Miracle-dz/UniFAR-FTUs huggingface dataset:
Electronic Circular Dichroism of Proteins from First-Principles Calculations

The circular dichroism (CD) spectra of 47 proteins in the far-ultraviolet have been calculated from first principles, using a parameter set derived from ab initio calculations on N-methylacetamide. These spectra agree well with experimental data, as shown by the Spearman rank correlation coefficients of 0.86, 0.80, and 0.94 between the computed and experimental intensities at 190, 208, and 220 nm, respectively. The computed spectra are most accurate for proteins that have a high α-helical content and are least accurate for a class of β-sheet-rich proteins, which have some irregular structure and are known as β-II proteins. To address the lack of resolution between the two negative peaks around 208 and 220 nm in the calculated spectra of α-helical proteins, narrower bandwidths have been explored. Other factors were investigated, including the dielectric constant of the protein, higher energy transitions of the amide chromophore, and the orientation of the ππ* electric transition dipole moment vector. Combi.
A new approach to the evaluation of the discharge parameters of the electrodeless fluorescent lamps

A new model was developed for the characterization and quantification of the 'inaccessible' discharge parameters in closed tube high power electrodeless fluorescent lamps. The results obtained applying the model are verifiable by means of a simple comparison of the primary equivalent resistance and reactance as a result of the measured V1, I1, 1 with the equivalent primary resistance and reactance inferred from the proposed model. The results are in good agreement at all operating lamp power levels. What is unexpected is the capacitive behaviour of the inductive coupled plasma at lower powers. The investigation method is suitable for the optimization of high power electrodeless lamps with a long discharge path operated at low frequencies, in order to improve the efficiency and the system stability, especially if the lamp has to be dimmed.
Comparison of Two Techniques to Develop Pedotransfer Functions for Water Retention

Two pedotransfer function (PTF) approaches can be used for obtaining the analytical expression of the whole retention curve: (i) soil basic data is used to estimate soil water retention at specific water potentials; and then an analytical expression of the retention curve is fitted to the estimated soil moisture values; and (ii) soil basic data is used for estimating the parameters of an analytical expression of water retention curves. The objective of this study was to compare the performance of both techniques using data representing the main Brazilian soils. First, we derived PTFs for the parameters of van Genuchten equation and for water contents at -6, -10, -33, -100, and -1500 kPa for the same development data set. Second, we compared the performance of both techniques for the same validation data set. The approach, based on the estimation of water contents at specific water potentials, provided better results: for the validation data set, this technique showed an average root mean squared error of 0.036 m 3 m -3 , compared with an averaged error of 0.098 m 3 m -3 of the technique based on the direct estimation of van Genuchten parameters. A possible explanation for this result might be related to the fact that soil moisture is controlled by different independent variables at different ranges of soil water potential, and those differences are not directly related to the van Genuchten parameters.
Au Nanoparticle-Based Surface Energy Transfer Probe for Conformational Changes of BSA Protein

In the present study, Au nanoparticle based surface energy transfer (SET) has been used to measure conformational changes in proteins. A significant photoluminescence (PL) quenching (91−97%) of tryptophan intensities of bovine serum albumin (BSA) protein is observed in the presence of Au nanoparticles, and the measured distances (r) between the donor (tryptophan) and the acceptor (Au nanoparticle) are 27.0, 22.9, and 25.7 A for E, N, and B forms of BSA protein, respectively. Results indicate that Au nanoparticle quenches BSA fluorescence mainly through a static quenching mechanism. Analysis suggests that binding constant and bound/unbound ratio varies with changing the conformation of protein. The PL quenching of dye varies from 47.2 to 86.6% with changing the conformation of protein without changing the radiative rate of dye. The measured distances (d) between the donor (dye) and the acceptor (Au nanoparticle) are 116.5, 76.1, and 86.4 A for E, N, and B forms of BSA protein, respectively, using the effic.
Colloidal Properties of Flocculent and Nonflocculent Brewing Yeast Suspensions

