jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Anjana E Sudheer | Golla Tejaswini | D. Murali | M. Posselt
Source: arXiv (Cornell University) (preprint, 2023-12-07)
Field: Materials Science — Materials Chemistry

First Principles Investigation on Structural and Optoelectronic Properties of newly designed Janus Lead Halides PbXY (X, Y = F, Cl, Br, I ) Here, we design a novel class of Janus structures PbXY(X,Y = F, Cl, Br, I) and propose it for the solar mediated photocatalytic water splitting hydrogen production as well as for the photovoltaic solarcell applications. Charge analysis shows that covalent bonding for less electronegative atoms and ionic bonding for more electronegative atoms. Strong dual bonding like ionic one side and covalent other side is observed when heavy and lighter atoms are part of the same Janus structures. The as designed Janus structures show good dynamical stability through phonon calculations. Basic electronic structure using Generalised Gradient Approximation(GGA) reveal both direct and indirect nature of band gap with large tunability. Heyd-Scuseria-Ernzerhof (HSE) electronic structure calculations are performed and wider band gaps are predicted for these Janus structures. The calculated effective masses of charge carriers show robust charge carrier dynamics. The orbital resolved electronic density of states (DOS) shows that the conduction band edge is composed of pz orbital of Pb atom. The partialcharge density calculated at conduction band minimum (CBM) also support the result obtained from PDOS analysis. Breaking of centrosymmetry, polarization in the out of plane direction, the z-oriented orbitals of CBM all points that these materials are suitable for shift current generation. The calculated optical absorption spectra show that the Janus structures are suitable for visible light absorption. The calculated potential difference between the top and bottom layer show significant variation and maximum (1.02 eV) is observed for PbClF. Further, we show that combining both potential difference and HSE bandgap, valence band maximum(VBM) and CBM straddle the water redox potentials, thus making the Janus structures suitable for water redox reactions. Janus ; Band gap ; Ionic bonding ; Density functional theory ; Heterojunction ; Direct and indirect band gaps ; Electronic structure ; Materials science ; Electronic band structure ; Chemistry ; Charge density ; Molecular physics ; Condensed matter physics ; Computational chemistry ; Optoelectronics ; Nanotechnology ; Ion ; Physics Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Advanced Photocatalysis Techniques
Authors: Dominik M. Florjan | Maciej J. Szary
Source: ChemRxiv (preprint, 2023-12-14)
Field: Materials Science — Materials Chemistry

Enhancing Surface Activity in MoTe2 Monolayers through P-Block Doping: A Comprehensive DFT Investigation Molybdenum ditelluride (MoTe2), a member of the transition metal dichalcogenides (TMDs), has recently garnered significant attention in the fast growing fields of two-dimensional electronics. However, despite its advantages, the intrinsic properties of MoTe2, like the low chemical activity of its basal plane, also resulted in several technological challenges. To overcome these limitations, several methods have been explored, with single atom doping emerging as a particularly promising approach. In this study, we employed density functional theory (DFT) to investigate the influence of single atom impurities on the chemical activity of MoTe2. A total of 22 dopants were selected from the p-block of the periodic table, ranging from boron to bismuth. Specifically, we examined the adsorption of oxygen molecules (O2) on the doped structures to assess their impact on layer chemical activity. Our findings revealed that doping was energetically favorable for all investigated atoms, and it had a significant effect on surface activity. Notably, doping with dopants from groups 13-15, especially those with low atomic number, results in significant increased adsorption strength, leading to weakening of the molecular bonding in O2 by up 5.72 eV, hinting at the potential use as catalyst. Additionally, we identified certain molecules, primarily from group 17, with a remarkably high adsorption energy to charge transfer ratio. This leads to excellent sensing characteristics, where the response to adsorption in their carrier concentration is increased 100-fold over the pristine MoTe2, while sensor recovery is estimated between 0.01 and 2 s. In summary, our investigation demonstrated that doping MoTe2 with p-block elements is a viable approach to chemical alteration of its surface activity, paving the way for various applications. Dopant ; Adsorption ; Doping ; Chemical physics ; Monolayer ; Density functional theory ; Transition metal ; Materials science ; Molecule ; Bismuth ; Atom (system on chip) ; Nanotechnology ; Electronegativity ; Impurity ; Computational chemistry ; Physical chemistry ; Catalysis ; Chemistry ; Organic chemistry ; Optoelectronics ; Metallurgy 2D Materials and Applications ; Advanced Thermoelectric Materials and Devices ; Graphene research and applications
Authors: Matthew W. Eskew | Patrick W. Reardon | Albert S. Benight
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2023-09-26)
Field: Chemistry — Physical and Theoretical Chemistry

