Miracle-dz/UniFAR-FTUs huggingface dataset:
Natural Abundance of Nitrogen‐15 as a Tool for Tracing Alder‐Fixed Nitrogen

Ratios of ' 5N to "N often differ between pools within ecosystems, and measurement of these natural-abundance ratios might allow transfers among pools to be traced. We tested this approach for its ability to trace biologically-fixed N in conifer plantations. Ratios of ' 5N to "N were measured in soil total-N, ammonium, and nitrate, and in foliage of Douglas-fir 1Pseudotsuga menziesii (Mirb.) Franco! and red alder (Alnus rubra Bong.) at four sites. Two ecosystems were sampled at each site, one a pure conifer stand and the other a mixed alder-conifer stand. Isotope ratios differed significantly among stands, but no pattern was consistent across all locations. Soil NH; at all sites (and soil nitrate at one site) was significantly depleted in '5N relative to other N pools. Isotope discrimination clearly occurs during N transfers at these sites, but the ' 5N natural-abundance method does not provide a simple picture of N cycling at the ecosystem level. Additional Index Words: stable isotopes, isotope discrimination. N fixation, N cycling, N mineralization.
A new concept for production and scaling up of bioactive compounds from Egyptian date palm (Zaghlool) cultivar using bioreactor

A promising and successful protocol for enhancement and production of total phenolic and peroxides compounds from Egyptian date palm cultivar Zaghlool cells in stirred tank reactor was established. The influence of cell culture cultivation in combination with Aspergillus niger extract, and methyl-jasmonate elicitors incorporation in the feeding medium on cell growth patterns and production of active compounds was investigated. The maximum value of cell growth parameters and the highest content of bioactive compounds were obtained from elicitation of modified MS-medium with Aspergillus niger extract at 0.1% in combination with methyl-jasmonate (100 µM), as compared with other concentrations after 10 days of cultivation. The chemical analyses of phenolic and peroxidase compounds were spectrophotometrically performed.
Atomic force microscopy studies of ZnS films grown on (100) GaAs by the successive ionic layer adsorption and reaction method

In this study zinc sulfide thin films were grown by the successive ionic layer adsorption and reaction (SILAR) technique on (100) GaAs substrates from aqueous precursor solutions. The atomic force microscopy (AFM) method was used to study the growth of the films up to a thickness of 180 nm. The ZnS thin films on (100) GaAs were smooth with an rms roughness of 0.2–1.9 nm depending on the film thickness. After the GaAs surface was covered with ZnS, the growth appeared to be nearly layerwise. In addition, in situ AFM studies were carried out to analyze the dissolution of (100) GaAs in water, which is a process competing with the thin film deposition by the SILAR.
Utilization of AC Impedance Measurements for Electrochemical Glucose Sensing Using Glucose Oxidase to Improve Detection Selectivity

The electrochemical detection of glucose using glucose oxidase (GOx) has been conducted by means of AC impedance measurements. In the absence of glucose, the Nyquist plots were straight line due to a reversible redox reaction involving the electron mediator. On the other hand, the Nyquist plots became a circular arc in the presence of glucose, and its radius decreased with an increase in the glucose concentration. The shape of the Nyquist plots were explained with assistance of numerical calculations. Since the reaction impedance due to direct oxidation of interfering species was significantly higher than that of glucose oxidation catalyzed by glucose oxidase, unfavorable influence from interfering species could be eliminated without needing a complicated sensor device. When ferrocenecarboxylic acid was used as an electron mediator, the calibration curve obtained from the Nyquist plots was not affected by the presence of ascorbic acid. Based on those findings, a sensing system, which has no interference from both ascorbic acid and uric acid, was fabricated by using [Os(bpy) 3 ]Cl 2 , which has a highly positive redox potential (0.65 V), as an electron mediator. A method to prepare calibration curves from AC impedance measurements with a fixed frequency was established so that this technique can be put to practical use.
Novel nanocomposite membranes based on blended sulfonated poly(ether ether ketone)/poly(vinyl alcohol) containing sulfonated graphene oxide/Fe3O4 nanosheets for DMFC applications

