jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ayana Ghosh | Palanichamy Gayathri | Monirul Shaikh | Saurabh Ghosh
Source: Journal of Physics Materials (article, 2024-04-01)
Field: Materials Science — Materials Chemistry

Structural mode coupling in perovskite oxides using hypothesis-driven active learning Abstract Finding the ground-state structure with minimum energy is paramount to designing any material. In ABO 3 -type perovskite oxides with Pnma symmetry, the lowest energy phase is driven by an inherent trilinear coupling between the two primary order parameters such as rotation and tilt with antiferroelectric displacement of the A-site cations as established via hybrid improper ferroelectric mechanism. Conventionally, finding the relevant mode coupling driving phase transition requires performing first-principles calculations which is computationally time-consuming as well as expensive. It involves following an intuitive iterative hit and trial method of (a) adding two or multiple mode vectors, followed by (b) evaluating which combination would lead to the ground-state energy. In this study, we show how a hypothesis-driven active learning framework can identify suitable mode couplings within the Landau free energy expansion with minimal information on amplitudes of modes for a series of double perovskite oxides with A-site layered, columnar and rocksalt ordering. This scheme is expected to be applicable universally for understanding atomistic mechanisms derived from various structural mode couplings behind functionalities, for e.g. polarization, magnetization and metal–insulator transitions. Ferroelectricity ; Perovskite (structure) ; Antiferroelectricity ; Polarization (electrochemistry) ; Ground state ; Materials science ; Coupling (piping) ; Phase transition ; Condensed matter physics ; Computer science ; Physics ; Dielectric ; Chemistry ; Optoelectronics ; Crystallography ; Quantum mechanics ; Physical chemistry Ferroelectric and Piezoelectric Materials ; Perovskite Materials and Applications ; Electronic and Structural Properties of Oxides
Authors: Sijun Wu | Y. Yang | Wang Li | Chaoliang Jia | Zhong Zhen Guan | Haiyang Chen | Yadong Zhu | Wenlong Li
Source: Journal of Drug Delivery Science and Technology (article, 2024-11-19)
Field: Materials Science — Materials Chemistry

Prediction of drug dissolution from sustained-release pellet by a portable near-infrared spectrometer Pellet ; Spectrometer ; Dissolution ; Materials science ; Infrared ; Drug ; Analytical Chemistry (journal) ; Nanotechnology ; Chemical engineering ; Chromatography ; Chemistry ; Optics ; Composite material ; Medicine ; Pharmacology ; Engineering ; Physics Crystallization and Solubility Studies ; Drug Solubulity and Delivery Systems ; Analytical Chemistry and Chromatography
Authors: Yifei Yue | Athulya S. Palakkal | Saad Aldin Mohamed | Jianwen Jiang
Source: ACS Applied Materials & Interfaces (article, 2024-10-21)
Field: Chemistry — Inorganic Chemistry

