jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ismail W. Almanassra | Eric C. Okonkwo | Omar Alhassan | Muataz Ali Atieh | Віктор Кочкодан | Tareq Al‐Ansari
Source: Powder Technology (article, 2020-09-12)
Field: Materials Science — Materials Chemistry

Stability and thermophysical properties test of carbide-derived carbon thermal fluid; a comparison between functionalized and emulsified suspensions In this study, the stability and thermophysical properties of chemically functionalized and gum-Arabic emulsified carbide-derived carbon (CDC)/ water thermal fluids were investigated. The stability of the thermal fluids were studied through zeta potential measurements and imaging methods. The results indicated that functionalized-CDC has a higher stability than the emulsified-CDC. LAMBDA thermal conductivity analyzer, differential scanning calorimeter, and discovery hybrid rheometer were used to evaluate the thermal conductivity, heat capacity and viscosity of the suspensions, respectively. The results demonstrated that the thermal conductivity enhancement was independent of temperature, decreases with gum-Arabic concentration, and significantly enhanced with CDC loading with a maximum enhancement of 26.1% for 0.3 wt% functionalized CDC. Increasing the CDC loading was found to increase the viscosity and decrease the specific heat of the suspensions. Finally, correlation equations proposed for predicting the thermal conductivity and dynamic viscosity of the CDC-water suspension had R2 values of 0.90 and 0.81, respectively. Thermal conductivity ; Differential scanning calorimetry ; Viscometer ; Viscosity ; Materials science ; Thermal stability ; Zeta potential ; Suspension (topology) ; Calorimeter (particle physics) ; Rheometer ; Carbide-derived carbon ; Chemical engineering ; Rheology ; Composite material ; Chemistry ; Thermodynamics ; Carbon nanotube ; Organic chemistry ; Nanotechnology ; Nanoparticle Diamond and Carbon-based Materials Research ; Nanofluid Flow and Heat Transfer ; Polymer Foaming and Composites
Authors: Michael D. Higham | David Mora‐Fonz | Alexey A. Sokol | Scott M. Woodley | C. Richard A. Catlow
Source: Journal of Materials Chemistry A (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Morphology of Cu clusters supported on reconstructed polar ZnO (0001) and (0001) surfaces Unbiased Monte Carlo procedures are applied to investigate the structure of Cu clusters of various sizes deposited over reconstructed polar ZnO surfaces. Polar ; Morphology (biology) ; Monte Carlo method ; Materials science ; Crystallography ; Chemistry ; Physics ; Geology ; Mathematics ; Statistics ; Paleontology ; Astronomy ZnO doping and properties ; nanoparticles nucleation surface interactions ; Copper-based nanomaterials and applications
Authors: Qinglei Ji | Mo Chen | Chun Zhao | Xiran Zhang | Xi Vincent Wang | Lihui Wang | Lei Feng
Source: IEEE Transactions on Industrial Electronics (article, 2020-12-03)
Field: Materials Science — Polymers and Plastics

Feedback Control for the Precise Shape Morphing of 4D-Printed Shape Memory Polymer Four-dimensional printing (4DP) is a newly emerged technology that uses smart materials for additive manufacturing and thus enables shape and/or property change upon stimulus after the printing process. Present study on 4DP has been focused on open-loop stimulus, which can hardly ensure high shape precision and predictable final states. In this article, a new closed-loop 4DP (CL4DP) process supplementing 4D printed actuation with closed loop control methods is proposed. Image feedback is used for enhancing the conventional open loop 4DP morphing process and a controller is implemented to regulate the intensity of the stimulus accordingly in real-time. To achieve precise control, a nonlinear affine system model is built by model identification with measurement data to describe the dynamic shape recovery process of the 4D-printed shape memory polymer (SMP). Precise shape control is achieved and the effects of controller parameters on the precision of CL4DP are studied. Traditionally, SMP has a discrete number of selected steady states. With CL4DP, such steady states can be continuous and arbitrary. Morphing ; Computer science ; Open-loop controller ; Control theory (sociology) ; Process control ; Affine transformation ; Feedback loop ; Process (computing) ; Control system ; Shape-memory polymer ; Closed loop ; Control engineering ; Shape-memory alloy ; Artificial intelligence ; Engineering ; Control (management) ; Mathematics Polymer composites and self-healing ; Advanced Materials and Mechanics ; Dielectric materials and actuators
Authors: Aliakbar Karimipour | Ali Amini | Mohammad Nouri | Annunziata D’Orazio | Roozbeh Sabetvand | Maboud Hekmatifar | Azam Marjani | Quang‐Vu Bach
Source: Computational Particle Mechanics (article, 2020-11-17)
Field: Chemistry — Physical and Theoretical Chemistry

