prediction of SOM or STN in the un-sampled areas. Wavelet transform and semivariance parameters could be used to guide the utilization of predicted values. VNIR ; Environmental science ; Soil science ; Soil organic matter ; Partial least squares regression ; Spatial variability ; Remote sensing ; Soil water ; Geology ; Mathematics ; Hyperspectral imaging ; Statistics Spectroscopy and Chemometric Analyses ; Geochemistry and Geologic Mapping ; Remote Sensing and Land Use
Authors: Jan Christoph König | Tobias Steinwedel | Dörte Solle | Patrick Lindner | Ingo de Vries | Thorleif Hentrop | Michael Findeis | Gernot T. John | Thomas Scheper | Sascha Beutel
Source: Journal of sensors and sensor systems (article, 2018-08-08)
Field: Chemistry — Analytical Chemistry

Development and characterisation of a new fluorescence sensor for online monitoring of bioprocesses Abstract. Fluorescence spectroscopy is a highly sensitive and non-invasive technique for the identification of characteristic process states and for the online monitoring of substrate and product concentrations. Nevertheless, fluorescence sensors are mainly used in academic studies and are not well implemented for monitoring of industrial production processes. In this work, we present a newly developed robust online fluorescence sensor that facilitates the analysis of fluorescence measurements. The set-up of the sensor was miniaturised and realised without any moveable part to be robust enough for application in technical environments. It was constructed to measure only the three most important biologic fluorophores (tryptophan, NADH and FAD/FMN), resulting in a significant data reduction compared to conventional a 2-D fluorescence spectrometer. The sensor performance was evaluated by calibration curves and selectivity tests. The measuring ranges were determined as 0.5–50 µmol L−1 for NADH and 0.0025–7.5 µmol L−1 for BSA and riboflavin. Online monitoring of batch cultivations of wild-type Escherichia coli K1 in a 10 L bioreactor scale were performed. The data sets were analysed using principal component analysis and partial least square regression. The recorded fluorescence data were successfully used to predict the biomass of an independent cultivation (RMSEP 4.6 %). Fluorescence ; Fluorescence spectroscopy ; Calibration ; Principal component analysis ; Biological system ; Analytical Chemistry (journal) ; Spectrometer ; Substrate (aquarium) ; Chemistry ; Chromatography ; Computer science ; Mathematics ; Artificial intelligence ; Biology Spectroscopy and Chemometric Analyses ; Viral Infectious Diseases and Gene Expression in Insects ; Water Quality Monitoring and Analysis
Authors: Ana S. C. Silva | Lennart Martens | Sven Degroeve
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2018-10-03)
Field: Chemistry — Spectroscopy

Accurate peptide fragmentation predictions allow data driven approaches to replace and improve upon proteomics search engine scoring functions The use of post-processing tools to maximize the information gained from a proteomics search engine is widely accepted and used by the community, with the most notable example being Percolator - a semi-supervised machine learning model which learns a new scoring function for a given dataset. The usage of such tools is however bound to the search engine's scoring scheme, which doesn't always make full use of the intensity information present in a spectrum. We aim to show how this tool can be applied in such a way that maximizes the use of spectrum intensity information by leveraging another machine learning-based tool, MS2PIP. MS2PIP predicts fragment ion peak intensities. We show how comparing these intensities to annotated experimental spectra by calculating direct similarity metrics provides enough information for a tool such as Percolator to accurately separate two classes of PSMs. This approach allows using more information out of the data (compared to simpler intensity based metrics, like peak counting or explained intensities summing) while maintaining control of statistics such as the false discovery rate. Computer science ; Search engine ; Data mining ; Similarity (geometry) ; Machine learning ; Fragmentation (computing) ; Artificial intelligence ; Function (biology) ; Information retrieval Advanced Proteomics Techniques and Applications ; Mass Spectrometry Techniques and Applications ; Machine Learning in Bioinformatics
Authors: Mesut Uysal | Eva Haviarová
Source: BioResources (article, 2018-05-22)
Field: Materials Science — Polymers and Plastics

