Miracle-dz/UniFAR-FTUs huggingface dataset:
Using Symmetry to Accelerate Materials Discovery

Using Symmetry to Accelerate Materials Discovery Wiley Spencer Morgan Department of Physics and Astronomy, BYU Doctor of Philosophy Computational methods are commonly used by materials scientists to make predictions about materials. These methods can achieve in hours what would take days or weeks to accomplish in a lab. However, there are limits to what computational methods can do and how accurate the predictions are. A limiting factor for computational materials science is the size of the search space. The space of potential materials is infinite. Selecting specific systems of elements on a fixed lattice to study reduces the number of possible arrangements of atoms in the lattice to a finite number. However, this number can still be very large. Additionally this list of arrangements will contain duplicates, i.e., two different atomic arrangements could be equivalent by a rotation or translation of the lattice. Using symmetry to eliminate the duplicates saves time and resources. In order to ensure that the final list of unique structures will fit into computer memory it is also useful to know how many unique arrangements there are before actually finding them. For this reason the Pòlya enumeration algorithm was created to determine the number of unique arrangements before enumerating them. A new atomic enumeration algorithm has also been implemented in the enumlib package. This new algorithm has been optimized to find the symmetrically unique arrangements for systems with large amounts of configurational freedom, such as high-entropy alloys, which have been too computationally expensive for other algorithms. A popular computational method in materials science is Density Functional Theory (DFT). DFT codes perform first principles calculations by calculating the electron energy using numerical integrals. It is well known that the accuracy of the integrals depends heavily on the number of sample points, k-points, used. We have conducted a detailed study of how k-point sampling methods effect the accuracy of DFT calculations. This study shows that the most efficient k-point grids are those that have the fewest symmetrically distinct k-points, we call these general regular (GR) grids. GR grids are, however, difficult to generate, requiring a search across many possible grids. In order to make GR grids more accessible to the DFT community we have implemented an algorithm that can search k-point grids for the grid that has the fewest symmetry reduction in a matter of seconds.
Determination of Rafoxanide in Plasma Using High Performance Liquid Chromatography (HPLC) and in Tissue Using HPLC-Thermospray Mass Spectrometry

Abstract Methods are described for the determination in plasma and tissue samples, of the drug rafoxanide which is used to control liver fluke in sheep and cattle. HPLC with UV detection is used to measure levels of the drug in plasma and combined HPLC-thermospray mass spectrometry is used to measure residue levels in tissue. The methods are both specific and sensitive with detection limits of 0.1 ug ml−1 for plasma and 0.02 ug g−1 for tissue.
A one-step practical strategy to enhance overall supercapacitor performance

We introduce a straightforward strategy to simultaneously improve the capacitance, rate capability, and cycle life of a supercapacitor by simply electrodepositing Ni-nanoparticles (Ni-NPs) on an as-prepared electrode. 3D-structured current collectors such as metal foams, metal meshes, and carbon meshes have been widely used in supercapacitors, secondary batteries, glucose sensors, etc. In particular, the 3D-metal foam readily improves device properties due to its unique 3D-nature and high surface area. However, there are practical constraints when applying 3D-current collectors to the industrial world, including high cost. Here, by simply electrodepositing Ni-NPs in a cost-efficient manner, a similar effect to that derived with the use of 3D-metal foam was realized. After deposition, Ni-NPs are preferentially located near the contact area between the active materials and a plate-type current collector, which allows for tight binding between the active materials and the current collector as well as facile charge transfer and high capacitance. The Ni-deposited Ni(OH)2 electrode pasted on a plate metal substrate showed 350% increased capacitance (1264 F g−1) and stability of 75% and 72% after 10 000 cycles and at a high current density of 20 A g−1, respectively. Given the simplicity and cost-efficiency of this method, it can be readily applied to other energy storage devices with practical applications in the industrial world.
Simple Rapid Validated RP-LC Method for the Estimation of Flurbiprofen in Rabbit Serum and Aqueous Humor