In this study, sulfonated graphene oxide (SGO)/Fe3O4 nanosheets were synthesized by hydrothermal method and incorporated into blend sulfonated poly(ether ether ketone) (SPEEK)/poly(vinyl alcohol) (PVA) matrix with different weight percent of (SGO)/Fe3O4 nanosheets. The performances of prepared membranes were investigated by water uptake, membrane swelling, mechanical and thermal stability, proton conductivity, methanol permeability and DMFC test. It was found that the water uptake and tensile strength of SPEEK membrane increased and proton conductivity and power density decreased by blending with PVA. Incorporation of SGO/Fe3O4 nanosheets into SPEEK/PVA matrix enhanced mechanical stability, proton conductivity and methanol barrier properties of membrane. The SPEEK/PVA/SGO/Fe3O4 nanocomposite membrane with optimal nanosheets content (5 wt%) exhibits low methanol permeability (8.83 × 10−7 cm2 s−1), high tensile strength (51.2 MPa), high proton conductivity (0.084 S cm−1 at 25 °C) and high power density (122.7 mW cm−2 at 80 °C) and suggests its potential application in DMFCs.
On the temperature rise in electron irradiated foils

Abstract The temperature rise in thin metallic foils under intense electron irradiation has been computed as a function of beam conditions, electron energy, and the physical properties of the foil. The model due to Gale and Hale was used in conjunction with the corrected Bethe electron energy loss formula for relativistic electrons. Although the nature of the assumptions made renders the results generally unapplicable to low thermal conductivity materials, a set of beam conditions etc. are specific for the particular case of a small temperature rise in a ceramic foil (UO2).
Enhanced Piezoelectric Properties of Praseodymium‐Modified Lead‐Free (Ba0.85Ca0.15)(Ti0.90Zr0.10)O3 Ceramics

The role of Pr6O11 addition on the structure, microstructure, electrical, and electromechanical properties of lead-free (Ba0.85Ca0.15)(Ti0.90Zr0.10)O3 piezoelectric ceramics has been systemically investigated. Addition of praseodymium (Pr) results in improved ferroelectric and piezoelectric properties. XRD analysis revealed the co-existence of rhombohedral (R) and tetragonal (T) phases at room temperature. High remanent polarization values (2Pr ~17 μC/cm2) and loop squareness of nearly 0.87 were obtained for the BCZT-0.04 wt%Pr ceramic, along with high piezoelectric coefficient (d33 = 435 pC/N) and transduction coefficient [(d33·g33) = 11589 × 10−15 m2/N]. Results are correlated with the crystal structure and microstructure that significantly influence the ferroelectric and piezoelectric properties near the R–T phase transition point. This material seems to be especially suitable for energy harvesting applications, exhibiting outstanding figure of merit.
The Eddy Structure Model of Turbulent Flamelet Propagation, the Expanding Spherical and Steady Planar Cases

Abstract A structural model of turbulence, composed of vortex tubes which are based on direct simulations of turbulence, is used to model the flame area enhancement found in direct simulations of passive flame propagation. The resulting model produces a turbulent premixed flame speed ST within a chamber which has the experimentally observed integral length scale and turbulence intensity behavior. The excess flame area is proportional to where R, is the flame radius,. is the Taylor length scale and the diameter of the vortex tube, u’ is the turbulence intensity and SL is the burning velocity. This first model yields a linear dependence between and and additionally, gives as the steady-state planar propagation, where A is the integral scale. This planar relation can also be expressed as s/t/ReJ\5SL, and this relation has been shown to correlate experimental turbulent flame speed results and direct turbulence simulations of passive flamelet propagation. A second propagation model uses a function that exhibit.
Stability and behaviour of low level spiked inorganic mercury in natural water samples