Estimating design values for two-pin moment resisting dowel joints with lower tolerance limit approach The lower tolerance limits (LTLs) for two-pin moment-resisting dowel joints, constructed of red oak and white oak, were estimated. Dowel joints are widely used in furniture manufacturing, especially for tables and chairs. Despite numerous studies to determine the strength capacities of dowel joints, their design values have not been established. For this purpose, T-shaped edgewise dowel joints were constructed to determine their ultimate failure load capacity levels. In tolerance analysis, the k-tolerance factor changes depending on sample sizes and confidence/proportion levels. Therefore, sample sizes were determined using a modified Faulkenberry-Week method for a univariate normally distributed data set created for a pilot study, which had 30 specimens. At least 215 specimens were required to make tolerance analyses at the 99/99 confidence/proportion level. Accordingly, 220 specimens were constructed. The LTL values were obtained at the 75/75, 90/75, 75/90, 90/90, 95/90, 90/95, 95/95, 99/95, 95/99, and 99/99 confidence/proportion levels to estimate reasonable design values. The results of the study indicated that the LTL method provides a sound design value estimate for dowel joints used in furniture frames. Dowel ; Univariate ; Structural engineering ; Confidence interval ; Moment (physics) ; Mathematics ; Statistics ; Engineering ; Multivariate statistics Textile materials and evaluations ; Wood Treatment and Properties
Authors: Yongjun Ding | Won Suk Lee | Minzan Li
Source: Frontiers of Agricultural Science and Engineering (article, 2018-01-01)
Field: Chemistry — Analytical Chemistry

Feature extraction of hyperspectral images for detecting immature green citrus fruit At an early immature growth stage of citrus, a hyperspectral camera of 369–1042 nm was employed to acquire 30 hyperspectral images in order to detect immature green fruit within citrus trees under natural illumination conditions. First, successive projections algorithm (SPA) were implemented to select 677, 804, 563, 962, and 405 nm wavebands and to construct multispectral images from the original hyperspectral images for further processing. Then, histogram threshold segmentation using <i>NDVI</i> of 804 and 677 nm was implemented to remove image backgrounds. Three slope parameters, calculated from the pairs 405 and 563 nm, 563 and 677 nm, and 804 and 962 nm were used to construct a classifier to identify the potential citrus fruit. Then, a marker-controlled watershed segmentation based on wavelet transform was applied to obtain potential fruit areas. Finally, a green fruit detection model was constructed according to Grey Level Co-occurrence Matrix (GLCM) texture features of the independent areas. Three supervised classifiers, logistic regression, random forest and support vector machine (SVM) were developed using texture features. The detection accuracies were 79%, 75%, and 86% for the logistic regression, random forest, and SVM models, respectively. The developed algorithm showed a great potential for identifying immature green citrus for an early yield estimation. Hyperspectral imaging ; Support vector machine ; Random forest ; Multispectral image ; Artificial intelligence ; Pattern recognition (psychology) ; Computer science ; Histogram ; Segmentation ; Mathematics ; Image (mathematics) Spectroscopy and Chemometric Analyses ; Leaf Properties and Growth Measurement ; Smart Agriculture and AI
Authors: Marina Caldeira Tonucci | Ana Luíza S Fidélis | Bruno Eduardo Lôbo Baêta | César Ricardo Teixeira Tarley | Sérgio Francisco de Aquino
Source: Polymer International (article, 2018-10-22)
Field: Chemistry — Analytical Chemistry

