jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Hilliary O. Frank | Francesco Paesani
Source: ChemRxiv (preprint, 2023-12-15)
Field: Chemistry — Inorganic Chemistry

Molecular driving forces for water adsorption in MOF-808: A comparative analysis with UiO-66 Metal-organic frameworks (MOFs), with their unique porous structures and versatile functionality, have emerged as promising materials for adsorption, separation, and storage of diverse molecular species. In this study, we investigate water adsorption in MOF-808, a prototypical MOF that shares the same secondary building unit (SBU) as UiO-66, and elucidate how differences in topology and connectivity between the two MOFs influence the adsorption mechanism. To this end, molecular dynamics (MD) simulations were performed to calculate several thermodynamic and dynam- ical properties of water in MOF-808 as a function of relative humidity (RH), from the initial adsorption step to full pore filling. At low RH, the μ3-OH groups of the SBUs form hydrogen bonds with the initial water molecules entering the pores, which triggers the filling of these pores before the μ3-OH groups in other pores become en- gaged in hydrogen bonding with water molecules. Our analyses indicate that the pores of MOF-808 become filled by water sequentially as the RH increases. A similar mechanism has been reported for water adsorption in UiO-66, a MOF that shares the same SBU with MOF-808. Despite this similarity, our study highlights distinct ther- modynamic properties and framework characteristics that influence the adsorption process differently in MOF-808 and UiO-66. Adsorption ; Hydrogen bond ; SBus ; Metal-organic framework ; Molecule ; Chemistry ; Porosity ; Chemical engineering ; Molecular dynamics ; Chemical physics ; Topology (electrical circuits) ; Nanotechnology ; Materials science ; Computational chemistry ; Physical chemistry ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; X-ray Diffraction in Crystallography ; Machine Learning in Materials Science
Authors: Mohamed El-Sayed Gaafar | S.Y. Marzouk
Source: Journal of the Mechanical Behavior of Materials (article, 2023-01-01)
Field: Materials Science — Ceramics and Composites

Low-temperature relaxation of various samarium phosphate glasses Abstract Glasses constructed, (1 − x ) (0.6595P 2 O 5 –0.0958ZnO–0.2447PbO) · x Sm 2 O 3 with x = 0.00, 0.0045, 0.0089, 0.0132, and 0.0261 mol%, had been created to investigate the attenuation of longitudinal ultrasonic waves at 2, 4, 6, and 14 MHz frequencies between 120 and 300 K. At a variety of temperatures, clear peaks of a large absorption curve have been seen. These peaks are dependent on the structure of the glass as well as the switching frequency. Maximum peaks have been shown to shift to higher temperatures, and the increase in overall frequency points to the presence of some kind of relaxation process. A thermally induced relaxation process is responsible for producing a calm approach, which has been identified as a result of this mechanism. A quiet approach has been defined as a consequence of a thermally triggered relaxation mechanism. The variance of the mean energy of activation of the mechanism counts on primarily the amount of Sm 2 O 3 mol%. Such dependency has been evaluated based on the loss of normal linear solid form, attaining low dispersion, and a large allocation of Arrhenius kind relaxation through temperature-autonomous relaxation power. The measured acoustical energy of activation values have been quantifiably represented based on the number of loss centers (amount of oxygen atoms that now move at a double-well potential). Activation energy ; Relaxation (psychology) ; Arrhenius equation ; Materials science ; Samarium ; Attenuation ; Dispersion (optics) ; Thermodynamics ; Power law ; Absorption (acoustics) ; Nuclear magnetic resonance ; Analytical Chemistry (journal) ; Chemistry ; Optics ; Composite material ; Mathematics ; Physical chemistry ; Physics Glass properties and applications ; Material Dynamics and Properties ; Solid-state spectroscopy and crystallography
Authors: Bolaji C. Dayo Owoyemi | Cecília C. P. da Silva | Amos Olalekan Akinyemi | Banky O. Amuwaolorun | Roxana Lili Roque-Flores | Gabriel Lima Barros de Araújo | Javier Ellena | Renato Lajarim Carneiro
Source: Scientific African (article, 2023-12-20)
Field: Chemistry — Physical and Theoretical Chemistry

