jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ertan Yıldırım
Source: GAZI UNIVERSITY JOURNAL OF SCIENCE (article, 2020-02-26)
Field: Chemistry — Organic Chemistry

Synthesis and Characterization of Poly (2-hydroxyethyl methacrylate) Homopolymer at Room Temperature via Reversible Addition–Fragmentation Chain Transfer (RAFT) Polymerization Technique Synthesis and characterization of Poly (2-hydroxyethyl methacrylate) (PHEMA) by RAFT technique at room temperature was first reported in this study. In this context, molecular weight, monomer conversion and semi-logarithmic kinetic curves of the RAFT polymerization, which is one of the controlled-living polymerization techniques, were determined by ATR-FTIR and NMR at certain time intervals. Linear change of molecular weight and monomer conversion with time, semi-logarithmic kinetic curve to the first degree kinetics of the synthesized PHEMA shows that the growth of polymer chains in a controlled manner. PHEMA polymers synthesized by RAFT technique at room temperature without the use of catalyst and metal types have the potential to be easily used in bio applications. It is also important for peptide and protein adsorption that this polymer has functional properties due to the carboxylic acid at the end of the RAFT agent. Chain transfer ; Reversible addition−fragmentation chain-transfer polymerization ; Raft ; Polymerization ; Polymer chemistry ; Monomer ; Materials science ; Polymer ; Methacrylate ; Radical polymerization ; Molar mass distribution ; Chemical engineering ; Composite material Advanced Polymer Synthesis and Characterization ; biodegradable polymer synthesis and properties ; Mass Spectrometry Techniques and Applications
Authors: Marzena Adamczyk | Małgorzata Grabarczyk
Source: Ionics (article, 2020-02-24)
Field: Chemistry — Electrochemistry

Combination of PbFE as an electrochemical sensor and cupferron as a complexing agent for the rapid determination of Mo(VI) Abstract An analytical procedure regarding the trace determination of molybdenum in natural water samples by adsorptive stripping voltammetry (AdSV) using the in situ plated lead film electrode (PbFE) was described. The method is based on adsorptive accumulation of the Mo(VI)-cupferron complex at the PbFE surface. The optimum analytical conditions include the supporting electrolyte containing 0.2-mol L −1 acetic buffer pH = 5.3, 1.45 × 10 −4 -mol L −1 Pb(II), and 2.0 × 10 −4 -mol L −1 cupferron. A linear response of Mo(VI) in the concentration range of 3.0 × 10 −8 to 1.0 × 10 −6 mol L −1 ( r = 0.997) was obtained with detection limit of 9.0 × 10 −9 mol L −1 using accumulation time of 50 s. The selectivity of the method was determined by investigating how the presence of foreign ions affects the determination of molybdenum. The interferences of surface-active substances and humic substances on the molybdenum voltammetric signal were precisely examined and effectively minimized by preliminary mixing with Amberlite XAD-7 resin. The application of the proposed procedure to the analysis of natural water samples was validated by the determination of molybdenum in certificate reference materials SPS-SW1 surface water, Bystrzyca river, tap, and mineral water. Amberlite ; Chemistry ; Adsorptive stripping voltammetry ; Detection limit ; Molybdenum ; Stripping (fiber) ; Tap water ; Supporting electrolyte ; Electrochemistry ; Voltammetry ; Metal ions in aqueous solution ; Inorganic chemistry ; Analytical Chemistry (journal) ; Nuclear chemistry ; Metal ; Electrode ; Chromatography ; Adsorption ; Materials science Electrochemical Analysis and Applications ; Analytical chemistry methods development ; Analytical Chemistry and Sensors
Authors: Hıdır Düzkaya | Süleyman Sungur Tezcan | Alper Acartürk | Mehmet Yılmaz
Source: El-Cezeri Fen ve Mühendislik Dergisi (article, 2020-07-07)
Field: Materials Science — Materials Chemistry

