Miracle-dz/UniFAR-FTUs huggingface dataset:
Jet Engine Exhaust Aerosol Characterization

ABSTRACT Jet engine exhaust aerosol was characterized with respect to mass concentration and composition of the carbonaceous aerosol fraction and the particulate sulfate as a function of engine power setting for fuel with low-sulfur content (6 ppm) and high-sulfur content (3000 ppm). The ratio of black carbon (BC) to total carbon (TC) varied from 11% with the engine in idle run to >80% at take-off thrust. The corresponding BC emission index was <0.6 g kg−1 fuel on a mass scale and <1.7 × 1015 kg−1 fuel on a number scale. The optical specific absorption coefficient of the BC aerosol was measured to 6 ± 1 m2 g−1 by filter reflectance analysis (λ ≊ 0.8 μm). The carbon aerosol split into a primary soot mode at 0.045 μm diameter with geometric standard deviation 1.5 and a coagulation mode at 0.18 μm diameter with geometric standard deviation 1.42. The mass emission index of particulate sulfate remained almost constant at <0.05 g kg−1 throughout the examined engine power setting between 11% and 71% take-off thr.
Nucleation characteristics of aqueous nickel ammonium sulphate solutions

The nucleation of nickel ammonium sulphate hexahydrate from aqueous solution has been studied by two different methods which involved measuring (a) the maximum allowable undercooling (the metastable zone width) and (b) the induction period before the onset of visible nucleation.Three different nucleation mechanisms were observed. For unseeded solutions (primary nucleation) the nucleation appeared to be homogeneous for supersaturations S > 1.8 and heterogeneous for S < 1.3. In the presence of a seed crystal secondary nucleation occurred.Expressing the nucleation kinetics by the empirical relationship J=kn(Δc)n, values of n(the “order” of the nucleation process)= 3.2, 2.0 and 1.1 were obtained for homogeneous, heterogeneous and secondary nucleation respectively. There was good agreement between the two different methods of measurement for primary heterogeneous nucleation (n= 2.0). Trace quantities (10 ppm) of polyacrylamide suppressed nucleation considerably, but did not appear to change the “order” of the nucleation process.
Recent advances in the modeling and simulation of metallocene catalysis, sequence distribution, chain conformations, and crystallization of polymers

This article is a review describing the latest advances in modeling and simulation of polymers. Sequence distributions in stereoblock polymers and copolymers greatly affect their chain conformations and thermal transitions. While no theory was able to fully predict the influence of chain conformations on polymer crystallization, modeling techniques have shown good reliance in simulating the conformational behavior of polymeric chains and the related physical properties. This is done by generating representative sequences, and studying the chain conformation and packing of such sequences into crystalline regions in multichain systems. Metallocene catalysts, a class of single site catalysts, also showed unprecedented performance in the polymerization of olefins, most notably their activity, copolymerization capabilities, and potential for precise control of stereostructures. These attributes are among the most important issues in the manufacture of polyolefins and olefin copolymers, and are too good to be ignored. These polymers consist of alternating atactic sequences, which are amorphous and act as elastomeric chains, and ordered isotactic or syndiotactic sequences which, if long enough, will crystallize and act as physical reinforcing crosslinks. Mesoscopic investigation utilizing computer modeling and simulation into the effects of the sequence length and sequence length distribution on the reinforcement of stereoblock and stereoregular polyolefins has also been reviewed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2524–2541, 2006
B-DNA's BII Conformer Substate Population Increases with Decreasing Water Activity. 1. A Molecular Dynamics Study of d(CGCGAATTCGCG)2

The BII substate of the biologically active B-DNA family is characterized by a different phosphate backbone geometry. In contrast to the current belief, the BII substate of the d(CGCGAATTCGCG)2 dodecamer is shownboth experimentally and by molecular dynamics simulationsto be significantly populated at water activities in the range of those in the cell nucleus. Three systems with different water contents show an increase in BI ⇌ BII transitions as the water activity decreases. In addition, the transition mechanism is investigated and the sequence dependence of these interconversion processes in the form of pyrimidine−purine interconversion dominance is demonstrated.
Performance comparison of AlGaAs, GaAs and InGaP tunnel junctions for concentrated multijunction solar cells