Calorimetric analysis using DNA thermal stability to determine protein concentration It was recently reported for two globular proteins and a short DNA hairpin in NaCl buffer that values of the transition heat capacities, <i>C</i><sub><i>p,DNA</i></sub> and <i>C</i><sub><i>p,PRO</i></sub>, for equal concentrations (mg/mL) of DNA and proteins, are essentially equivalent (differ by less than 1%). Additional evidence for this equivalence is presented that reveals this phenomenon does not depend on DNA sequence, buffer salt, or T<sub>m</sub>. Sequences of two DNA hairpins were designed to confer a near 20°C difference in their T<sub>m</sub>'s. For the molecules, in NaCl and CsCl buffer the evaluated <i>C</i><sub><i>p,PRO</i></sub> and <i>C</i><sub><i>p,DNA</i></sub> were equivalent. Based on the equivalence of transition heat capacities, a calorimetric method was devised to determine protein concentrations in pure and complex solutions. The scheme uses direct comparisons between the thermodynamic stability of a short DNA hairpin standard of known concentration, and thermodynamic stability of protein solutions of unknown concentrations. In all cases, evaluated protein concentrations determined from the DNA standard curve agreed with the UV-Vis concentration for monomeric proteins. For samples of multimeric proteins, streptavidin (tetramer), Herpes Simplex Virus glycoprotein D (trimer/dimer), and a 16 base pair DNA duplex (dimer), evaluated concentrations were greater than determined by UV-Vis by factors of 3.94, 2.65, and 2.15, respectively. Thermal stability ; Stability (learning theory) ; Protein stability ; DNA ; Chemistry ; Materials science ; Thermodynamics ; Physics ; Computer science ; Biochemistry thermodynamics and calorimetric analyses ; RNA and protein synthesis mechanisms ; Protein purification and stability
Authors: Davide Accomasso | Nadia Ben Amor | Maurizio Persico | Giovanni Granucci
Source: ChemRxiv (preprint, 2023-03-14)
Field: Chemistry — Physical and Theoretical Chemistry

Computational design of covalently bound dimers for singlet fission We present two different computational approaches to design covalently bound dimers for singlet fission. Both designs aim at maximizing the effective coupling between the initial singlet excited state S* and the double triplet state TT, by tuning the interaction (mainly through-space) between the chromophore units. Design I is based on a preliminary search for the optimal relative arrangements of chromophores in a space of possible stacked pair geometries. Then, the optimized dimeric arrangements are used as targets for the covalent connection of the two chromophores. In design II, all viable ways to covalently bind the two chromophores are considered, using a given set of linkers. Next, the most promising covalent dimers for singlet fission, among our tested candidates, are identified. The application of our approaches to a locked 1,3-diphenyl-isobenzofuran chromophore and a diamino-fluoroquinone compound allowed to design several promising dimers for singlet fission, featuring large S*-TT effective couplings and favorable energetics. Chromophore ; Covalent bond ; Singlet state ; Singlet fission ; Chemistry ; Excited state ; Photochemistry ; Computational chemistry ; Chemical physics ; Physics ; Atomic physics ; Organic chemistry Photochemistry and Electron Transfer Studies ; Luminescence and Fluorescent Materials ; Photoreceptor and optogenetics research
Authors: Praveen Kumar Reddy Bapatu | Anuj Kumar Sharma
Source: International Journal of Pharmacy and Pharmaceutical Science (article, 2023-01-01)
Field: Chemistry — Analytical Chemistry

