jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Sarah Kowsari Mogadam | Mahdi Salimi | Seyyed Mohammad Taghi Bathaee | Davar Mirabbasi
Source: Scientia Iranica (article, 2023-04-11)
Field: Materials Science — Materials Chemistry

A Novel Lyapunov-Based Nonlinear Controller Design for Model-Based MPPT of the Thermoelectric Generators A novel model-based approach for closed-loop control and maximum power point tracking(MPPT) of thermoelectric generators (TEG) has been presented using the nonlinear Lyapunov-based approach. As the TEG power derivative is always zero at maximum power point (MPP), the TEG power derivative can be employed as a feedback signal for the controller. Hence, the reference value of controller will always be zero which simplifies the controller structure significantly. Since the reference calculation block can be removed, there is no need for a cascade multi-loop controller and for this reason, the controller dynamic response can be improved. Due to the elimination of reference calculation unit, the proposed controller enjoys a superior performance, e.g., during temperature and load changes. The asymptotic stability of proposed controller has been proved. To evaluate the accuracy and efficiency of the proposed approach, it is simulated by using MATLAB software. Moreover, the experimental responses are provided by employing the TMS320F28335 digital signal processor from Texas Instruments. According to the simulation and experimental results and despite temperature and load values changes in a wide range, it is shown that the proposed closed-loop system enjoys a stable and robust performance as well as fast dynamic response and zero steady-state error. Control theory (sociology) ; Controller (irrigation) ; Computer science ; Lyapunov function ; Maximum power point tracking ; Nonlinear system ; Open-loop controller ; MATLAB ; Cascade ; Maximum power principle ; Power (physics) ; Control engineering ; Engineering ; Inverter ; Control (management) ; Closed loop Advanced Thermoelectric Materials and Devices ; Advanced Thermodynamics and Statistical Mechanics ; Energy Harvesting in Wireless Networks
Authors: Nwambu Chidume | GI Chibueze | E. I. Nwankwo | Chilee M. Ekwedigwe
Source: Journal of Civil Engineering and Environmental Sciences (article, 2023-10-17)
Field: Materials Science — Biomaterials

Taguchi analysis of the tensile behaviour of unaged and hygrothermally aged asymmetric helicoidally stacked CFRP composites Taguchi method was used to predict and optimize the effects of hygrothermal aging on the tensile behavior of asymmetric helicoidally stacked Carbon Fiber Reinforced Plastic (CFRP) composites. This research is in furtherance to the previous work, which dealt purely with experiments. MR70 12P carbon fiber epoxy prepreg sheets were manufactured into laminated composites comprising constant inter-ply pitch angles ranging from 0o to 30o. The composites were tested in tension as either dry unaged specimens or following hygrothermal aging in seawater at the constant temperatures of 40 oC and 60 oC for 2000 hrs. Optimizations were conducted based on Taguchi L18 orthogonal array considering two design parameters viz. inter-ply stacking angles and hygrothermal aging temperature. The result depicted that the combination of aging temperature (C) and stacking angles are major factors in determining the tensile behavior of composite materials (p = 0.011). The model explains 86.6% of tensile strength variability, with a predicted R-squared value of 93.04%. The model’s robustness is supported by the adjusted R-squared value of 77.6%. Analysis of variance shows that inter-ply stacking angles are the main significant factor affecting the tensile behaviors at a 95% confidence level. A confirmation test was carried out to validate the optimized results and it was found that there were improvements in S/N ratios from initial to optimal setting. Materials science ; Ultimate tensile strength ; Taguchi methods ; Composite material ; Stacking ; Orthogonal array ; Composite number ; Tensile testing ; Epoxy Calcium Carbonate Crystallization and Inhibition ; Material Selection and Properties ; Mechanical Behavior of Composites
Authors: Changmin Oh | Ji Hyeon Im | Munhyung Bae | Jong‐Wha Jung
Source: ACS Omega (article, 2023-09-26)
Field: Chemistry — Organic Chemistry