Accelerating Discovery of Mechanically Stable Metal–Organic Frameworks for Vinylidene Fluoride Storage by Active Learning Metal-organic frameworks (MOFs) are versatile nanoporous materials for a wide variety of important applications. Recently, a handful of MOFs have been explored for the storage of toxic fluorinated gases (Keasler et al. <i>Science,</i> <b>2023,</b> <i>381,</i> 1455), yet the potential of a great number of MOFs for such an environmentally sustainable application has not been thoroughly investigated. In this work, we apply active learning (AL) to accelerate the discovery of hypothetical MOFs (hMOFs) that can efficiently store a specific fluorinated gas, namely, vinylidene fluoride (VDF). First, a force field was developed for VDF and utilized to predict the working capacities (<b>Δ<i>N</i></b>) of VDF in an initial data set of 4502 MOFs from the computation-ready experimental MOF (CoRE-MOF) database that successfully underwent featurization and grand-canonical Monte Carlo simulations. Next, the initial data set was diversified by Greedy sampling in an unexplored sample space of 119,387 hMOFs from the ab initio REPEAT charge MOF (ARC-MOF) database. A budget of 10,000 samples (i.e., <10% of total ARC-MOFs) was selected to train a random forest model. Then, <b>Δ<i>N</i></b> in the unlabeled ARC-MOFs were predicted and top-performing ones were validated by simulations. Integrating with the stability requirement, mechanically stable ARC-MOFs were finally identified, along with high <b>Δ<i>N</i></b>. Furthermore, by Pareto-Frontier analysis, we revealed that long linear linkers can enhance <b>Δ<i>N</i></b>, while bulkier multiphenyl linkers or interpenetrated frameworks improve mechanical strength. From this work, we efficiently discover top-performing MOFs for VDF storage by AL and also demonstrate the importance of integrating stability to identify stable promising MOFs for a practical application. Nanoporous ; Metal-organic framework ; Materials science ; Nanotechnology ; Organic chemistry ; Chemistry Metal-Organic Frameworks: Synthesis and Applications ; Machine Learning in Materials Science ; Corrosion Behavior and Inhibition
Authors: A. Landa | Per Söderlind | Emily E. Moore | Aurélien Perron
Source: Metals (article, 2024-01-03)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Thermodynamics and Magnetism of SmFe12 Compound Doped with Zr, Ce, Co and Ni: An Ab Initio Study Alloys that are Ni-doped, such as the (Sm1−yZry)(Fe1−xCox)12 and (Ce0.5Sm0.5)Fe10Co2 systems, are studied because of their magnetic properties. The (Sm1−yZry)(Fe1−xCox)11−zTiz and (Ce.1−xSmx)Fe9Co2Ti alloys are considered contenders for vastly effective permanent magnets because of their anisotropy field and Curie temperature. Ti can act as a stabilizer for the SmFe12 compound but substantially suppresses saturation magnetization. To maintain the saturation magnetization in the scope of 1.3–1.5 T, we propose substituting a particular quantity of Fe and Co in the (Sm1−yZry)(Fe1−xCox)12 and (Ce0.5Sm0.5)Fe10Co2 alloys with Ni. By performing ab initio calculations, we show that Ni incorporation results in increased thermodynamic stability and, in contrast to Ti, has a parallel spin moment aligned to the moment of the SmFe12 compound and improves its saturation magnetization without affecting the anisotropy field or Curie temperature. Curie temperature ; Magnetism ; Condensed matter physics ; Magnetization ; Materials science ; Ab initio quantum chemistry methods ; Saturation (graph theory) ; Anisotropy ; Magnetic moment ; Ab initio ; Magnetic anisotropy ; Doping ; Curie ; Ferromagnetism ; Chemistry ; Magnetic field ; Physics Magnetic Properties of Alloys ; Magnetic Properties and Applications ; Magnetic properties of thin films
Authors: Ernst Gamsjäger | Manfred Wießner
Source: Entropy (article, 2024-05-26)
Field: Chemistry — Physical and Theoretical Chemistry

Extended Regression Analysis for Debye–Einstein Models Describing Low Temperature Heat Capacity Data of Solids Heat capacity data of many crystalline solids can be described in a physically sound manner by Debye-Einstein integrals in the temperature range from 0K to 300K. The parameters of the Debye-Einstein approach are either obtained by a Markov chain Monte Carlo (MCMC) global optimization method or by a Levenberg-Marquardt (LM) local optimization routine. In the case of the MCMC approach the model parameters and the coefficients of a function describing the residuals of the measurement points are simultaneously optimized. Thereby, the Bayesian credible interval for the heat capacity function is obtained. Although both regression tools (LM and MCMC) are completely different approaches, not only the values of the Debye-Einstein parameters, but also their standard errors appear to be similar. The calculated model parameters and their associated standard errors are then used to derive the enthalpy, entropy and Gibbs energy as functions of temperature. By direct insertion of the MCMC parameters of all 4·105 computer runs the distributions of the integral quantities enthalpy, entropy and Gibbs energy are determined. Markov chain Monte Carlo ; Heat capacity ; Debye ; Enthalpy ; Debye function ; Thermodynamics ; Statistical physics ; Monte Carlo method ; Gibbs free energy ; Gibbs sampling ; Entropy (arrow of time) ; Physics ; Mathematics ; Bayesian probability ; Statistics ; Debye length ; Quantum mechanics thermodynamics and calorimetric analyses ; Chemical Thermodynamics and Molecular Structure ; Thermodynamic and Structural Properties of Metals and Alloys
Authors: Jean‐François Liégeois | Jean-Luc Hayen | Hossein Taouba
Source: Journal of Chemical Education (article, 2024-11-29)
Field: Chemistry — Physical and Theoretical Chemistry

