Miracle-dz/UniFAR-FTUs huggingface dataset:
Comparative Study of Eight Equations of State for Predicting Hydrocarbon Volumetric Phase Behavior

The objective of this study is to present a review of eight equations of state (EOS's) and compare their ability to predict the volumetric and phase equilibria of gas-condensate systems. Included in the study are the Peng-Robinson (PR), the Soave-Redlich-Kwong (SRK), the Schmidt-Wenzel (SW), the Usdin-McAuliffe (UM), the Heyen, the Kubic, the Adachi-Lu (AL), and the Patel-Teja (PT) EOS's. The SW equation exhibits a superior predictive capability for volumetric properties of condensate systems. The PR equation is found to represent the phase equilibrium behavior of condensate systems accurately. In terms of compressibility factors, the SW and PT equations give better predictions than other equations.
Role of iron addition on grain boundary conductivity of pure and samarium doped cerium oxide

The present paper reports the effect of iron doping (0.5, 1.5 mol%) on the densification and electrical properties of cerium oxide (CeO2) and 20 mol% samarium-doped cerium oxide (SDC) electrolytes for intermediate temperature solid oxide fuel cell (ITSOFC) applications. A single-step solution combustion method was used for doping and the resultant powder was compacted into green pellets and subsequently sintered at 1200 °C. X-ray diffraction (XRD) studies indicated the presence of a cubic fluorite CeO2 structure without the formation of a secondary phase and the stoichiometry was confirmed by X-ray fluorescence spectroscopy. In the as-compacted green pellets, the XRD peak position shifted to lower or higher angles depending on the ionic radii of the dopants due to lattice level mixing. Addition of iron resulted in smaller crystallite sizes ( 40 nm) after sintering. Densification was found to be higher (95%) in iron-doped samples than in bare samples (<90%) due to viscous flow sintering. Upon sintering the calculated strain value showed a lower value due to the segregation of iron from the lattice. Raman spectroscopic studies indicate that sintering marginally modifies the oxygen vacancy concentration in the SDC system, and found it to be higher than in CeO2. Addition of iron into the SDC improved the grain boundary conductivity 1.8 fold, but only a minor change was noticed for CeO2. The activation energy for the grain boundary conductivity was found to be lower for 1.5 mol% (1.06 eV) iron-doped SDC than for pure SDC (1.24 eV). Our results indicate that lattice level mixing of iron in SDC improves the density at relatively lower sintering temperatures and scavenges the grain boundary impurities, thereby increasing the grain boundary conductivity.
Facile synthesis of Cu2ZnSnS4 nanocrystals

A facile, greener and inexpensive method was developed to synthesize high quality quarternary Cu2ZnSnS4 (CZTS) nanocrystals at temperature lower than 220 °C, in which Cu2ZnSn(S2CNEt2)10, oleylamine and oleic acid were used as the precursor, activation agent and capping agent, respectively.
Film thickness measurements of SiO2 by XPS

The preferred XPS methodology for measurement of SiO 2 film thickness on polished silicon surfaces is discussed. A precise measurement of the photoelectron attenuation length was made using nuclear reaction analysis (NRA) to calibrate the film thicknesses. Antic oxide films on Si, which are very reproducible in thickness, are used as test samples. Appropriate corrections for the problem of adventitions carbon are shown. Under some conditions, the phenomenon of photoelectron diffraction has a significant effect on the measurements, and improvements to the precision by rotating the sample about the normal during data acquisition are demonstrated
Interactions between Hydrophobically Modified Associating Polyacrylamide and Cationic Surfactant at the Water‐Octane Interface: Interfacial Dilational Viscoelasticity and Relaxation Processes