Influence of synthesis conditions on the production of molecularly imprinted polymers for the selective recovery of isovaleric acid from anaerobic effluents Abstract Two molecularly imprinted polymers (MIPs) – poly(methacrylic acid‐ co ‐TRIM) (TRIM, trimethylolpropanetrimethacrylate) and poly(acylamide‐ co ‐TRIM) – were synthesized in different solvents for the selective recovery of isovaleric acid (template) generated during the anaerobic digestion process. The chemical and structural characterizations of the synthetic adsorbent were carried out by Fourier transform infrared spectroscopy, TGA and porosimetry through N 2 adsorption–desorption isotherms. The selective and adsorptive performances of the imprinted polymers were evaluated by kinetic, isothermal, thermodynamic and selectivity studies and by adsorbent reuse experiments. The poly(methacrylic acid‐ co ‐TRIM) synthesized with dimethyl sulfoxide:chloroform presented higher selectivity and adsorption capacity for isovaleric acid in the presence of six volatile fatty acids. The kinetic results were well adjusted to the pseudo‐ n th order and intraparticle diffusion models, leading to k values of 10 −4 and 6 × 10 −5 for the best synthesis of MIPs and not‐imprinted polymers, respectively. Moreover, the Sips model best described the adsorption isotherm and generated a maximum adsorption capacity of ca 209 mg g −1 (at 25 °C). Cycles of MIP use–desorption–reuse indicated that the selective adsorbent performed better than commercial adsorbents, losing less than 3% of adsorption capacity after three cycles. © 2018 Society of Chemical Industry Adsorption ; Methacrylic acid ; Chemistry ; Desorption ; Molecularly imprinted polymer ; Fourier transform infrared spectroscopy ; Polymer ; Selectivity ; Nuclear chemistry ; Chemical engineering ; Organic chemistry ; Polymerization ; Catalysis Analytical chemistry methods development ; Adsorption and biosorption for pollutant removal ; Radioactive element chemistry and processing
Authors: Minami Kuroda | Shogo Tachibana | Naoya Sakamoto | Hisayoshi Yurimoto
Source: American Mineralogist (article, 2018-12-05)
Field: Materials Science — Ceramics and Composites

Fast diffusion path for water in silica glass Diffusion experiments of (H2O)-H-2 at 900-750 degrees C and water vapor pressure of 50 bar found diffusion of water in SiO2 glass more than one order of magnitude faster than that reported previously. The fast diffusion profile of water was observed as an extended tail of the normal water diffusion profile by a line scan analysis with SIMS, and it can be fitted with a diffusion model with a constant diffusivity. The obtained fast diffusion coefficient suggests that the diffusion species responsible for the fast diffusion is not molecular hydrogen but molecular water. The diffusivity and activation energy for the fast water diffusion can be explained by the correlation between diffusivities of noble gases in silica glass and their sizes. Because noble gases diffuse through free volume in the glass structure, we conclude that molecular water can also diffuse through the free volume. The abundance of free volume in the silica glass structure estimated previously is higher than that of H-2 observed in the fast diffusion in this study, suggesting that the free volume was not fully occupied by (H2O)-H-2 under the present experimental condition. This implies that the contribution of the fast water diffusion to the total water transport in volcanic glass becomes larger under higher water vapor pressure conditions. Diffusion ; Thermal diffusivity ; Volume (thermodynamics) ; Chemistry ; Water vapor ; Molecular diffusion ; Effective diffusion coefficient ; Analytical Chemistry (journal) ; Thermodynamics ; Materials science ; Mineralogy ; Chromatography ; Organic chemistry Glass properties and applications ; Material Dynamics and Properties ; Luminescence Properties of Advanced Materials
Authors: Yang Jian-zhou | Jiajia Jiang | Juncheng Jiang | Xuhai Pan | Yong Pan | Lei Ni
Source: Journal of Thermal Analysis and Calorimetry (article, 2018-06-13)
Field: Materials Science — Materials Chemistry

Thermal instability and kinetic analysis on m-chloroperbenzoic acid Thermal decomposition ; Adiabatic process ; Thermodynamics ; Diffusion ; Chemistry ; Pyrolysis ; Kinetic energy ; Thermal runaway ; Thermal analysis ; Thermal ; Materials science ; Organic chemistry ; Physics Thermal and Kinetic Analysis ; Energetic Materials and Combustion ; Chemical Thermodynamics and Molecular Structure
Authors: Zhimin Lv | Shimin Yang | Lei Chen | Yucheng Li | Changlun Chen
Source: Scientia Sinica Chimica (article, 2018-07-31)
Field: Chemistry — Inorganic Chemistry