Solubility and Extractability in the Pharmaceutical Sciences: A Demonstration to Address These Essential Concepts Understanding the solubility and extractability of organic compounds plays a crucial role in the pharmaceutical and biomedical fields. It is essential to learn these concepts early in the course curriculum. The aim of this demonstration is to help students understand the basic principles of solubility and extractability in a practical, interactive, and interesting way. This is accomplished with the help of a series of simple experiments in which common reagents and molecules will be used. The demonstration covers three main topics. The first part is designed to explain the intrinsic solubility in water. This solubility will depend on a number of properties, including their ratio of polar/nonpolar groups and their ability to form hydrogen bonds. The second part investigates potential ionization in water using results obtained from conductimetry experiments. The third part is related to the concept of extractability by presenting the results obtained for pH-dependent extractions of representative compounds from an aqueous medium with an organic medium. A quantification of the extracted compound at each pH is performed after the evaporation of the organic solvent. Extractability curves are then drawn, using the weights obtained after evaporation and discussed. Solubility ; Chemistry ; Solvent ; Evaporation ; Reagent ; Aqueous solution ; Organic chemistry ; Thermodynamics ; Physics Various Chemistry Research Topics ; Innovative Teaching Methods ; Engineering Education and Pedagogy
Authors: Brenda B. Harmon | Deepika Das | Annette W. Neuman | Simbarashe Nkomo | Nichole L. Powell | Austin B. Scharf
Source: Journal of Chemical Education (article, 2024-05-08)
Field: Chemistry — Physical and Theoretical Chemistry

Cultivating a Meaningful Application of IMFs through Backward Laboratory Course Design This paper describes the development of a first- and second-year inquiry-based laboratory course focused on the development of a meaningful application of intermolecular forces (IMFs). Instead of broad expository coverage of topics, we used backward design: the techniques and concepts for the course were structured around what students are expected to be able to do at the end-individually isolate caffeine from a consumer product as a culminating lab practical, using IMFs to justify solvent choices and determining procedural details. We have found that instructors can select a challenging multilevel experiment that incorporates the application of IMFs in multiple ways and backward design the course so that students are able to complete this experiment individually and autonomously at the end of the semester. By incorporating evidence-based pedagogies to foster meaningful learning and repetition of techniques and IMF concepts in different contexts, we promoted opportunities to learn from mistakes and prioritized student decision making. This approach involved faculty collaboration and spanned several semesters of iteration. In our experience, a cumulative lab practical motivates students to learn the techniques and take responsibility for learning. We propose that the backward design process with a central theme, such as the application of IMFs in our case, is especially well suited to planning a chemistry laboratory course. However, even with an entire laboratory course centered around applications of this critical concept, we discovered there were still gaps in students' abilities to apply IMFs. Course (navigation) ; Mathematics education ; Computer science ; Engineering ; Psychology Various Chemistry Research Topics ; Experimental Learning in Engineering ; Innovative Teaching Methods
Authors: Miha Slapničar | Luka Ribič | Iztok Devetak | Luka Vinko
Source: Center for Educational Policy Studies Journal (article, 2024-03-29)
Field: Chemistry — Physical and Theoretical Chemistry