The interfacial dilational viscoelastic properties of hydrophobically associating block copolymer composed of acrylamide (AM) and a low amount of 2‐ethylhexyl acrylate (EHA) (<1.0 mol%) with a hydrolyzed degree of about 1.5–2.0% at the octane‐water interfaces were investigated by means of two methods: the interfacial tension response to sinusoidal area variations (oscillating barriers method) and the relaxation of an applied stress (interfacial tension relaxation method) respectively. The influence of cationic surfactant cetyl trimethylammonium bromide (CTAB) on the dilational viscoelastic properties was studied. The results obtained by oscillating barriers method showed that dilational modulus decreased moderately with the increase of CTAB concentration. The results obtained by interfacial tension relaxation measurements showed that two main relaxation processes exist in the interface at 7,000 ppm polymer concentration: one is the fast process involving the exchange of hydrophobic blocks between the proximal region and distal region in the interface; the other is the slow relaxation process involving conformational changes of polymer chain in the interface. By adding CTAB, the slow process changed obviously due to the strong electrostatic interaction between oppositely charged surfactant and hydrolyzed part of polymer chain. Only when the CTAB concentration was close to the “equal charge point,” the associations formed mainly by the hydrophobic interaction like that in SDS/polymer system appeared and the characteristic time of fast process decreased obviously. The information of relaxation processes obtained from interfacial tension relaxation measurements can explain the results from dilational viscoelasticity measurements very well.
Phytoextraction of heavy metals by hemp during anaerobic sewage sludge management in the non-industrial sites

The aim of our research was to estimate the efficiency of monoaecian fibrous hemp (Cannabis sativa L., “Benico” variety) for heavy metals phytoextraction from soil-sludge substratum during anaerobic sewage sludge management in non-industrial sites. Below are the results from a pot experiment with hemp as a plant which phytoextracts zinc, copper and nickel. On the basis of heavy metals analysis in substratum it was ascertained that an increase of hemp biomass caused thirtyfold reduction of zinc, thirty-fivefold reduction of copper and tenfold reduction of nickel in light soil of sewage sludge fertilized in comparison with their concentration at the beginning of the pot experiment.
Simulations of diesel–methanol dual-fuel engine combustion with large eddy simulation and Reynolds-averaged Navier–Stokes model

A comparison of large eddy simulation and Reynolds-averaged Navier–Stokes combustion models was performed using simulations of a diesel–methanol dual-fuel engine. The two models share the assumption that the reaction rate for each species is determined by the chemical kinetic processes as well as the relative magnitude of mixing and reaction effects, which are characterized by a kinetic timescale and a turbulence timescale. The main difference in the two models lies in their formulations of the turbulence timescale. The turbulence timescale in the Reynolds-averaged Navier–Stokes model is proportional to the eddy turnover time, while the turbulence timescale in the large eddy simulation model is the time needed for the mixture to reach perfectly mixed conditions based on the scalar dissipation rate. The models were tested using data from experiments on a modified heavy-duty diesel engine. Test cases using low methanol ratios, high methanol ratios and different initial temperatures were examined. In general, the ignition delay increases as the methanol ratio increases. In the models, this was found to occur due to the chemical interaction of the methanol and the diesel fuel. In addition, methanol auto-ignition occurs when the initial temperature is over 425 K. The large eddy simulation model and Reynolds-averaged Navier–Stokes model give similar predictions for the low methanol ratio cases. The large eddy simulation model shows improved capability to predict the high methanol ratio cases and methanol auto-ignition cases, represented by good agreement with experimental results.
Avaliação da disponibilidade de nitrogênio no solo para o trigo em Latossolo Vermelho do Distrito Federal

Em razao da grande importância do nitrogenio na nutricao mineral das plantas, instalou-se um experimento em condicoes de campo em um Latossolo Vermelho, no ano agricola 2005, no campo experimental da Embrapa Cerrados, Planaltina (DF), com o objetivo de realizar a calibracao de metodos de determinacao desse nutriente no solo para a cultura do trigo. Utilizou-se o delineamento experimental de blocos ao acaso com seis repeticoes, e os tratamentos foram seis doses de N: 0, 70, 140, 210, 280 e 350 kg ha-1. Amostras de solo das camadas de 0-20 e 20-40 cm foram retiradas, e tres diferentes extratores quimicos foram utilizados para avaliacao da disponibilidade de N no solo. Os maiores coeficientes de determinacao, obtidos pela regressao quadratica entre a produtividade do trigo e o N do solo extraido pelos diferentes extratores, foram observados nas analises das amostras da camada de 0-20 cm, de acordo com a seguinte ordem: KCl 2 mol L-1 a 100 °C (R2 = 0,997**) > H2O2/MnO2 (R2 = 0,992**) > tampao pH 11,2 + NO3- (R2 = 0,985**) > tampao pH 11,2 (R2 = 0,960**). Os elevados valores dos coeficientes de determinacao indicam que a camada de 0-20 cm e a mais recomendada em analises de rotina de N no solo para o trigo. Considerando a simplicidade de analise e o elevado coeficiente de determinacao, o metodo da solucao-tampao pH 11,2 + NO3- pode ser indicado para analise de rotina de N no solo. Os niveis criticos economicos de N no solo calculados pelos diferentes extratores quimicos, para as relacoes preco do quilograma de N/preco do quilograma do trigo de 5 a 7, foram: 90 a 68 mg kg-1 (H2O2/MnO2), 87 a 66 mg kg-1 (KCl 2M a 100 oC), 81 a 62 mg kg-1 (tampao pH 11,2 + NO3-) e 64 a 47 mg kg-1 (tampao pH 11,2). Ja os niveis criticos calculados pelo metodo matematico de Cate - Nelson foram: 94 mg kg-1 (H2O2/MnO2), 90 mg kg-1 (KCl 2M a 100 oC), 82 mg kg-1 (tampao pH 11,2 + NO3-) e 61 mg kg-1 (tampao pH 11,2).
ROSEOFLAVIN AS A BLUE LIGHT RECEPTOR ANALOG: SPECTROSCOPIC CHARACTERIZATION