Development and validation of new stability indicating HPLC method for assay of Pitavastatin in tablet dosage form The accurate quantification of pharmaceutical compounds in tablet dosage forms is paramount for ensuring product quality and efficacy. Pitavastatin, a potent HMG-CoA reductase inhibitor prescribed for hypercholesterolemia management, necessitates robust analytical methods to determine its content with precision and reliability. This abstract presents the development and validation of a new stability-indicating high-performance liquid chromatography (HPLC) method for the assay of Pitavastatin in tablet formulations. The HPLC method was meticulously optimized to achieve optimal separation of Pitavastatin from potential degradation products and excipients commonly found in tablet matrices. Chromatographic conditions, including the selection of a suitable stationary phase, mobile phase composition, and detection wavelength, were carefully tailored to ensure accurate and reproducible quantification of Pitavastatin. Validation studies were conducted to assess the method&#39;s specificity, linearity, accuracy, precision, robustness, and system suitability, in accordance with regulatory guidelines. Additionally, stress testing experiments were performed to evaluate the method&#39;s stability-indicating capability under various forced degradation conditions, simulating potential degradation pathways encountered during product storage and handling. Chromatography ; Pitavastatin ; High-performance liquid chromatography ; Dosage form ; Chemistry ; Pharmacology ; Medicine Analytical Methods in Pharmaceuticals ; Analytical Chemistry and Chromatography ; Drug Solubulity and Delivery Systems
Authors: Taito Hashimoto | Ryusei Oketani | Ichiro Hisaki
Source: Acta Crystallographica Section A Foundations and Advances (article, 2023-08-22)
Field: Chemistry — Physical and Theoretical Chemistry

Construction of non-stoichiometric cocrystals of hydrogen-bonded organic framework based on pyrene/hydropyrene system Stoichiometry ; Pyrene ; Hydrogen ; Hydrogen bond ; Chemistry ; Materials science ; Organic chemistry ; Combinatorial chemistry ; Molecule Crystallography and molecular interactions ; Nonlinear Optical Materials Research ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Anthony Brown | Qingfei Pan | Li Fan | Émilie Indersie | Cheng Tian | Nikolai A. Timchenko | Liyuan Li | Baranda S. Hansen | Haiyan Tan | Meifen Lu | Junmin Peng | Shondra M. Pruett‐Miller | Jiyang Yu | Stefano Cairo | Liqin Zhu
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2023-01-24)
Field: Chemistry — Inorganic Chemistry

Ribonucleotide Reductase Subunit Switching in Hepatoblastoma Drug Response and Relapse Prognosis of children with high-risk hepatoblastoma (HB), the most common pediatric liver cancer, remains poor. In this study, we found ribonucleotide reductase (RNR) subunit M2 ( <i>RRM2</i> ) was one of the key genes supporting cell proliferation in high-risk HB. While standard chemotherapies could effectively suppress RRM2 in HB cells, they induced a significant upregulation of the other RNR M2 subunit, RRM2B . Computational analysis revealed distinct signaling networks RRM2 and RRM2B were involved in HB patient tumors, with RRM2 supporting cell proliferation and RRM2B participating heavily in stress response pathways. Indeed, RRM2B upregulation in chemotherapy-treated HB cells promoted cell survival and subsequent relapse, during which RRM2B was gradually replaced back by RRM2. Combining an RRM2 inhibitor with chemotherapy showed an effective delaying of HB tumor relapse in vivo. Overall, our study revealed the distinct roles of the two RNR M2 subunits and their dynamic switching during HB cell proliferation and stress response. Ribonucleotide reductase ; Hepatoblastoma ; Downregulation and upregulation ; Cancer research ; Protein subunit ; Cell growth ; In vivo ; Chemotherapy ; Biology ; Paclitaxel ; Medicine ; Internal medicine ; Gene ; Biochemistry ; Genetics Metal-Catalyzed Oxygenation Mechanisms ; RNA modifications and cancer ; ATP Synthase and ATPases Research
Authors: Xiao Liang | Emek G. Durmusoglu | Maria Lunina | Pedro Ludwig Hernández‐Martínez | Vytautas Valuckas | Fei Yan | Yulia Lekina | Vijay Kumar Sharma | Tingting Yin | Son Tung Ha | Zexiang Shen | Handong Sun | Arseniy I. Kuznetsov | Hilmi Volkan Demir
Source: arXiv (Cornell University) (preprint, 2023-06-12)
Field: Materials Science — Materials Chemistry

