jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Luke R. Sadergaski | Hunter B. Andrews | David Rai | Vasileios Anagnostopoulos
Source: Applied Spectroscopy Practica (article, 2024-03-01)
Field: Chemistry — Analytical Chemistry

Comparing Designed Training Sets to Optimize Multivariate Regression Models for Pr, Nd, and Nitric Acid Using Spectrophotometry Chemometric regression models were developed for the quantification of praseodymium (Pr, 0–1000 µg/mL), neodymium (Nd, 0–1000 µg/mL), and nitric acid (HNO 3 , 0.1–5 M) using spectrophotometry. Designed calibration sets were composed of 20 samples each: 10 model points and 10 lack-of-fit (LOF) points. The D-optimal designs effectively minimized the number of samples required to build models, and each design resulted in similar prediction performance, suggesting that statistical design of experiments can provide a reliable framework for selecting training set samples in three-variable systems. Partial least squares regression (PLSR) models were validated against a one-factor-at-a-time validation set composed of 125 samples (three variables, five levels). The top PLS-1 models resulted in average percent root mean square error of prediction error values of 3.5%, 1.7%, and 1.2% for Pr(III), Nd(III), and HNO 3 , respectively. Power set augmentations of the model and LOF samples were investigated to optimize the number of training set samples. PLSR models built using just required model points (10) had similar predictive capabilities as models including the LOF points (20) but with fewer samples. The number of validation samples was also varied systematically to learn how many samples are needed to validate regression models. This work addresses long-standing questions in the field of chemometrics to help make this approach amenable to the near-real-time quantification of hazardous species in remote settings. Chemometrics ; Partial least squares regression ; Multivariate statistics ; Mean squared error ; Calibration ; Regression analysis ; Training set ; Linear regression ; Set (abstract data type) ; Statistics ; Computer science ; Regression ; Mathematics ; Artificial intelligence ; Machine learning Spectroscopy and Chemometric Analyses ; Electrochemical Analysis and Applications ; Pesticide Residue Analysis and Safety
Authors: Abebayehu Abdela Gelgelu | Mieraf Asfaw | Bart Buffel | Belete Sirahbizu | Frederik Desplentere
Source: Journal of Natural Fibers (article, 2024-05-31)
Field: Materials Science — Polymers and Plastics

Natural Fibers Density Measurement Methods: Factors Affecting Density Result in Helium Gas Pycnometry Fiber density can be used to estimate composite weight and to evaluate fiber content for property predictions in fiber-reinforced composites. Yet, natural fibers don't have fixed density value given on datasheet and their density measurement is affected by various factors. This study compares various standard natural fiber's density mearusing methods and identifies determinant factors to, then, estimate the density of Enset fibers by using the optimal combination. The advantages and disadvantages of five standard methods were compared considering the characteristics of natural fibers' and methods' effectiveness where Helium gas Pycnometry is selected afterward. Standard calibration sphere and synthetic fiber with known density is measured for validation. The study analyzed the impact of variables on result's precision and accuracy. Then, Density of Enset fiber have been measured with varied factors including uniformity and duration purging, volume cell type and amount of fiber in a cell, and fiber size. The result showed that fluctuation is minimized, and accuracy and precision is enhanced for the larger volume cell, larger mass of fiber in a cell, smaller size fiber and longer uniform purging. Finally, measured density of Enset using the best combination of factors is 1.38 0.01 g/cm 3 . Gas pycnometer ; Natural gas ; Helium ; Materials science ; Composite material ; Environmental science ; Waste management ; Engineering ; Physics ; Porosity ; Atomic physics Textile materials and evaluations ; Natural Fiber Reinforced Composites ; Material Properties and Processing
Authors: Steinn Ýmir Ágústsson | Alfred J. H. Jones | Davide Curcio | Søren Ulstrup | Jill A. Miwa | Davide Mottin | Panagiotis Karras | Philip Hofmann
Source: Review of Scientific Instruments (preprint, 2024-05-01)
Field: Materials Science — Surfaces, Coatings and Films