Asymmetric Synthesis of Four Stereoisomers of 2,2-Dimethyl-3-hydroxy-4-(1′-angeloyloxy)-6-acetylchromane from <i>Ageratina grandifolia</i> and Plausible Absolute Stereochemistry of the Natural Product 2,2-Dimethyl-3-hydroxy-4-(1'-angeloyloxy)-6-acetylchromane is a natural product isolated from <i>Ageratina grandifolia</i> that exhibits inhibitory activity against yeast α-glucosidase. Initially, its structure was proposed to be 4-hydroxy-3-((<i>S</i>)-1'-angeloyloxy-(<i>R</i>)-2',3'-epoxy-3'-methyl)butylacetophenone with an epoxide, but the structure was later revised to 2,2-dimethyl-3<i>R</i>-hydroxy-4<i>S</i>-(1-angeloyloxy)-6-acetylchromane. In this study, we present a total synthesis of 2,2-dimethyl-3-hydroxy-4-(1'-angeloyloxy)-6-acetylchromane from <i>A. gradifolia</i> and its stereoisomers. The key features of their synthesis include Sharpless asymmetric dihydroxylation of a readily available benzopyran substrate and subsequent Mitsunobu or Steglich reaction to provide both cis- and trans-isomers with chiral control. The absolute stereochemistry of the natural product was determined to be 2,2-dimethyl-3<i>S</i>-hydroxy-4<i>R</i>-(1'-angeloyloxy)-6-acetylchromane based on optical rotations of the synthesized compounds. The absolute configuration of the synthesized stereoisomers was confirmed by Mosher ester analysis. In addition, we provided ECD spectra for the four stereoisomers, which will allow verification of the absolute configuration of the natural product. Synthesis of all four stereoisomers of 2,2-dimethyl-3-hydroxy-4-(1'-angeloyloxy)-6-acetylchromane would facilitate the exploration of their potential biomedical applications. Chemistry ; Stereochemistry ; Absolute configuration ; Natural product ; Epoxide ; Organic chemistry ; Catalysis Chemical synthesis and alkaloids ; Sesquiterpenes and Asteraceae Studies ; Phytochemistry and Biological Activities
Authors: Ary Machado de Azevedo | Juliano Leonel Gonçalves | A. P. Salazar | D. D'O. Cardoso | P. V. Gonzales | V. A. V. Ferreira | W. V. Nunes
Source: Brazilian Journal of Radiation Sciences (article, 2023-04-27)
Field: Materials Science — Materials Chemistry

Radiometric survey with Remotely Piloted Land Vehicle in Chemical, Biological, Radiological and Nuclear Defense operations This article addresses the development of a remotely piloted vehicle for the chemical, biological, radiological, and nuclear army defense system, able itself to perform radiometric surveys remotely favoring the process of local mapping and investigation of possible dispersions of radioactive materials in radiological and nuclear accidents and incidents. Tests were carried out to verify the efficiency of the developed prototype and it can be verified that the vehicle has a great applicability and optimizes the radiological protection process. Radiological weapon ; Radiometric dating ; Environmental science ; Process (computing) ; Nuclear weapon ; Computer science ; Remote sensing ; Radiochemistry ; Geology ; Physics ; Chemistry ; Nuclear physics Graphite, nuclear technology, radiation studies ; Space exploration and regulation ; Nuclear Issues and Defense
Authors: Razieh Ghasemi | E. Rastkhah | S. Naij | T. Rabiee | Hamzeh Hosseinpour | S. Naeij | J. Rafiei | F. Fatemi
Source: Majallah-i ̒ulūm va funūn-i hastah/ī (article, 2023-02-22)
Field: Chemistry — Inorganic Chemistry

