Miracle-dz/UniFAR-FTUs huggingface dataset:
Ab initio calculations of 6‐ and 7‐carbon meteoritic amino acids and their diastereomers

Abstract– To better explain the unusual distribution and relative abundances of several 6‐ and 7‐carbon amino acids found in meteorites, their thermodynamic properties were studied using accurate ab initio techniques. In addition to optimized structures and relative energies, vibrational frequency and thermochemical analysis of different diastereomers were performed at temperatures relevant to conditions of synthesis of these amino acids in meteorites. The results of calculations were compared with the measured content of the amino acids in the Murchison meteorite. The distribution of several longer chain amino acids in meteorites seems to point to at least some thermodynamic control in their formation. For diastereomeric compounds, on the other hand, the comparison suggests that their synthetic conditions, or those of their precursors, were far from thermodynamic equilibrium.
Frequency dependent Kelvin probe force microscopy on silicon surfaces

At the example of cross-sectionally prepared p-p+-silicon epilayers on silicon, this work studies the frequency dependence of the contact potential difference detected in Kelvin probe force microscopy. The experimental setup employs a single-path off-resonance technique, which has been modified in order to enlarge the frequency range to 1–330kHz. It works with stiff cantilevers at approximately 340kHz resonance frequency and electrical signal amplitudes below 20pm. The setup utilizes multiple-channel digital lock-in amplification and a dedicated background correction, whose principle and experimental realization is described in detail and whose effect on the contact potential difference results is studied exemplarily.
Bioprinting oxygen releasing microparticles for improved cell tissue viability

by DANIEL REYNA SORIANO A major challenge in regenerative medicine/tissue engineering is the difficulty of providing adequate oxygen to all cells within implanted engineered tissues before full vascularization is achieved. To overcome this limitation, a variety of oxygen-releasing particles have been developed to improve cell and tissue survival. However, most of these particles are used in random mixtures within scaffolding materials, which usually leads to an uneven distribution of oxygen in bioengineered tissues. An ideal oxygen supply requires a precise depositing control of oxygen-releasing particles in scaffolds. Cell bioprinting is a novel tissue fabrication approach, in which the bio-printer can be programmed to deposit cells and/or biomaterials of various types and sizes in a very precise manner. In this study we have applied the inkjet printing technology to deposit calcium peroxide (CaO2) using various designed concentrations. On top of that, a hydrogel was deposit to provide encapsulation enabling progressive oxygen release. Various rates were utilized searching for optimal cell viability and growth in a period of 10 days under hypoxic environment (~1%O2). This controlled oxygen-releasing platform (CaO2 two printing times scaffold) increase levels of cell viability by approximately 300% in comparison to control samples without CaO2 present during the experiment. In vii consequence, these biomaterials were able to extend cell viability and growth under hypoxic conditions. Results indicate the use of bio-printing technology to precisely deposit oxygen exerting biomaterials in vitro. Such technology shows promising application in regenerative medicine/tissue engineering where currently oxygen diffusion limits the engineering of tissue implants.
MIXED CONVECTIVE HEAT AND MASS TRANSFER FLOW OF A VISCOUS FLUID IN A VERTICAL CHANNEL WITH THERMAL RADIATION AND SORET EFFECT

W e made an attempt in this dissipation study effect of radiation and thermo-diffusion on non-Darcy convective heat and mass transfer flow of a viscous, electrically conducting fluid through a porous medium in a vertical channel in the presence of heat generating sources. The governing equations flow, heat and mass transfer are solved by using regular perturbation method with δ, the porosity parameter as a perturbation parameter. The velocity, temperature, concentration, shear stress and rate of Heat and Mass transfer on the walls are evaluated numerically for different variations of parameter.
A method for estimating the diffuse attenuation coefficient (KdPAR) from paired temperature sensors