Abstract New reversed-phase liquid chromatographic methods, with UV detection, were developed for the quantitative estimation of flurbiprofen in rabbit blood serum and aqueous humor. The mobile phase and other chromatographic conditions were optimized to minimize interference from biological matrix and at the same time provide sufficient sensitivity for the method to be adopted for in vivo studies of ophthalmic formulations of flurbiprofen. Acetonitrile was used to precipitate proteins from serum or aqueous humor during sample preparation. A mobile phase of methanol: acetonitrile: phosphate buffer pH 5.6 (40:20:40) was employed with UV detection at 248 nm for estimation of drug in both the biological matrix. The retention time and asymmetry factor for the proposed method of estimation in serum and aqueous humor was found to be 3.1312±0.0101 min and 1.1310±0.0091 respectively. The linear regression equations obtained by least square regression method, were Area (µV sec) = 52.27 × Conc. (in ng/ml)–1618.70 in serum and Area (µV sec) = 61.79 × Conc. (in ng/ml) − 783.24 in aqueous humor. The results of analysis were treated statistically, as per ICH guidelines for validation of analytical procedures, USP-2003, and by recovery studies. The results were found to be accurate, reproducible and free from interference. The developed methods were further used for estimation of flurbiprofen in rabbit serum and aqueous humor following single topical administration of in-house aqueous drop and market formulation to rabbit eye.
Self-interaction-corrected local density approximation pseudopotential calculations of the structural phase transformations of ZnO and ZnS under high pressure

The structural phase transformations under high pressure of ZnO and ZnS have been investigated by using the Vogel-Kruger-Pollmann (VKP) scheme, in which the electronic self-interaction correction to the local density approximation (LDA) is introduced in a non-self-consistent manner within the pseudopotential approach. In these calculations, I have used highly optimized pseudopotentials and a plane-wave expansion of the wavefunctions. Moreover, the electronic structures of the zinc-blende (ZB) and rock-salt (RS) phases of both compounds have been similarly calculated. It has been found that the VKP scheme provides a highly improved description, relative to the LDA results, for the structural and electronic structure properties of the considered systems. However, the so-calculated transition pressures of the ZB-to-RS transition for both ZnO and ZnS are found to be significantly larger than the experimental data. RS-ZnO is predicted to be an indirect-gap semiconductor, with a wide band gap of 4.2 eV.
On-Line Measurements of the Polycyclic Aromatic Hydrocarbons (PAH) in Counter-Flow Ethylene Diffusion Flame

Abstract The detailed structure of counter-flow, ethylene diffusion flame has been studied under atmospheric conditions. The temperature and mole fraction profiles of major, minor, aromatic and polycyclic aromatic hydrocarbon (PAH) species have been determined under the strain rate of 56.6 s−1. Flame sampling was achieved by using a heated quartz microprobe connected to a silica-coated stainless steel sampling line which transferred the sample to an on-line Gas Chromatograph/Mass Spectrometer (GC/MS). Rapid insertion method was used to obtain the temperature profiles with a silica coated Pt/Pt+139% Rh thermocouple. Visually, the flame showed 3 different color zones: Blue, yellow and orange. The blue zone with a maximum flame temperature of 1577°C was located in the oxidizer side of the flame. The most abundant hydrocarbon pyrolysis product was C2H2, which was located in the yellow zone. Benzene was measured as the most abundant aromatic species with 220 ppm maximum level, located in the yellow zone. Naphthalene (50 ppm) and pyrene (5 ppm) were the most abundant PAH formed. Increasing strain rate resulted in decreasing residence times and cooler flame temperature thereby leading to die observation of fewer number and lower peak levels of aromatics and PAH when compared to the lower strain rate ethylene flame studied before (Olten and Senkan, 1999).
Recovery of CaO by Reductive Decomposition of Spent Gypsum in a CO−CO2−N2 Atmosphere