Optimization of uranium bioreduction by shewanella RCRI7 using Response Surface Design Method (RSM) in industrial waste تمام ترکیبات اورانیم، سمی و رادیواکتیو هستند. سمی بودن این عنصر می‌تواند کشنده باشد. با توجه به سمیت شیمیایی و رادیواکتیویته اورانیم، ضروری است از ورود آن به طبیعت جلوگیری شود. پسماندهای خروجی از مراکز صنعتی- هسته­ای نیز دارای مقادیر مختلفی از اورانیم می­باشد و لذا حذف این عنصر از پساب این مراکز از اهمیت ویژه­ای برخوردار است. از سویی دیگر، نظر به اهمیت این عنصر و محدودیت منابع آن، بازیابی اورانیم از پسماندها، دارای ارزش اقتصادی نیز می­باشد. در پژوهش حاضر، از روش سطح پاسخ (RSM) بر اساس طرح مرکب مرکزی به منظور بررسی و بهینه­سازی پارامترهای مختلف بر فرایند احیای اورانیم توسط باکتری 7Shewanella RCRI در پساب واقعی استفاده گردید. معادله­ی درجه دوم پیشنهاد شده با ضریب همبستگی 94/0=2R از کفایت مناسبی برخوردار بوده و حداکثر راندمان احیای اورانیم توسط 7Shewanella RCRI در شرایط بهینه (pH=5/6-7/5، دمای 63/26 درجه سانتی­گراد و زمان 117 ساعت)، 98% براورد شده است. در گام بعدی به منظور تعامل بین متغیرها، رویه­های سه­بعدی با تقابل pH و دما; دما و زمان;pH و زمان به دست آمده و در پایان بر اساس بهینه­های پیشنهادی احیای اورانیم در پساب واقعی توسط دو روش XRD و اسپکتروفتومتری مورد بررسی قرار گرفته است. بر اساس نتایج به­دست آمده، باکتری 7Shewanella RCRI می­تواند، به عنوان باکتری با ارزش در احیای زیستی اورانیم از پساب خروجی مراکز صنعتی معرفی گردد. از سوی دیگر استفاده از روش سطح پاسخ می‌توانند درک جامعی از فرایند و مکانیسم احیای زیستی اورانیم توسط باکتری 7Shewanella RCRI و پشتیبانی نظری برای انجام این فرایند ارایه دهد. Response surface methodology ; Uranium ; Chemistry ; Materials science ; Chromatography ; Metallurgy Radioactive element chemistry and processing ; Nuclear Materials and Properties
Authors: Nihat Çelik | Alaaddin Toktaş
Source: Sakarya University Journal of Science (article, 2023-08-02)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Mathematical Modelling of Shear Cutting Process of Grain Oriented Electrical Steels Using Regression Modelling This article proposes a regression model for the shear-cutting process of grain-oriented electrical steel magnetic cores of transformers made from different gages and magnetic properties of steels. In the experimental runs, 3 levels for thickness (230, 270, and 300 µm) and 4 levels for magnetic features of electrical steels are considered. Core steels are supplied as foils and slit to designed lengths in slitting machinery along the rolling direction of coils. The best magnetic features rely on the rolling direction of the coil and the transverse direction of the coil is subject to the shear-cutting process. The result of cutting operations, discontinuities, and degradations in magnetic properties may occur because of deterioration in crystallography and strain gradation on laminated sheets. Shear-cutting process factors have a strong influence on magnetic degradation even the magnitude of the no-load loss of the transformer core. In this study, the mathematical relation between shear cutting factors sheet thickness ST, counts of hits CH, and the response burr length BL is determined using regression modeling. For this purpose, the process parameters of GEORG TBA 400 cut-to-length machinery in use core production is studied. The calculated coefficient of determination is close to almost 1.00 i.e., R2 = 0.9896 which means the factors are sufficient to model the response, and the model is obtained with a good prediction performance. The aim of the present study is building up a useful process control tool for the machinery and raise a discussion alike process in industry. Classification of discontinuities ; Electrical steel ; Shear (geology) ; Electromagnetic coil ; Materials science ; Transformer ; Gradation ; Structural engineering ; Mechanical engineering ; Composite material ; Computer science ; Engineering ; Mathematics ; Electrical engineering ; Voltage ; Mathematical analysis Magnetic Properties and Applications ; Microstructure and Mechanical Properties of Steels ; Metallurgical Processes and Thermodynamics
Authors: Si‐Young Choi | Jinhyuk Jang | Yeongrok Jin | Heung‐Sik Park | Jaegyu Kim | Kyeong Tae Kang | Kyoung‐June Go | Gi‐Yeop Kim | Seungbum Hong | Jun Hee Lee | Daesu Lee | Myung‐Geun Han | Yimei Zhu | Sang‐Wook Cheong | Chan‐Ho Yang | Woo Seok Choi | Jaekwang Lee
Source: Research Square (preprint, 2023-10-18)
Field: Materials Science — Materials Chemistry

