jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Hafiza Sumaira Waheed | Mazia Asghar | Hamid Ullah | Muhammad Yaseen | Asad Ali | Akram Ibrahim | A. Laref | Ramesh Sharma
Source: ACS Omega (article, 2024-05-15)
Field: Materials Science — Materials Chemistry

Computational Insight into the Physical Properties of Bulk MP (M = Li, Na, K) for Energy Applications In this study, we applied density functional theory to compute the electronic, optical, and thermal properties of MP (M = Li, Na, K). We find that the materials under consideration are stable, owing to the lack of negative frequencies in the phonon spectra. LiP exhibits an indirect band gap of 1.43 eV. NaP and KP have direct band gaps of 1.67 and 1.76 eV, respectively. The family of these composites shows strong absorption, observed by their very sharp absorption edges and confirmed by their direct transition from the valence to conduction band. They exhibit strong absorption below 4.0 eV in the optical spectra, which could serve in a solar cell device. The thermal calculations show high zT values of 0.74, 0.78, and 0.64 at 300 K for LiP, NaP, and KP, respectively. Thus, our results could be promising for electronic and thermal devices. Energy (signal processing) ; Materials science ; Physics ; Engineering physics ; Chemistry ; Physical chemistry ; Quantum mechanics MXene and MAX Phase Materials ; 2D Materials and Applications ; Inorganic Chemistry and Materials
Authors: Weicheng Li | Haoyun Yang | Kye Stachowski | Andrew Norris | Katie Lichtenthal | Skyler Kelly | Paul Gollnick | Vicki H. Wysocki | Mark P. Foster
Source: Proceedings of the National Academy of Sciences (article, 2024-12-30)
Field: Materials Science — Materials Chemistry

Structural basis of nearest-neighbor cooperativity in the ring-shaped gene regulatory protein TRAP from protein engineering and cryo-EM The homo-dodecameric ring-shaped <i>trp</i> RNA binding attenuation protein (TRAP) from <i>Alkalihalobacillus halodurans (Aha)</i> binds up to twelve tryptophan ligands (Trp) and becomes activated to bind a specific sequence in the 5' leader region of the <i>trp</i> operon mRNA, thereby downregulating biosynthesis of Trp. Thermodynamic measurements of Trp binding have revealed a range of cooperative behavior for different TRAP variants, even if the averaged apparent affinities for Trp have been found to be similar. Proximity between the ligand binding sites, and the ligand-coupled disorder-to-order transition has implicated nearest-neighbor interactions in cooperativity. To establish a solid basis for describing nearest-neighbor cooperativity in TRAP, we engineered variants constructed with two subunits connected by a flexible linker (dTRAP). We mutated the binding sites of alternating protomers such that only every other site was competent for Trp binding (WT-Mut dTRAP). Ligand binding monitored by NMR, calorimetry, and native mass spectrometry revealed strong cooperativity in dTRAP containing adjacent binding-competent sites, but a severe binding defect when the wild-type sites were separated by mutated sites. Cryo-EM experiments of dTRAP in its ligand-free apo state, and both dTRAP and WT-Mut dTRAP in the presence of Trp, revealed progressive stabilization of loops that gate the Trp binding site and participate in RNA binding. These studies provide important insights into the thermodynamic and structural basis for the observed ligand binding cooperativity in TRAP. Such insights can be useful for understanding allosteric control networks and for the development of those with defined ligand sensitivity and regulatory control. Cooperativity ; Trap (plumbing) ; k-nearest neighbors algorithm ; Basis (linear algebra) ; Protein engineering ; Gene ; Computational biology ; Chemistry ; Biology ; Physics ; Biochemistry ; Computer science ; Artificial intelligence ; Mathematics Enzyme Structure and Function ; RNA and protein synthesis mechanisms ; Biochemical and Molecular Research
Authors: Rajesh Bera | Miguel Dosil | Gerasimos Konstantatos
Source: Nano Letters (article, 2024-10-28)
Field: Materials Science — Materials Chemistry