Reductive decomposition of spent CaSO4 was studied using a packed-bed reactor to regenerate an alternative CaO sorbent. The reactor was operated at various process conditions including an increasing CO concentration, CO/CO2 concentration ratio (0.067−1), and temperature (1123−1273 K). In all cases, N2 was used as a balancing gas. The regeneration of CaO from CaSO4 was found to be most effective in the CO−CO2−N2 atmosphere and strongly depended on the CO/CO2 concentration ratio. At 1273 K, an apparent conversion value of 0.91 for the decomposition of CaSO4 to CaO was obtained in a 2 vol % CO and 30 vol % CO2 atmosphere. On the other hand, in a CO−N2 atmosphere, CaS was predominantly produced. The SO2 absorption capacity of CaO regenerated from CaSO4 was higher than that of limestone-calcined CaO. A larger pore diameter of the regenerated CaO was considered to be responsible for the higher SO2 absorptivity.
Quantum Chemical Calculation of O-H Vibration in LiOH Ab-initio Analysis of Hydrogen Isotopes in Ceramic Breeder Materials

The stretching vibrational frequency of O-H in LiOH crystal was calculated using CRYSTAL98 code. Hartree-Fock (HF) and hybrid (B3LYP) methods were used. By taking account of reduced mass, O-D or O-T frequencies could be also estimated. The obtained O-D frequencies were 2,994 cm-1 in HF level and 2,740 cm-1 in B3LYP. Agreement with experimental data, 2,713 cm-1 reported by Buchanan et al., was much better in B3LYP than in HF. The result of the present calculation supported the assignment in our previous FT-IR study, where O-D vibration in the Li2O single crystal that was treated by thermal absorption of D2 was observed. The peak observed at 2,715 cm-1 was attributed to O-D in LiOD phase. The present study showed that the quantum chemical analysis combined with the FT-IR was a powerful tool to study the behavior of hydrogen isotopes in the ceramic breeder materials.
Tris(2-hydroxy­anilinium) hexa­chloro­stannate(IV) chloride trihydrate

In the title compound, (C6H8NO)3[SnCl6]Cl·3H2O, the asymmetric unit contains three independent cations of protonated o-amino­phenol, one hexa­chloro­stannate(IV) and one chloride anion, and three mol­ecules of water. The crystal structure can be described as double layers of [SnCl6] octa­hedra and 2-hydroxy­anilinium cations parallel to the (10\overline{1}) plane, with the chloride ions and the water mol­ecules sandwiched between the double layers. A myriad of hydrogen bonds, namely, cation–cation, cation–anion, cation–water and water–water, result in a complex network of inter­molecular bonds reinforcing the cohesion of the ionic structure.
Excluded‐Volume Effect for Two‐ and Three‐Dimensional Lattice Models

An analysis is undertaken of mean‐square sizes of self‐avoiding walks enumerated exactly on various two‐ and three‐dimensional lattices. It is suggested that for all three‐dimensional lattices the mean‐square size tends to an asymptotic relation 〈rn2〉≃A1n6/5+A2, while for two‐dimensional lattices the corresponding relation is 〈rn2〉≃B1n3/2+B2n. The constants A1, B1 decrease as the coordination of the lattice increases. Estimates of A1, A2 are given for the fcc, bcc, simple cubic, and diamond lattices, and of B1, B2 for the triangular and simple quadratic lattices.
Energy transformations in two tropical Oxbow lakes

The flow and pattern of energy utilization in two tropical ecosystems where polyculture of fishes was practiced were studied. The rates of organic production made by the two tropical natural aquatic systems (oxbow lakes) were studied for two annual cycles. The study of utilization of energy in two tropical lakes revealed that herbivores were more efficient in energy utilization than autotrophs. The energy available in these systems was supplied by allochthonous source. Silver carp and grass carp were found to be most efficient in conversion of energy in the grazing food chain of the lake. The efficiency of the system to fish production was found to be 0.06 (OL-I) −0.05% (OL-II) of the total available solar radiation. Various forms of life are all accompanied by energy changes, in the studied lakes were found to form a food web.
Qualidade tecnológica de grãos e farinhas de trigo nacionais e importados Technological quality of national and imported wheat grain and wheat flours