A new method for estimating the diffuse attenuation coefficient for photosynthetically active radiation (KdPAR) from paired temperature sensors was derived. We show that during cases where the attenuation of penetrating shortwave solar radiation is the dominant source of temperature changes, time series measurements of water temperatures at multiple depths (z1 and z2) are related to one another by a linear scaling factor (α). KdPAR can then be estimated by the simple equation KdPAR = ln(α)/(z2−z1). A suggested workflow is presented that outlines procedures for calculating KdPAR according to this paired temperature sensor (PTS) method. This method is best suited for conditions when radiative temperature gains are large relative to physical noise. These conditions occur frequently on water bodies with low wind and/or high KdPARs but can be used for other types of lakes during time periods of low wind and/or where spatially redundant measurements of temperatures are available. The optimal vertical placement of temperature sensors according to a priori knowledge of KdPAR is also described. This information can be used to inform the design of future sensor deployments using the PTS method or for campaigns where characterizing sub‐daily changes in temperatures is important. The PTS method provides a novel method to characterize light attenuation in aquatic ecosystems without expensive radiometric equipment or the user subjectivity inherent in Secchi depth measurements. This method also can enable the estimation of KdPAR at higher frequencies than many manual monitoring programs allow.
Kinetic Modeling of Slow Energy Release in Non-Ideal Carbon Rich Explosives

We present here the first self-consistent kinetic based model for long time-scale energy release in detonation waves in the non-ideal explosive LX-17. Non-ideal, insensitive carbon rich explosives, such as those based on TATB, are believed to have significant late-time slow release in energy. One proposed source of this energy is diffusion-limited growth of carbon clusters. In this paper we consider the late-time energy release problem in detonation waves using the thermochemical code CHEETAH linked to a multidimensional ALE hydrodynamics model. The linked CHEETAH-ALE model dimensional treats slowly reacting chemical species using kinetic rate laws, with chemical equilibrium assumed for species coupled via fast time-scale reactions. In the model presented here we include separate rate equations for the transformation of the un-reacted explosive to product gases and for the growth of a small particulate form of condensed graphite to a large particulate form. The small particulate graphite is assumed to be in chemical equilibrium with the gaseous species allowing for coupling between the instantaneous thermodynamic state and the production of graphite clusters. For the explosive burn rate a pressure dependent rate law was used. Low pressure freezing of the gas species mass fractions was also included to account for regions where the kinetic coupling rates become longer than the hydrodynamic time-scales. The model rate parameters were calibrated using cylinder and rate-stick experimental data. Excellent long time agreement and size effect results were achieved.
Global Warming of 1.5oC

Climate models project robust differences in regional climate characteristics between present-day and global warming of 1.5°C, and between 1.5°C and 2°C. These differences include increases in: mean temperature in most land and ocean regions (high confidence), hot extremes in most inhabited regions (high confidence), heavy precipitation in several regions (medium confidence), and the probability of drought and precipitation deficits in some regions (medium confidence).
The band gap of Cu2ZnSnSe4: Effect of order-disorder

The order-disorder transition in kesterite Cu2ZnSnSe4 (CZTSe), an interesting material for solar cell, has been investigated by spectrophotometry, photoluminescence (PL), and Raman spectroscopy. Like Cu2ZnSnS4, CZTSe is prone to disorder by Cu-Zn exchanges depending on temperature. Absorption measurements have been used to monitor the changes in band gap energy (Eg) of solar cell grade thin films as a function of the annealing temperature. We show that ordering can increase Eg by 110 meV as compared to fully disordered material. Kinetics simulations show that Eg can be used as an order parameter and the critical temperature for the CZTSe order-disorder transition is 200 ± 20 °C. On the one hand, ordering was found to increase the correlation length of the crystal. But on the other hand, except the change in Eg, ordering did not influence the PL signal of the CZTSe.
Effects of Soil Salinity on Growth, Ion Relations, and Compatible Solute Accumulation of Two Sumac Species: Rhus glabra and Rhus trilobata