Controlled synthesis and structure characterization of a new fluconazole polymorph using analytical techniques and multivariate method In the crystallization and search for higher multicomponent forms of fluconazole (FLZ), a metastable FLZ polymorph (concomitant) that manifests in the same crystallization system and transforms into the stable FLZ form (II) after the lyophilization process was observed. In this report, we demonstrated and showed how this FLZ polymorph 10 (Mw = 306.79 g/mol) of the monoclinic C2 space group was detected and reproduced through a controlled lyophilized experiment, and modeled differentiation between vibrational and absorption modes of FLZ functionalities like C=O, OH, –CH2 and –NH. The FLZ polymorph shows strong O–H···N and weak C−H···X (X = N, and F) hydrogen bond and the presence of pi-pi bond interactions in the overlapping triazole rings. The combination of vibrational spectroscopic techniques (Raman/FT-IR) and principal component analysis (PCA) aid the development of important models for polymorph screening and identification. In addition, X-ray diffraction (powder and single crystal) techniques support the polymorph characterization and structure depiction. The PCA models and X-ray diffraction analyses confirmed the newness of FLZ polymorph 10, and further solid-state characterization using thermal techniques (DSC and TGA) affirmed its uniqueness and novelty. Finally, the thermal stability and solubility studies on the new FLZ polymorph were determined to understand its structure properties and compare these with previously reported polymorphs of FLZ. Crystallography ; Raman spectroscopy ; Monoclinic crystal system ; Chemistry ; Crystallization ; Hydrogen bond ; Polymorphism (computer science) ; Powder diffraction ; Infrared spectroscopy ; Crystal structure ; Materials science ; Molecule ; Organic chemistry Crystallography and molecular interactions ; Drug Solubulity and Delivery Systems ; Antimicrobial agents and applications
Authors: Jie Du | Min Zhang | Liqing Qiu | Arun S. Mujumdar | Yamei Ma
Source: Food Safety and Health (article, 2023-07-01)
Field: Materials Science — Biomaterials

Novel technologies for improving quality of tofu products and their packaging: A critical overview Abstract There are many kinds of tofu products, and they are mainly found in Asia. This paper mainly summarizes and classifies the tofu products of different countries through the analysis of the characteristics of different products and the differences between them. The storage conditions for most bean products are typically harsh, resulting in the shelf life of some fresh beans limited to 3–5 days. The new packaging technology avoids the shortcomings of traditional packaging, which makes it more effective to store. In this paper, biodegradable packaging materials, nanomaterials, active packaging, and intelligent packaging were reviewed. The significance of this review is to introduce various types of tofu products to gain a more comprehensive understanding of their advantages and disadvantages and to apply different packaging techniques to improve the preservation environment of tofu products. The purpose is to find suitable packaging technology, materials, and development route of tofu products. Active packaging ; Packaging engineering ; Shelf life ; Quality (philosophy) ; Computer science ; Food packaging ; Biochemical engineering ; Business ; Food science ; Engineering ; Chemistry ; Marketing Nanocomposite Films for Food Packaging ; Food composition and properties ; Postharvest Quality and Shelf Life Management
Authors: Tong Yang | Ke Yang | Tao Zhu | Ting Song | Tian Bao | Jun Zhou | Shijie Wang | Yunjiang Jin | Martin Callsen | Ming Yang
Source: The Journal of Physical Chemistry C (article, 2023-03-14)
Field: Materials Science — Materials Chemistry

Structural Reconstruction Modulated Physical Properties of Titanium Oxide at the Monolayer Limit To suppress surface dangling bonds, monolayer oxides derived from non-layered bulks usually undergo a pronounced structural reconstruction. It remains challenging to resolve these structural reconstructions and the induced distinct modulation of intrinsic properties. In this study, the structural reconstruction-modulated electronic, polaronic, and exitonic properties of a non-layered oxide at the monolayer limit are unraveled. Based on first-principles calculations and tight-binding simulations for a stable titanium dioxide (TiO2) monolayer, we show that its distinct surface Kagome sublattices host a topologically nontrivial flat band at the valence band edge. The strong electron–hole interaction in this monolayer oxide gives rise to a large exciton binding energy of around 2.49 eV. Interestingly, the monolayer TiO2 also exhibits strong electron–lattice coupling, which favors the formation of small electron polarons and thus greatly reduces its band gap energy into the visible light range. This work could be useful to understand the structural reconstruction-induced modulation of exotic physical and chemical properties for a broad range of non-layered oxides at the monolayer limit. Monolayer ; Materials science ; Polaron ; Chemical physics ; Band gap ; Exciton ; Condensed matter physics ; Dangling bond ; Oxide ; Electronic band structure ; Electron ; Molecular physics ; Nanotechnology ; Chemistry ; Silicon ; Physics ; Optoelectronics Electronic and Structural Properties of Oxides ; 2D Materials and Applications ; Perovskite Materials and Applications
Authors: Kelsey Horace-Herron | Naren Vikram Raj Masna | Peyman Dehghanzadeh | Soumyajit Mandal | Swarup Bhunia
Source: Scientific Reports (article, 2023-04-04)
Field: Chemistry — Physical and Theoretical Chemistry