Circumscribed ferroelectricity by phonon-decoupled oxygen tetrahedra in brownmillerite oxides Brownmillerite ; Ferroelectricity ; Tetrahedron ; Phonon ; Materials science ; Condensed matter physics ; Oxygen ; Crystallography ; Chemistry ; Optoelectronics ; Physics ; Perovskite (structure) ; Dielectric ; Quantum mechanics Ferroelectric and Piezoelectric Materials ; Multiferroics and related materials ; Electronic and Structural Properties of Oxides
Authors: Rebecca von Hellfeld | Craig Christie | Davina Derous | Juliano Morimoto
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2023-10-31)
Field: Chemistry — Analytical Chemistry

Super food or super toxic? Turmeric and spirulina as culprits for the toxic effects of food dyes in <i>Drosophila</i> Abstract Prolonged exposure to food dyes, even for those considered safe for consumption, are known to have toxic effects. However, we lack a proper understanding of the underlying compounds that are responsible for the observed toxicity. In this study, we tested the toxic physiological effects of three common commercially available natural food dyes (red, green, blue), and their main ingredients (turmeric and spirulina), on Drosophila melanogaster oviposition, larval development, and larval foraging behaviour. Larval development and egg-to-adult survival was significantly impacted by blue and green dyes. These effects were recapitulated when flies were fed with increasing concentrations of turmeric and spirulina, suggesting that turmeric is a toxic component of the food dye. Red dye, which contains neither turmeric or spirulina, had little impact on fly health and behaviour. Green and blue food dyes decreased egg laying, an effect similar to that observed in increasing concentrations of turmeric and, to a lesser extent, spirulina. When given a choice, larvae preferred to feed as follows: control &gt; red &gt; blue &gt; green diet patches, a pattern inversely correlating with the previously observed toxicity. Our results show that, despite turmeric being often considered a super food, it can have toxic effects that the impact organismal physiology and health. Spirulina (dietary supplement) ; Larva ; Biology ; Toxicology ; Toxicity ; Food science ; Functional food ; Food additive ; Botany ; Chemistry ; Ecology Dye analysis and toxicity ; Bee Products Chemical Analysis ; Dyeing and Modifying Textile Fibers
Authors: Heba I. Elkhouly | Mohamad. F. Aly | Ragab K. Abd El-Magied
Source: Journal of Engineering Science and Sustainable Industrial Technology (article, 2023-05-01)
Field: Materials Science — Polymers and Plastics