The effects of soil salinity on growth, photosynthetic pigments, ion relations, and compatible solute accumulation of two sumac seedlings (Rhus glabra and Rhus trilobata) treated with five salinity levels in a completely randomized block design with four replications were studied. Both species were inhibited by soil salinity, but salt-damaged symptoms appeared much earlier and more severely in R. glabra, and relative height growth rates (RGRH) and photosynthetic pigment contents were much higher on average in R. trilobata. The biomass increment, root/shoot ratio, and relative shoot dry weight (DW) were significantly affected only in R. glabra. Rhus trilobata showed stable potassium (K+) concentration and low sodium (Na+) accumulation in roots, stems, and leaves, and a proline concentration 10 times greater than that of R. glabra. Overall, our findings suggest that R. trilobata is more salt-tolerant than R. glabra, which is presumably rooted in its better performance in ionic homeostasis and osmotic regulation.
Anisotropic Thermal Diffusivity and Conductivity of YBCO(123) and YBCO(211) Mixed Crystals. II

The electron and phonon contributions to the thermal conductivity and diffusivity of the YBa2Cu3O7-x (YBCO(123)) matrix phase in the mixed crystal were separated by use of the Kadanoff theory. The phonon mean free path l ph and the phonon relaxation time τ ph were determined. The phonon thermal conductivity and diffusivity were analyzed based on the Tewordt and Wölkhausen theory to estimate the electron-phonon coupling parameter λ and the strength of the various phonon scattering mechanisms.
AQUASIM-a tool for simulation and data analysis of aquatic systems

A survey over the capabilities of a new simulation and data analysis program for laboratory, technical and natural aquatic systems is given. In this program, the spatial configuration of a model system is represented by compartments, which are connected by links. The program allows the user to define an arbitrary number of substances to be modelled and it is extremely flexible in the formulation of transformation processes. It not only offers the possibility of performing simulations of the time evolution of the user-specified system, but it provides also methods for system identification (sensitivity analysis and automatic parameter estimation) and it allows us to estimate the uncertainty of calculated results. These features, together with the user-friendly interface, very much support scientist in analyzing their data. Three examples illustrate the capabilities of the program.
Understanding language through visual imagination

This thesis introduces a multimodal approach to natural language understanding by presenting a generative language–vision model that can generate videos for sentences and a comprehensive approach for using this capability to solve natural language inference, video captioning and video completion without task-specific training. The only training required is for acquiring a lexicon from captioned videos similar to the way children learn language through exposure to perceptual cues. The model generates videos by sampling the visual features of objects described in the target sentences over time. The evaluation results show that the model can reliably generate videos for sentences describing multiple concurrent and sequential actions, and that the ability to reason about language using visual scenes enables language tasks to be reduced to vision tasks and be solved more robustly using information obtained via vision. Thesis Supervisor: Boris Katz Title: Principal Research Scientist
PROCEEDINGS OF THE 3RD INTERNATIONAL CONFERENCE ON MOLECULAR SIMULATION Conformational search simulations of Trp-cage using genetic crossover

We applied an effective conformational sampling method using genetic crossover to Trp-cage mini-protein. In this method, we incorporate the genetic crossover, which is one of the operations of genetic algorithm, in parallel molecular dynamics simulations. The genetic crossover can search the global conformational space by exchanging the corresponding parts between a pair of conformations of a protein. In this study, we applied this method to an a -helical protein, Trp-cage mini protein, which has 20 amino-acid residues. The conformations obtained from the simulations are in good agreement with the experimental results
Paralleling control technique with no intercommunication signals for resonant controller-based inverters