Near-Unity Emitting, Widely Tailorable and Stable Exciton Concentrators Built from Doubly Gradient 2D Semiconductor Nanoplatelets The strength of electrostatic interactions (EI) between electrons and holes within semiconductor nanocrystals profoundly impact the performance of their optoelectronic systems, and different optoelectronic devices demand distinct EI strength of the active medium. However, achieving a broad range, fine-tuning of the EI strength for specific optoelectronic applications is a daunting challenge, especially in quasi 2-dimensional core-shell semiconductor nanoplatelets (NPLs), as the epitaxial growth of the inorganic shell along the direction of the thickness that solely contributes to the quantum confined effect significantly undermines the strength of the EI. Herein we propose and demonstrate a novel doubly-gradient (DG) core-shell architecture of semiconductor NPLs for on-demand tailoring of the EI strength by controlling the localized exciton concentration via in-plane architectural modulation, demonstrated by a wide tuning of radiative recombination rate and exciton binding energy. Moreover, these exciton-concentration-engineered DG NPLs also exhibit a near-unity quantum yield, remarkable thermal and photo stability, as well as considerably suppressed self-absorption. As proof-of-concept demonstrations, highly efficient color converters and high-performance light-emitting diodes (external quantum efficiency: 16.9%, maximum luminance: 43,000 cd/m2) have been achieved based on the DG NPLs. This work thus opens up new avenues for developing high-performance colloidal optoelectronic device applications. Optoelectronics ; Exciton ; Semiconductor ; Materials science ; Quantum dot ; Diode ; Nanotechnology ; Physics ; Condensed matter physics Quantum Dots Synthesis And Properties ; Perovskite Materials and Applications ; 2D Materials and Applications
Authors: S. Koley
Source: arXiv (Cornell University) (preprint, 2023-09-14)
Field: Materials Science — Materials Chemistry

Intercalation in 2H-TaSe 2 for modulation of electronic properties and electrochemical energy storage Two-dimensional transition metal dichalcogenides (TMDs) exhibit an extensive variety of novel electronic properties, such as charge density wave quantum spin Hall phenomena, superconductivity, and Dirac and Weyl semi-metallic properties. The diverse properties of TMDs suggest that structural transformation can be employed to switch between different electronic properties. Intercalation and zero valence doping of molecules and atoms into the van der Waals gap of TMDs have emerged as effective approaches to modify the charge order states of the material. This eventually leads to phase transition or the formation of different phases, thus expanding the electronic, thermoelectric and optical applications of these materials. In this study, electronic and electrochemical energy storage properties of such an intercalated TMD, namely, 2H-TaSe 2 via intercalation of lithium (Li), sodium (Na) and potassium (K) have been investigated. The intercalation of these ions into the dichalcogenide resulted in a modified band structure and novel structural effects, leading to the emergence of a 1 eV band gap. Possibility of electrochemical energy storage application is also explored in this study. Furthermore, the importance of multi orbital electron-electron correlations in intercalated TaSe 2 is also investigated via dynamical-mean-field theory with local density approximation. Materials science ; Condensed matter physics ; Intercalation (chemistry) ; Band gap ; Density functional theory ; Electronic structure ; Charge density wave ; Chemical physics ; Lithium (medication) ; Valence (chemistry) ; Superconductivity ; Chemistry ; Computational chemistry ; Physics ; Inorganic chemistry 2D Materials and Applications ; Graphene research and applications ; Quantum Dots Synthesis And Properties
Authors: Vipul Kumar | Dr Jigar Y. Soni
Source: Journal of Survey in Fisheries Sciences (article, 2023-01-08)
Field: Chemistry — Analytical Chemistry

Isolation, Characterisation And Biological Assessment Of Chemical Ingredients Of Some Dye Producing Plants The primary goals of this research were to conduct a biological evaluation and to isolate and characterize chemical components from certain plants that produce color. Research into these plants' possible uses in fields as diverse as textiles and medicine is the overarching goal. By using spectroscopic methods, the chemical components derived from these plants were detected and studied. In addition, several tests were used to assess the biological activities of these compounds, which helped to reveal any possible pharmacological qualities they may have. The results of this research shed light on the many applications of dye-producing plants by adding to our knowledge of their chemical make-up and biological capabilities. Isolation (microbiology) ; Biochemical engineering ; Biology ; Biotechnology ; Engineering ; Microbiology Dye analysis and toxicity
Authors: V. I. Yukalov | E. P. Yukalova
Source: arXiv (Cornell University) (preprint, 2023-01-03)
Field: Materials Science — Materials Chemistry