Abstract Wheat flour has a wide range of applications in the food industry, with an important economic and nutritional role in the human diet. It is known that the nutritional and technological aspects of wheat flour depend on the cultivation, harvesting, drying and storage conditions of the wheat grains used as raw material. This research aimed at analyzing the technological quality of samples of national and imported wheat grains, as well as of flour samples obtained from them. For this, physical-chemical (moisture, wet gluten, mineral content, falling number, hectoliter weight) and farinographic (water absorption, development time, stability) analyses were carried out. Physical-chemical analyses showed significant differences (p < 0.05) in the mineral content, wet gluten and falling number of the imported and national grain samples, and also among the flour samples obtained from them. Moisture was the only physical-chemical parameter that did not present a significant difference (p < 0.05) among the national and imported samples. Imported wheat grains and their flours presented higher values for wet gluten (28.0-33.4 %) and falling number (322.33-428.33 seconds), when compared to the national samples. Farinographic analyses showed a significant difference (p < 0.05) in water absorption, development time and stability among the national and imported wheat flour samples. Moreover, the farinographic analyses presented noteworthy values for water absorption (54.43-59.30 %) and stability (10.0-24.75 minutes) for the imported wheat flours. These results showed a lower technological quality of the national wheat grains and flours studied, when compared to the imported samples, with a negative interference in their industrial use and economic value.
Two-dimensional NMR studies of native coenzyme F430

Modern two-dimensional (2D) NMR spectroscopic methods are used to determine signal assignments and structural features of the recently discovered nickel(II)-containing coenzyme F430. This is the first detailed {sup 1}H and {sup 13}C NMR study of the native form of coenzyme F430. With the use of COSY, HOHAHA, NOESY, and ROESY {sup 1}H-{sup 1}H correlated spectroscopies in combination with HMQC and HMBC {sup 1}H-{sup 13}C correlated spectroscopies, signal assignments were made for all carbon atoms and nonexchangeable protons. The data confirm 16 of the 21 specific {sup 13}C NMR signal assignments made earlier for native F430 by classical 1D NMR methods and provide assignment (or reassignment) of the remaining carbon atoms. The {sup 1}H NMR signal assignments reported here are in good agreement with the partial assignments reported previously for the pentamethyl ester derivative of F430 (F430M) in CD{sub 2}Cl{sub 2} solution. In addition, long-range through-bond {sup 1}H-{sup 13}C connectivities confirm aspects of the F430 structure deduced from studies of F430M by traditional spectroscopic and chemical methods.
Photothermal monitoring of respiratory chain redox state in single live cells

Due to the central role of respiratory chain (RC) in the metabolism of the cell, much attention has been directed at developing efficient techniques for diagnostics of RC at cell level. Proposed method of direct monitoring of the redox state of RC in single live cells is based on photothermal (PT) measurement of photo-induced thermal phenomena in mitochondrial hemoproteins. Thermal output of absorbed light energy depends upon their redox state (oxidized/reduced). PT microscopy method was applied for experimental studies of two in vitro models: (1) solutions of RC component - cytochrome c - and (2) for mice hepatocytes in suspension. Parameters of PT responses obtained from solution and from single cells after their irradiation with laser pulse (532 nm, 8 ns) were found to be different for oxidized and reduced forms for cytochrome c solutions and for KCN and Antimicine A treated cells in comparison to intact ones. This difference may be caused by alteration of the quantum yields of thermal (non-radiative) relaxation for light absorbing molecules - RC components - as they undergo redox state change under influence of RC inhibitors. Obtained results allow to suggest new approach for monitoring of functional activity of RC in single cell through the measurement of PT response at specific wavelengths.
Study on surface modification by surface‐modifying macromolecules and its applications in membrane‐separation processes

Surface-modifying macromolecules (SMMs) are oligomeric fluoropolymers synthesized by polyurethane chemistry and tailored with fluorinated end groups. In the literature, several formulations of SMMs have been developed and blended with base polymers of polyurethanes and polyethersulfone for surface modification. It has been shown that SMMs migrate to the surface and the fluorine end groups orient themselves toward the air–polymer interface, reducing the surface energy of the hydrophilic base polymer to values close to that of polytetrafluoroethylene (Teflon). Because only a small amount of SMMs was needed, the bulk properties of the base polymer remained relatively unchanged. The properties of the SMM polymers were characterized, including molecular weights, elemental analysis, and thermal transitions. The morphology and surface properties of the SMM-modified and unmodified membranes were assessed. The use of SMMs has been tested for use in ultrafiltration, pervaporation, and biomedical applications. SMM-modified membranes offer advantages over unmodified membranes and the use of SMMs will continue to be the focus of future studies. This study reviews the recent development of surface-modifying macromolecules (SMMs) and SMM-blended membranes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2902–2916, 2003
Nonblinking green emission from single H3 color centers in nanodiamonds