Paralleling inverters remains a challenging task despite the advances that have proposed techniques based on frequency and amplitude droop methods. Problems arise when high performance inverters with very low output impedance (such as those employing resonant controllers) are to be directly connected in parallel through a near zero impedance cable. The present paper proposes a solution that retains most of the benefits of using resonant controllers while allowing good sharing when inverters are locally paralleled with very low or near zero impedance connection between them. Low THD content and good current sharing are simultaneously obtained by controlling the load angle through an LMS estimator and by synthesizing a variable inductance in series with the output impedance of the inverter, while the harmonic current sharing is achieved by controlling the gain of the resonant controllers at the selected frequencies. The method can be used with only a single voltage loop or it can be used in a high performance multi-loop approach.
Kinetics of Active Oxygen Species with Implications for Atmospheric Ozone Chemistry

Photochemical processes involving singlet oxygen (O2(a1Δ)), oxygen atoms, and ozone are critical in determining atmospheric ozone concentrations. Here we report on kinetic measurements and modeling that examine the importance of the reactions of vibrationally excited ozone. Oxygen atoms and O2(a1Δ) were produced by UV laser photolysis of ozone. Time-resolved absorption spectroscopy was used for O3 concentration measurements. It was found that vibrationally excited ozone formed by O + O2 + M O3(ν) + M recombination reacts effectively with O2(a1Δ) and O atoms. The reaction O3(υ) + O2(a1Δ) O + 2O2 results in a reduction of the ozone recovery rate due to O atom regeneration, whereas the reaction O3(υ) + O 2O2 removes two odd oxygen species, resulting in incomplete ozone recovery. The possible impact of these reactions on the atmospheric O2(a1Δ) and O3 budgets at altitudes in the range of 80–100 km is considered.
Flow characterisation of flames in an acoustically excited chamber

Flame-acoustic wave interactions have been studied widely in the combustion community; however the whole physicochemical mechanism is still not clear. The present research aims to further investigate the unfinished areas and focus on the acoustic excitation effect on flow and flame characteristics. An experimental approach has been adopted, and the results have been analysed and discussed. PIV diagnostic system and high speed schlieren visualisation system have been applied and built together with a signal synchronisation system which enables the phase-locked observation. The acoustic field and the interactions between acoustic waves and flames in an acoustically excited tube were studied in detail. The acoustic wave induced by external excitation and its effect on both cold jet fuel flow and jet flames have been investigated. Results indicate that the flame behaviour is affected mostly by the variation of the excitation frequency. The infrasound (Frequency < 20 Hz) was observed to have less influence on air motion. The natural flame flicker was suppressed by the forcing infrasound because of the excitation effect on the fuel jet. In the case of harmonic frequencies at which a standing wave is formed, the ambient air and flame were less affected by the excitation in the velocity node area. In contrast, the cold fuel jet, flame and ambient air experienced large velocity variations in the anti-node area. At non-resonant frequencies, which are between the 1st and 2nd harmonic frequencies (65 Hz to 220 Hz), the flame pattern and luminosity were very different in each excitation case. The frequency analysis of flames has shown that flame/acoustic coupling behaviour results in a complex nonlinear coupling effect. The excitation frequency may be coupled with the sub-harmonic frequencies and the flame flickering frequency. These frequencies were then found to couple with each other and create complex nonlinear frequency couplings. It can be seen that the surrounding air, cold jet fuel flow and flames are strongly affected by the excitation frequencies, phase angles and the nozzle location relative to the tube, and the coupling effect creates complex flame dynamics.
A computational study on possible active species in nickel(II)-catalyzed 1-butene dimerization in [BMIM]+[AlCl4]− ionic liquid solution

The butene insertion step of nickel complex-catalyzed butene dimerization in the presence of a [BMIM]+[AlCl4]− ionic liquid has been studied using density functional theory. The possibility of anion coordination from the ionic liquid to the catalyst complex has explicitly been taken into account. The calculated relative energies of various possible active catalyst complexes suggest that anion coordination to the nickel center may be thermodynamically favorable. Phosphine-free complexes which are only coordinated by one or two anions are higher in energy and show higher activation barriers for butene insertion. The lowest activation barrier has been found for a mono-phosphine nickel complex. Explanations for the calculated barriers based on structural data are offered.
Analysis of the uptake of native versus modified albumin by renal tubular epithelial cells (LB59)