Enhanced removal of uranium(VI) from aqueous solution by a novel LDH@MOF-76 composite <p indent="0mm">In this article, LDH@MOF-76 composite was successfully prepared by using a hydrothermal method and applied for the sorption of U(VI) from aqueous solution. The as-prepared composite displayed a typical porous and rod-like structure. The sorption performance of LDH@MOF-76 toward U(VI) was investigated by batch experiments. The results indicated that the LDH@MOF-76 could rapidly and effectively remove U(VI) from aqueous solution, with an excellent sorption capacity <sc>(433.91 mg/g),</sc> which is much higher than pure LDH <sc>(107.21 mg/g)</sc> and MOF-76 <sc>(269.14 mg/g).</sc> The high sorption capacity of the LDH@MOF-76 toward U(VI) resulted from the special one-dimensional channels of MOF-76 and the electrostatic attraction between U(VI) and LDH@MOF-76. Regeneration experiments revealed the LDH@MOF-76 had a good recycle performance. Based on the zeta potential and XPS analysis, the possible mechanism of U(VI) sorption involved the surface complexation and electrostatic attraction. In addition, the intraparticle diffusion model provided a good explanation for the sorption process. In summary, LDH@MOF-76 material can be a promising material to efficiently remove U(VI) from aqueous solution. Composite number ; Aqueous solution ; Uranium ; Materials science ; Chemistry ; Nuclear chemistry ; Composite material ; Metallurgy ; Organic chemistry Radioactive element chemistry and processing ; Extraction and Separation Processes ; Chemical Synthesis and Characterization
Authors: Wen Bing Wu | Sun Xue | Jian Hua Chen | Xiao Li
Source: RSC Advances (article, 2018-01-01)
Field: Chemistry — Inorganic Chemistry

High removal of thiophene from model gasoline by porous MIL-101(Cr)/SA hybrid membrane Membrane separation technologies have great promising potential for applications in several industries. Metal-organic frameworks (MOFs), for their large surface areas, low framework densities, transition-metal ions in the skeleton and high pore volumes relative to other porous matrices, have great potential for the removal of sulfur from gasoline with high efficiency. In the present study, a novel porous membrane adsorbent MIL-101(Cr)/SA was prepared by immobilizing MIL-101(Cr) onto sodium alginate (SA) matrix, which can combine the size/shape selectivity of MIL-101(Cr) with the processability and mechanical stability of SA polymer. The physico-chemical properties of MIL-101(Cr)/SA were investigated by FT-IR, SEM, BET, XRD and EDX methods. To investigate the effects of some important factors on the adsorption behavior for thiophene, a batch of experiments were performed by changing the concentration of porogen polyethylene glycol in the MIL-101(Cr)/SA, solution temperature, initial thiophene concentration and contact time. Meanwhile, benzothiophene, thiophene and 3-methyl thiophene were used to test the selectivity of MIL-101(Cr)/SA. The MIL-101(Cr)/SA showed an excellent uptake capacity of 671 mg g<sup>-1</sup> under the optimal adsorption conditions. Selectivity testing indicated that the uptake capacity of MIL-101(Cr)/SA follows the order of benzothiophene > thiophene > 3-methyl thiophene. Kinetics experiments indicated the pseudo-second-order model displayed good correlation with adsorption kinetics data. The Crank model showed that the intraparticle solute diffusion is the rate-controlling adsorption step. Regeneration experiment result shows that the prepared MIL-101(Cr)/SA has excellent adsorption and desorption efficiencies. Thiophene ; Gasoline ; Porosity ; Membrane ; Chemical engineering ; Chemistry ; Materials science ; Environmental science ; Organic chemistry ; Engineering Metal-Organic Frameworks: Synthesis and Applications ; Catalysis and Hydrodesulfurization Studies ; Catalytic Processes in Materials Science
Authors: Noboru Itouyama | Hiroto Habu
Source: TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES AEROSPACE TECHNOLOGY JAPAN (article, 2018-01-01)
Field: Chemistry — Analytical Chemistry