Non-invasive authentication of mail packages using nuclear quadrupole resonance spectroscopy Abstract The international postal network is one of the most widely used methods for correspondence throughout the world. Most postal traffic across the globe consists of legitimate interpersonal, business-consumer, and business-business communications. However, the global postal system is also utilized for criminal activity. In particular, it is often utilized to ship and distribute contraband, including illegal psychoactive drugs such as fentanyl and heroin, to consumers. Existing technological solutions are capable of identifying synthetic opioids and other illegal drugs within packages, but are accompanied by several disadvantages that make them unsuitable for large-scale authentication of international mail traffic. This paper presents a novel method for non-invasive authentication of mail packages that overcomes these challenges. The approach uses nuclear quadrupole resonance (NQR) spectroscopy to detect and quantify the presence of known active pharmaceutical ingredients (APIs) within the package. It has been experimentally demonstrated using a bench top prototype. Test results from a variety of package types demonstrate the effectiveness of the proposed authentication approach. Authentication (law) ; Computer security ; Variety (cybernetics) ; Computer science ; Internet privacy ; Artificial intelligence Crystallography and molecular interactions ; Mass Spectrometry Techniques and Applications ; Molecular Sensors and Ion Detection
Authors: Ulrike Demmer | Olivier N. Lemaire | Mélissa Belhamri | Ulrich Ermler
Source: Crystals (article, 2023-10-19)
Field: Materials Science — Materials Chemistry

Ethoxylate Polymer-Based 96-Well Screen for Protein Crystallization Crystallization is the limiting step in X-ray structure determination of biological macromolecules. As crystallization experiments can be largely automatized, the diversity of precipitant solutions is often the determinant factor to obtain crystals of high quality. Here, we introduce a 96-well screening kit of crystallization conditions, centered on three ethoxylate-based organic polymers as precipitants and various additional compounds to promote crystal formation. This crystallization screen was tested on various non-standard proteins from bacteria and archaea. Structure determination succeeded for seven out of thirteen targets based on crystals that frequently diffracted to a higher resolution than those obtained with commercially available screening kits. Crystallization hits were rarely similar among the three ethoxylate-based organic polymers and, in comparison, with already available crystallization screens. Hence, the presented crystallization screen is an efficient tool to complement other screens and increase the likelihood of growing crystals suitable for X-ray structure determination. Crystallization ; Protein crystallization ; Polymer ; Materials science ; Macromolecule ; Crystal growth ; Diffraction ; Crystal (programming language) ; Limiting ; Crystallization of polymers ; Resolution (logic) ; Chemical engineering ; Crystallography ; Chemistry ; Organic chemistry ; Computer science ; Optics ; Biochemistry Enzyme Structure and Function ; Protein Structure and Dynamics ; Biochemical and Molecular Research
Authors: Sunghwan Kim | Seon-Chil Kim
Source: Materials (article, 2023-10-20)
Field: Materials Science — Materials Chemistry

The Kinetics of Carrier Trap Parameters in Na8Al6Si6O24(Cl,S)2 Hackmanite Tenebrescence has been reported to have a high potential for personal ultraviolet (UV) detection. Color changes can detect UV doses and can also be used as visual sensors for X-rays. Hackmanite is known to exhibit tenebrescence. This study investigated the kinetics of electron-trapping levels contributing to the luminescence of Na<sub>8</sub>Al<sub>6</sub>Si<sub>6</sub>O<sub>24</sub>(Cl,S)<sub>2</sub> hackmanite using thermoluminescence. The glow curves were measured at a heating rate of 5 K/s on hackmanite irradiated with X-rays. The physical parameters of the electron-trapping levels were evaluated by analyzing them using the deconvolution, peak shape, and initial rise methods. The Na<sub>8</sub>Al<sub>6</sub>Si<sub>6</sub>O<sub>24</sub>(Cl,S)<sub>2</sub> hackmanite had at least five trapping levels, with activation energies of 0.78, 1.12, 1.86, 1.26, and 1.18 eV and corresponding peak trap lifetimes of 3.59, 2.71, 1.47, 3.34, and 3.91 s, respectively. The estimated migration time was 15.0 s. Thermoluminescence ; Trapping ; Kinetics ; Luminescence ; Analytical Chemistry (journal) ; Penning trap ; Irradiation ; Materials science ; Ultraviolet ; Electron ; Atomic physics ; Deconvolution ; Chemistry ; Optics ; Optoelectronics ; Physics Luminescence Properties of Advanced Materials ; Glass properties and applications ; Advanced Photocatalysis Techniques
Authors: Junfeng Qiao | Giovanni Pizzi | Nicola Marzari
Source: arXiv (Cornell University) (preprint, 2023-03-12)
Field: Materials Science — Materials Chemistry