Optimization of Wear Parameters for Glass Fabric-Epoxy Composites using Response Surface Methodology and Flower Pollination Algorithm The importance of glass fiber-reinforced epoxy lies in its physical and mechanical properties, making it suitable for various manufacturing applications. Additionally, it plays a significant role in enhancing the abrasive wear performance of materials. In this study, a Response Surface Methodology (RSM) was developed to optimize the control variables (including type and weight of filler, normal load, abrasive size, and abrading distance) for glass fabric-epoxy (G-E) composites with different organic (date seed (DS)) and inorganic (silicon carbide (SiC), aluminum oxide (Al2O3) fillers. The samples were prepared using a semi-automatic technique. The analysis of variance (ANOVA) was used to construct an empirical model to demonstrate the relationship between the control factors (filler weight, abrasive) and responses (specific wear rate) in glass fiber-reinforced epoxy. The results of the analysis showed that the filler weight, abrasive size, and their interaction have a significant effect on the specific wear rate. An integrated RSM and Flower Pollination Algorithm (FPA) approach was used to optimize the wear parameters. The results showed that the FPA approach demonstrated good agreement between the predicted and experimental values. Epoxy ; Composite material ; Materials science ; Response surface methodology ; Glass fiber ; Pollination ; Algorithm ; Computer science ; Botany ; Pollen ; Machine learning Textile materials and evaluations ; Industrial Vision Systems and Defect Detection
Authors: Andrzej Pacana | Karolina Czerwińska
Source: Tehnicki vjesnik - Technical Gazette (article, 2023-09-05)
Field: Materials Science — General Materials Science

Universal Model for the Quality Analysis of Aluminium Alloys Castings The production of products in foundry technology is fraught with many problems, including the impossibility of controlling all parameters affecting casting quality. It is important to take effective improvement measures related to the implication of non-destructive testing (NDT), but these methods are rarely combined in the diagnostic cycle. As part of quality assurance, it is also important to identify the root causes of problems. In view of this, it is appropriate to develop a model that facilitates diagnosis and the search for the key causes of nonconformity, which would be a combination of NDT and quality management methods. The originality of the model presented in the study is reflected in the combination of NDT and quality management methods. The model presents a universal method that can be implemented in foundries to ensure the stability of production processes. The application of the model brings tangible benefits in the form of an increase in the speed of detection and a reduction in non-conformities in aluminium castings, which significantly increases the quality level of the products offered. Further research directions will address the application of the model within foundry processes characterised by loss of quality stability. Aluminium ; Metallurgy ; Materials science ; Quality (philosophy) ; Physics Material Properties and Applications ; Diverse Industrial Engineering Technologies ; Metallurgical Processes and Thermodynamics
Authors: Razieh Khajehyar | Milad Vahidi | Robert R. Tripepi
Source: Research Square (preprint, 2023-09-07)
Field: Chemistry — Analytical Chemistry

Using Hyperspectral Signatures for Predicting Foliar Nitrogen and Calcium Content of Tissue Cultured Little-leaf Mockorange (Philadelphus microphyllus A. Gray) Shoots <title>Abstract</title> Determining foliar mineral status of tissue cultured shoots can be costly and time consuming, yet hyperspectral signatures might be useful for determining mineral contents of these shoots. In this study, hyperspectral signatures were acquired from tissue cultured little-leaf mockorange (<italic>Philadelphus microphillus</italic>) shoots to determine the feasibility of using this technology to predict foliar nitrogen and calcium contents. After using a spectroradiometer to take hyperspectral images for determining foliar N and Ca contents, the correlation between the hyperspectral bands, vegetation indices, and hyperspectral features were calculated from the spectra. Features with high correlations were selected to develop the models via different regression methods including linear, random forest (RF), and support vector machines. The results showed that non-linear regression models developed through machine learning techniques, including RF methods and support vector machines provided satisfactory prediction models with high R<sup>2</sup> values (%N by RF with R<sup>2</sup> = 0.72, and %Ca by RF with R<sup>2</sup> = 0.99), that can estimate nitrogen and calcium content of little-leaf mockorange shoots grown in vitro. Overall, the RF regression method provided the most accurate and satisfactory models for both foliar N and Ca estimation of little-leaf mockorange shoots grown in tissue culture. Hyperspectral imaging ; Shoot ; Nitrogen ; Spectroradiometer ; Linear regression ; Support vector machine ; Horticulture ; Mathematics ; Random forest ; Botany ; Chemistry ; Agronomy ; Biology ; Artificial intelligence ; Computer science ; Reflectivity ; Statistics ; Physics ; Optics Spectroscopy and Chemometric Analyses ; Leaf Properties and Growth Measurement ; Remote Sensing in Agriculture
Authors: Arun S. Moorthy | Edward P. Erisman | Anthony J. Kearsley | Yuxue Liang | Edward Sisco | W.E. Wallace
Source: ChemRxiv (preprint, 2023-05-09)
Field: Chemistry — Spectroscopy