Autonomous micro-focus angle-resolved photoemission spectroscopy Angle-resolved photoemission spectroscopy (ARPES) is a technique used to map the occupied electronic structure of solids. Recent progress in x-ray focusing optics has led to the development of ARPES into a microscopic tool, permitting the electronic structure to be spatially mapped across the surface of a sample. This comes at the expense of a time-consuming scanning process to cover not only a three-dimensional energy-momentum (E, kx, ky) space but also the two-dimensional surface area. Here, we implement a protocol to autonomously search both k- and real-space in order to find positions of particular interest, either because of their high photoemission intensity or because of sharp spectral features. The search is based on the use of Gaussian process regression and can easily be expanded to include additional parameters or optimization criteria. This autonomous experimental control is implemented on the SGM4 micro-focus beamline of the synchrotron radiation source ASTRID2. Angle-resolved photoemission spectroscopy ; Photoemission spectroscopy ; Synchrotron radiation ; Beamline ; Physics ; Optics ; Process (computing) ; Gaussian ; Focus (optics) ; Space (punctuation) ; Computer science ; Electronic structure ; Spectral line ; Quantum mechanics Electron and X-Ray Spectroscopy Techniques ; Machine Learning in Materials Science ; Advanced Electron Microscopy Techniques and Applications
Authors: Sudip Sasmal | Markus Schröder | Oriol Vendrell
Source: The Journal of Chemical Physics (article, 2024-02-12)
Field: Chemistry — Spectroscopy

Compact sum-of-products form of the molecular electronic Hamiltonian based on canonical polyadic decomposition We propose an approach to represent the second-quantized electronic Hamiltonian in a compact sum-of-products (SOP) form. The approach is based on the canonical polyadic decomposition of the original Hamiltonian projected onto the sub-Fock spaces formed by groups of spin-orbitals. The algorithm for obtaining the canonical polyadic form starts from an exact sum-of-products, which is then optimally compactified using an alternating least squares procedure. We discuss the relation of this specific SOP with related forms, namely the Tucker format and the matrix product operator often used in conjunction with matrix product states. We benchmark the method on the electronic dynamics of an excited water molecule, trans-polyenes, and the charge migration in glycine upon inner-valence ionization. The quantum dynamics are performed with the multilayer multiconfiguration time-dependent Hartree method in second quantization representation. Other methods based on tree-tensor Ansätze may profit from this general approach. Hamiltonian (control theory) ; Atomic orbital ; Quantum mechanics ; Electronic structure ; Tensor product ; Mathematics ; Physics ; Mathematical physics ; Pure mathematics ; Electron ; Mathematical optimization Advanced NMR Techniques and Applications ; Tensor decomposition and applications ; Quantum many-body systems
Authors: A. Rajesh Kannan | N. Siva Shanmugam | V. Rajkumar | M. Vishnukumar | S.G. Channabasavanna | Junho Oh | Than Trong Khanh Dat | Jonghun Yoon
Source: Materials (article, 2024-09-29)
Field: Materials Science — Materials Chemistry

Microstructure, Mechanical Properties and Corrosion Performance of Laser-Welded NiTi Shape Memory Alloy in Simulated Body Fluid Laser-welding is a promising technique for welding NiTi shape memory alloys with acceptable tensile strength and comparable corrosion performance for biomedical applications. The microstructural characteristics and localized corrosion behavior of NiTi alloys in a simulated body fluid (SBF) environment are evaluated. A microstructural examination indicated the presence of fine and equiaxed grains with a B2 austenite phase in the base metal (BM), while the weld metal (WM) had a coarse dendritic microstructure with intermetallic precipitates including Ti<sub>2</sub>Ni and Ni<sub>4</sub>Ti<sub>3</sub>. The hardness decreased from the BM to the WM, and the average hardness for the BM was 352 ± 5 HV, while it ranged between 275 and 307 HV and 265 and 287 HV for the HAZ and WM, respectively. Uni-axial tensile tests revealed a substantial decrease in the tensile strength of NiTi WM (481 ± 19 MPa), with a reduced joint efficiency of 34%. The localized corrosion performance of NiTi BM was superior to the WM, with electrochemical test responses indicating a pitting potential and low corrosion rate in SBF environments. The corrosion rate of the NiTi BM and WM was 0.048 ± 0.0018 mils per year (mpy) and 0.41 ± 0.019 mpy, respectively. During welding, NiTi's strength and biocompatibility properties changed due to the alteration in microstructure and formation of intermetallic phases as a result of Ti enrichment. The performance and safety of welded medical devices may be impacted during welding, and it is essential to preserve the biocompatibility of NiTi components for biomedical applications. Materials science ; Shape-memory alloy ; Microstructure ; Nickel titanium ; Metallurgy ; Welding ; Corrosion ; Alloy ; Composite material Shape Memory Alloy Transformations
Authors: Jing Cheng | Yu Han | Zhifeng Zhang | Hongxiang Jiang | Ping Wu | Zhouguang Wang | Zhibiao Chen | Liquan Wu
Source: Journal of Materials Science Materials in Medicine (article, 2024-07-29)
Field: Materials Science — Materials Chemistry