SF6 Alternatifi Yalıtkan Gazların Çevresel ve Fizyokimyasal Özellikleri Research on alternative dielectric gases to eliminate the disadvantages of SF 6 , which is widely used in GIS and switching systems in the power system engineering, has been an important study topic in the literature for nearly 40 years. Because of environmental priorities defined by international agreements such as the Kyoto Protocol and Doha Amendment, the restrictions on the use of SF 6 make these studies an obligation. Although the number of alternative dielectric gases studied for this purpose is quite high, these gases can be classified under the titles of non-synthetics, hydrocarbons (HCs), fluorocarbons (FCs), hydrofluorocarbons (HFCs), fluoronitriles (FNs), fluoroketones (FKs) and other synthetic gases. In this study, the gases classified under these titles are compared using the dielectric constant relative to SF 6 , Global Warming Potential (GWP), atmospheric lifetime, boiling point and toxicity parameters used in the comparison of dielectric gases. When compared with these parameters, non-synthetic air, CO 2 , and N 2 , C 3 F 7 CN from FNs, and C 5 F 10 O and C 6 F 12 O from FKs stand out among alternative gases to SF 6 . These alternatives are used in some innovative power system industry applications and have a widespread use potential in the insulating gas industry instead of SF 6 . Global-warming potential ; Dielectric ; Refrigerant ; Environmental science ; Dielectric gas ; Boiling point ; Montreal Protocol ; Global warming ; Greenhouse gas ; Materials science ; Engineering physics ; Thermodynamics ; Meteorology ; Physics ; Climate change ; Heat exchanger ; Composite material ; Optoelectronics ; Ozone layer High voltage insulation and dielectric phenomena ; Membrane Separation and Gas Transport ; Spacecraft and Cryogenic Technologies
Authors: Abdur Rehman Laili | R. Endut | Norshamsuri Ali | M. H. Laili | M. S. Amirul | S. A. Aljunid | C. B. M. Rashidi | M Nasir Ismail
Source: AIP conference proceedings (article, 2020-01-01)
Field: Chemistry — Analytical Chemistry

Prediction of soil macronutrient (nitrate and phosphorus) using near-infrared (NIR) spectroscopy and machine learning Determination of basic soil macronutrients such as nitrogen (N), phosphorus (P) and potassium (K) that dissolve from organic matter (OM) prior to the plantation of fruit and vegetable corps is one of the important process of soil preparation towards precision farming. In this paper comparative analysis is performed for detection algorithm on OM, (N) and (P) sample using near infrared spectroscopy (NIRS) spectrometer in reflective mode with an effective range of 900nm to 1700nm. In pre-processing we execute data dimension reduction by combining multiple feature selection such as data normalization, permutation feature importance, principle component analysis, fisher linear discriminant and filter-based feature selection. Pre-processing able to reduce 50% data dimension. For prediction model development we combine with multiple classification algorithm such as multiclass decision jungle, decision forest, logistic regression and neural network to come out with highest accuracy of N and P detection. We conclude that near infrared spectroscopy combines with feature selection and multiclass classification able to determine nitrogen and phosphorus. Feature selection ; Principal component analysis ; Linear discriminant analysis ; Artificial intelligence ; Dimensionality reduction ; Computer science ; Chemometrics ; Pattern recognition (psychology) ; Mathematics ; Machine learning Spectroscopy and Chemometric Analyses ; Smart Agriculture and AI ; Water Quality Monitoring and Analysis
Authors: Scott | K Sugibuchi | Y Kurogi | N Endo | A Sheikholeslami | P Gulak
Source: Nature Electronics (article, 2020-10-19)
Field: Materials Science — Materials Chemistry

