Miracle-dz/UniFAR-FTUs huggingface dataset:
The Vertical Distribution of a Dye Tracer in a Layered Soil

Solute transport under field conditions is often inconclusive and difficult to measure because of the poor spatial resolution of sampling devices. Dye tracers can complement concentration measurements by characterizing the spatial structure of solute flow through soils. This study assessed the influence of antecedent water content, tillage, and residue cover on the pattern of soil water flow in the field as exhibited by a dye tracer. A random walk method for estimating the vertical distribution of the stained soil fraction was used to evaluate the degree to which the advective dispersive equation corresponded to field plot transport. The dye-tracer study was conducted on 12 0.9-m-diameter plots within a 2-ha field in southern Costa Rica. A 4-cm depth of Brilliant Blue FCF solution at 5 g L{sup {minus}1} was applied to plots at a rate of 6.81 cm h{sup {minus}1} using a spray nozzle. Plots were later excavated to record the vertical distribution of stained soil. The dye patterns demonstrated that significant bypassing can occur within the surface horizon under rainfall intensities below the steady state infiltration rate. Compared with pre-wetted soil, plots with an initially low antecedent water content exhibited significantly greater spreading of dye within the soil profiles. Themore » random walk simulations indicated that the advective-dispersive equation could not describe dye staining patterns unless the dispersion coefficients estimated from column experiments were increased by one order of magnitude. Tillage did not significantly influence the mean penetration and spreading of dye within the entire soil profile, compared with other undisturbed, pre-wetted subplots, but it increased the interaction of the soil with the dye near the surface as indicated by a significantly greater fraction of stained soil in the Ap horizon. « less
VARIETAL DIFFERENCES IN ANTIOXIDANT ACTIVITY AND PHENOLIC COMPOSITION OF ASPARAGUS

by Esra Cakir, M.S. Washington State University August 2007 Chair: Joseph R. Powers The study was focused on two areas of inquiry. The first involved analyzing nine varieties of asparagus; ‘Jersey Knight’, ‘Jersey Deluxe’, ‘Jersey Supreme’, ‘Jersey Giant’, ‘Guelph Millenium’, ‘UC 157’, ‘Purple Passion’, ‘Morehouse Select’ and ‘Syn4’ for total phenolics (TPH), rutin content, and antioxidant activity using Folin-Ciocalteu procedure, colorimetric AlCl3 method, and the 1,1 diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay, respectively. TPH of varieties ranged from 29.09 to 35.16 mg rutin equivalent/g dry weight basis (dwb) while rutin content varied from 12.09 to 16.09 mg/g dwb. TPH levels were well correlated with rutin content (R≥0.90, p<0.05). Rutin contributed approximately 45% of total phenolics. ‘Guelph Millenium’ contained the greatest TPH and rutin contents while Purple Passion had the least. DPPH scavenging activity of asparagus varieties ranged from 10.70 to 15.30 mg rutin/g dwb. Secondly, asparagus extracts were analyzed by reversed-phase high performance liquid chromatography (HPLC) equipped with a diode array detector to determine the content and profile of phenolics. Rutin was identified as the major phenolic compound, followed by chlorogenic acid, in all varieties. HPLC coupled to a radical scavenging method was
High carbon doping efficiency of bromomethanes in gas source molecular beam epitaxial growth of GaAs

Carbon tetrabromide (CBr4) and bromoform (CHBr3) have been studied as carbon doping sources for GaAs grown by gas source molecular beam epitaxy (GSMBE) with elemental Ga and thermally cracked AsH3. Hole concentrations in excess of 1×1020 cm−3 have been measured by Hall effect in both CBr4‐ and CHBr3‐doped GaAs, which agrees closely with the atomic C concentration from secondary‐ion mass spectrometry, indicating complete electrical activity of the incorporated carbon. The GaAs growth rate is unaffected by the CBr4 and CHBr3 fluxes over the range of dopant flow investigated. The efficiencies of carbon incorporation from CBr4 and CHBr3 are, respectively, 750 and 25 times that of trimethylgallium (TMG), which is commonly employed as a carbon doping source in metalorganic MBE (MOMBE). The sensitivity of carbon incorporation to varying substrate temperature and V/III ratio has been observed to be significantly reduced with CBr4 and CHBr3 from that obtained under similar growth conditions with TMG in MOMBE.
Electrodes for Nonaqueous Oxygen Reduction Based upon Conductive Polymer-Silver Composites

