Miracle-dz/UniFAR-FTUs huggingface dataset:
Morphology of Blends of Linear and Long-Chain-Branched Polyethylenes in the Solid State: A Study by SANS, SAXS, and DSC

Differential scanning calorimetry (DSC), small-angle neutron scattering (SANS), and X-ray scattering (SAXS) have been used to investigate the solid-state morphology of blends of linear (high density) and long-chain-branched (low-density) polyethylenes (HDPE/LDPE). The blends are homogeneous in the melt, as previously demonstrated by SANS using the contrast obtained by deuterating the linear polymer. However, due to the structural and melting point differences ({approximately} 20 C) between HDPE and LDPE, the components may phase segregate on slow cooling (0.75 C/min). For high concentrations ({phi} {ge} 0.5) of HDPE, relatively high rates of crystallization of the linear component lead to the formation of separate stacks of HDPE and LDPE lamellae, as indicated by two-peak SAXS curves. For predominantly branched blends, the difference in crystallization rate of the components becomes smaller and only one SAXS peak is observed, indicating that the two species are in the same lamellar stack. Moreover, the phases no longer consist of the pure component and the HDPE lamellae contain up to 15--20% LDPE (and vice versa). Rapid quenching into dry ice/2-propanol ({minus}78 C) produces only one SAXS peak (and hence one lamellar stack) over the whole concentration range. The blends show extensive cocrystallization, along with a tendency for themore » branched material to be preferentially located in the amorphous interlamellar regions. For high concentrations ({phi} > 0.5) of HDPE-D, the overall scattering length density (SLD) is high and the excess concentration of LDPE between the lamellae enhances the SLD contrast between the crystalline and amorphous phases. Thus, the interlamellar spacing (long period) is clearly visible in the SANS pattern. The blend morphology is a strong function of the quenching rate, and samples quenched less rapidly (e.g., into water at 23 C) are similar to slowly cooled blends. « less
Electrical resistivity anisotropy of Gd at high pressure

Measurements of electrical resistivity of single- and polycrystalline Gd were performed in a large volume cubic anvil press in the h.c. p. phase region at room temperature up to 16 kbar. The anisotropy of electrical resistivity of h.c. p. Gd, observed at room pressure and temperature, is maintained at elevated pressure for the entire h.c. p. range. When the low pressure dependence of anisotropy is extrapolated to higher pressure beyond the stability region of the h.c. p. phase, the anisotropy disappears at approximately 205 kbar. The pressure-induced decrease in anisotropy is discussed in terms of related anisotropies of compressibility and the spin-disorder component of electrical resistivity.
Modification of lignin

Wood is a composite material in which lignin forms the adhesive and reinforcing component. The paper describes varous ways to modify the isolated or degraded lignin to useful polymeric products. As an example of complex reaction systems the association reactions and pre-equilibria of lignin with sulphur dioxide are discussed. Holz ist ein Kompositmaterial, in dem Lignin als Bindemittel wirkt. Es wird beschrieben, wie isoliertes Lignin in nutzliche polymere Produkte umgewandelt werden kann. Die Assoziation und Ausgangsgleichgewichte von Lignin mit Schwefeldioxid werden als Beispiel von komplexen Reaktionssystemen besprochen.
4d transition-metal doped hematite for enhancing photoelectrochemical activity: theoretical prediction and experimental confirmation

To explore the photoelectrochemical efficiency of hematite as a photoanode, we comprehensively investigate the electronic structures of hematite doped with 4d transition-metal X (X = Y, Zr, Mo, Tc, Rh, and Ru) based on the density-functional theory (DFT). The results indicate that the bandgap of hematite can be reduced by doping with the transition metal atoms, which leads to the enhanced absorption coefficient of long-wavelength photons in the visible light region. In addition, the carrier concentration can be improved by Zr, Mo, Tc, and Ru dopants. More interesting, the incorporation of Ru can also modify the conduction band edge and hence reduce the effective electron mass, leading to better electron mobility. Subsequent experiments confirm that the photoelectrochemical (PEC) activity of Ru doped hematite film is significantly improved. For example, the highest photocurrent density value of 9 at. % Ru doped hematite is 4.7 times that of the undoped material at E = 1.23 V. Based on both calculations and experiments, the enhanced PEC activities of Ru doped hematite are derived from the improved electrical conductivity and increased visible light absorption coefficient.
Doxorubicin Loaded Polyurethanes Nanoparticles