RETRACTED ARTICLE: Molecular dynamics performance for coronavirus simulation by C, N, O, and S atoms implementation dreiding force field: drug delivery atomic interaction in contact with metallic Fe, Al, and steel Molecular dynamics ; Materials science ; Coronavirus ; Matrix (chemical analysis) ; Work (physics) ; Force field (fiction) ; Metal ; Coronavirus disease 2019 (COVID-19) ; Field (mathematics) ; Chemical physics ; Nanotechnology ; Atomic physics ; Molecular physics ; Chemistry ; Physics ; Thermodynamics ; Composite material ; Computational chemistry ; Metallurgy thermodynamics and calorimetric analyses ; Energetic Materials and Combustion ; SARS-CoV-2 and COVID-19 Research
Authors: Thomas O. S. Akowuah | Ernest Teye | Julius Kofi Hagan | Kwasi Nyandey
Source: Journal of Spectroscopy (article, 2020-10-14)
Field: Chemistry — Analytical Chemistry

Rapid and Nondestructive Determination of Egg Freshness Category and Marked Date of Lay using Spectral Fingerprint The potential of nondestructive prediction of egg freshness based on near-infrared (NIR) spectra fingerprints would be beneficial to quality control officers and consumers alike. In this study, handheld NIR spectrometer in the range of 740 nm to 1070 nm and chemometrics were used to simultaneously determine egg freshness based on marked date of lay for eggs stored under cold and ambient conditions. The spectra acquired from the eggs were preprocessed using multiplicative scatter correction and principal component analysis (MSC-PCA). Linear discriminant analysis (LDA) was used to build identification model to predict the category of freshness, while partial least square regression (PLS-R) was used to determine the marked date of lay. The performance of LDA model was above 95% identification rate in both calibration and prediction set for the eggs stored under ambient and cold storage. For eggs stored in ambient storage, LDA had 95.54% identification rate at 5 principal components, while at cold storage LDA has 100% identification rate at 5 principal components for determining the marked date of lay, and partial least square regression (PLS-R) gave R = 0.87 and RMSEI = 2.57 for ambient storage and R = 0.88 and RMSEI = 2.66 for cold storage in independent set, respectively. The results show that handheld spectrometer and multivariate analysis could be used for rapid and nondestructive measurement of egg freshness. This provides a novel solution for egg integrity prediction along the value chain. Partial least squares regression ; Chemometrics ; Principal component analysis ; Linear discriminant analysis ; Multivariate statistics ; Principal component regression ; Spectrometer ; Mathematics ; Calibration ; Analytical Chemistry (journal) ; Statistics ; Pattern recognition (psychology) ; Artificial intelligence ; Chemistry ; Computer science ; Chromatography ; Optics ; Physics Spectroscopy and Chemometric Analyses ; Advanced Chemical Sensor Technologies ; Identification and Quantification in Food
Authors: Mathew Alphonse | V.K. Bupesh Raja | M. Gupt
Source: Tribology in Industry (review, 2020-06-15)
Field: Materials Science — Materials Chemistry