Progress toward the development of current collector-conductive polymer-silver (cc-cp-Ag) composite cathodes for nonaqueous metal air batteries is presented here, where the contribution of each component toward the overall oxygen reduction activity of the multifunctional cc-cp-Ag composite is studied. First, the effect of the chemical identity of the current collector (carbon versus gold) on the electrochemical reduction of oxygen is examined, accompanied by a conductive polymer deposition study. These two studies together demonstrate that a conductive polymer deposit can eliminate any competitive electrochemistry due to the current collector. Second, the role of the conductive polymer in improving physical strength of the composite electrode is evaluated using an electrode durability test. Third, a systematic study of the Ag loading effect is undertaken to determine the minimum silver loading required for significant enhancement in oxygen reduction activity.
Oriented purple membrane multilayers of halobacteria fabricated by langmuir–blodgett and electrophoretic sedimentation techniques

Organised films containing oriented patches of purple membranes and consisting of 15–75 layers and approximately 1000 layers were fabricated by the Langmuir–Blodgett and electrophoretic sedimentation techniques respectively. ‘Surface pressure vs. molecular area’ isotherms for monolayers of purple membranes suspended in hexane and deposited on the air/water interface were studied. Circular dichroism and absorption spectroscopy were used to investigate the effect of an organic solvent on the chromophore binding site in the purple membranes. Kinetic methods based on flash excitation were employed to determine the influence of the film deposition conditions on the photoelectric response of bacteriorhodopsin and on the M412 intermediate relaxation. Structural characteristics for multilayers prepared from water and hexane purple membrane suspensions were determined by low-angle X-ray scattering. The influence of the layer deposition conditions on the electrical, physical and photoelectrical properties of ordered structures containing bacteriorhodopsin is discussed.
Anharmonic Protein Motions and Heme Deformations in Myoglobin Cyanide Probed by Absorption and Resonance Raman Spectroscopy

The Soret absorption of myoglobin cyanide in a 65% glycerol/water mixture was measured as a function of temperature between 20 and 300 K. The data were analyzed by using an earlier model relating each transition into the vibronic manifold of the electronic B-state to a Voigtian band profile (Cupane et al. Eur. Biophys. J. 1995, 23, 385, 1995). Its Gaussian part contains a temperature-dependent component due to the coupling of low-frequency modes to the Soret transition. The analysis of the vibronic substructure was facilitated by comparison with vibronic coupling parameters derived from the line intensities in the polarized Raman spectra taken with Soret excitation. From the depolarization ratios of several Raman lines, the existence of asymmetric heme macrocycle distortions was inferred, which lift the degeneracy of the excited B state. Raman intensities and depolarization ratios were then analyzed by a theory that formulates the polarizability tensor in terms of a time-independent perturbation theory. T.
SAFETY ISSUES IN NUCLEAR HYDROGEN PRODUCTION WITH THE VERY HIGH TEMPERATURE REACTOR (VHTR)

Nuclear Hydrogen Production (NHP) schemes use high-temperature nuclear heat and steam to split water, thermo/electrochemically. This focuses attention on high-temperature coolants: supercritical water, gaseous helium, and liquid salts. Each has been studied within a reactor concept – the SCWR, the VHTR or the LS-VHTR respectively. Nuclear Hydrogen Production is particularly attractive for hydrocarbon upgrading in the Alberta Tar Sands, where liquid salt heat-transfer fluids have also been proposed for in-situ tar liquefaction. This paper considers the heat transfer characteristics of these fluids, and discusses safety issues in the context of NHP, with the gaseous helium VHTR and the liquid salt VHTR.
Production of γ-butyrolactone from biomass-derived 1,4-butanediol over novel copper-silica nanocomposite

γ-Butyrolactone was produced highly selectively from biomass-derived 1,4-butanediol by vapor-phase dehydrocyclization over novel copper-silica nanocomposite catalyst. Compared with usual Cu(12)/SiO2, the highly Cu-loaded SiO2 nanocomposite (80 wt%) exhibited high catalyst performance with 98% yield on 400 h stream without significant deactivation even in the absence of H2.
Stereochemistry of peptides containing 1‐aminocyclopentanecarboxylic acid (Acc5): Solution and solid‐state conformations of Boc‐Acc5‐Acc5‐NHMe