Four tunnel junction (TJ) designs for multijunction (MJ) solar cells under high concentration are studied to determine the peak tunnelling current and resistance change as a function of the doping concentration. These four TJ designs are: AlGaAs/AlGaAs, GaAs/GaAs, AlGaAs/InGaP and AlGaAs/GaAs. Time‐dependent and time‐average methods are used to experimentally characterize the entire current–voltage profile of TJ mesa structures. Experimentally calibrated numerical models are used to determine the minimum doping concentration required for each TJ design to operate within a MJ solar cell up to 2000‐suns concentration. The AlGaAs/GaAs TJ design is found to require the least doping concentration to reach a resistance of <10−4 Ω cm2 followed by the GaAs/GaAs TJ and finally the AlGaAs/AlGaAs TJ. The AlGaAs/InGaP TJ is only able to obtain resistances of ≥5 × 10−4 Ω cm2 within the range of doping concentrations studied. Copyright © 2010 John Wiley & Sons, Ltd.
Ion velocities in vacuum arc plasmas

Ion velocities in vacuum arc plasmas have been measured for most conducting elements of the Periodic Table. The method is based on drift time measurements via the delay time between arc current modulation and ion flux modulation. A correlation has been found between the element-specific ion velocity and average ion charge state; however, differently charged ions of the same element have approximately the same velocity. These findings contradict the potential hump model but are in agreement with a gasdynamic model that describes ion acceleration as driven by pressure gradients and electron-ion friction. The differences between elements can be explained by the element-specific power density of the cathode spot plasma which in turn determines the temperature, average charge state, and ion velocity of the expanding vacuum arc plasma.
Microwave Energy Absorption Behavior of Foamed Berry Puree Under Microwave Drying Conditions

The microwave energy absorption behavior of foamed berry puree was studied considering the variations in the physical properties of the material. The absorptions of microwave energy within foamed berry puree indicated fluctuating trends in decay as microwave drying progressed, which were attributed to the effects of temperature, moisture content, and density of the material. Mathematical models of the dielectric constant ϵ′ and dielectric loss factor ϵ″ as a function of temperature and moisture content were developed using second-order functions. During microwave drying of foamed berry puree, moisture content had the most important negative influence on the dielectric constant and dielectric loss factor, followed by temperature and porosity.
Development of High Precision Plant Simulator for Pressurized Water Reactor Plants using Distributed Architecture

As advanced monitoring and controlling systems have been developed, accuracy of real-time simulators must be improved and simulation limits must be extended. Therefore the authors have developed a distributed simulation system to achieve high processing performance using low cost hardware. Moreover, the authors have developed a thermal-hydraulic computer code, using drift-flux non-equilibrium model. This code can realize a high precision two-phase flow analysis, to be considered to have the same prediction capability as two-fluid models, while achieving high speed and stability for real-time simulators. The distributed plant simulator for PWR plants was realized as a result. The distributed simulator consists of multi-processors connected to each other by an optical fiber network. Controlling software for synchronized scheduling and data transfer was also developed. In terms of the code development, the numerical calculation method and implemented correlation chosen for this code are described. The simula.
Asthma Hospital Admissions and Ambient Air Pollutant Concentrations in New York City

Air pollution is considered a risk factor for asthma. In this paper, we analyze the association between daily hospital admissions for asthma and ambient air pollution concentrations in four New York City counties. Negative binomial regression is used to model the association between daily asthma hospital admissions and ambient air pollution concentrations. Potential confounding factors such as heat index, day of week, holidays, yearly population changes, and seasonal and long-term trends are controlled for in the models. Nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO) show the most consistent statistically significant associations with daily hospitalizations for asthma during the entire period (1996-2000). The associations are stronger for children (0 - 17 years) than for adults (18 - 64 years). Relative risks (RR) for the inter-quartile range (IQR) of same day 24-hour average pollutant concentration and asthma hospitalizations for children for the four county hospitalization totals were: NO2 (IQR = 0.011 ppm, RR = 1.017, 95% CI = 1.001, 1.034), SO2 (IQR = 0.008 ppm, RR = 1.023, 95% CI = 1.004, 1.042), CO (IQR = 0.232 ppm, RR = 1.014, 95% CI = 1.003, 1.025). In the case of ozone (O3) and particulate matter (PM2.5) statistically significant associations were found for daily one-hour maxima values and children’s asthma hospitalization in models that used lagged values for air pollution concentrations. Five-day weighted average lag models resulted in these estimates: O3 (one-hour maxima) (IQR = 0.025 ppm, RR = 1.049, 95% CI = 1.002, 1.098), PM2.5 (one-hour maxima) (IQR = 16.679 μg/m3, RR = 1.055, 95% CI = 1.008, 1.103). In addition, seasonal variations were also explored for PM2.5 and statistically significant associations with daily hospital admissions for asthma were found during the colder months (November-March) of the year. Important differences in pollution effects were found across pollutants, counties, and age groups. The results for PM2.5 suggest that the composition of PM is important to this health outcome, since the major sources of NYC PM differ between winter and summer months.
Grain boundary segregation in [100] symmetrical tilt bicrystals of an Fe-Si alloy