The stability and partitioning of inorganic mercury (Hg2+) in natural waters was tested under different storage conditions. The experiments were carried out by spiking labelled Hg2+ to natural concentrations (from 3 to 13 ng L−1) in marine, coastal lagoon, lake, river, and rain waters. Hg2+ was labelled with high specific activity 197Hg. The experiments tested the dissolved and particulate-bound fractions in 10 to 13 days time trends under different storage conditions, namely temperature, natural and preserved by acidification, and container materials (Teflon, borosilicate glass and polyethylene). The concentration of labelled Hg2+ in non-preserved waters decreased significantly depending on the type of water and the storage conditions. In the case of marine and lake waters it was stable over a period of 10 days, whereas in the case of river and lagoon waters 20% of labelled Hg was lost. The partitioning of labelled Hg2+ between the solid and dissolved fractions during the storage period varied with the type of water and the storage conditions. For short term storage periods (1 day after labelled Hg2+ spiking) a significant amount of Hg2+ was transferred to particulates, ranging from 40 to 70%, with refrigerated samples reaching equilibrium more slowly. The labelled Hg2+ in water samples preserved by 1% HCl addition was stable at room temperature (20 °C) and in a refrigerator (5 °C) when stored in Teflon and borosilicate glass, but significant losses were observed when stored in polyethylene.
SILVER(I) N-HETEROCYCLIC CARBENES

This review presents a detailed overview on the synthesis of AgI–NHCs and their role as carbene transferring agents as an easy access to various important transition metal-NHC complexes. The nature of NHC ligands, counter anions and solvents are recognized as key factors in the determination of AgI–NHCs and their derivatives. The lack of Ag–Ccarbene bond coupling in various AgI–NHCs suggests the lability of Ag–Ccarbene bond, which appears to be an appropriate reason in the transfer of carbene. It has been suggested by various authors that carbene transfer from AgI–NHCs is particularly useful when the carbene N-functionality contains base sensitive functional groups or acidic hydrogen. Importantly AgI–NHCs are less air sensitive than the free carbenes and are easy to synthesize. These properties allow them to be handled easily in further operations. Apart from the carbene transferring property, the nature of Ag–Ccarbene bond, the influence of NHC on the Ag…Ag contacts and the molecular aggregation to generate novel structural motifs and supramolecular assemblies have also been emphasized.
Characterizing Intrinsic Bioremediation in a Petroleum Hydrocarbon-Contaminated Aquifer by Combined Chemical, Isotopic, and Biological Analyses

Chemical, isotopic, and biological parameters were evaluated over a 1-year period to characterize microbial processes associated with intrinsic bioremediation in a petroleum hydrocarbon-contaminated aquifer located in Studen, Switzerland. Chemical parameters measured included oxidants such as O2, NO3 −, and SO4 2−, reduced species such as Fe2+ and CH4, and dissolved inorganic carbon (DIC). Stable carbon isotope analyses of DIC were used to differentiate between different processes that contribute to DIC production. Microbial populations were identified by sequence analysis of archaeal 16S rDNA and in situ hybridization using a general DNA binding dye (DAPI) and specific probes targeting the domain Archaea (Arch915) and Bacteria (Eub338), as well as the species Methanosaeta concilii (Rotcl1) and Methanospirillum sp. (Rotcl2). Groundwater exhibited reduced conditions and elevated concentrations of DIC within the contaminated zone. Spatially distinct values of δ13C ranging from −16.5l%c to −4.44%o were found, indicating the presence of different ongoing microbial processes. Detected microbial populations (% of DAPI-stained cells) within the contaminated zone belonged to Archaea (9±2% to 31±13%) and Bacteria (13±3% to 32±13%). In wells with methanogenic activity, Methanosaeta concilii accounted for up to 26% of all DAPI-detected microorganisms. These results demonstrate that this novel combination of chemical, isotopic, and biological analysis provides valuable insights that can be used for the characterization of microbial processes in contaminated aquifers.
State of The Art on Chemistry and Applications of Organoarsenic Compounds