On the challenge of unambiguous identification of fentanyl analogs: exploring measurement diversity using standard reference mass spectral libraries Fentanyl analogs are a class of designer drugs that are particularly challenging to unambiguously identify due to the mass spectral and retention time similarities of unique compounds. In this paper, we use agglomerative hierarchical clustering to explore the measurement diversity of fentanyl analogs and better understand the challenge of unambiguous identifications using analytical techniques traditionally available to drug chemists. We consider four measurements in particular: gas chromatography retention indices, electron ionization mass spectra, electrospray ionization tandem mass spectra and direct analysis in real time mass spectra. Our analysis demonstrates how simultaneously considering data from multiple measurement techniques increases the observable measurement diversity of fentanyl analogs, which can reduce identification ambiguity. This paper further supports the use of multiple analytical techniques to identify fentanyl analogs (among other substances), as is recommended by the Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG). Fentanyl ; Identification (biology) ; Mass spectrum ; Electrospray ionization ; Hierarchical clustering ; Ionization ; Mass spectrometry ; Chemistry ; Tandem mass spectrometry ; Computer science ; Analytical Chemistry (journal) ; Cluster analysis ; Chromatography ; Artificial intelligence ; Pharmacology ; Biology Mass Spectrometry Techniques and Applications ; Analytical Chemistry and Chromatography ; Forensic Toxicology and Drug Analysis
Authors: Mohd Rashidi Abdull Manap | Ahmad Fadly Jusoh | Lim Xiang Chuin | Nur Diana Farhana Muhamad Zulkifli | Qhurratul Aina Kholili | Fatin Abu Hasan | Danish Aiman Akmal Mohd Effendy | Ramizah Azis
Source: Indonesian Journal of Chemistry (article, 2023-10-16)
Field: Chemistry — Analytical Chemistry

Discrimination of Biodiesel-Diesel of B7 and B10 by Infrared Spectroscopy with Dendogram Spectroscopists face an ongoing challenge in identifying fuel spectra due to a wide range of fuel formulations and the increasing abuse of biodiesel-diesel blends. In Malaysia, a new type of biodiesel-diesel blend known as B7 and B10 has been introduced, which requires rapid and reliable discrimination methods. However, current identification methods are costly and time-consuming. To overcome this issue, a spectroscopy study was conducted using a portable Fourier transform infrared (FTIR) spectrometer to identify biodiesel-diesel blends. The study found that direct identification using spectral libraries was reliable in identifying complex samples but unable to differentiate B7 and B10 due to the libraries' focus on hydrocarbons rather than esters. Instead, FTIR spectroscopy provided unique spectral peaks for each blend. Spectral range influences the discrimination, and the truncated region 1697–1777 and 1164–1224 cm−1 was shown to be reliable for discriminating the B7 and B10. The study concluded that a combination of algorithms, libraries, and hierarchical cluster analysis (HCA) in FTIR spectroscopy could effectively differentiate the blends. The primary objective was to differentiate B7 and B10 by analyzing liquid samples collected in Malaysia using HCA and IR spectroscopies. FTIR spectroscopy provides molecular-specific vibrational signals and is proven as a rapid identification method. Diesel fuel ; Fourier transform infrared spectroscopy ; Biodiesel ; Spectroscopy ; Chemistry ; Infrared spectroscopy ; Analytical Chemistry (journal) ; Fourier transform ; Identification (biology) ; Chromatography ; Chemical engineering ; Organic chemistry ; Physics ; Catalysis ; Engineering ; Botany Spectroscopy and Chemometric Analyses ; Biodiesel Production and Applications ; Spectroscopy Techniques in Biomedical and Chemical Research