The orientation and temperature dependences of the segregation of P, Si and C at [100] symmetrical tilt grain boundaries of an Fe-3.5 at. % Si alloy were determined by AES analysis of in situ fractured bicrystals. The obtained anisotropy of the segregation enthalpy of all three elements is characterized by its low absolute values for the {013} and {012} boundaries. Both of these boundaries belong to the low classification levels after Paidar and possess high values of interplanar spacing which can be used as a simple geometric criterion of the boundary ‘specialty’. The data are consistent with the construction of the grain boundary segregation diagram showing the dependence of the segregation enthalpy on both the boundary orientation and the maximum solid solubility of the solute.
Long Term Osmotic Dehydration Processes of Orange Peel at Atmospheric Pressure and by Applying a Vacuum Pulse

Osmotic dehydration is a useful tool to obtain orange peel products with good sensory acceptance and stability. Osmodehydration of orange peel has been carried out in different osmotic solutions (65 Brix sucrose, 55 Brix glucose and concentrated rectified grape must) at 40 and 50 C for different durations (0–10 days), at atmospheric pressure and by applying a vacuum pulse at the beginning of the process. Changes in sample composition (water and soluble solid contents), weight, volume, density and porosity were analyzed. In all conditions, samples reached the same sample solute content as the osmotic solution at about 24 h of treatment, and the concentration rate was faster when vacuum pulse was applied. Mass transfer behavior showed that impregnation of the peel pores occurred to a great extent, not only when applying vacuum pulse, but also in treatments at normal pressure, due to the capillary effects and pressure gradients generated in the tissue associated with structural changes. Impregnation contributed to compositional changes and weight development of the sample. The greater the osmotic solution viscosity, the lower the impregnation level at equilibrium, which was always promoted by vacuum pulse.
Brand Heritage and Word of Mouth: The Mediating Role of Brand Personality, Product Involvement and Customer Satisfaction

The present study aims to review the effect of brand heritage on its personality. According to Aker (1996) the personalities of the brand are considered as honesty, excitement, efficiency, expertise, and power. The present study has been performed via descriptive-survey method and the population consists of university students who use Adidas brand. 400 questionnaires were distributed among them through stratified random sampling and finally 384 questionnaires were taken back and evaluated. To analyze the data SPSS and Amos software, structural equation modeling was applied. The results show that brand personality has an impact on word of mouth communications in Adidas brand. Also brand personality impacts the customer satisfaction. Honesty and efficiency which are counted as brand personality aspects are influential in customer satisfaction but excitement, expertise and power did not have any effect on it in Adidas brand.
Microbial Products of Activated Sludge in Biological Wastewater Treatment Systems: A Critical Review

Activated sludge is subjected to transient conditions, resulting in the enhanced production of microbial products (i.e., extracellular polymeric substances, soluble microbial products, and internal storage products). The authors review the status of the microbial products formed by activated sludge in wastewater treatment systems. They outline the fundamental facets of their formation and metabolism, define their key characteristics and important roles, and identify the interrelationships between the microbial products and activated sludge processes as well as discuss their implications. In addition, they appraise present understanding about their conversion kinetics. Finally, the authors also summarize modeling works on the microbial products formation processes and discuss a model incorporating their formation and utilization in activated sludge systems.
Adsorption Characteristics of Trace Volatile Organic Compounds on Activated Carbon Fibres at Room Temperature