This work investigates the emission properties of single color centers in natural diamond nanoparticles for potential use as single photon sources and photostable biomarkers. Two emitters, H3 and H4, were identified by their sharp zero-phonon lines at 503 nm and 496 nm, respectively, in the photoluminescence spectra. Using a modified Hanbury Brown and Twiss setup, we observed complete photon antibunching for the H3 center. No fluorescence blinking was detected for a single H3 emitter on the ms timescale, indicating weak coupling between the electronic transition A11↔B11 and adjacent metastable states of this nitrogen-vacancy-nitrogen point defect.
Preparation of Porous Glass‐Ceramics with a Skeleton of NASICON‐Type Crystal CuTi2(PO4)3

A novel porous glass-ceramic with a skeleton of CuTi{sub 2}(PO{sub 4}){sub 3} was prepared by controlled crystallization of a glass and subsequent chemical leaching of the resulting dense glass-ceramic. A volume-crystallized dense glass-ceramic composed of CuTi{sub 2}(PO{sub 4}){sub 3} and Cu{sub 3}(PO{sub 4}){sub 2} whose surface was covered by a CuO thin layer was prepared by reheating a glass with a nominal composition of 50 CuO{center_dot}20TiO{sub 2}{center_dot}30P{sub 2}O{sub 5} (in mol%) glass in air. When the resultant glass-ceramic was leached with dilute H{sub 2}SO{sub 4}, Cu{sub 3}(PO{sub 4}){sub 2} and CuO phases were dissolved out selectively, leaving a crystalline CuTi{sub 2}(PO{sub 4}){sub 3} skeleton. The specific surface area and the average pore radius of the porous glass-ceramic obtained were approximately 45 m{sup 2}{center_dot}g{sup {minus}1} and 9 nm, respectively. The porous glass-ceramic showed catalytic activity in the conversion reaction of propene into acrolein.
Consistent formula for the refractive index of AlxGa1−xAs below the band edge

We present a semi‐empirical, analytic formula for the refractive index of AlxGa1−xAs below the band edge. The formula describes experimental refractive indices to within ±0.02 accuracy over the wavelength range from 1.5 to 0.75 μm and over the complete range of AlGaAs compositions.
A novel growth method for ZnAl2O4 single crystals

ZnAl2O4 is a well‐known wide band gap compound semiconductor (Eg=3.8eV), ceramic, opto‐mechanical, anti‐thermal coating in aero‐space vehicles and UV optoelectronic devices. A novel method for the growth of single crystals of a ternary oxide material was developed as a fruit of a long term work. Material to be grown as metal incorporated single crystal was taken as precursor and put into a bath containing acid as reaction speed up reagent (catalyst) as well as solvent with a metal foil as cation scavenger. Using this method, ZnAl2O4 crystals having hexagonal facets are prepared from a single optimized bath. Structural and compositional properties of crystals were studied using Philips, Xpert ‐ MPD: X‐ray diffractometer and Philips, ESEM‐TMP + EDAX. Thus technique was found to be a new low cost and advantageous method for growth of single crystals of ternary oxide a material. We hope that these data be helpful either as a scientific or technical basis in material processing.
Experimental Study of Turbulent Non-Turbulent Interface in a Planar Mixing Layer using Kinetic Energy Criteria

Using kinetic energy (KE) criteria, the Turbulent NonTurbulent Interface (TNTI) in a planar mixing layer has been identified and studied in this paper. The mixing layer is generated in a simple way by blocking the top half of the wind tunnel test section with a mesh of suitable solidity. High resolution particle image velocimetry (PIV) is used to acquire the velocity data. The threshold for identifying the interface is obtained using the area algorithm suggested by [2]. The mean and rms profiles of velocity and the spanwise vorticity with respect to the TNTI show finite jump at the interface location. The fractal dimension of the KE interface based on the box counting method is found to be ∼1.2.