Organoarsenic compounds have been known for over 200 years and in that time have given insight into important theoretical topics in chemistry from valency to aromaticity. They have also proved to have beneficial pharmacological effects. Organoarsenic compounds are produced industrially with uses as insecticides, herbicides, and fungicides. In general these applications are declining in step with growing concerns about their impact on the environment and human health. The parent compound is arsine. Despite their toxicity, organoarsenic biomolecules are well known.
Lead-tellurium oxysalts from Otto Mountain near Baker, California: X. Bairdite, Pb2Cu42+Te26+O10(OH)2(SO4)(H2O), a new mineral with thick HCP layers

Abstract Bairdite, Pb2Cu42+Te26+O10(OH)2(SO4)(H2O), is a new tellurate-sulfate from Otto Mountain near Baker, California, U.S.A. It occurs in vugs in quartz associated with khinite, cerussite, goethite, and hematite. It is interpreted as having formed from the partial oxidation of primary sulfides and tellurides during or following brecciation of quartz veins. Bairdite is monoclinic, space group P21/c, with unit-cell dimensions a = 14.3126(10), b = 5.2267(3), c = 9.4878(5) Å, b = 106.815(7)°, V = 679.41(7) Å3, and Z = 2. Bairdite occurs as diamond-shaped tabular crystals up to about 250 mm long and 5 mm thick, in subparallel and fan-shaped aggregates. The color is lime green, the streak is pale lime green, and the luster is adamantine. The Mohs hardness is estimated at between 2 and 3. Bairdite is brittle with an irregular fracture and one perfect cleavage on {100}. The calculated density based on the empirical formula is 6.062 g/cm3. Bairdite is biaxial (+), with calculated indices of refraction of a = 1.953, b = 1.966, and g = 2.039. The measured 2V is 47(2)°, dispersion is r < v, strong and the optical orientation is Y = b; Z ^ a = 34° in obtuse angle b. The pleochroism is strong: Z (pale green) <<< X (green) < Y (green). Electron microprobe analyses (average of 4) provided: PbO 34.22, CaO 0.06, CuO 23.80, TeO3 26.34, SO3 5.74, H2O 2.81 (structure), total 92.97 wt%. The empirical formula (based on 17 O atoms pfu) is: Pb2.05Ca0. 01Cu2+3.99Te6+2.00S0. 96O17.00H4. 16. The eight strongest powder X-ray diffraction lines are [dobs in Å (hkl) I]: 4.77 (110,102) 50, 4.522 (002,011,111) 66, 3.48 (multiple) 62, 2.999 (311,411) 97, 2.701 (502,113,213) 79, 2.614 (013,020) 100, 1.727 (multiple) 65, and 1.509 (911,033,324) 83. The crystal structure of bairdite (R1 = 0.072 for 1406 reflections with Fo > 4σF) contains edge-sharing chains of Te6+O6 and Cu2+O6 octahedra parallel to b that are joined by corner-sharing in the a direction, forming thick stair-step-like hexagonal close packed layers parallel to {100}. The polyhedral sheet has similarities to those in the structures of timroseite and paratimroseite. The thick interlayer region contains PbO10 polyhedra and half-occupied SO4 groups. Raman and infrared spectral data are presented
Hyalotekite from reedmergnerite-bearing peralkaline pegmatite, Dara-i-Pioz, Tajikistan and from Mn skarn, Långban, Värmland, Sweden: a new look at an old mineral