Mxene-bpV plays a neuroprotective role in cerebral ischemia-reperfusion injury by activating the Akt and promoting the M2 microglial polarization signaling pathways Studies have shown that the inhibition of phosphatase and tensin homolog deleted on chromosome 10 (PTEN)was neuroprotective against ischemia/reperfusion(I/R) injury. Bisperoxovanadium (bpV), a derivative of vanadate, is a well-established inhibitor of PTEN. However, its function islimited due to its general inadequacy in penetrating cell membranes. Mxene(Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub>) is a novel two-dimensional lamellar nanomaterial with an excellent ability to penetrate the cell membrane. Yet, the effects of this nanomaterial on nervous system diseases have yet to be scrutinized. Here, Mxene(Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub>) was used for the first time to carry bpV(HOpic), creating a new nanocomposite Mxene-bpV that was probed in a cerebral I/R injury model. The findings showed that this synthetic Mxene-bpV was adequately stable and can cross the cell membraneeasily. We observed that Mxene-bpV treatment significantly increased the survival rate of oxygen glucose deprivation/reperfusion(OGD/R)--insulted neurons, reduced infarct sizes and promoted the recovery of brain function after mice cerebral I/R injury. Crucially, Mxene-bpV treatment was more therapeutically efficient than bpV(HOpic) treatment alone over the same period. Mechanistically, Mxene-bpV inhibited the enzyme activity of PTEN in vitro and in vivo. It also promoted the expression of phospho-Akt (Ser<sup>473</sup>) by repressing PTEN and then activated the Akt pathway to boost cell survival. Additionally, in PTEN transgenic mice, Mxene-bpV suppressed I/R-induced inflammatory response by promoting M2 microglial polarization through PTEN inhibition. Collectively, the nanosynthetic Mxene-bpV inhibited PTEN' enzymatic activity by activating Akt pathway and promoting M2 microglial polarization, and finally exerted neuroprotection against cerebral I/R injury. PTEN ; Tensin ; Protein kinase B ; PI3K/AKT/mTOR pathway ; Neuroprotection ; Materials science ; Cell biology ; Cancer research ; Phosphatase ; Signal transduction ; Pharmacology ; Biology ; Phosphorylation Polyoxometalates: Synthesis and Applications ; Advanced Nanomaterials in Catalysis ; Sulfur-Based Synthesis Techniques
Authors: Sameer Panda | Swetalina Mishra | Somalika Pradhan | Nitesh Dhar Badgayan
Source: Journal of the Mechanical Behavior of Materials (review, 2024-01-01)
Field: Materials Science — Polymers and Plastics

Exploring the mechanical and thermal properties of rubber-based nanocomposite: A comprehensive review Abstract The emergence and progression of synthetic rubber have paved the way in variegated prospects across various engineering and technological fields. Nonetheless, its inherent limitations such as poor mechanical and thermal properties including wear resistance, poor tensile strength, and lower thermal conductivity, as evident in styrene butadiene rubber and silicone rubber, have constrained its utility in numerous load-bearing scenarios. This limitation has been addressed by incorporating specific nanofillers into various rubber compositions, resulting in promising outcomes up to a certain threshold. Many nanofillers were trialed, such as graphite oxide, aluminum oxide, carbon nanotubes, and boron nitride. However, an attempt should be made to explore the disparity in dimensional attributes of nanofillers and their effect on different properties of rubber, thereby delineating the scope for future research. The exploration of dimensionally distinct nanofillers, such as 1D multiwalled carbon nanotubes and 2D graphene, can overcome these limitations and augment rubber’s mechanical properties and thermal properties. The study also delineates the scope of future research, which should be focused on optimizing the nanofillers’ dispersion and interfacial bonding within the rubber matrix by trying dimensionally different nanofillers. Nanocomposite ; Natural rubber ; Materials science ; Materials processing ; Thermal ; Composite material ; Polymer science ; Engineering ; Process engineering ; Physics ; Thermodynamics Polymer Nanocomposites and Properties ; Polymer Nanocomposite Synthesis and Irradiation ; Tribology and Wear Analysis
Authors: Golestan Rouhollahi | Kaveh Mollazade | Himan Nourbakhsh
Source: Scientific Reports (article, 2024-11-18)
Field: Chemistry — Analytical Chemistry