Intraband Exciton Dynamics of n-Doped Silver Selenide Quantum Dots Ag<sub><i>x</i></sub>Se (<i>x</i> > 2) colloidal quantum dots (CQDs) have recently emerged as a promising environmentally friendly material contender for mid- and long-wave infrared optoelectronics, leveraging their intraband transition (1S<sub>e</sub>-1P<sub>e</sub>). However, multicarrier interactions in CQDs, particularly Auger recombination, have profound implications on the optoelectronic properties of the materials and their potential in device applications. Understanding the intraband excited-state dynamics in n-doped Ag<sub><i>x</i></sub>Se is therefore essential for the assessment and successful implementation of this material platform in devices. We, herein, investigate the carrier dynamics of Ag<sub><i>x</i></sub>Se in both solution and thin-film states using a femtosecond mid-infrared transient absorption spectrometer. Our observations reveal that the multicarrier Auger process depends on the degree of doping in Ag<sub><i>x</i></sub>Se CQDs and accelerates when the Fermi energy (<i>E</i><sub>F</sub>) level approaches the 1P<sub>e</sub> state. The calculated intraband Auger coefficients (<i>C</i><sub>A</sub>) are measured to be on the order of ∼10<sup>-28</sup> cm<sup>6</sup> s<sup>-1</sup>, significantly larger compared to analogous n-doped HgS/Se CQDs. Quantum dot ; Exciton ; Selenide ; Doping ; Cadmium selenide ; Condensed matter physics ; Materials science ; Nanocrystal ; Nanotechnology ; Chemical physics ; Chemistry ; Physics ; Optoelectronics ; Selenium Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Nanocluster Synthesis and Applications
Authors: Chi‐Wei Lee | Hung Su | Yi-Wen Hsu | Lin-Zhen Su | Yen‐Hung Wu | Chia-Yi Hou | Shu-Yu Shih | Jentaie Shiea
Source: Journal of the American Society for Mass Spectrometry (article, 2024-04-15)
Field: Chemistry — Spectroscopy

Rapid Characterization of Undeclared Pharmaceuticals in Herbal Preparations by Ambient Ionization Mass Spectrometry for Emergency Care In Asia, some herbal preparations have been found to be adulterated with undeclared synthetic medicines to increase their therapeutic efficiency. Many of these adulterants were found to be toxic when overdosed and have been documented to bring about severe, even life-threatening acute poisoning events. The objective of this study is to develop a rapid and sensitive ambient ionization mass spectrometric platform to characterize the undeclared toxic adulterated ingredients in herbal preparations. Several common adulterants were spiked into different herbal preparations and human sera to simulate the clinical conditions of acute poisoning. They were then sampled with a metallic probe and analyzed by the thermal desorption-electrospray ionization mass spectrometry. The experimental parameters including sensitivity, specificity, accuracy, and turnaround time were prudently optimized in this study. Since tedious and time-consuming pretreatment of the sample is unnecessary, the toxic adulterants could be characterized within 60 s. The results can help emergency physicians to make clinical judgments and prescribe appropriate antidotes or supportive treatment in a time-sensitive manner. Chemistry ; Mass spectrometry ; Chromatography ; DART ion source ; Electrospray ionization ; Traditional medicine ; Ionization ; Medicine ; Organic chemistry ; Electron ionization Mass Spectrometry Techniques and Applications ; Pesticide Residue Analysis and Safety ; Forensic Toxicology and Drug Analysis
Authors: Thomas Herzog | Atefeh Habibpourmoghadam | S. Locmelis | Antonio Calà Lesina | Sebastian Polarz
Source: Advanced Functional Materials (article, 2024-09-05)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Oxygen Vacancy Controlled Hyperbolic Metamaterial Based on Indium Tin Oxide (ITO) Nanotubes with Switchable Optical Properties Abstract Nanostructured metamaterials can offer optical properties beyond what is achievable in conventional media, such as negative refraction or sub‐wavelength imaging. Due to their structural anisotropy, the class of high aspect ratio metamaterials is of interest for the possibility of achieving hyperbolic optical properties, i.e., both metallic and dielectric behavior based on the excitation direction. Although investigated numerically, the fabrication of tailor‐made metamaterials is complex or often beyond the reach of current technology. For wire metamaterials composed of aligned metallic nanowires in a dielectric matrix, since the free carrier concentration in metals is fixed, light‐matter interaction cannot be adjusted after fabrication. Here, metamaterials based on plasmonic ITO nanotubes with controllable hyperbolic response are introduced. The synthesis is achieved by a template‐based liquid‐phase technique. The tuning mechanism is based on controlling the carrier density in ITO via oxygen vacancy concentration. The process is reversible, the photonic features are activated by creating oxygen vacancies and can be switched off by filling them up again. Further, it is shown that the carrier concentration can also be controlled via a static electric field. Optical simulations support the experimental findings and highlight the parameters that determine the optical response of the metamaterial. Materials science ; Indium tin oxide ; Indium ; Oxygen ; Oxide ; Optoelectronics ; Vacancy defect ; Metamaterial ; Tin ; Tin oxide ; Nanotechnology ; Thin film ; Doping ; Condensed matter physics ; Metallurgy Metamaterials and Metasurfaces Applications ; Advanced Memory and Neural Computing ; Polydiacetylene-based materials and applications