Abstract In specimens of Mn skarn from the type locality of Långban, hyalotekite, (Ba,Pb,K)4Ca2− (Si,B,Be)12O28F, occurs in a matrix consisting mostly of aegirine (⩽22 mol.% CaMnSi2O6), andradite (⩽27 mol.% Mn3Fe2Si3O12), hematite, pectolite, quartz, calcite, baryte, barylite, and hedyphane. Melanotekite, plumbian taramellite, ferrian K-feldspar (to 6.5 wt.% Fe2O3), rhodonite, a talc-like mineral, apophyllite, and several Pb-As-Sb-O minerals are found in trace amounts. In a single specimen of reedmergnerite-microcline pegmatite from Dara-i-Pioz, hyalotekite occurs in close association with microcline. Other accessory minerals are albite, aegirine, pyrochlore, eudialyte, and polylithionite. The optical constants for hyalotekite from Långban and Dara-i-Pioz are, respectively, α = 1.656, 1.646, β = 1.659–1.660, 1.649, γ = 1.670–1.671, 1.659 (all ± 0.002), 2Vγ (mcas) = 57.2–60.5 ± 0.5°, 57.0 ± 1.1°(λ = 589 nm). Cell parameters of the Dara-i-Pioz hyalotekite for a body-centred triclinic cell are: a = 11.284(2), b = 10.930(1), c = 10.272(8) Å, α = 90.35(2)°, β = 90.11(3)°, γ = 89.98(1)°. Electron and ion microprobe data show that Långban hyalotekite is heterogeneous even within a given sample; the most important substitutions are Pb = Ba, K and coupled B = Si and B = Be. Minor constituents include Mn in the Långban hyalotekite and Na in the Dara-i-Pioz hyalotekite, which also differs in its significantly higher Ba/Pb ratio. Conditions suggested for hyalotekite formation at Långban and Dara-i-Pioz are P ⩽ 4 kbar, T ⩾ 500°C, silica saturation, peralkalinity, and relatively high oxygen fugacities and low sulphur fugacities. These temperatures must have been sufficiently high to allow for miscibility of Pb with Ba (and K) despite the lone pair of electrons of Pb2+.
Analytical predictions of shapes of laminar diffusion flames in microgravity and earth gravity

Flame shape is an important observed characteristic of flames that can be used to scale flame properties such as heat release rates and radiation. Flame shape is affected by fuel type, oxygen levels in the oxidiser, inverse burning and gravity. The objective of this study is to understand the effect of high oxygen concentrations, inverse burning, and gravity on the predictions of flame shapes. Flame shapes are obtained from recent analytical models and compared with experimental data for a number of inverse and normal ethane flame configurations with varying oxygen concentrations in the oxidiser and under earth gravity and microgravity conditions. The Roper flame shape model was extended to predict the complete flame shapes of laminar gas jet normal and inverse diffusion flames on round burners. The Spalding model was extended to inverse diffusion flames. The results show that the extended Roper model results in reasonable predictions for all microgravity and earth gravity flames except for enhanced oxygen normal diffusion flames under earth gravity conditions. The results also show trends towards cooler flames in microgravity that are in line with past experimental observations. Some key characteristics of the predicted flame shapes and parameters needed to describe the flame shape using the extended Roper model are discussed.
A Review of Atomic Force Microscopy in Parkinson's Research

Use of the atomic force microscope in Parkinson’s disease research has increased due to the discovery that mis-sense mutations (A53T and A30P) in -synuclein (-syn) have been linked to early-onset Parkinson’s disease in several families. -syn, in fibrillar formation, has been identified as a component of the cytoplasmic inclusions known as Lewy bodies, which are characteristic of the Parkinson’s disease brain. Three papers, on accelerated in-vitro fibril formation by a mutant -syn linked to early-onset Parkinson's disease, -syn membrane interactions and lipid specificity, and acceleration of oligomerization, not fibrillization, is a shared property of both -syn mutations linked to early-onset Parkinson’s disease, are examined for their use of atomic force microscopy in imaging -syn fibril formation.
DEVELOPMENT AND VALIDATION OF A STABILITY-INDICATING HYDROPHILIC INTERACTION LIQUID CHROMATOGRAPHIC METHOD FOR THE DETERMINATION OF SULFAQUINOXALINE SODIUM IN WATER SOLUBLE POWDER FORMULATION