Predicting the S-ovalbumin content and determining the freshness of chicken eggs via transmittance spectroscopy The quality and freshness of eggs deteriorate during storage, impacting their role as a crucial dietary and industrial component. This study utilizes transmittance spectroscopy (200-1000 nm) to predict the S-ovalbumin content and to identify optimal wavelengths for assessing egg freshness levels. Three hundred fresh eggs were evaluated over 21 days of storage at ambient (25 ± 2 °C, 45 ± 5% R.H.) and refrigerated (5 ± 0.5 °C, 75 ± 5% R.H.) conditions by measuring quality indicators (Haugh unit, air cell height, yolk index, S-ovalbumin, and albumin/yolk pH). The samples were divided into several clusters using the fuzzy C-means algorithm based on these parameters. The changes in the S-ovalbumin concentration increased significantly (p < 0.01) across the storage conditions. Employing the first three principal components of preprocessed transmittance spectra as inputs to artificial neural networks enabled the discrimination of fresh from old eggs with 92% accuracy and the prediction of S-ovalbumin content with R = 0.93 and RMSE = 0.09. The light transmittance at wavelengths of 228 and 280 nm, as determined via the RELIEF algorithm, was used to classify the eggs into fresh/old (74.43% accuracy) and fresh/semi-fresh/old (72.85% accuracy) groups, demonstrating the efficacy of spectroscopy for non-destructive egg quality evaluation. Ovalbumin ; Transmittance ; Haugh unit ; Yolk ; Spectroscopy ; Chemistry ; Food science ; Biological system ; Materials science ; Analytical Chemistry (journal) ; Biology ; Chromatography ; Optoelectronics ; Physics ; Immunology Spectroscopy and Chemometric Analyses ; Advanced Chemical Sensor Technologies ; Meat and Animal Product Quality
Authors: Ali Tabatabaeian | Reza Mohammadi | P.V. Harrison | Mohammad Fotouhi
Source: Sensors (article, 2024-08-10)
Field: Chemistry — Organic Chemistry

Characterisation and Application of Bio-Inspired Hybrid Composite Sensors for Detecting Barely Visible Damage under Out-of-Plane Loadings Traditional inspection methods often fall short in detecting defects or damage in fibre-reinforced polymer (FRP) composite structures, which can compromise their performance and safety over time. A prime example is barely visible impact damage (BVID) caused by out-of-plane loadings such as indentation and low-velocity impact that can considerably reduce the residual strength. Therefore, developing advanced visual inspection techniques is essential for early detection of defects, enabling proactive maintenance and extending the lifespan of composite structures. This study explores the viability of using novel bio-inspired hybrid composite sensors for detecting BVID in laminated FRP composite structures. Drawing inspiration from the colour-changing mechanisms found in nature, hybrid composite sensors composed of thin-ply glass and carbon layers are designed and attached to the surface of laminated FRP composites exposed to transverse loading. A comprehensive experimental characterisation, including quasi-static indentation and low-velocity impact tests alongside non-destructive evaluations such as ultrasonic C-scan and visual inspection, is conducted to assess the sensors' efficacy in detecting BVID. Moreover, a comparison between the two transverse loading types, static indentation and low-velocity impact, is presented. The results suggest that integrating sensors into composite structures has a minimal effect on mechanical properties such as structural stiffness and energy absorption, while substantially improving damage visibility. Additionally, the influence of fibre orientation of the sensing layer on sensor performance is evaluated, and correlations between internal and surface damage are demonstrated. Composite number ; Materials science ; Plane (geometry) ; Composite material ; Structural engineering ; Engineering ; Geometry ; Mathematics Polydiacetylene-based materials and applications ; Smart Materials for Construction ; Advanced MEMS and NEMS Technologies
Authors: Hua-Zhen Deng | Hanwen Zhang | Biao Huang | Jin-Huan Deng | Siping Luo | Weihua Li | Yi Lei | Xiaolei Liu | Fan Lin
Source: Frontiers in Neuroscience (review, 2024-07-31)
Field: Materials Science — Materials Chemistry