Projectability disentanglement for accurate and automated electronic-structure Hamiltonians Maximally-localized Wannier functions (MLWFs) are a powerful and broadly used tool to characterize the electronic structure of materials, from chemical bonding to dielectric response to topological properties. Most generally, one can construct MLWFs that describe isolated band manifolds, e.g. for the valence bands of insulators, or entangled band manifolds, e.g. in metals or describing both the valence and the conduction manifolds in insulators. Obtaining MLWFs that describe a target manifold accurately and with the most compact representation often requires chemical intuition and trial and error, a challenging step even for experienced researchers and a roadblock for automated high-throughput calculations. Here, we present a powerful approach that automatically provides MLWFs spanning the occupied bands and their natural complement for the empty states, resulting in Wannier Hamiltonian models that provide a tight-binding picture of optimized atomic orbitals in crystals. Key to the success of the algorithm is the introduction of a projectability measure for each Bloch state onto atomic orbitals (here, chosen from the pseudopotential projectors) that determines if that state should be kept identically, discarded, or mixed into a disentangling algorithm. We showcase the accuracy of our method by comparing a reference test set of 200 materials against the selected-columns-of-the-density-matrix algorithm, and its reliability by constructing Wannier Hamiltonians for 21737 materials from the Materials Cloud. Wannier function ; Pseudopotential ; Atomic orbital ; Hamiltonian (control theory) ; Electronic structure ; Valence (chemistry) ; Computer science ; Physics ; Quantum mechanics ; Electron ; Mathematics Machine Learning in Materials Science ; Advanced Chemical Physics Studies ; Catalysis and Oxidation Reactions
Authors: Jaleh Varshosaz
Source: Journal of Composites and Compounds (article, 2023-09-29)
Field: Materials Science — Biomaterials

Advancements in Nanostructured Drug Delivery Systems: A Commentary on Multifunctional Approaches for Cancer and Inflammatory Disease Treatment Nanostructured drug delivery systems (NDDS) represent a transformative advancement in medical science, offering innovative solutions for the treatment of cancer and inflammatory diseases. These systems utilize nanoscale materials to enhance the efficacy and specificity of drug delivery, allowing for targeted therapy that minimizes side effects. By improving the bioavailability of therapeutic agents, NDDS can significantly increase treatment effectiveness. Furthermore, their ability to navigate biological barriers opens new avenues for overcoming challenges in conventional drug delivery methods. Drug delivery ; Disease ; Cancer ; Drug ; Medicine ; Cancer drugs ; Intensive care medicine ; Nanotechnology ; Pharmacology ; Materials science ; Internal medicine Nanoparticle-Based Drug Delivery ; RNA Interference and Gene Delivery ; Nanoplatforms for cancer theranostics
Authors: Salman Khan | Atteeq Uz Zaman | Massab Junaid | Tauheed Shehbaz | Muhammad Awais Khan | Fahd Nawaz Khan | Muhammad Ramzan Abdul Karim
Source: Digital Manufacturing Technology (article, 2023-09-20)
Field: Materials Science — Polymers and Plastics