A poly(ether-ester-urethane) block copolymer based on Poly ( e -caprolactone) and Polyethylene glycol (PEGCL) was employed for the production of Doxorubicin loaded polymeric nanoparticles to be used as a drug delivery system. Nanoparticles were obtained by means of the nanoprecipitation/solvent evaporation technique, possessing a spherical shape and an average diameter of about 80 nm . The optimisation of the formulation process led to high formulation yield and appreciable drug content. One of the main findings arising from the present study is represented by the protective activity played by nanoparticles in terms of preventing doxorubicin degradation in physiological conditions; moreover the observed time-delayed release of the drug was associated to PEGCL chemical structure.
Uncertainty assessment in modelling soil acidification at the European scale : A case study

When modelling soil acidification at the European scale, it is inevitable that both model and data have varying degrees of associated uncertainty. The present study attempted to quantify the uncertainty in long-term forecasts of soil solution concentrations of Al{sup 3+} and No{sub 3}{sup {minus}} concentrations resulting from the uncertainty in small resolution European-scale maps and input data, using the Netherlands as a case study. Large-scale forecasts were made with a relatively simple dynamic process-oriented model, SMART2. Model outputs were considered as block median concentrations and the block areal fractions in which concentrations exceeded a critical level. Sources of uncertainty considered included (1) uncertainty in soil and vegetation maps (categorical data), and (2) uncertainty in soil and vegetation-related parameters (continuous data). The uncertainty in model outputs was quantified by an efficient two-step Monte Carlo simulation approach, which takes spatial correlation into account. The uncertainty in the input data at the European scale led to major uncertainties in the predicted Al{sup 3+} concentration. Uncertainties in the areas where the Al{sup 3+} concentration exceeded the maximum allowable concentration were much smaller. The uncertainties in soil-related parameters contributed most to the uncertainty in the Al{sup 3+} concentration, whereas the uncertainty contributed by the soilmore » and vegetation maps was negligible. For the NO{sub 3}{sup {minus}} concentration, however, the uncertainty originated mainly from the soil and vegetation maps. Evaluation of the different error sources is of great practical significance, as it identified which sources need further improvement. The present study shows that the uncertainty contribution of the different error sources depends greatly on the model output considered. « less
CO Oxidation on Gold in Acidic Environments: Particle Size and Substrate Effects

The electrooxidation of carbon monoxide on titania- and carbon-supported gold nanoparticles of mean diameters <6.5 nm was studied in 0.5 M HClO4. The samples were prepared by physical vapor deposition, and the activity of the supported particles compared with the reaction at bulk, polycrystalline gold. Carbon-supported gold exhibited activity for CO oxidation only at potentials similar to that observed for bulk gold. Decreasing the particle size below ∼2.5 nm resulted in a sharp decay in catalytic activity. Titania-supported gold exhibited catalytic activity at overpotentials significantly below those of bulk gold, and the activity was strongly particle-size-dependent. A maximum in activity was observed at ∼3.0 nm, and a sharp reduction in activity is observed below ∼2.5 nm. The results highlight two important effects. Titania is responsible for a strong substrate-induced activity for CO electrooxidation on gold particles. In addition to the induced activity at low overpotentials, this titania-supported g.
Aflatoxin Movement in Soil