Authors: Bozhou Li | Xinyu Wang | Raza Syed Muhammad Ehtesham | Ye Tian | Lu Liu | Fuqiang Jiang
Source: ACS Omega (article, 2024-01-24)
Field: Materials Science — Materials Chemistry

Bidirectional Lifetime Tuning of Er 1530 nm Emission Induced by Yb Wide-range NIR lifetimes of lanthanide ion-doped nanocrystals are highly desired for numerous bioapplications. As one of the most promising NIR emission bands, the lifetime of Er<sup>3+</sup> at 1.5 μm can be as long as ∼10 ms and be greatly shortened by increasing the doping level of either activator Er<sup>3+</sup> or sensitizer Yb<sup>3+</sup>. However, the shortened lifetime is mostly accompanied by the quenching effects, highly restraining the light signal intensity. Alternatively, prolonging the lifetime of Er<sup>3+</sup> NIR lifetime without luminescence quenching is of vital significance as it raises the upper limit of the lifetime range and maintains the effective signal intensity. In this work, we revealed that Yb<sup>3+</sup> can bidirectionally tune the NIR lifetime of Er<sup>3+</sup>. By introducing Yb<sup>3+</sup>, in addition to the substantially improved luminescence intensities, the prolonged NIR lifetime can be generated in low-Er<sup>3+</sup>-doped NaYF<sub>4</sub> nanocrystals, while monotonously decreased lifetime appears in Er<sup>3+</sup> heavily doped nanocrystals. To investigate the mechanisms of this bidirectional lifetime tuning and meanwhile avoid additional structural influences, the size and morphology of nanocrystals with different doping compositions were controlled to be similar. The decay dynamics of Er<sup>3+</sup> NIR emissions of different nanocrystals were simulated to explain the effects of Yb<sup>3+</sup>. This work provides insights into the manipulation of the NIR lifetime in Er<sup>3+</sup>/Yb<sup>3+</sup>-codoped nanocrystals. Nanocrystal ; Materials science ; Luminescence ; Doping ; Activator (genetics) ; Quenching (fluorescence) ; Ion ; Lanthanide ; Optoelectronics ; Photon upconversion ; Ytterbium ; Nanotechnology ; Fluorescence ; Optics ; Chemistry Luminescence Properties of Advanced Materials ; Luminescence and Fluorescent Materials ; Radiation Detection and Scintillator Technologies
Authors: Morteza Teymoori | Arda D. Yalçınkaya
Source: Scientific Reports (article, 2024-08-09)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Fano resonances induced by strong conductive coupling in cross-shaped metasurfaces for tunable EIT-like phenomena Highly efficient Metamaterials are necessary for applications in sensing, communication, etc. Fano resonance and electromagnetically induced transparency-like phenomena are essential for obtaining high Q-factor and sensitive Metamaterials. Employing both numerical simulations and experimental analysis, we investigate the emergence of Fano resonance in cross-resonator Metamaterials facilitated by the conductive coupling between dark and bright resonators. We analyze the gradual shift of the fano resonance by tuning the dark resonator and finally form an electromagnetically induced transparency-like transmission peak. The strong coupling of the resonator is observed in the form of an anti-crossing and discussed through analytical models. We demonstrate that the coupling strength of the dark and bright resonance in our metamaterial is proportional to the asymmetry parameter, albeit at the cost of the Fano resonance's Q-factor. The findings and methods introduced in this study can be used to develop highly efficient THz Metamaterials for various applications operable in room conditions. Coupling (piping) ; Fano plane ; Electrical conductor ; Fano resonance ; Physics ; Nuclear magnetic resonance ; Optics ; Materials science ; Plasmon ; Quantum mechanics ; Mathematics ; Geometry Metamaterials and Metasurfaces Applications ; Plasmonic and Surface Plasmon Research ; Advanced Antenna and Metasurface Technologies
Authors: Yuyang Han | Christian Pederson | Bethany E. Matthews | Nicholas Yama | Maxwell F. Parsons | Kai‐Mei C. Fu
Source: Applied Physics Letters (article, 2024-01-22)
Field: Materials Science — Materials Chemistry