Time to switch to ferroelectronics? Computer science Ferroelectric and Piezoelectric Materials ; Electronic and Structural Properties of Oxides ; Magnetic and transport properties of perovskites and related materials
Authors: Kyung-Min Lee | Danielle Yarbrough | Mena M. Kozman | Timothy J. Herrman | Jinhyuk Park | Rui Wang | Dmitry Kurouski
Source: Journal of Regulatory Science (article, 2020-08-30)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Sensitive SERS Characterization and Analysis of Chlorpyrifos and Aldicarb Residues in Animal Feed using Gold Nanoparticles The spectroscopic method based on surface-enhanced Raman spectroscopy (SERS) technique combined with chemometric methods was developed for simple, cost-effective, and efficient analysis of chlorpyrifos (CPF) and aldicarb (ALD) pesticide residues in animal feed. Animal feeds free from the pesticides were spiked at different concentrations of CPF (0-20 mg/kg) and aldicarb (0-100 µg/kg). Gold nanoparticles were mixed with sample extract for SERS measurement. A significant spectral difference induced by the presence and different level of CPF and ALD concentration in animal feed was observed between the pesticide spiking groups. Different chemometric models applied on training datasets showed excellent classification rates (100 percent) while the models on external validation dataset exhibited lower correct classification rates (50.0-76.7 percent) with no false-negative error. The selected chemometric models for CPF and ALD quantification also showed a high predictive ability and performance. The developed models displayed no statistical significant difference between model predicted and reference values in the external validation dataset (p &lt; 0.01). The study results indicate that the SERS spectroscopic method could be an effective and efficient analytical tool for pesticide analysis in highly complex animal feed matrices for screening at a point of sampling to improve food and feed safety. https://doi.org/10.21423/jrs-v08lee Aldicarb ; Chlorpyrifos ; Colloidal gold ; Chemistry ; Characterization (materials science) ; Pesticide residue ; Nanoparticle ; Chromatography ; Pesticide ; Nanotechnology ; Biology ; Materials science ; Agronomy Gold and Silver Nanoparticles Synthesis and Applications ; Analytical chemistry methods development ; Pesticide Residue Analysis and Safety
Authors: Konstantin Kahnert | Christoph N. Schlaffner | Jan Muntel | Ruchi Chauhan | Bernhard Y. Renard | Judith A. Steen | Hanno Steen
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2020-05-13)
Field: Chemistry — Spectroscopy

FLEXIQuant-LF: Robust Regression to Quantify Protein Modification Extent in Label-Free Proteomics Data Abstract Improvements in LC-MS/MS methods and technology have enabled the identification of thousands of modified peptides in a single experiment. However, protein regulation by post-translational modifications (PTMs) is not binary, making methods to quantify the modification extent crucial to understanding the role of PTMs. Here, we introduce FLEXIQuant-LF, a software tool for large-scale identification of differentially modified peptides and quantification of their modification extent without prior knowledge of the type of modification. We developed FLEXIQuant-LF using label-free quantification of unmodified peptides and robust linear regression to quantify the modification extent of peptides. As proof of concept, we applied FLEXIQuant-LF to data-independent-acquisition (DIA) data of the anaphase promoting complex/cyclosome (APC/C) during mitosis. The unbiased FLEXIQuant-LF approach to assess the modification extent in quantitative proteomics data provides a better understanding of the function and regulation of PTMs. The software is available at https://github.com/SteenOmicsLab/FLEXIQuantLF . Posttranslational modification ; Proteomics ; Identification (biology) ; Computer science ; Quantitative proteomics ; Computational biology ; Function (biology) ; Data mining ; Chemistry ; Biology ; Biochemistry ; Cell biology ; Enzyme Advanced Proteomics Techniques and Applications ; Genomics and Phylogenetic Studies ; Glycosylation and Glycoproteins Research
Authors: Renee Salz | Robbin Bouwmeester | Ralf Gabriels | Sven Degroeve | Lennart Martens | Pieter‐Jan Volders | Peter A.C. ’t Hoen
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2020-12-11)
Field: Chemistry — Spectroscopy

The Personalized Proteome: Comparing Proteogenomics and Open Variant Search Approaches for Single Amino Acid Variant Detection Abstract Discovery of variant peptides such as single amino acid variant (SAAV) in shotgun proteomics data is essential for personalized proteomics. Both the resolution of shotgun proteomics methods and the search engines have improved dramatically, allowing for confident identification of SAAV peptides. However, it is not yet known if these methods are truly successful in accurately identifying SAAV peptides without prior genomic information in the search database. We studied this in unprecedented detail by exploiting publicly available long-read RNA seq and shotgun proteomics data from the gold standard reference cell line NA12878. Searching spectra from this cell line with the state-of-the-art open modification search engine ionbot against carefully curated search databases resulted in 96.7% false positive SAAVs and an 85% lower true positive rate than searching with peptide search databases that incorporate prior genetic information. While adding genetic variants to the search database remains indispensable for correct peptide identification, inclusion of long-read RNA sequences in the search database contributes only 0.3% new peptide identifications. These findings reveal the differences in SAAV detection that result from various approaches, providing guidance to researchers studying SAAV peptides and developers of peptide spectrum identification tools. Proteogenomics ; Shotgun proteomics ; Database search engine ; Proteomics ; Shotgun ; Computational biology ; Identification (biology) ; Proteome ; Computer science ; Search engine ; Biology ; Bioinformatics ; Genomics ; Information retrieval ; Genome ; Gene ; Genetics Advanced Proteomics Techniques and Applications ; RNA and protein synthesis mechanisms ; Machine Learning in Bioinformatics
Authors: Mohamad Hushnie Haron | Mohd Nasir Taib | Nurlaila Ismail | Nor Azah Mohd Nor | Saıful Nizam Tajuddin
Source: Journal of Electrical & Electronic Systems Research (article, 2020-12-21)
Field: Chemistry — Organic Chemistry