Statistical model of a superfluid solid A microscopic statistical model of a quantum solid is developed, where inside a crystalline lattice there can exist regions of disorder, such as dislocation networks or grain boundaries. The cores of these regions of disorder are allowed for exhibiting fluid-like properties. If the solid is composed of Bose atoms, then the fluid-like aggregations inside the regions of disorder can exhibit Bose-Einstein condensation and hence superfluidity. The regions of disorder are randomly distributed throughout the sample, so that for describing the overall properties of the solid requires to accomplish averaging over the disordered aggregation configurations. The averaging procedure results in a renormalized Hamiltonian of a solid that can combine the properties of a crystal and superfluidity. The possibility of such a combination depends on the system parameters. In general, there exists a range of the model parameters allowing for the occurrence of superfluidity inside the disordered aggregations. This microscopic statistical model gives the opportunity to answer which real quantum crystals can exhibit the property of superfluidity and which cannot. Superfluidity ; Hamiltonian (control theory) ; Physics ; Condensed matter physics ; Quantum ; Statistical physics ; Dislocation ; Lattice (music) ; Quantum mechanics ; Mathematics Material Dynamics and Properties ; Advanced Thermodynamics and Statistical Mechanics ; Theoretical and Computational Physics
Authors: . | Renee C. Tan | Edgardo C. Morales | Reynaldo M. Subang
Source: Engineering and Technology Journal (article, 2023-08-12)
Field: Chemistry — Inorganic Chemistry

DESIGN AND DEVELOPMENT OF A COCONUT SHELL SHAVER MACHINE This research focuses on the conceptualization and creation of an innovative coconut shell shaver machine, aimed at significantly enhancing the efficiency of shell cleaning for handicrafts while prioritizing safety. The proposed design aims to achieve an elevated level of cleaning proficiency across the coconut shell's surface. This advancement intends to alleviate the labor burden of handicraft artisans, streamline the processing time for coconut shell crafts, and ultimately elevate the overall production rate of coconut shell crafts. The machine's structure encompasses a motor housed within a protective casing, interconnected through belts and pulleys to a centrally-positioned shaft. This shaft is equipped with circular brushes at both ends. The circular brushes are thoughtfully encased by a steel plate, meticulously engineered to safeguard against dust during operation and ensure operator safety. The intended outcome of this innovation is to amplify the capabilities of local farmers in the Province of Surigao del Norte, particularly at the village level. The fabrication of the device adheres to standardized measurements, with subsequent phases involving thorough testing and precise adjustments to optimize its operational performance. A comprehensive demonstration of the coconut shell shaver machine is also slated for presentation during the evaluation process. Shell (structure) ; Handicraft ; Engineering ; Manufacturing engineering ; Mechanical engineering Coconut Research and Applications ; Date Palm Research Studies ; Belt Conveyor Systems Engineering
Authors: Hamed Abbasian
Source: Advanced Theory and Simulations (article, 2023-12-10)
Field: Materials Science — Materials Chemistry

Modulating Optical Properties of Graphene with the help of Two‐Dimensional Metal‐Organic Networks Abstract We utilize density functional theory to explore dicarbonitrile‐polyphenyl networks overlaid on graphene as a method for manipulating the density of Li atoms in a specific assembly pattern. Ab initio molecular dynamics calculations affirm the thermal stability of the introduced systems. We scrutinized the electronic structure and optical properties of the resultant systems, illustrating a systematic modulation of optical characteristics. Our results suggest that the optical excitation frequencies of (Li‐dicarbonitrile‐polyphenyl)/G can be efficiently tuned by systematically adjusting the density of Li atoms on graphene. Graphene ; Excitation ; Materials science ; Density functional theory ; Modulation (music) ; Chemical physics ; Ab initio ; Thermal stability ; Metal ; Thermal ; Molecular dynamics ; Nanotechnology ; Optoelectronics ; Computational chemistry ; Chemistry ; Physics ; Quantum mechanics ; Thermodynamics Graphene research and applications ; Molecular Junctions and Nanostructures ; Luminescence and Fluorescent Materials