The conformational analysis of a protected homodipeptide of 1‐aminocyclopentanecarboxylic acid (Acc5) has been carried out. 1H‐nmr studies establish a β‐turn conformation for Boc‐Acc5‐Acc5‐NHMe in chloroform and dimethylsulfoxide solutions involving the methylamide NH in an intramolecular hydrogen bond. Supportive evidence for the formation of an intramolecular hydrogen bond is obtained from ir studies. X‐ray diffraction studies reveal a type III β‐turn conformation in the solid state stabilized by a 4 → 1 hydrogen bond between the Boc CO and methylamide NH groups. The ϕ,ψ values for both Acc5 residues are close to those expected for an ideal 310‐helical conformation (ϕ≃ ± 60°, ψ∼ ±30°).
Ionic-equilibrium time inside ceramic cups in unsaturated porous media

In order to improve the methodology of collecting soil solutions with porous ceramic cups without suction, we developed a method to estimate an ionic-equilibrium time (t C/C ∞) inside cups first filled with distilled water. Characterization of t C/C ∞ was used to select the minimum interval time between two extractions with different water contents (θ) or water pressures (ψ). The method is based on an analytical solution of the general equation of cylindrical diffusion. The model is used for approximating the molecular diffusion coefficient (D) vs. 0 or ψ and predicting the evolution toward ionic equilibrium inside the cups. It was satisfactorily validated, using KNO 3 as a solute, with a fine sand, a silty day soil, and a peat-perlite mixture. The results showed that t C/C ∞ is (i) dependent on molecular diffusion, which has a particular relationship with 0 for each medium, and (ii) proportional to the squared radius of the cup. The best results obtained near saturation showed that the times necessary to obtain a concentration close to equilibrium with standard cups (22.6-mm diam.) were 4 d with the peat-perlite mixture and =2 wk for the sand and the silty clay soil. Furthermore, t C/C ∞ can take up to 1 mo when diffusivity in sand decreases drastically with low water content. The length of time needed to reach equilibration limits the usefulness of this sampling method for conditions where changes in solute concentration with time are weak, such as diffusion phenomena with slow or nonexistent displacement of solute. Nevertheless, the equilibration time may be reduced to 30 h by using smaller cups (9.6-mm diam.) with high-water-content media.
On the structure of molecularly imprinted polymers by modifying charge on functional groups through molecular dynamics simulations

Molecularly imprinted polymers (MIPs) have been widely applied in many fields owing to their advantages. The recognition mechanism between target molecules and MIPs and the influence of dominant factor on the recognition process are still poorly understood. In this paper, a cubic methacrylate-based MIP model was constructed, and the charge on carboxyl group atoms was changed artificially to investigate the recognition process. It is found that the diffusion coefficients of the target molecules (cholesterol) are not affected by polymer network structure. The recognition process is mainly determined by the mesh sizes of the polymer network. In addition, the structure of modified MIP systems was also discussed from the viewpoints of radial distribution function and hydrogen bonds system. These results suggest that the polymer matrix structure would be enhanced with an increase in charge. Thus, it influences the structure of the water molecules in the system a little.
The fluorescence lifetime of BRI1-GFP as probe for the noninvasive determination of the membrane potential in living cells

As the excited state lifetime of a fluorescent molecule depends on its environment, it is possible to use it as a probe for physico-chemical parameters of the surrounding medium. Whereas this is well known for many solid guest/host systems, only few reports of quantitative, temporal resolved in vivo studies to monitor the nano-environment for a protein-coupled chromophore such as GFP are known from literature. Here we present a novel approach to determine the membrane potential of living (plant) cells based on the fluorescence lifetime (FLT) analysis of membrane-located GFP. By using confocal sample scanning microscopy (CSSM) combined with fluorescence lifetime imaging microscopy, we recently showed that the phytohormone brassinolide (BL) induces cell wall expansion and a decrease in the FLT of the BRI1-GFP in living cells of Arabidopsis thaliana seedlings. BRI1 is the dominant functional receptor for BL in Arabidopsis and locates to the plasma membrane. Although the dependence of the FLT of GFP on its physico-chemical environment such as pH-value, refractive index and pressure has been reported, the observed FLT decrease of BRI1-GFP in response to BL application could not be explained by these parameters. However, our in vivo FLT and CSSM analyses indicate that the BLinduced change in the FLT of BRI1-GFP is caused by hyperpolarisation of the plasma membrane (Em). Thus, our results indicate that BRI1-GFP serves as sensitive and non-invasive probe for recording the Em of the plasma membrane in living plant cells with high spatio-temporal resolution.
Sensitivity of the OMI ozone profile retrieval (OMO3PR) to a priori assumptions