The orthokinetic flocculation rates of four suspensions of Saccharomyces cerevisiae and Saccharomyces uvarum (calsbergensis) were measured using steady shear rheometry and light microscopy. These results, along with cell ζ potential values previously reported by the authors, allowed us to test the applicability of DLVO (Derjaguin, Landau, Verwey, and Overbeek) mediated orthokinetic flocculation models. The findings also permitted examination of the validity of the elastic floe model and allowed estimation of the force required to separate cell doublets. Cellular suspensions of brewing yeast were subjected to a high shear treatment to reduce any floes to single cells. Periodic samples were then taken while shearing the suspension at 200 s−1, and the extent of flocculation was determined via light microscopy. The logarithm of floe concentration was linearly dependent on shearing time. It was possible to estimate orthokinetic capture coefficients (αo) for the four strains, with values ranging from 0.00025 to 0.0010. By using measured and “typical” colloidal parameters, a theoretical αo value was derived which was much lower than the experimental values (i. e., αot ≪ 0.0001). Thus, it was concluded that the DLVO flocculation model could not be used to explain brewing yeast flocculation. Flow behavior of the yeast suspensions followed the Bingham model above a critical shear rate. Values of this critical shear rate (which predicts the point at which cell doublets separate) were used to calculate the force required to separate doublet cells. A calculated force of 2.2 × 10−11 N was similar to that of lectin‐like bonds that are believed to be involved in yeast flocculation. As well, the elastic floe model could be employed to predict Bingham yield stress values.
Thermogelation hydrogels of methylcellulose and glycerol–methylcellulose systems

The effects of the concentrations of methylcellulose (MC) solutions and glycerol as a additive on gel properties were investigated with rheological, test-inversion-tube, and breakthrough-vacuum methods. The results showed that glycerol favored the sol–gel transition of MC solutions, and the gel temperature was approximately proportional to the glycerol volume ratio; however, the gel strength decreased as the glycerol volume ratio increased. To further understand the gel structure, rubber elasticity theory was cited and proved to be consistent with the experimental results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4120–4126, 2006
Low temperature‐coefficient for solar cells processed from solar‐grade silicon purified by metallurgical route

This study is dedicated to the temperature (T)‐variation of the photovoltaic performances of solar cells made from solar‐grade silicon directly purified by metallurgical route (SoGM‐Si). Experimental results were systematically compared with those for standard electronic‐grade silicon (EG‐Si) solar cells. We showed that the conversion efficiency (η) of SoGM‐Si cells decreases much less when T increases than the η of EG‐Si cells. This major difference is due to a strong increase with T of the short‐circuit current density (Jsc) of the SoGM‐Si solar cells. We showed that this a priori unexpected result could be described and explained by numerical simulations, by taking into account the main particularities of SoGM‐Si: dopant compensation, moderate minority carrier diffusion length and larger amount of boron–oxygen complexes. These results are significant since T of a solar module under illumination being generally higher than 25°C, modules made from low‐cost SoGM‐Si cells should have performances closer to those of standard EG‐Si solar panels. Copyright © 2011 John Wiley & Sons, Ltd.
Ru(III), Os(VIII), Pd(II) and Pt(IV) catalysed oxidation of glycyl–glycine by sodium N-chloro-p-toluenesulfonamide: comparative mechanistic aspects and kinetic modelling

The Ru(III)/Os(VIII)/Pd(II)/Pt(IV)-catalysed kinetics of oxidation of glycyl–glycine (Gly-Gly) by sodium N-chloro-p- toluenesulfonamide (chloramine-T; CAT) in NaOH medium has been investigated at 308 K. The stoichiometry and oxidation products in each case were found to be the same but their kinetic patterns observed are different. Under comparable experimental conditions, the oxidation-kinetics and mechanistic behaviour of Gly-Gly with CAT in NaOH medium is different for each catalyst and obeys the underlying rate laws: Rate = k [CAT]t [Gly-Gly]0 [Ru(III)][OH−]x Rate = k [CAT]t[Gly-Gly]x [Os(VIII)]y[OH−]z Rate = k [CAT]t[Gly-Gly]x [Pd(II)][OH−]y Rate = k [CAT]t[Gly-Gly]0 [Pt(IV)]x[OH−]y Here, and x, y, z Ru(III) > Pt(IV) > Pd(II). This trend may be attributed to the different d-electronic configuration of the catalysts. Further, the rates of oxidation of all the four catalysed reactions have been compared with uncatalysed reactions, under identical experimental conditions. It was found that the catalysed reaction rates are 7- to 24-fold faster. Based on the observed experimental results, detailed mechanistic interpretation and the related kinetic modelling have been worked out for each catalyst. Copyright © 2008 John Wiley & Sons, Ltd.
Influence of Chitosan Layer on the Properties of Surface Modified Poly(lactide-co-glycolide) Nanoparticles