Determination of Substantial Chemical Compounds of Agarwood Oil for Quality Grading Agarwood is a resin saturated heartwood producing its ownessential oil. This oil comprises of a complex mixture of chromone derivatives, oxygenated sesquiterpenes and sesquiterpene hydrocarbons. This mixture has a heavy woody scentand is one of the contributors to the Agarwood oil quality. In this paper, a study that focuses on the approach to select the substantial chemical compounds for Agarwood quality grading was carried out. GC-MS analysis was used to extract the chemical compounds from the Agarwood oil. The data were then preprocessed using techniques such as missing values ratio, natural logarithm and min. max. normalization. Next, synthetic data were generated using MUNGE to fulfil the passing condition of sampling adequacy test. To determine the substantial compounds, PCA and Pearson's correlation were used. This approach was successful in determining three substantial compounds namely -agarofuran, agarofuran and 10-epi--eudesmol. These substantial chemical compounds will be used later to predict the quality of Agarwood oil. Agarwood ; Grading (engineering) ; Chemistry ; Biochemical engineering ; Chromatography ; Process engineering ; Computer science ; Medicine ; Engineering ; Pathology Wood and Agarwood Research ; Image Processing and 3D Reconstruction ; Biological Stains and Phytochemicals
Authors: A. O. Okewale | Chiedu N. Owabor | Jency James
Source: Research Journal of Applied Sciences Engineering and Technology (article, 2020-04-15)
Field: Materials Science — Materials Chemistry

Thermodynamic, Adsorption and Optimization Studies on Carbon Steel in Hydrochloric Acid Environment using Okro Leaf Extract as Corrosion Inhibitor This present study seeks to exploit the use of eco-friendly, Okro leaf extract as an inhibitor in mitigating corrosion on carbon steel metal in acidic environment Gravimetric method was used to study the corrosion process. It was revealed that the inhibition efficiency of the extract on carbon steel decreases as temperature increases. This trend confirmed the physical adsorption mechanism for the corrosion process that resulted in a high rate of corrosion of the carbon steel. Activation energy Ea, enthalpy (ΔHº), and entropy (ΔSº) calculated showed good interactions. The rise in activation energy with inhibitor concentration confirmed the physical (physisorption) adsorption mechanism for the corrosion of a carbon steel surface. The positive value of adsorption enthalpy (ΔHº) obtained confirmed the endothermic nature of the corrosion process. The activation entropy (ΔSº) values obtained were all negatives which show that the activated complex in the rate-determining step represents association rather than dissociation step. Corrosion inhibition occurred by an attribute of inhibitor molecules adsorption on the surface of carbon steel which is seen to be in conformity with Langmuir, Freundlich, and El-Awady adsorption isotherm models. To obtain the least weight loss of carbon steel, optimization of the process variables affecting the corrosion process was carried out using Response Surface Methodology (RSM). Three parameters were varied viz; inhibitor concentration, contact time and temperature, and their effects on weight loss of carbon steel were established. The obtained data fitted well to the quadratic model which was also validated. The model predicted the lowest weight loss of 0.045 g with the optimal condition of inhibitor concentration of 198.71 ppm, 2.04 hrs of contact time, and 40.29°C of temperature. Adsorption ; Corrosion ; Enthalpy ; Carbon steel ; Materials science ; Gravimetric analysis ; Corrosion inhibitor ; Freundlich equation ; Hydrochloric acid ; Langmuir adsorption model ; Endothermic process ; Langmuir ; Physisorption ; Chemistry ; Activation energy ; Inorganic chemistry ; Metallurgy ; Thermodynamics ; Organic chemistry Corrosion Behavior and Inhibition
Authors: Yumei Li | Xianbing Cao | Yanping Cao | Yuxu Feng | Jingjun Ji | Jiuying Xie | Xin Wang
Source: Food Science & Nutrition (article, 2020-04-02)
Field: Chemistry — Organic Chemistry