Inquiry-Based Chemistry Education Activities in a Non-formal Educational Setting for Gifted Students Student giftedness is a complex, developmentally dynamic and contextual phenomenon that teachers confront every day. In the classroom, teachers often meet students who have exceptional potential or achieve very high learning goals. The aim of this study is to illustrate the evaluation of inquiry-based learning activities in a specific context (Diversity in Science towards Social Inclusion learning modules) implemented in a non-formal educational setting for gifted students in relation to their level of individual interest and their autonomous and controlled motivation, comparing different groups of students. We investigate how these activities affect the students’ attitudes towards inquiry-based learning, their situational interest and their interest in science careers. A total of 264 Slovenian lower secondary school students participated in the study. The students participated in non-adapted and adapted activities based on the inquiry-based learning approach. The data were collected using pre- and post-activity questionnaires. Participation in the study, which took place in the period between the 2021/22 and the 2022/23 school years, was voluntary. The data was collected anonymously and used for research purposes only. The results show several statistically significant differences in how students’ level of individual interest, au-tonomous motivation and controlled motivation for learning chemistry affects their attitudes towards inquiry-based learning, their situational interest in Diversity in Science towards Social Inclusion activities and their interest in science careers. For the gifted and non-gifted students who participated in “Forensics Science” lab activities before and after the adaptations to the modules, the results related to their attitudes towards inquiry-based learning and situational interest are also reported. Thus, the results of the study provide useful insights for researchers in the field of chemistry education as well as for chemistry teachers in lower and upper secondary schools. The presented study is a good example of best practices that chemistry teachers can apply in teaching chemistry, thus enabling all students, not only the gifted ones, to learn chemistry using the inquiry-based learning approach. Mathematics education ; Chemistry education ; Gifted education ; Chemistry ; Pedagogy ; Psychology ; Medical education ; Medicine Various Chemistry Research Topics ; Problem and Project Based Learning ; Science Education and Pedagogy
Authors: Laura Castañeda Gómez | Jianjun Wang | Javier Pérez‐Burillo | Virpi Pajunen | Mika Sillanpää | Janne Soininen
Source: Freshwater Biology (article, 2024-06-22)
Field: Materials Science — Biomaterials

Strong and weak trait–environment associations in subarctic stream diatoms Abstract Ecological traits are functional characteristics measurable at the species level and provide valuable insights into how organisms respond to environmental constraints. Here, we investigated how diatom trait‐groups and individual species respond to environmental variables, and identified indicator species that are particularly sensitive to environmental variation. Diatoms were sampled at 129 sites in the subarctic streams of Norwegian islands and mainland, and were categorised into three trait groups: high‐profile species that live in an erect position, low‐profile species living in low position along the surface, and motile diatoms. Data were analysed using a recently developed method known as Hierarchical Modelling of Species Communities, which is a flexible framework for joint species distribution modelling. We found that diatom trait‐groups responded relatively weakly to measured environmental variables but showed positive or negative relationships with major ion levels of the water (e.g., conductivity, calcium [Ca 2+ ], sodium [Na + ] or chlorine [Cl − ]). Variance partitioning showed a similar, important contribution of the chemical variables for all of the trait groups, while the contributions of physical variables and especially random (spatial) factors were notably lower for all trait groups. Our findings also highlighted considerable among‐species variation in their relation to environmental variables within the trait groups. Notably, we identified a high number of indicator species within each trait group that were explained by specific environmental factors, mostly chemical variables (conductivity, pH, total nitrogen and phosphorus, Ca 2+ , Na + , Cl − ). Our study suggests that certain diatom species can be considered as useful environmental indicators but the variability in species preferences within the trait group may in some circumstances hamper the use of ecological traits in environmental assessments. Thus, we suggest using species‐level ecology combined with trait information to better track environmental change when using diatoms as indicators. Subarctic climate ; Trait ; Ecology ; Diatom ; Biology ; Environmental science ; Geography Diatoms and Algae Research ; Aquatic Ecosystems and Phytoplankton Dynamics ; Freshwater macroinvertebrate diversity and ecology
Authors: Ana Cano-Ortíz | José Carlos Piñar Fuentes | Eusébio Cano
Source: Research Journal of Ecology and Environmental Sciences (article, 2024-03-08)
Field: Chemistry — Analytical Chemistry