The present study investigates the effect of chitosan coating layer on the properties of poly(lactic-co-glycolic acid) nanoparticles. Two concentrations of chitosan (0.1% and 0.5%) as well as two procedures, namely coating or post-coating were developed. The size of all chitosan modified particles was larger than the size of nonmodified PLGA-nanoparticles. The surface charge of the modified nanoparticles was positive (up to +57.0 mV) compared to the negative charge of PLGA-nanoparticles (−23.6 mV). The positive charge of all types of the modified particles decreased drastically 6 hours after incubation with a mucin, suggesting the electrostatic mechanism of their interaction.
Geologic Diversity of Arizona and its Margins: Excursions to Choice Areas

The 100th annual meeting of The Geological Society of America (GSA) was held in Phoenix, Arizona in October 1987. The occasion presented an opportunity for the organizing committee to provide, through 34 field trips, a comprehensive expose of the geology of Arizona. Thirty-three of the field guides to these trips are included herein. Field-trip plans were made with two chief goals in mind: to provide to participants a sense of the discovery and momentum that attend geologic research and exploration in the Southwest during this, the close of the first century of GSA; and to underscore the quality of geologic exposures and the natural aesthetic appeal of the Southwest in general and Arizona in particular. It seemed very appropriate that the 100th meeting of GSA be held in the Grand canyon State.
Laminar Flame Speeds of DMF/Iso-octane-Air-N2/CO2 Mixtures

Laminar combustion characteristics of 2,5-dimethylfuran (DMF)/iso-octane/air/diluent (15% N2/85% CO2) mixtures at atmospheric pressure and the initial temperature of 393 K were studied using the outwardly propagating spherical flame and high speed schlieren photography. Effects of DMF concentration in the fuel mixture and dilution ratio on flame properties were investigated, such as laminar flame speed, adiabatic temperature, effective Lewis number, and laminar flame thickness. Results show that laminar flame speed varied little, while the flame instability was slightly promoted as DMF concentration in the blends is increased. For all the fuels at fixed equivalence ratio, flame front morphology showed that the flame stability was enhanced with increasing dilution ratio. In addition, a linear relationship between the normalized laminar flame speed and the dilution ratio was found and an empirical formula was proposed for all the four different fuels at different equivalence ratios.
Community Structure of Ammonia Oxidizing Bacteria and Their Potential to Produce Nitrous Oxide and Carbon Dioxide in Acid Tea Soils

The potentials of nitrous oxide (N 2 O) and carbon dioxide (CO 2 ) production in acid tea soils from Indonesia and Japan were investigated in a laboratory incubation experiment, and the community structures of ammonia-oxidizing bacteria in these soils were characterized using PCR-DGGE approaches. The soils used were sampled from tea plantations in Shizuoka, Japan and in Bogor and Malino, Indonesia. All of the soils were acidic (pH 3.45 to 4.00). The N 2 O and CO 2 production in Shizuoka was almost 5 times higher than in Bogor and Malino. All of the amoA gene sequences defined belong to the genus Nitrosospira sp. with cluster 2 and cluster 3a.
EVALUATING FUTURE RESERVOIR STORAGE IN THE RIO GRANDE USING NORMALIZED CLIMATE PROJECTIONS AND A WATER BALANCE MODEL