Advances in diffuse glioma assessment: preoperative and postoperative applications of chemical exchange saturation transfer Chemical Exchange Saturation Transfer (CEST) is a technique that uses specific off-resonance saturation pulses to pre-saturate targeted substances. This process influences the signal intensity of free water, thereby indirectly providing information about the pre-saturated substance. Among the clinical applications of CEST, Amide Proton Transfer (APT) is currently the most well-established. APT can be utilized for the preoperative grading of gliomas. Tumors with higher APTw signals generally indicate a higher likelihood of malignancy. In predicting preoperative molecular typing, APTw values are typically lower in tumors with favorable molecular phenotypes, such as isocitrate dehydrogenase (IDH) mutations, compared to IDH wild-type tumors. For differential diagnosis, the average APTw values of meningiomas are significantly lower than those of high-grade gliomas. Various APTw measurement indices assist in distinguishing central nervous system lesions with similar imaging features, such as progressive multifocal leukoencephalopathy, central nervous system lymphoma, solitary brain metastases, and glioblastoma. Regarding prognosis, APT effectively differentiates between tumor recurrence and treatment effects, and also possesses predictive capabilities for overall survival (OS) and progression-free survival (PFS). Glioma ; Isocitrate dehydrogenase ; Grading (engineering) ; Magnetic resonance imaging ; Primary central nervous system lymphoma ; Medicine ; Central nervous system ; Pathology ; Cancer research ; Radiology ; Biology ; Internal medicine Lanthanide and Transition Metal Complexes ; Magnetism in coordination complexes ; Advanced MRI Techniques and Applications
Authors: Kendall Wontor | Carly Clisham | J.P. Hummel | James V. Cizdziel
Source: Journal of Forensic Sciences (article, 2024-06-29)
Field: Chemistry — Analytical Chemistry

Analysis of automotive paint layers on plastic substrates using chemical imaging μ‐FTIR and O‐PTIR microspectroscopy Automobile paint chips are a crucial piece of trace evidence for forensic investigators. This is because automotive paints are composed of multiple layers, including the primer, basecoat, and clearcoat, each of which has its own chemical composition that can vary by vehicle make, model, year, and manufacturing plant. Thus, Fourier-transform infrared (FTIR) spectral databases for automobile paint systems have been established to aid law enforcement in, for example, narrowing search parameters for a suspect's vehicle. Recently, car manufacturers have implemented primers on plastic substrates that are much thinner (~5 μm) than those on metal substrates, making it more difficult to manually separate for analyses. Here, we evaluated FTIR microspectroscopy (μ-FTIR) and optical photothermal infrared spectroscopy (O-PTIR) to chemically image cross sections of paint chips without manually separating the layers. For μ-FTIR, transmission and transflection modes provided the highest quality spectra compared to reflection and μ-ATR analyses. Point analysis was preferable to chemical imaging, as peaks were identified in the point (MCT) detector's lower spectral range that was below the imaging (FPA) detector's cutoff, such as those associated with titanium dioxide. Reduced spectral range can lead to a similar issue in O-PTIR analyses depending on instrument configuration. However, its complementary Raman spectra showed strong titanium dioxide peaks, providing an alternate means of identification. Both techniques are likely to become more relevant as they are non-destructive and avoid manual separation of the layers. O-PTIR is particularly well-suited for analysis of the thin primer layer due to its superior spatial resolution. Fourier transform infrared spectroscopy ; Materials science ; Optics ; Analytical Chemistry (journal) ; Chemistry ; Chromatography Spectroscopy and Chemometric Analyses ; Spectroscopy Techniques in Biomedical and Chemical Research ; Cultural Heritage Materials Analysis