We have assessed the sensitivity of the operational OMI ozone profile retrieval (OMO3PR) algorithm to a number of a priori assumptions. We studied the effect of stray light correction, surface albedo assumptions and a priori ozone profiles on the retrieved ozone profile. Then, we studied how to modify the algorithm to improve the retrieval of tropospheric ozone. We found that stray light corrections have a significant effect on the retrieved ozone profile but mainly at high altitudes. Surface albedo assumptions, on the other hand, have the largest impact at the lowest layers. Selection of an ozone profile climatology which is used as a priori information has small effects on the retrievals at all altitudes. However, the usage of climatological a priori covariance matrix has a significant effect. Based on these sensitivity tests, we made several modifications to the OMO3PR algorithm: the a priori ozone climatology was replaced with a new climatology (TpO3), the a priori covariance matrix was calculated from the climatological ozone variance values, and the surface albedo was assumed to be linearly dependent on wavelength in the UV2 channel. We found that the a priori covariance matrix basically defines the vertical distribution of degrees of freedom for a retrieval. Moreover, all the studied versions of the OMO3PR algorithm were equally effective in reducing uncertainty in the retrieved ozone profile. This implies that the posterior error values depend mostly on the assumed a priori errors. Our case study over Europe showed that the new version produced over 10% smaller ozone abundances which reduced the systematic overestimation of ozone in the OMO3PR algorithm and improved correspondence with IASI retrievals.
The Lower Oxidation States of Gallium. III. The Constitution of Ga 2 Cl 4 and its Analogy with Ga(AlCl 4 )

Dielectric constant measurements on benzene solutions of Ga/sub 2/Cl/sub 4/ give a dipole moment of 8.9 Debye units for this solute at infinite dilution. The same Raman spectrum is observed for benzene solutions of Ga/sub 2/Cl/sub 4/ and Ag(GaCl/sub 4/). These results together with molecular weight data lead to the conclusion that Ga/sub 2/Cl/sub 4/ exists in benzene as the solvated ion pairs Ga/sup +/(GaCl/sub 4/)- which aggregate with increasing concentration. Consideration of the absence of a stable gallium(I) chloride and the acid-base interaction resulting in the formation of Ga(GaCl/sub 4/) leads to the concept of stabilization of lower oxidation states toward disproportionation by strong Lewis acids and to the preparation of Ga(AlCl/sub 4/). The similarity of Ga(GaCl/sub 4/) and Ga(AlCl/sub 4/) is discussed. (auth)
Valence and conduction intersubband transitions in SiGe, Ge-rich, quantum wells on [001] Si0.5Ge0.5 substrates: A tight-binding approach

Electronic and optical properties of germanium-rich Si∕SiGe quantum wells grown on Si0.5Ge0. 5 substrates are investigated by a nearest neighbor tight-binding Hamiltonian. The basis set includes spds* orbitals with both spin states. Appropriate scaling laws account for strain effects. We present full electronic band structure calculations both for valence and conduction bands. Confinement effects on the electronic states are considered in detail. Optical spectra related to hole and electron intersubband transitions are derived. Our results for optical absorption due to valence intersubband transitions show excellent agreement with experimental spectra and previous k∙p calculations. For the same quantum well samples, spectra due to conduction intersubband absorption are provided here.
Influence of the tacticity dependent microstructure on the space charge distribution of poly(vinyl chloride)

The space charge distribution of three samples of poly(vinyl chloride) of different isotactic content has been studied by the thermal step technique, with a view to investigating the influence of some defined microstructural features on that important behaviour. It has been observed that the space charge increases substantially as the content of the local tetrad configuration, mmr, at the end of isotactic sequences increases. A first tentative interpretation is given.
Cyanopolyynes as indicators of late-time chemistry and depletion in star-forming regions