We develop and implement new tools for assessing the future of surface water supplies in downstream reaches of the Rio Grande, for which Elephant Butte Reservoir is the major storage reservoir. First, a normalization procedure is developed to adjust natural Rio Grande streamflows simulated by dynamical models in downstream reaches. The normalization accounts for upstream anthropogenic impairments to flow that are not considered in the model, thereby yielding downstream flows closer to observed values and more appropriate for use in assessments of future flows in downstream reaches. The normalization is applied to assess the potential effects of climate change on future water availability in the Rio Grande Basin at a gage just above Elephant Butte reservoir. Model simulated streamflow values were normalized force simulated flows to have the same mean and variance as observed flows over a historical baseline period, yielding normalization ratios that can be applied to future flows when water management decisions are unknown. At the gage considered in this study, the effect of the normalization is to reduce all simulated flow values by nearly 72% on average, indicative of the large fraction of natural flow diverted from the river upstream from the gage. The normalized streamflow scenarios are then implemented as the main boundary condition in a simple water balance model to analyze future policy options, using reservoir storage and downstream releases to compare management choices. It takes four years of twice the average annual inflow to fill Elephant Butte Reservoir to full operating capacity, starting from near-empty initial conditions as occurred in late 2018. In terms of increasing downstream releases and increasing reservoir storage, reducing direct reservoir evaporation was the best option from a strictly hydrologic perspective. Increasing the future inflows by reducing upstream diversions increases reservoir storage and Caballo releases, but there was also an increase in reservoir evaporation. Lastly, maintaining a minimum storage threshold for reservoir storage increases future average storage, but also leads to an increase in reservoir evaporation and a decrease in releases. Water stored in Elephant Butte Reservoir is lost via the positive correlation between increasing reservoir storage, and thus the increased surface area, and the subsequent rise in direct reservoir evaporation. Therefore, the water balance model suggests the most hydrologically efficient policy option involves reducing reservoir evaporation, although the water balance model does not consider the costs of methods to reduce evaporation.
Polyhydrogenation of [60]- and [70]-fullerenes

Reduction with Zn–conc. HCl in either benzene or toluene solution, results in rapid and quantitative conversion of [60]- and [70]-fullerenes into mainly C60H36 and C70H36/38. Significant amounts of more highly hydrogenated derivatives are also formed. Mass spectra under EI conditions can be obtained free of peaks due to either less-hydrogenated species or the parent fullerenes, provided they are obtained immediately, since both compounds undergo rapid light-catalysed degradation in the presence of oxygen, to give the parent fullerenes, oxygen-containing derivatives (fullerenols) and lower hydrides; C60H18 is the main product from C60H36. Formation of reduced fullerenes up to C60D44 and C70D48 on reaction of [60]- and [70]-fullerenes with Zn–conc. DCI, is attributed to the higher stability of C–D compared with C–H bonds, which provides greater compensation for the loss of resonance energy and the greater steric compression that accompanies reduction beyond the 36 H level. Laser-desorption time-of-flight mass spectrometry indicates that the absence of the corresponding higher hydrides (as opposed to deuterides) is not due to decomposition during EI mass spectrometry. The hydrides do not undergo hydrogen exchange with D2O either alone or in the presence of either sodium hydrogen carbonate or sodium hydroxide. C60H36 has considerable thermal stability but that for C70H36/38 is lower. HPLC chromatograms, as well as IR, UV–VIS, 1H NMR, and mass spectra have been obtained for both compounds. Each appears to be highly resistant to further reduction by hydrogen–catalyst, but shows a surprising tendency to form trimethylene adducts, by an unknown mechanism.
Characterization of electrochemically prepared polyaminopyridines

Polymer-modified electrodes have been prepared by electrochemical oxidation of 2-aminopyridine and 4-aminopyridine in acetonitrile and their chemical properties have been characterized. The polymer films thus prepared were insulators but can be doped with Ag+ or Fe(CN) to produce semiconducting films. The doping must have been accomplished by the complexation of Ag+ with functional groups or trapping of Fe(CN) in the polymer matrix. It has also been demonstrated that these films can be used for chemical analysis of Ag+ by first collecting Ag+ and running subsequent differential pulse voltammetric experiments. The dynamic linearity was excellent in the concentration range of 10−7–10−2 M and the detection limit was about 5 × 10−8M.
Characterization of dissolved compounds in submerged anaerobic membrane bioreactors (SAMBRs)