Crops contaminated with > 20 µg kg⁻¹ aflatoxin cannot be transported across state lines. Contaminated preharvest crops are often disposed of by plowing the crop into the soil, thereby creating the potential for aflatoxin contamination of groundwater. The objective of this study was thus to determine the leaching and adsorption potential of aflatoxin in soils. Leaching and adsorption studies were conducted with a silt loam, clay loam, sandy loam, and silty clay loam soil. Soil columns were utilized in the leaching experiment. The length of the column and the volume of soil used were 30.54 cm and 1234 cm³, respectively. A total of 2.5 mg aflatoxin B₁ was applied to the soil surface and the column was leached with 1 L of water under saturated conditions for 24 h. The results demonstrate that aflatoxin B₁ or its derivatives, aflatoxin B² and G², were retained within the upper 20 cm of all soil types. Between 80 and 92% of the total amount of aflatoxin applied was retained in the upper 2.5 cm of the soil columns. No aflatoxin was found in the leachate from any of the soils. Freundlichs isotherm was used to establish adsorption coefficients for the soils by the slurry technique. The concentrations of aflatoxin used to establish the constants were 0.1, 1.0, 5.0, and 10 mg L⁻¹. The resulting adsorption coefficients were 238, 76, 46, and 17 mg kg⁻¹ for the silty clay loam, silt loam, clay loam, and sandy loam, respectively. As a result of the two experiments, aflatoxin contamination of groundwater would not be expected to occur unless the soils were extremely sandy or shallow.
Clarification of photocatalysis induced by iron ion species naturally contained in a clay compound

When clay undergoes isomorphic replacement of a cation (e.g. Al3+, Mg2+) by an Fe2+ ion, the Fe ion in the crystal structure of clay is called structural-Fe. The octahedral sites of a structural-Fe are occupied by O2− ions as in Fe(III) oxide (e.g. α-Fe2O3); however, the photocatalysis of structural-Fe has not yet been understood in detail. In this study, structural-Fe(II) in clay was oxidized to Fe(III), following which the photocatalytic activity of clay was investigated in terms of the degradation of acetic acid. After the oxidation of structural-Fe(II), hydrous ferric oxide (HFO, Fe2O3·nH2O) as well as structural-Fe(III) coexisted as the products. To clarify the intrinsic photocatalyses of both species, clay compounds with varying amounts of HFO were prepared and examined in terms of the photocatalytic degradation. Kinetic analysis revealed that the photocatalytic activity of HFO is 30 times higher than that of structural-Fe(III), indicating that HFO is the main species that causes active and efficient photocatalysis in clay.
Studies of Lithium-Exchanged Nafion as an Electrode Binder for Alloy Negatives in Lithium-Ion Batteries

The use of lithium-exchanged Nafion as a polymer binder for alloy negative electrodes in lithium-ion batteries is demonstrated. Commercial Nafion solution was ion exchanged with LiOH in order to remove the mobile protons and prepare the lithium-containing polymer. The resulting Li-Nafion solution, crystalline silicon, and carbon black were used to prepare composite electrodes having final proportions of 8% binder, 80% silicon, and 12% carbon by weight, respectively. The prepared electrodes gave reversible specific capacities ranging from 800 to nearly 1000 mAh/g when cycled between 0.9 and 0.17 V. The capacity retention of the investigated electrode samples was very good, suggesting that lithium-exchanged Nafion is a promising binder for alloy negative electrodes of Li-ion batteries.
Sintering of titanate based dielectrics doped with lithium fluoride and calcium borosilicate glass

The effect of LiF and CBS glass additives on the microstructure and dielectric property of BaTiO3 (BT) ceramics was studied. The phase of BaLiF3 was observed from the interaction between BT and LiF when the samples were sintered at 900 °C for 1 h. Crystal grains with Ba and F in atomic ratios of 1:3 were observed from the SEM and TEM analysis of the microstructures. Abnormal grain growth (AGG) was observed to occur in the BT ceramics sintered at 950 °C. Further improvement to the composition was achieved by employing a two-stage process. This included CBS glass shell coating of the BT particles in the first stage, and the addition of LiF in the second stage. The composition thus formed had very good permittivity (1725) and an extremely low dielectric loss value (0.008).
Sulfur dioxide exposure and environmental justice: a multi-scale and source-specific perspective