Investigation on Tribological Behavior During Friction Drilling Process - A Review Friction drilling is a nontraditional hole making process getting tremendous attention recently. In this process, tool is penetrated into the work piece due to the softening caused by the heat, which is developed between tool and the work piece. Materials less than 5mm thickness can be used for friction drilling. Wide varieties of materials such as tool steel, high speed steel, tungsten carbide and H13 steel can be used either with conical profile as friction drilling tool. For improving tool life nanocoating can be applied. This review mainly focuses on various optimization techniques such as Taguchi method and design of experiments, which can be utilized in friction drilling. Surface roughness, conicity and tribological response are also addressed in this study. Various parameters like cutting feed and speed, which play prominent role during friction drilling process are suitably dealt with. Tribology ; Process (computing) ; Drilling ; Lubricity ; Materials science ; Petroleum engineering ; Mechanical engineering ; Engineering ; Computer science ; Composite material ; Metallurgy Metal Alloys Wear and Properties ; Advanced machining processes and optimization ; Tunneling and Rock Mechanics
Authors: Cheng Hu | Shaoyang Kong | Rui Wang | Fan Zhang | Lianjun Wang
Source: Remote Sensing (article, 2020-06-11)
Field: Chemistry — Analytical Chemistry

Insect Mass Estimation Based on Radar Cross Section Parameters and Support Vector Regression Algorithm Radar cross section (RCS) parameters of insect targets contain information related to their morphological parameters, which are helpful for the identification of migratory insects. Several morphological parameter estimation methods have been presented. However, most of these estimations are performed based on polynomial fitting methods, using only one or two parameters, which may limit the estimation accuracy. In this paper, a new insect mass estimation method is proposed based on support vector regression (SVR). Several RCS parameters were extracted for the estimation of insect mass. Support vector regression based on recursive feature elimination (SVRRFE) was used to obtain the optimal feature subset. Specifically, a dataset including 367 specimens was included to evaluate the performance of the proposed method. Fifteen features were extracted and ranked. The optimal feature subset contained six features and the optimal mass estimation accuracy was 78%. Additionally, traditional insect mass estimation methods were analyzed for comparison. The results prove that the proposed method is more effective and accurate for insect mass estimation. It needs to be emphasized that the poor number of experimental insects available may limit the further improvement of estimation accuracy. Support vector machine ; Computer science ; Polynomial regression ; Estimation ; Feature (linguistics) ; Limit (mathematics) ; Radar ; Algorithm ; Pattern recognition (psychology) ; Regression ; Regression analysis ; Feature vector ; Artificial intelligence ; Mathematics ; Statistics ; Machine learning ; Engineering Spectroscopy and Chemometric Analyses ; Smart Agriculture and AI ; Remote Sensing in Agriculture
Authors: Vitor Vecina dos Santos | Bruno Albuquerque de Castro | Amanda Binotto | Jorge Alfredo Ardila‐Rey | Guilherme Beraldi Lucas | André Luiz Andreoli
Source:  (article, 2020-11-14)
Field: Materials Science — Materials Chemistry

An Application of Wavelet Analysis to Assess Partial Discharge Evolution by Acoustic Emission Sensor Under normal operation, insulation systems of high voltage electrical devices, like power transformers, are constantly subjected to multiple types of stresses (electrical, thermal, mechanical, environmental, etc.), which can lead to a degradation of the machine insulation. One of the main indicators of the dielectric degradation process is the presence of partial discharges (PD). Although it starts due to operational stresses, PD can cause a progressive insulation deterioration, since it is characterized by localized current pulses that emit heat, UV radiation, acoustic, and electromagnetic waves. In this sense, acoustic emission (AE) transducers are wildly applied in PD detection. The goal is to reduce maintenance costs by predictive actions and avoid total failures. Becasue of the progressive deterioration, the assessment of the PD evolution is crucial for improving the maintenance planning and ensure the operation of the transformer. Based on this issue, this article presents a new wavelet -based analysis in order to characterize the PD evolution. Three levels of failures were carried out in a transformer and the acoustic signals captured by a lead zirconate titanate piezoelectric transducer were processed by discrete wavelet transform. The experimental results revealed that the energy of the approximation levels increasing with the failure evolution. More specifically, levels 4, 6, 7, and 10 presented a linear fit to characterize the phenomena, enhancing the applicability of the proposed approach to transformer monitoring. Acoustic emission ; Partial discharge ; Lead zirconate titanate ; Transformer ; Transducer ; Wavelet ; Materials science ; Condition monitoring ; Acoustics ; Voltage ; Wavelet transform ; Piezoelectricity ; High voltage ; Computer science ; Electronic engineering ; Dielectric ; Electrical engineering ; Engineering ; Optoelectronics ; Composite material ; Ferroelectricity ; Physics High voltage insulation and dielectric phenomena ; Power Transformer Diagnostics and Insulation ; Electrical Fault Detection and Protection
Authors: Natalie G. Barnes | Anthony W. Parker | Amjed A. Ahmed Mal Ullah | Patricia A. Ragazzon | John A. Hadfield
Source: Bioorganic & Medicinal Chemistry (article, 2020-08-05)
Field: Chemistry — Organic Chemistry