Creation of color centers in diamond by recoil implantation through dielectric films The need of near-surface color centers in diamond for quantum technologies motivates the controlled doping of specific extrinsic impurities into the crystal lattice. Recent experiments have shown that this can be achieved by momentum transfer from a surface precursor via ion implantation, an approach known as “recoil implantation.” Here, we extend this technique to incorporate dielectric precursors for creating nitrogen-vacancy (NV) and silicon-vacancy (SiV) centers in diamond. Specifically, we demonstrate that gallium focused-ion-beam exposure to a thin layer of silicon nitride or silicon dioxide on the diamond surface results in the introduction of both extrinsic impurities and carbon vacancies. These defects subsequently give rise to near-surface NV and SiV centers with desirable properties after annealing. Diamond ; Ion implantation ; Materials science ; Vacancy defect ; Silicon ; Impurity ; Doping ; Recoil ; Annealing (glass) ; Dielectric ; Gallium ; Optoelectronics ; Material properties of diamond ; Ion ; Atomic physics ; Chemistry ; Crystallography ; Metallurgy Diamond and Carbon-based Materials Research ; Metal and Thin Film Mechanics ; Advanced Surface Polishing Techniques
Authors: Vladimir Pavlenko | K.M. Temirkulova | A. Yu. Zakharov | Yermek Aubakirov | Zhanibek Ayaganov
Source: Eurasian Chemico-Technological Journal (article, 2024-02-15)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Optimization of the Porous Structure of Carbon Electrodes for Hybrid Supercapacitors with a Redox Electrolyte Based on Potassium Bromide This work investigates the electrochemical behavior of hybrid supercapacitors with carbon-based electrodes of different porosity using 5M NaNO3 + 0.5M KBr electrolyte to optimize energy storage processes. Three types of carbon materials were synthesized: activated carbon from rice husk (RH) with a specific surface area of ~2300 m2/g and pore size &lt; 1 nm, and templated carbons from magnesium citrate (MP-8) and glucose with SiO2 as a template (G7), having surface areas of 1976 and 1320 m2/g and pore sizes of 3.4 and 7 nm, respectively. The microporous structure of activated carbon (AC) obtained from RH shows limitations in the diffusion of electrolyte ions, which affects the charge-discharge kinetics. In contrast, the larger mesoporous structures of templated carbons promoted better adsorption and ion transport, significantly affecting the dynamics of redox reactions. The RH/MP-8 hybrid capacitor, combining high surface area and large pore size, demonstrated a 54% increase in specific capacitance, 128% increase in specific energy and 51% increase in energy efficiency at high current densities of 5 A/g, comparing to the symmetric RH/RH hybrid capacitor. This study highlights the critical importance of the relationship between electrode pore structure and electrolyte composition for optimizing supercapacitor performance, which provides valuable information for the development of efficient energy storage technologies. Supercapacitor ; Electrolyte ; Redox ; Potassium ; Electrode ; Porosity ; Potassium bromide ; Bromide ; Inorganic chemistry ; Carbon fibers ; Materials science ; Chemical engineering ; Chemistry ; Electrochemistry ; Composite number ; Metallurgy ; Composite material Supercapacitor Materials and Fabrication ; Conducting polymers and applications ; Aerogels and thermal insulation
Authors: Giovanni Gardan | Gian Carlo Montanari
Source: IEEE Access (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Investigating Optimal Approaches for Energizations of DC Systems: The Stepwise Technique The increasing presence of HVDC (High Voltage Direct Current) links and MVDC (Medium Voltage Direct Current) connections in transmission networks needs an in-depth knowledge of the mechanisms that could affect life and reliability of electrical asset components. As for all electrical systems in general, a crucial factor affecting availability of a HVDC asset is the insulation system reliability. One of the most common causes of premature electrical failure of asset components is electrical insulation breakdown or loss of serviceability. MV/HV extrinsic accelerated aging of organic insulation is mainly due to partial discharges (PD). Their presence, even if not promoting immediate breakdown, is almost a certain cause of apparatus life not matching specifications. This paper focuses on energizations on HVDC insulation systems, and, in general, supply voltage variations, which could be affected by PD due to manufacturing, laying, interface, or structural defects (as butt gaps). To minimize PD inception risk, a theory-driven, stepwise voltage application concept is proposed. The basic idea arises from the consideration that the factor playing a key role in PD inception is the jump voltage, and the electric field distribution in insulation during voltage transients is driven by permittivity (capacitance). Thus, energizing an insulation system with a first step lower than the partial discharge inception voltage in AC ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PDIV<sub>AC</sub></i> ) and then growing voltage by smaller steps minimizing jump voltage would allow almost PD-free operation (apart from the risk of low-repetition PD at DC steady state if nominal voltage exceeds <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PDIV<sub>DC</sub></i> ). The