Recent studies examining racial and ethnic inequities in exposure to urban air pollution have led to advances in understanding the nature and extent of overall concentration exposures by pollutant, demarcated by disadvantaged groups. However, the stability of inequities at various spatial units and the exposure by air pollution sources are often neglected. In this case study from the Dallas–Fort Worth (Texas, USA) area, we used Geographic Information Systems (GIS) and an air dispersion model to estimate environmental justice impacts at different spatial scales (i.e., zip code, census tract, block group) and by source (i.e., industrial pollution sources, vehicle pollution sources, industry and vehicle pollution sources combined). Using whites as a reference, blacks and other races were more likely to be exposed to higher sulfur dioxide (SO2) concentrations although the Odds Ratio (OR) varied substantially by pollution source type [e.g., industrial pollution source based: (OR=1.80; 95% CI (Confidence Interval): 1.79–1.80) vs. vehicle pollution source based: (OR=2.70; 95% CI: 2.68–2.71)] and varied less between spatial scales [for vehicle pollution sources, (OR=2.70; 95% CI: 2.68–2.71) at the census tract level but was (OR=2.54; 95% CI: 2.53–2.55) at the block group scale]. Similar to the pattern of racial inequities, people with less education (i.e., less than 12 years of education) and low income (i.e., per capital income below $20 000) were more likely to be exposed to higher SO2 concentrations, and those ORs also varied greatly with the pollution sources and slightly with spatial scales. It is concluded that the type of pollution source plays an important role in SO2 pollution exposure inequity assessment, while spatial scale variations have limited influence. Future studies should incorporate source–specific exposure assessments when conducting studies on environmental justice.
Numerical investigation of FLUID COKING™ units, Part I: hydrodynamics of a scaled cold flow model

The hydrodynamics of a FLUID COKING™ unit were investigated with computational fluid dynamics (CFD) by simulating a scaled cold flow model. Steady state flow hydrodynamics were then analysed by focusing on the local voidage distribution and solids velocity. The influence of simulation time on interpretation and analysis of results was evaluated first, and a short-time simulation was found to be able to provide useful information. The predicted flow behaviour was compared both quantitatively and qualitatively with previous experimental findings. The influences of nozzle-insertion, feed distribution, and solids circulation rate were investigated. The numerical simulations indicated that the nozzle insertion and solids circulation have little impact on the flow hydrodynamics for the range of conditions studied. © 2011 Canadian Society for Chemical Engineering
Comparative study of chemical composition and antioxidant activity of ethanolic extracts from Algerian Lavandula stoechas L. and Rosmarinus tournefortii de Noé.

The purpose of the study was the analysis of extracts from Rosmarinus tounefortii de Noe and Lavandula stoechas L. and the assessment of their in vitro antioxidant. The ethanolic extracts of studied plants recorded yields of 19.3 and 30.6% for L stoechas and R. tournefortii, respectively. These extracts had high percentages of polyphenols and flavonoids. Antioxidant activity was assessed in vitro using two different tests. Free radical scavenging activity (DPPH) test revealed that ethanolic extracts of rosemary (IC50= 11.6 ± 0.1 mg/l) and lavender (IC50= 18.3 ± 0.3 mg/l) exhibited higher DPPH scavenging activity compared to that of the synthetic antioxidant BHT (IC50= 28 ± 0.7 mg/l), and studied essential oils. For reducing power test, the strongest effect was exhibited by butylated hydrxytoluene (BHT).
Subcellular imaging of cell cultures and tissue for boron localization with laser‐SNMS

Non‐resonant laser secondary neutral mass spectrometry (NR‐laser‐SNMS) has been used for examining human melanoma cells grown in cell cultures and human glioblastoma xenografts grown in NMRI nude mice. Cells were incubated and mice were treated with boron‐containing drugs. Ion‐induced electron images were used to identify individual cells. Elemental and molecular images were obtained from the cancer cells with very high sensitivity and subcellular resolution. The measurement of the K/Na ratio demonstrated that for both cell cultures and tissue materials the preparation techniques used were appropriate for preserving the chemical and structural integrity of the living cell. The boron images show intra‐ and extracellular boron signals with different intensities. Molecular images show distinct features partly correlated with the cell structure. Copyright © 2004 John Wiley & Sons, Ltd.
Mechanical Surface Modification of Lithium Metal: Towards Improved Li Metal Anode Performance by Directed Li Plating

The effect of mechanical surface modification on the performance of lithium (Li) metal foil electrodes is systematically investigated. The applied micro‐needle surface treatment technique for Li metal has various advantages. 1) This economical and efficient technique is able to cover a wide range of surface area with a simple rolling process, which can be easily conducted. 2) This technique achieves improved rate capability and cycling stability, as well as a reduced interfacial resistance. The micro‐needle treatment improves the rate capability by 20% (0.750 mAh at a rate of 7C) and increases the cycling stability by 200% (85% of the initial discharge capacity after 150 cycles) compared to untreated bare Li metal (0.626 mAh at a rate of 7C, 85% of the initial discharge capacity after only 70 cycles). 3) This technique efficiently suppresses Li formation of high surface area Li during the Li deposition process, as preferred sites for controlled Li plating are generated.
The carbon content of topsoil and its geographical distribution in France