A 2-step synthesis of Combretastatin A-4 and derivatives as potent tubulin assembly inhibitors Combretastatin ; Chemistry ; Tubulin ; Wittig reaction ; Stereochemistry ; Microtubule ; Chemical synthesis ; In vitro ; Stereoselectivity ; Suzuki reaction ; Cell cycle ; Cell cycle checkpoint ; Cell culture ; Combinatorial chemistry ; Cell ; Aryl ; Biochemistry ; Organic chemistry ; Alkyl ; Catalysis ; Cell biology Synthesis and biological activity ; Click Chemistry and Applications ; 14-3-3 protein interactions
Authors: Cailing Huo | Shipu Wu | Yiming Yang | Chengcheng Liu | Youhua Wang
Source: IEEE Access (article, 2020-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Residual Flux Density Measurement Method of Single-Phase Transformer Core Based on Time Constant Residual flux density in the single-phase transformer core can dramatically increase inrush current when the transformer is energized. To reduce inrush current, it is necessary to study residual flux density measurement. This paper proposes a new residual flux density measurement method based on time constant. Firstly, the generation principle of residual flux density is analyzed under different magnetization states, and it is found that the positive relative differential permeability is smaller than the negative at different residual flux density. To obtain the relative differential permeability, when an appropriate DC excitation is applied, the measurement circuit is equivalent to a first-order RL circuit. Then, combining magnetic circuit and transient circuit analysis, the relationship between time constant and relative differential permeability is obtained. It is conclusion that the positive time constant is less than the negative. Residual flux density direction is determined by comparing the positive and negative time constant, and the magnitude of residual flux density is calculated by the relationship between residual flux density and the difference of the positive and negative time constant. Finally, the empirical formula between residual flux density and time constant difference of the square core is obtained in finite element method, and then verified on the experimental platform. Compared with other measurement methods, the relative error of proposed empirical formula is within 4.58 %, and it has higher accuracy in this paper. The proposed method in this paper can provide a reference for selecting the demagnetization voltage, which improves the effectiveness of demagnetization. Residual ; Magnetic flux ; Inrush current ; Transformer ; Relative permeability ; Flux (metallurgy) ; Constant (computer programming) ; Magnetization ; Materials science ; Voltage ; Mechanics ; Control theory (sociology) ; Physics ; Mathematics ; Magnetic field ; Algorithm ; Computer science ; Composite material Magnetic Properties and Applications ; Non-Destructive Testing Techniques ; Magnetic Field Sensors Techniques
Authors: Oleksandr O. Sofronov | Giulia Giubertoni | Alberto Pérez de Alba Ortíz | Bernd Ensing | Huib J. Bakker
Source: The Journal of Physical Chemistry Letters (article, 2020-04-15)
Field: Chemistry — Physical and Theoretical Chemistry