Investigation for Ignition of ADN-based Ionic Liquid with Visible Pulse Laser We evaluated the ignition probability of high-energy ionic-liquid droplet due to breakdown from visible pulse laser. The high-speed camera result, pressure profile, temperature trace from an R-type thermal couple, and radical measurement results using an image-intensifier charged-coupled device camera revealed the ignitability of this system. In addition, we simulated a simple thermal-diffusion model and investigated the temperature distribution for comparison with the experimental results. As a result, the probability of ignition due to a single pulse is low; however, potential for gasification and atomization of the ionic-liquid droplet is probable. Ignition system ; Thermal diffusivity ; Materials science ; Laser ; Ionic bonding ; Pulse (music) ; Diffusion ; Optics ; Thermal ; Minimum ignition energy ; Analytical Chemistry (journal) ; Nuclear engineering ; Chemistry ; Thermodynamics ; Ion ; Chromatography ; Physics Analytical chemistry methods development ; Laser-induced spectroscopy and plasma ; Mass Spectrometry Techniques and Applications
Authors: Cheng-Fu Yang | Ming Huang | Jingjing Yang | Fuchun Mao
Source: Scientific Reports (article, 2018-11-20)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Homogeneous Multifunction Devices Designing and Layered Implementing Based on Rotary Medium Multifunctional device with homogeneous anisotropic material parameters are proposed and designed based on linear transformation optics and rotary medium. Four examples including rotating concentrator, rotating amplifying device, rotating shrinking device and rotating transparent device are reported. All of them have bi-functional effects, i.e., they possess concentrating, amplifying, shrinking and transparent effects respectively while have the fields been rotated an angle of π/N simultaneously in common, where N is the sides number of polygon. All these devices have potential applications, such as energy accumulation or controlling, military camouflage, wireless communication system and radar/antenna protection. Furthermore, alternating isotropic layered structure based on effective medium theory is utilized to remove the anisotropic property of these devices. Simulation results show that the layered structure device behaves almost as perfect as the ideal one when it has sufficient divided layers. The feasibility of designing multifunctional device by natural isotropic materials instead of metamaterials with complicated artificial composite structure would dramatically reduce the fabrication difficulty and move the device a step further towards the practical application. Metamaterial ; Isotropy ; Transformation optics ; Fabrication ; Computer science ; Concentrator ; Polarizer ; Materials science ; Anisotropy ; Antenna (radio) ; Wireless ; Optics ; Optoelectronics ; Physics ; Telecommunications Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Optical Wireless Communication Technologies
Authors: Evan Hepler-Smith
Source: Historical Studies in the Natural Sciences (article, 2018-06-01)
Field: Chemistry — Physical and Theoretical Chemistry

“A Way of Thinking Backwards” This article addresses the history of how chemists designed syntheses of complex molecules during the mid-to-late twentieth century, and of the relationship between devising, describing, teaching, and computerizing methods of scientific thinking in this domain. It details the development of retrosynthetic analysis, a key method that chemists use to plan organic chemical syntheses, and LHASA (Logic and Heuristics Applied to Synthetic Analysis), a computer program intended to aid chemists in this task. The chemist E. J. Corey developed this method and computer program side-by-side, from the early 1960s through the 1990s. Although the LHASA program never came into widespread use, retrosynthetic analysis became a standard method for teaching and practicing synthetic planning, a subject previously taken as resistant to generalization. This article shows how the efforts of Corey and his collaborators to make synthetic planning tractable to teaching and to computer automation shaped a way of thinking taken up by chemists, unaided by machines. The method of retrosynthetic analysis made chemical thinking (as Corey perceived it) explicit, in accordance with the demands of computing (as Corey and his LHASA collaborators perceived them). This history of automation and method-making in recent chemistry suggests a potentially productive approach to the study of other projects to think on, with, or like machines. Retrosynthetic analysis ; Computer science ; Plan (archaeology) ; Heuristics ; Automation ; Generalization ; Task (project management) ; Management science ; Operations research ; Artificial intelligence ; Engineering ; Epistemology ; Chemistry ; Archaeology ; Systems engineering ; Philosophy ; History History and advancements in chemistry ; Various Chemistry Research Topics ; Philosophy and History of Science