The adsorption characteristics of volatile organic compounds (VOCs) on viscose rayon-based activated carbon fibres (ACFs) were investigated. ACFs with specific surface areas of 640 m2/g and 1460 m2/g were used to adsorb trace volatile organic compounds in nitrogen streams at atmospheric pressure at or near room temperature (25°C and 30°C). The experimental results showed that ACFs with different surface areas exhibited different dynamic adsorption behaviours at or near room temperature.
Trivalent Actinide and Lanthanide Separations by Dialkyl-Substituted Diphosphonic Acids

Abstract: The dialkyl-substituted diphosphonic acids are powerful solvent extraction reagents for actinide separation and preconcentration from biological, environmental, and nuclear waste samples. In spite of the intensive scrutiny of the solvent extraction properties of these compounds, only the extraction of Eu(III) and Am(IIl), among the lanthanides and trivalent actinides, has been investigated thus far. In this work, we report the extraction of all members of the lanthanide series, plus lanthanum, yttrium, Am(III), Cm(III), and Cf(III), by two representative diphosphonic acids (i.e., P,P’-di(2-ethylhexyl) methylenediphosphonic acid (H2DEH[MDP)) and the P,P’-di(2-ethylhexyl) ethylenediphosphonic acid (H2DEH[EDP])]. H2DEH[MDP] shows very efficient extraction of all ions investigated, but little selectivity, except for the heaviest lanthanides. H2DEH[EDP], on the other hand, exhibits less efficient extraction, but much higher selectivity, with an average separation factor between contiguous elements of 1.8, and extraction equilibrium constants spanning about three orders of magnitude along the lanthanide series. The extraction data for H2DEH[EDP] also exhibit a significant tetrad effect. The differences in affinity and selectivity for the lanthanides and trivalent actinides observed with the two extractants are discussed in terms of chelating ring size, monofunctional character, extractant aggregation, and metal extraction stoichiometries.
Epoxy-Terminated Self-Assembled Monolayers: Molecular Glues for Polymer Layers

Dense, homogeneous, and complete self-assembled monolayers (SAMs) with epoxy surface groups were fabricated from epoxysilanes to serve as a template for chemical anchoring of polymer layers. A combination of scanning probe microscopy, ellipsometry, XPS, X-ray reflectivity, and contact angle measurements was used to study their morphology and surface properties. Self-assembly of epoxysilane molecules resulted in the formation of homogeneous SAMs 0.85 nm thick with the surface roughness 0.22 nm. Epoxysilane SAMs were truly monomolecular films with a virtually normal molecular orientation of densely packed molecules, which were firmly attached to the substrate. The formation of stable polymer layers from carboxy-terminated polystyrenes on reactive SAM surfaces was demonstrated.
Synthesis of Alumina- and Alumina/Silica-Coated Titania Particles in an Aerosol Flow Reactor

In situ coating of titania aerosol particles with alumina and alumina−silica mixtures by chemical vapor deposition, cluster deposition, and sintering was demonstrated in a hot-wall, continuous flow tubular reactor. Titania particles with diameters in the range 0.2−0.8 μm were produced by the reaction of TiCl4 with O2 at 1300 and 1500 °C and were passed through a coating region where they were mixed with AlCl3 or mixtures of AlCl3 and SiCl4. Uniform and dense coatings of Al2O3 were obtained at both 1300 and 1500 °C using AlCl3 inlet concentrations that corresponded to Al2O3 mass loading of less than 1 wt %. The coating thickness could be controlled from 5 to 20 nm which corresponded to deposition rates up to 50 nm/s. Uniform and dense coatings of Al2O3/SiO2 were obtained at 1300 °C when the SiO2/Al2O3 weight ratio was less than 2:1. It is proposed that coating takes place in two modes: (a) chemical vapor deposition of AlCl3 and SiCl4 on the particle surface and (b) gas-phase reactions of the metal chlorid.
Infrared Spectra of Amide Groups in α-Helical Proteins: Evidence for Hydrogen Bonding between Helices and Water