Peptide Side-COOH Groups Have Two Distinct Conformations under Biorelevant Conditions The carboxyl (COOH) side chain groups of amino acids, such as aspartic acid, play an important role in biochemical processes, including enzymatic proton transport. In many theoretical studies, it was found that the (bio)chemical reactivity of the carboxyl group strongly depends on the conformation of this group. Interestingly, up to now there has been no experimental investigation of the geometry and the stability of different COOH conformers under biorelevant conditions. Here, we investigate the conformational isomerism of the side chain COOH group of <i>N</i>-acetyl aspartic acid amide using polarization-resolved two-dimensional infrared spectroscopy. We find that the carboxyl group shows two distinct near-planar conformers (syn and anti) when dissolved in water at room temperature. Both conformers are significantly populated in aqueous solution (75 ± 10% and 25 ± 10% for syn and anti, respectively). Molecular dynamics simulations show that the anti conformer interacts more strongly with water molecules than the syn conformer, explaining why this conformer is significantly present in aqueous solution. Conformational isomerism ; Chemistry ; Aqueous solution ; Amide ; Side chain ; Molecule ; Hydrogen bond ; Stereochemistry ; Aspartic acid ; Infrared spectroscopy ; Amino acid ; Crystallography ; Organic chemistry Crystallography and molecular interactions ; Protein Structure and Dynamics ; Mass Spectrometry Techniques and Applications
Authors: Alexander Kantardjiev | Petko M. Ivanov
Source: Entropy (article, 2020-10-21)
Field: Chemistry — Physical and Theoretical Chemistry

Entropy Rules: Molecular Dynamics Simulations of Model Oligomers for Thermoresponsive Polymers We attempted to attain atomic-scale insights into the mechanism of the heat-induced phase transition of two thermoresponsive polymers containing amide groups, poly(<i>N</i>-isopropylacrylamide) (PNIPAM) and poly(2-isopropyl-2-oxazoline) (PIPOZ), and we succeeded in reproducing the existence of lower critical solution temperature (LCST). The simulation data are in accord with experimental findings. We found out that the entropy has an important contribution to the thermodynamics of the phase separation transition. Moreover, after decomposing further the entropy change to contributions from the solutes and from the solvent, it appeared out that the entropy of the solvent has the decisive share for the lowering of the free energy of the system when increasing the temperature above the LCST. Our conclusion is that the thermoresponsive behavior is driven by the entropy of the solvent. The water molecules structured around the functional groups of the polymer that are exposed to contact with the solvent in the extended conformation lower the enthalpy of the system, but at certain temperature the extended conformation of the polymer collapses as a result of dominating entropy gain from "released" water molecules. We stress also on the importance of using more than one reference molecule in the simulation box at the setup of the simulation. Molecular dynamics ; Polymer ; Entropy (arrow of time) ; Statistical physics ; Dynamics (music) ; Materials science ; Biological system ; Computer science ; Chemistry ; Thermodynamics ; Computational chemistry ; Physics ; Organic chemistry Advanced Physical and Chemical Molecular Interactions ; Phase Equilibria and Thermodynamics ; Advanced Thermodynamics and Statistical Mechanics
Authors: Paulo Siani | Stefano Motta | Lorenzo Ferraro | Asmus Ougaard Dohn | Cristiana Di Valentin
Source: Journal of Chemical Theory and Computation (article, 2020-09-03)
Field: Materials Science — Materials Chemistry

Dopamine-Decorated TiO<sub>2</sub> Nanoparticles in Water: A QM/MM vs an MM Description Nanoparticle functionalization is a modern strategy in nanotechnology to build up devices for several applications. Modeling fully decorated metal oxide nanoparticles of realistic size (few nanometers) in an aqueous environment is a challenging task. In this work, we present a case study relevant for solar-light exploitation and for biomedical applications, i.e., a dopamine-functionalized TiO<sub>2</sub> nanoparticle (1700 atoms) in bulk water, for which we have performed an extensive comparative investigation with both MM and QM/MM approaches of the structural properties and of the conformational dynamics. We have used a combined multiscale protocol for a more efficient exploration of the complex conformational space. On the basis of the results of this study and of some QM and experimental data, we have defined strengths and limitations of the existing force field parameters. Our findings will be useful for an improved modeling and simulation of many other similar hybrid bioinorganic nanosystems in an aqueous environment that are pivotal in a broad range of nanotechnological applications. QM/MM ; Nanoparticle ; Nanotechnology ; Materials science ; Molecular dynamics ; Aqueous solution ; Nanometre ; Oxide ; Computer science ; Chemistry ; Computational chemistry ; Physical chemistry Quantum Dots Synthesis And Properties ; Spectroscopy and Quantum Chemical Studies ; Gold and Silver Nanoparticles Synthesis and Applications