Physicochemical parameter based estimation of discarding points for frying oil using data interpolation and principal component transformation Data interpolation and principal component transformation (PCT) were used to compute the discarding points of a frying oil by measuring the physicochemical parameters-acid value, carbonyl value, and total polar compounds. Herein, the discarding point refers to the time point (associated with the value of each physicochemical parameter) at which the frying oil should be discarded. First, a primary visual analysis was performed for the obtained data by using line charts. Second, a curve interpolation method was used to compute the discarding points for each parameter and thus determine the discarding points for the frying oil. At 190, 205, and 220°C, the frying oil reached the discarding points at 22.1, 17.7, and 13 hr, respectively. The discarding area was also visualized on the corresponding surfaces for the originally obtained data and the interpolated data to investigate the discarding points. Third, the PCT was conducted for the three parameters at each temperature; the discarding point estimation for the three parameters could be reduced to the estimation from the first principal component (FPC), thereby simplifying this process. At 190, 205, and 220°C, the frying oil reached the discarding points when the FPCs were 10.4524, 6.2881, and -1.7629 at the time points 22.1, 17.7, and 13 hr, respectively. Finally, a verification experiment revealed that the correlation between the results obtained by our interpolation method or PCT and the verified data was higher than 0.98, which demonstrates the effectiveness of our method. Interpolation (computer graphics) ; Principal component analysis ; Data point ; Mathematics ; Component (thermodynamics) ; Point (geometry) ; Transformation (genetics) ; Statistics ; Applied mathematics ; Computer science ; Geometry ; Artificial intelligence ; Chemistry Edible Oils Quality and Analysis ; Spectroscopy and Chemometric Analyses ; Free Radicals and Antioxidants
Authors: Laith Warid Farhan | Faleh H. M. Almahdawi | Adel Sherif Hammadi
Source: Iraqi Journal of Chemical and Petroleum Engineering (article, 2020-03-29)
Field: Chemistry — Analytical Chemistry

Dissolving Precipitated Asphaltenes Inside Oil Reservoirs Using Local Solvents There are several oil reservoirs that had severe from a sudden or gradual decline in their production due to asphaltene precipitation inside these reservoirs. Asphaltene deposition inside oil reservoirs causes damage for permeability and skin factor, wettability alteration of a reservoir, greater drawdown pressure. These adverse changing lead to flow rate reduction, so the economic profit will drop. The aim of this study is using local solvents: reformate, heavy-naphtha and binary of them for dissolving precipitated asphaltene inside the oil reservoir. Three samples of the sand pack had been prepared and mixed with a certain amount of asphaltene. Permeability of these samples calculated before and after mixed with asphaltenes. Then, the permeability of samples calculated after solvents injection into that porous media. After that, all the values of samples permeability converted to average permeability damage compared with the pure samples. The results show the average permeability damage of samples that mixed with 20 gm was 24 %, but after reformate injected reduced to 14 %. After injected heavy naphtha to porous media, the average permeability reduced only to 17%. The binary solvent had been prepared from reformatted mixed with heavy naphtha gained the best results because it dropped the average permeability damage to 10%. Asphaltene ; Naphtha ; Permeability (electromagnetism) ; Dissolution ; Solvent ; Chemical engineering ; Porous medium ; Porosity ; Chemistry ; Chromatography ; Petroleum engineering ; Materials science ; Composite material ; Geology ; Organic chemistry ; Membrane Petroleum Processing and Analysis ; Enhanced Oil Recovery Techniques ; Hydrocarbon exploration and reservoir analysis
Authors: Tim Steinhaus | Alexander Mokros | Mikula Thiem | Markus Münz | Christian Beidl
Source: TUbilio (Technical University of Darmstadt) (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Ultra-low emissions with OME at the CI engine – Implementation and potential for reduction of the immission level Reduction (mathematics) ; Environmental science ; Automotive engineering ; Computer science ; Engineering ; Mathematics Catalytic Processes in Materials Science