Infrared spectral frequencies of amide vibrational modes are sensitive to secondary structure. In this work, evidence is presented that accessibility to water additionally affects spectral positions. The dimeric α-helical coiled-coil GCN4-P1‘ was 13C labeled in the amide carbonyl groups of buried Leu or exposed Ala. At 20 °C, the amide I‘ peak for 13C Ala amide is at 1585 cm-1, whereas the position for 13C Leu is at 1606 cm-1. These shifts permit the distinction of solvent-exposed and buried amide groups. Lowering temperature increases H-bond strength, producing a shift to lower frequency. In the temperature range from 10 to 273 K in aqueous glycerol, the amide transitions assigned to solvent-exposed regions of the helices undergo the strongest temperature-dependent shifts, similar to that of the peptide bond model compound, N-methylacetamide, in the same aqueous solvent. In addition, spectral shifts of the amide bands for N-methylacetamide and the solvent-exposed component of the proteins follow the glas.
Removal of red 3BS dye from wastewater using emulsion liquid membrane process

Emulsion Liquid Membrane (ELM) is one of the process that has very high potential for industrial wastewater treatment of dyes. In this research, Red 3BS dye was extracted from simulated wastewater using Tridodecylamine as the carrier agent, sodium hydroxide as the stripping agent, kerosene as the diluent and span 80 was used as emulsifier. The important parameters affecting the Emulsion Liquid Membrane (ELM) extraction process including external phase concentration, treat ratio (emulsion/ external phase), concentration of carrier and agitation speed were investigated. The results show that the Red 3BS dye can be extracted almost 70% from simulated wastewater. The highest Red 3BS dye extraction was obtained by using 0.07 M Tridodecylamine, 5% (w/v) Span 80, 250 rpm agitation speed, 0.5 M thiourea in 1.0 M sodium hydroxide as the stripping agent, 1:3 treat ratio and kerosene as the diluent. As a conclusion, the Emulsion Liquid Membrane has a high potential in the extraction of dye from wastewater.
Axial and Radial Investigation of Hydrodynamics in a Bubble Column; Influence of Fluids Flow Rates and Sparger Type

A detailed investigation of local hydrodynamics in a pilot plant bubble column has been performed using various techniques, exploring both axial and radial variations of the gas hold-up, bubble average diameter and frequency, surface area. A wide range of operating conditions has been explored up to large gas and liquid flow rates, with two sparger types. Two main complementary techniques were used: a quasi local measurement of gas hold-up via series of differential pressure sensors to get the axial variation and a double optic probe giving radial variations of gad hold-up, bubble average size and frequency and surface area.According to axial evolutions, three zones, where radial evolutions have been detailed, have been separated: at the bottom the gas injection zone, the large central region or column bulk and the disengagement zone at the column top. It was found that significant axial and radial variations of the two phase flow characteristics do exist even in the so called homogeneous regime. The normalized profiles of bubble frequency appear sparger and gas velocity independent contrary to bubble diameter, gas hold-up and interfacial area normalized profiles. In any case bubbles are larger in the sparger zone than elsewhere.The main result of this work is the very strong effect of liquid flow on bubble column hydrodynamics at low gas flow rate. First the flow regime map observed in batch mode is dramatically modified with a drastic reduction of the homogeneous regime region, up to a complete heterogeneous regime in the working conditions (uG> 0.02 m/s). On the contrary, liquid flow has limited effects at very high gas flow rates.A large data bank is provided to be used for example in detailed comparison with CFD calculations.
Kinetics of Heterogeneous Catalytic Ozone Decomposition in Water on an Activated Carbon

Abstract Ozone decomposition in water in the presence of an activated carbon has been studied. Variables investigated were agitation speed, carbon particle size, temperature and pH. In all cases, the presence of activated carbon improved the ozone decomposition rate. Between pH 2 and 7 the ozone decomposition rate due to both the homogeneous and heterogeneous mechanisms hardly varied while a significant increase was noticed with increasing pH. A kinetic study based on a Langmuir-Hinselwood type mechanism for the heterogeneous surface reaction was undertaken. According to this mechanism the heterogeneous ozone decomposition kinetics can be simplified to follow a first order process. Fit of experimental results to the kinetic equations derived from the mechanism allowed for the determination of the apparent first order rate constants of the ozone surface heterogeneous reaction and adsorption equilibrium constants.