Two submerged anaerobic membrane bioreactors (SAMBRs) with essentially 100% cell recycle (150 days retention time, SRT), one with powdered activated carbon addition (PAC 1.7 g L−1) and one without, were continuously fed a low-strength feed (450 mg COD L−1) in order to investigate membrane fouling and to characterize the foulants. The SAMBR which did not receive PAC experienced more fouling, and the molecular weight (MW) distribution showed that there was a greater amount of high-MW compounds in this reactor when compared with the reactor with PAC. Size exclusion chromatography showed that although extracellular polymeric substances (EPS) seemed to contribute to the soluble chemical oxygen demand (COD) inside the reactor, it was mainly rejected by the membrane. High-MW protein and carbohydrate material originating mainly from cell lysis and EPS seemed to be the main organics that contributed to the internal fouling of the membrane. Copyright © 2006 Society of Chemical Industry
Process flow sheet synthesis: Reaching targets for idealized coal gasification

The gasification of coal is a process that has been commonly used to produce a mixture of gases containing primarily carbon dioxide and hydrogen, called syngas. This syngas is used as an intermediate in the production of many chemicals such as ammonia, synthetic hydrocarbons, and methanol (to name a few). Coal gasification has a reputation for being “dirty” in terms of its emissions in comparison with other syngas creation technologies, such as methane reforming. However, there is remarkably little information on what the “best case” for coal gasification could actually be and how existing process perform relative to that “best case. ” The goal of this article is to formulate a preliminary and conceptual flow sheet for the gasification process; this flow sheet is not intended to be a finalized design or a definitive solution. It is intended to illustrate the method of setting and achieving design objectives and provide a basis of comparison for either new or existing processes. Thermodynamics can be used to describe any process, or system of processes. Of particular interest are the properties of enthalpy and Gibbs free energy. Using these two thermodynamic properties together as vectors on a diagram of free energy (ΔG) against enthalpy (ΔH), it becomes possible to develop better process flow sheets that combine the thermodynamics of chemical reactions and the dynamics of physical operations on a single diagram. This article will discuss the selection of the independent mass balances that best describe the process as a whole, then the choosing of design objectives, how these objectives might be achieved, and their implications for the process as a whole. Using these ideas one is able to show how to improve the carbon and operating efficiency of a gasification process, making the process more reversible. It was found that there will always be a price to pay for using coal as the feedstock for creating synthesis gas but there is room for improvement, most notably in how combustion is carried out and how energy is used internally within a process. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3258–3266, 2014
Limitations and Applicability of the Interfacial Shear Rheology in the Study of Monolayer Films at the Air-Water Interface

This article studies the applicability of a new technique in determining the interfacial shear rheology properties of surface active compounds relevant to the petroleum industry. It presents the theory behind the determination of the rheological parameters and the results of tests performed on a set of petroleum related compounds (asphaltenes, tetra-acid model compound, fatty acid, and surfactant). It is concluded that this technique is not mature enough to determine the properties of the studied compounds.
Factors affecting silver biosorption by an industrial strain of Saccharomyces cerevisiae

Factors affecting silver biosorption by Saccharomyces cerevisiae biomass, obtained as a waste product from industry, were examined. Maximum removal of silver from solution was achieved within 5 min. Increasing the concentration of biomass in experimental flasks from 1 to 8 mg cm -3 decreased both silver accumulation, from 224.7 to 89.5 μmol Ag g -1 dry wt, and associated H + ion release, from 109.4 to 31.7 μmol H + g -1 dry wt. The presence of 1.0 mol dm -3 cadmium or methionine decreased silver biosorption by 40% and 93% respectively. Boiling in 100 mmol dm -3 NaOH or 10 mmol dm -3 sodium dodecyl sulphate decreased silver biosorption by 54% and 25% respectively. A temperature increase from 4°C to 55°C decreased silver biosorption by 9%. The metabolic state of the yeast had no effect on silver biosorption. Decreasing the pH of the silver solution caused a reduction in metal removal by the biomass.