Abstract. An estimate of organic carbon stored in French soils to a depth of 30 cm was made using data from geo‐referenced databases. We produced statistics on carbon stocks in soils according to land use, different land uses and soil type. Then, using a combination of maps of soil and land use we were able to estimate regional and national carbon stocks. This soil carbon map of France allowed us to identify the main controlling factors of the carbon distribution: land use, soil type in some cases, clay content, and elevation. Carbon stocks in French soils were found to be about 3.1 Pg (1015g).
Network Connectivity and Long-Range Continuity of Lamellar Morphologies in Block Copolymer Thin Films

The connectivity, and thus long-range continuity of the domains, in a lamellar polystyrene-block-poly(methyl methacrylate) copolymer in thin films depends on the volume fraction of each block and can be shifted by homopolymer addition to substrate-spanning continuity of either the polystyrene (PS) or poly(methyl methacrylate) (PMMA) domains. Essential features of the lamellar morphology were captured by a simple network analysis that quantified the number of branch points and end points in the lamellar domains. The transition in network continuity from the PS to PMMA domain as a function of copolymer volumetric composition (from fPMMA = 0.45 to 0.55) was correlated with a 5-fold increase in the PMMA branch point density and a concomitant 3-fold reduction in the PMMA end point density. These results indicate that the copolymer’s composition drastically impacts the self-assembled lamellar morphology in thin films and is an important design consideration when using such materials for lithographic application.
Portable resistive pulse-activated lens-free cell imaging system

We demonstrate a portable lens-free cell imaging system activated by resistive pulses that are induced by biological cells in a microfluidic channel. This imaging on-chip flow cytometer integrates CMOS with microfluidics as a standalone on-chip analytical device. The preliminary version of this system is able to provide dual-parametric study (light contrast image and modulated electrical pulse) for each biological cell. Red blood cells and a tumor cell line (HepG2) are used to demonstrate the performance of this chip for flow analysis of biological samples.
Synthesis, characterization, and mechanical properties evaluation of thermally stable apophyllite vinyl ester nanocomposites

The objective of this study is to prepare layered organosilicates with enhanced thermal stability that can be used to formulate high-temperature polymer nanocomposites. Fourier transform infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (WAXD), and thermal gravimetric analysis (TGA) characterization results of the modified silicates indicate that the organic pendant group has been chemically grafted on to the backbone of layered silicate and the organically modified apophyllite is thermally stable up to approximately 430°C. The organically modified apophyllite was mixed along with vinyl ester resin and styrene diluent in a sonic dismembrator and the mixture cured to form a nanocomposite specimen. Transmission electron microscopy (TEM) results of the nanocomposites showed mixed morphology with predominant fraction of organosilicates exhibiting an intercalated structure. Tapping mode atomic force microscopy (TMAFM) observation of the nanocomposite showed striated layered silicates dispersed in the resin matrix. The nanocomposites formulated with organosilicates containing reactive terminal pendant group were found to have a higher tensile strain than the nanocomposites formulated with organosilicates containing inert pendant group. Copyright © 2007 John Wiley & Sons, Ltd.
Acute Toxicity and Sub-Lethal Effects of Non-Point Source Pollutants on Invertebrates

Acute Toxicity and Sub-Lethal Effects of Non-Point Source Pollutants on Invertebrates by Jocelyn Ann Romano University Program in Integrated Toxicology Nicholas School of the Environment and Earth Sciences Duke University Date:_______________________ Approved: ___________________________ Dan Rittschof, Co-Chair ___________________________ Patricia McClellan-Green, Co-Chair ___________________________ Richard Di Giulio ___________________________ David Hinton ___________________________ Celia Bonaventura An abstract of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the University Program in Integrated Toxicology in the Graduate School of Duke University 2007 Copyright by Jocelyn Ann Romano 2007