Albumin is most abundant protein in blood and plays important homeostatic roles in the regulation of oncotic pressure and as a carrier of many small proteins, peptides and hormones. Albumin in the circulation can be covalently modified at surface lysine residues and thus the circulation contains a mixture of native albumin (i.e. not modified) and modified albumin. A significant amount of albumin is lost from the blood each day as a result of the filtration occurring in the capillaries of the renal glomeruli. This filtered albumin in the early filtrate is thought to be mostly taken up by and degraded in the early renal proximal tubular epithelial cells, while a small proportion is excreted in the final urine. This degradation of albumin by proximal tubules operates via the megalin scavenger receptor and an endocytic pathway.
Electronic energy bands of metal hydrides — palladium and nickel hydride

Electronic energy band calculations for transition metal hydrides have provided a new theoretical understanding of these materials. The calculations show when the proton model has relevance and when the anion model is more appropriate, the essential feature being the structure of the hydride. The structure in turn is determined by the lowest energy state of the solid. The relative positions of the electronic energy levels are found to be a strong function of the interatomic distances. The relative stability and structures of the metal hydrides can be understood in terms of their band structures. The calculations lead to a unifying new model, the “band model”, for interpreting and understanding the electronic properties of these materials.Energy band calculations of the palladium‐hydrogen system for various structures have been carried out and illustrate the above conclusions. The calculations were carried out with the hydrogen atoms occupying various interstitial positions in the face centered cubic palladium lattice to represent varying hydrogen contents for PdHx (specifically, for x = 0.25, 0.75, 1.0, and 2.0). In contrast to the simple proton model for this system, the calculations are able to show why β‐phase PdH saturates at higher hydrogen concentrations than the known concentration of holes in palladium d bands. Calculations for nickel hydride also show why the simple bandfilling concept fails. This result is in agreement with recent experimental electronic specific heat measurements. Both systems demonstrate that the rigid band model is not applicable.
Determination of the absorption and reduced scattering coefficients of human skin and bladder by spatial frequency domain reflectometry

A non-invasive method to measure the optical properties of a turbid medium such as biological tissue is described. To determine the absorption and reduced scattering coefficient, the sample is illuminated with spatially intensity modulated light and the backscattered light is analyzed. The spatial modulation of the backscattered light and the diffuse reflectivity of the sample are used to deduce its optical coefficients from a table generated by Monte Carlo simulations. The sensitivity of the method is analyzed. Error influences on the method are investigated. The optical coefficients of human skin in vivo and of human bladder ex vivo are determined at 400, 500, 633, 700 nm and 633 nm respectively.
Green chemistry approach to synthesis of some new trifluoromethyl containing tetrahydropyrimidines u

A simple, efficient and modified Biginelli procedure was carried out for the synthesis of tetrahydropyrimidines 4a-o by a solvent-free and catalyst-free condition, by the condensation of 1,3-dicarbonyl compound 1, arylaldehydes 2 and urea/thiourea 3. Neat reactants subjected to microwave irradiation gave the required products more quickly and in better yield in comparison to traditional methodologies. The observed yields and improvement in reaction rates are due to the solvent free conditions coupled with the use of microwave radiation.
Mark–Houwink Parameters of Biosynthetic Poly(γ‐glutamic acid) in Aqueous Solution

A combined viscosity–light scattering–gel permeation chromatography (GPC) study was carried out on bacterially produced poly(γ-glutamic acid) (PGGA). PGGA samples with weight-average molecular weights ranging from 8×104 up to 8×105 g·mol–1 dissolved in phosphate buffer at 0.13 M ionic strength were used. It was found that the Mark–Houwink relation is acceptably obeyed, giving K and a values of 1.84×10–6 dL·g–1 and 1.16, respectively. As expected, GPC analysis showed that PGGA does not follow the universal calibration plot and that deviations can not be avoided by modifying the ionic strength.