effectiveness of this approach is proved by means of tests carried out on a simple test object consisting of flat XLPE (Crossed Linked Polyethylene) specimens with electrodes designed to cause surface PD, having available an innovative PD detection system which performs automatically and effectively both during voltage transients and in DC steady-state conditions. The experimental results show that the stepwise voltage energization, compared to the single step energization, could decrease significantly the number and magnitude of detected PD during energization transients, leading therefore the reduction of one order of magnitude of PD associated energy and relevant damage. Partial discharge ; Electrical engineering ; Voltage ; Insulation system ; Decoupling (probability) ; Capacitor ; High voltage ; Computer science ; Transformer ; Reliability engineering ; Engineering ; Control engineering High voltage insulation and dielectric phenomena ; Electrostatic Discharge in Electronics ; Lightning and Electromagnetic Phenomena
Authors: Chin-Yuan Ong | Chun-Shing Lee | Xin-Yuan Gao | Qiang Zhai | Z. Yu | Rui Shi | Hai-Yao Deng | Chi-Hang Lam
Source: Physical review. E (article, 2024-05-23)
Field: Materials Science — Materials Chemistry

Relating fragile-to-strong transition to fragile glass via lattice model simulations Glass formers are, in general, classified as strong or fragile depending on whether their relaxation rates follow Arrhenius or super-Arrhenius temperature dependence. There are, however, notable exceptions, such as water, which exhibit a fragile-to-strong (FTS) transition and behave as fragile and strong, respectively, at high and low temperatures. In this work, the FTS transition is studied using a distinguishable-particle lattice model previously demonstrated to be capable of simulating both strong and fragile glasses [C.-S. Lee, M. Lulli, L.-H. Zhang, H.-Y. Deng, and C.-H. Lam, Phys. Rev. Lett. 125, 265703 (2020)0031-900710.1103/PhysRevLett.125.265703]. Starting with a bimodal pair-interaction distribution appropriate for fragile glasses, we show that by narrowing down the energy dispersion in the low-energy component of the distribution, a FTS transition is observed. The transition occurs at a temperature at which the stretching exponent of the relaxation is minimized, in agreement with previous molecular dynamics simulations. Condensed matter physics ; Lattice (music) ; Glass transition ; Statistical physics ; Transition (genetics) ; Fragile x ; Materials science ; Physics ; Chemistry ; Composite material Material Dynamics and Properties ; Glass properties and applications ; Theoretical and Computational Physics
Authors: Shima Mirzaei | Shirin Moradi | Morteza Karimi | Sara Esmaeili | Nazim S. Gruda | Sasan Aliniaeifard
Source: Agronomy (article, 2024-01-31)
Field: Chemistry — Analytical Chemistry

Gamma-Aminobutyric Acid-Mediated Alkalinity Stress Alleviation in Lollo Rosso Lettuce under Diverse Light Spectra The agricultural sector faces challenges due to climate change and the growing global population. Alkaline stress could adversely impact plant growth and crop production. This stressor diminishes water quality essential for crop cultivation, consequently impairing plant growth and overall productivity. Gamma-aminobutyric acid (GABA), a non-protein amino acid, may exhibit multifaceted roles in plant responses to adverse environmental conditions. Optimization of crop production in controlled environmental agriculture under artificial light attracted much attention. In the present study, we investigated the effects of different light spectra and GABA concentrations on Lollo Rosso lettuce plants under alkaline stress. Seedlings were placed under different light spectra [red (R), blue (B), white (W), 3R:1B, and 2R:1B:1far red (FR)] and treated with GABA (0 and 50 µmol). Alkaline conditions were instituted by applying NaHCO3 at a concentration of 40 mM. The experiment incorporated a control treatment without NaHCO3. In general, R light exposure caused the highest growth performance of lettuce plants. GABA augmented biomass production in control and alkaline-treated plants across all light spectra. Additionally, it increased the concentrations of photosynthetic and protective pigments under alkaline conditions. GABA also improved the photosynthetic performance under all light spectra. Non-photochemical quenching and pigmentation were enhanced by exposure to B light, especially in plants treated with GABA. Alkaline stress induced an increase in soluble carbohydrate content in the lettuce leaves. These findings highlight the support of GABA application in facilitating coping plants to alkaline stress. Alkalinity ; Stress (linguistics) ; Chemistry ; Botany ; Agronomy ; Biology Spectroscopy and Chemometric Analyses