Effect of Mass and Temperature Rate on the Thermal Properties of High-Density Polyethylene Using Differential Scanning Calorimetry Mass and heating rates alter the thermal properties, molecular structure, and phase changes of the materials. This study aimed to investigate the influence of sample mass (10-30 mg) and heating rate (4-15 °C/min) on the thermal characteristics of high-density polyethylene (HDPE) using differential scanning calorimetry (DSC). The experiments were conducted in two cycles. In the first cycle, samples of different masses (10-30 mg) were heated to 180 °C followed by cooling at a constant heating rate of 10 °C/min with a mass flow rate of 20 ml/min of purging gas (nitrogen). In the second cycle, a sample mass of 15 mg was used to investigate the thermal characteristics while varying the temperature rates (4, 6, 8, 10, and 15 °C/min). It was concluded that the variation in sample mass significantly affected the thermal properties of HDPE, leading to a slight increase in the melting temperature and latent heat, which shifted towards higher temperatures. In contrast, the temperature rate caused a reduction in the latent heat and crystallization temperatures. The thermograms obtained from the experiments provided insight into the thermal behavior of HDPE under different conditions, and the findings emphasized the importance of carefully considering the effects of mass and temperature rate when measuring the thermal properties of HDPE. Differential scanning calorimetry ; High-density polyethylene ; Materials science ; Polyethylene ; Analytical Chemistry (journal) ; Mass flow rate ; Thermal ; Latent heat ; Crystallization ; Thermodynamics ; Composite material ; Chemistry ; Chromatography Polymer crystallization and properties ; Microplastics and Plastic Pollution ; Natural Fiber Reinforced Composites
Authors: Juan Enrique Tacoronte Morales | Carla Bernal Villavicencio | Xavier Cervantès | María Elizabeth Canchingre | María Teresa Cabrera Pedroso
Source:  (article, 2023-11-15)
Field: Chemistry — Organic Chemistry

GC-MS Analysis of Defensive Secretions of a Cuban Endemic Millipede of the Genus Rhinocricus—Chemical Prospecting of Neotropical Biodiversity The poly-component composition of repugnatorial secretions isolated from Rhinocricus duvernoyi Kasrh 1981 eco-geographical populations, inhabiting in the eastern zone of Cuban archipelago, was analyzed using GC-MS. Were identified several benzoquinonoids and related derivatives, revealing the existence of a singular compositional heterogeneity at a geographical scale. The preliminary molecular-geographic mapping of the Cuban archipelago detailed the presence of 3 chemotypes in the east region. The work reports a structural-chromatographic molecular database containing the components of defensive secretions. Millipede ; Archipelago ; Chemotype ; Biodiversity ; Prospecting ; Genus ; Geography ; Endemism ; Biology ; Ecology ; Zoology ; Botany ; Geology ; Geochemistry Chemical synthesis and alkaloids ; Fungal Biology and Applications ; Allelopathy and phytotoxic interactions
Authors: Ольга Валерьевна Лысенко | V. K. Ikonnikov
Source: Technology audit and production reserves (article, 2023-10-31)
Field: Materials Science — General Materials Science

Investigation of energy efficiency of hydrogen production in alkaline electrolysers The object of research is the energy efficiency of the electrolysis process in electrolyzers with alkaline electrolyte electrical parameters. The existing problem consists in obtaining the energy efficiency of the process in an electrolyzer with an alkaline electrolyte of more than 65 %. To solve this problem, it is proposed to manufacture an electrolyzer with metal electrodes made of stainless steel and separated from each other by a gas-tight membrane (Bologna cloth) to separate hydrogen and oxygen gases. To establish the energy efficiency characteristics, an experimental installation was made, and the necessary measuring equipment was also used. In the course of the work, a research methodology was developed and the necessary calculation of the measured values was carried out. As a result, the influence of the operating voltage on the consumption of the current flowing through the electrodes of the electrolyzer and the power consumed by it was revealed, the values of which increase with the increase of the operating voltage. It was established that the energy efficiency of the process in electrolyzers with an alkaline electrolyte decreases with an increase in the operating voltage. At operating voltages of 3 V, 4 V, and 5 V, the energy efficiency is 85.7 %, 77 %, and 70 %, respectively. The proposed technique involves conducting experimental studies directly on a functioning electrolyzer. The practical implementation of the use of a gas-tight membrane (Bologna fabric) can help reduce the cost of manufacturing an electrolyzer. Therefore, the presented research will be useful for the industrial production of hydrogen. Electrolysis ; Alkaline water electrolysis ; Electrolytic process ; Electrolyte ; Polymer electrolyte membrane electrolysis ; Power to gas ; High-pressure electrolysis ; Process engineering ; Hydrogen ; Voltage ; Hydrogen production ; High-temperature electrolysis ; Materials science ; Electrode ; Chemistry ; Engineering ; Electrical engineering Material Properties and Applications ; Advanced Power Generation Technologies ; Environmental and Industrial Safety