Analysis of Toxic Contaminants in Agriculture: Educational Strategies to Avoid Their Influence on Food A diagnosis of the current state of the crops is made regarding the control of weeds, use of pesticides, fungicides; with an assessment of the state of the plant covers in the crop, and its control by different types of herbicides, and we detected a high loss of biological diversity; and some of these compounds are mentioned due to their high toxicity. Similarly, the use of pesticides and fungicides is discussed due to their repercussions on health. In order to avoid the unhealthiness caused by the applications of these products, phytosanitary and educational control strategies are proposed; promoting the inspection of fruit and vegetable markets, and modifying the contents in higher professional and university education. To this end, we propose an active teaching methodology, through which the student acquires skills and responsibility for the use of chemical agents in agriculture, which serves to prevent the entry of these contaminants into the food chain. Of the different polluting chemical agents, in the case of herbicides we highlight Oxyfluorfen and Glyphosate with high toxicity and whose consumption is very high. In the case of pesticides and fungicides, among others are Organochlorine compounds, which have been detected in blood, and Carbon Tetrachloride and Chloroform, considered potent hepatotoxic and neurotoxic. The basic objective of this study is the awareness and acquisition of knowledge by future teachers about polluting agents, which will subsequently have an impact on society. Contamination ; Agriculture ; Environmental science ; Business ; Biology ; Ecology Dye analysis and toxicity
Authors: Felix Buthmann | Philip Laby | Djamal Hamza | Jörg Koop | Gerhard Schembecker
Source: Separations (article, 2024-02-10)
Field: Chemistry — Analytical Chemistry

Spatially and Temporally Resolved Analysis of Bleeding in a Centrifugal Partition Chromatography Rotor Centrifugal Partition Chromatography (CPC) is a separation technique that utilizes immiscible liquid phases to purify compounds. The selection of solvents in Liquid–Liquid Chromatography offers flexibility and optimization possibilities for specific separation tasks. Understanding the hydrodynamics inside the apparatus is crucial for optimizing a CPC process. The phase retention ratio (Sf) determines the apparatus’s operating point and separation efficiency. However, stationary phase leakage, known as bleeding, complicates the immobilization of this phase. We used a partly transparent single-disc rotor to investigate the time and space dependency of bleeding inside a CPC apparatus, enabling real-time and localized determination of the phase retention ratio. By tracking the retention values over time, we observed the bleeding phenomenon and its progression from the inlet to the rotor outlet. Depending on the phase system used, the CPC was utilizable for a separation task for only 173–500 dimensionless residence times. Systems with a higher stability parameter (as described in the literature) showed a lower bleeding rate and increased stability over time. Accordingly, our results demonstrate the importance of maintaining an optimal ratio of mobile to stationary phase for efficient separation. Partition (number theory) ; Rotor (electric) ; Chemistry ; Chromatography ; Physics ; Mathematics ; Combinatorics Chromatography in Natural Products ; Phytochemistry and biological activity of medicinal plants ; Phytochemical Studies and Bioactivities
Authors: Kevin J. Hughes | Kavita A. Iyer | Robert E. Bird | Julian Ivanov | Saswata Banerjee | Gilles Georges | Qiongqiong Angela Zhou
Source: ChemRxiv (preprint, 2024-04-01)
Field: Materials Science — Materials Chemistry

Trends in carbon nanotube research and development: Alandscape view of emerging applications and materials Developing new materials for biomedical applications represents a dynamic and fast-growing interdisciplinary field of research. In this study, six emerging areas were identified in nanoscale materials in the context of biomedical applications by leveraging big data from the CAS Content Collection using quantitative analysis based on natural language processing (NLP). These emerging areas in biomaterials include self-healing, bioelectronic, programmable, lipid-based, protein-based, and antibacterial materials. In this perspective, we will examine the use of nanoscale materials in these areas. These uses range from enhancing the physical and electronic properties of materials used to interface with human tissue, to executing complex functions such as programmable drug delivery. Carbon nanotube ; Nanotechnology ; Research development ; Materials science ; Ecology ; Biology Carbon Nanotubes in Composites ; Nanotechnology research and applications