Objective: This study aims to develop and validate a stability-indicating hydrophilic interaction liquid chromatographic method for the determination of sulfaquinoxaline sodium (SQXS) in the presence of sulfaquinoxaline related compound A (SQXA) in a commercially available water soluble powder formulation. Methods: The analytes were separated on zwitterionic hydrophilic interaction liquid chromatography (ZIC-HILIC) column with a solvent mixture of 200mM ammonium acetate (NH4AC) solution and acetonitrile (ACN) (10:90; v/v) at pH adjusted to 5.7 by glacial acetic acid. The mobile phase flow was fixed at 0.5 ml/min and the analytes were monitored at 263nm at ambient temperature. Forced degradation experiments were carried out by exposing sulfaquinoxaline sodium standard and the water soluble powder formulation for thermal, photolytic, oxidative and acid-base hydrolytic stress conditions. Results: The results showed that SQXA and the other degradation products were fully resolved from sulfaquinoxaline sodium and thus the proposed ZIC-HILIC method is stability-indicating. Conclusion: The method was validated as per ICH and USP guidelines and found to be adequate for routine quantitative determination of SQXS in the presence of SQXA and other degradation impurities in commercially available water soluble powder dosage forms.
Grape Stalks Waste as Low Cost Biosorbents: An Alternative for Metal Removal from Aqueous Solutions

Abstract Grape stalks waste generated in the wine production process has been investigated as metal sorbent for Pb(II), Ni(II), Cu(II), and Cd(II) from aqueous solutions. Kinetic studies revealed that the initial uptake was rapid and equilibrium was established in one hour. The results obtained from batch experiments at initial pH 6.0±0.5 were described by the Langmuir isotherm. The highest value of the Langmuir maximum uptake, (q max ), was found for cadmium (0.248 mmol g−1) followed by lead (0.241 mmol g−1), nickel (0.181 mmol g−1), and copper (0.159 mmol g−1). Column experiments were also performed at a constant metal concentration of around 0.250 mmol dm−3 at pH 6.0±0.5 and the results were modelled by means of the reactive transport code RETRASO (REactive TRAnsport of SOlutes) applying a Langmuir sorption mechanism as well. The values obtained from both experimental approaches are found to coincide fairly well. The Langmuir constants (L mol−1) determined are: Copper (1.5 · 103 and 1.0 · 104), Nickel (1.4 · 103 and 2.5 · 103), Lead (8.3 · 104 and 3.5 · 103), and Cadmium (7.0 · 103 and 4.5 · 103), where values in parenthesis correspond to the batch and column determinations, respectively.
XPS determination of uranium oxidation states

This contribution is both a review of different aspects of X‐ray photoelectron spectroscopy that can help one determine U oxidation states and a personal perspective on how to effectively model the X‐ray photoelectron spectroscopy of complicated mixed‐valence U phases. After a discussion of the valence band, the focus lingers on the U4f region, where the use of binding energies, satellite structures, and peak shapes is discussed in some detail. Binding energies were shown to be very dependent on composition/structure and consequently unreliable guides to oxidation state, particularly where assignment of composition is difficult. Likewise, the spin orbit split 4f7/2 and 4f5/2 peak shapes do not carry significant information on oxidation states. In contrast, both satellite‐primary peak binding energy separations, as well as intensities to a lesser extent, are relatively insensitive to composition/structure within the oxide–hydroxide–hydrate system and can be used to both identify and help quantify U oxidation states in mixed valence phases. An example of the usefulness of the satellite structure in constraining the interpretation of a complex multivalence U compound is given. Copyright © 2011 John Wiley & Sons, Ltd.