Quantitative results for the time-dependent behaviour of the fractional abundance of HC3N in dense cores are given. In addition to the standard 'early-time' HC3N maximum found for many situations in which elements other than hydrogen are initially in atomic form, a secondary maximum occurs for a variety of conditions after depletion has become significant. The secondary maximum can be sufficiently large and occur for a sufficiently wide range of physical conditions that the assertion that the presence of high fractional abundances of cyanopolyynes implies chemical and dynamical youth for the cyanopolyyne emission peak in TMC-1 and other star-forming regions may not be secure.
Serial Batch Elution of Electric Arc Furnace Oxidizing Slag Discharged from Normal Steelmaking Process into Fresh Water

The serial batch leaching test of an electronic arc furnace oxidizing slag was performed on the basis of JIS K 0058-1 to investigate the safety of the slag and to clarify the elution mechanism. The slag which was discharged at the time of refining of normal steel was used for this experiment. The slag was dissolved in water whose initial pH was 6.0. After that, the slag was naturally dried. This operation was performed 12 times successively.The dissolution behaviors of Ca and Mg were expressed by the parabolic law. That of Si was expressed by the linear law. The dissolutions of them from the slag were controlled by the diffusion through pore and the surface layer through the surface layer where compositions of FeO and Al2O3 were high. Generally, the dissolve concentrations decreased with the increase in the number of the elution times. The environmentally regulated substances were not detected or less than the levels of the environmental quality standards for soil. Ba, Mn, Mo, K, Na, Sr and W were detected as minor element except for the environmentally regulated elements. Generally, the detected environmentally regulated substances and the other minor elements decreased with the number of the elution times. During the elution of the slag, the pH of the aqueous solution steeply increased initially, and it decreased afterwards. The pH decreased with the increase in the number of the elution times.
Crystal structure of bis{[4'-(4-tolyl)-2,2':6'2''-terpyridine-k3N,N',N'']- [μ-5-hydroxybenzene-1,3-dicarboxylate-k2O,O']zinc(II)} tetrahydrate [Zn(C22H17N3)(C8H6O5)]2 ) 4H2O

C 60 H 54 N 6 O 14 Zn 2 , monoclinic, P 12 1 / c 1 (no. 14), a = 13.0900(9) Å, b = 14.8630(7) Å, c = 14.061 Å, * = 97.92°, V = 2709.6 Å 3 , Z = 4, R gt (F) = 0.067, wR ref (F 2 ) = 0.190, T = 293 K.
Cocrystal Screening of Stanolone and Mestanolone Using Slurry Crystallization

A slurry crystallization technique was used in cocrystal screening of two nonionizable pharmaceutical host compounds, stanolone and mestanolone, with 11 pharmaceutically acceptable guest acids. Crystallization was performed simply by adding crystallization solvents to solid mixtures of a host and a guest, which had been prepared using lyophilization of their dimethyl sulfoxide solution. Powder X-ray diffraction and thermogravimetric/differential thermal analysis were used to identify new solid forms. Two resultant new forms, stanolone l-tartaric acid 1:1 cocrystal and mestanolone salicylic acid 1:1 cocrystal, were characterized using single-crystal X-ray diffraction. The hosts, despite having the same steroidal skeleton and the same functional groups that form strong hydrogen bonds, each formed a cocrystal with a different guest molecule. All functional groups of the host and guest molecules that form strong hydrogen bonds were engaged in hydrogen bonding, but, despite the highly analogous molecular struc.
Rheology and adsorption of aqueous polymer solutions

The behavior of aqueous solutions of partly hydrolyzed polyacrylamide polymers, numbers 500 and 700, was studied, including viscosity, thermal stability, adsorption and transport in porous media. The addition of sodium chloride to the solutions decreased their viscosity and decreased the amount of polymer which was adsorbed out of the solution. The higher molecular weight polymer developed greater viscosities than the lower molecular weight polymer. The polymers were not stable at 275 to 300/sup 0/F in an oxygen-free environment. The adsorption of polymer in consolidated porous media was significantly less than adsorption on unconsolidated sandstone or silica sand.