Abstract— The blue light absorption band of roseoflavin is polarized along the axis roughly connecting N3‐C8 positions. A weak, second π→π* transition with a polarization angle of ca. 25° is hidden under the short wavelength side of the blue absorption band. The excited state of roseoflavin is somewhat more basic than the ground state, by a 1.5 pKa unit. The fluorescence quantum yield and lifetime of roseoflavin are substantially lower than those of other flavins, thus making it kinetically less efficient as a blue light photoreceptor.
Comparison of major volatile compounds from Riesling and Cabernet Sauvignon grapes (Vitis vinifera L.) from fruitset to harvest

Background and Aims: Research on concentration changes of volatile compounds during grape physiological development has focused on the period from veraison to harvest. This study compared the developmental changes in the major volatile compounds released after the crushing of Riesling and Cabernet Sauvignon grapes sampled from fruitset to harvest during the 2007–2008 season. Methods and Results: Volatile compounds were extracted from the headspace of crushed Riesling and Cabernet Sauvignon grapes sampled throughout berry development using solid-phase microextraction and analysed by gas chromatography–mass spectrometry. A multivariate statistical approach coupled with analysis of variance was applied to compare the developmental changes in volatile compounds for the two cultivars. In both cultivars, E-2-hexenal was the most abundant volatile compound, and it showed a significant increase in concentration after veraison. Benzene derivatives discriminated ripe Cabernet Sauvignon grapes, whereas monoterpenes and sesquiterpenes discriminated both cultivars pre-veraison with a broader range of terpenes observed in the Cabernet Sauvignon samples compared with the Riesling samples. At veraison, terpene production in both varieties was low, but Riesling grapes produced some terpenes (geraniol and α-muurolene) post-veraison. Generally, esters and aldehydes were the major class of compounds from Riesling grapes, while Cabernet Sauvignon showed a greater tendency to form alcohols. Conclusions: Both Riesling and Cabernet Sauvignon grapes had a more complex volatile compound composition pre-veraison than post-veraison. This study suggests that some compounds that contribute to grape aroma may be produced pre-veraison, and not simply accumulate after veraison. Significance of the Study: Understanding the timing of volatile compound production and cultivar differences will guide viticulture researchers and growers in the optimisation of vineyard strategies to enhance grape aroma attributes that may, in turn, contribute to wine aroma.
Luminescent Zn and Cd Coordination Polymers

The hydrothermal reactions of Zn(ClO4)2·6H2O and Cd(ClO4)2·6H2O with 1,3-bis(2H-tetrazol-5-yl)benzene in an aqueous ethanol and an aqueous methanol/pyridine medium, respectively, yielded a 3D and a 2D metal-organic coordination framework [Zn(1,3-BTB)] (1) and [Cd(1,3-BTB)2(Py)2(H2O)2] [Cd[Cd(Py)(H2O)]2(1,3-BTB)2] (2) (1,3-BTB = 1,3-ditetrazolylbenzene, Py = pyridine), respectively. Species 1 possesses an open network structure with no guest molecules residing in its small cavities. The structural characterisation of 2 shows a 2D layered framework consisting of nano-sized polytube structures which are stacked one on top of another in the (110) plane giving small channels along the b and c axes. Additionally, compounds 1 and 2 exhibit strong fluorescence at room temperature in the solid state. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Composition control in emulsion copolymerization

MECHANISTIC MODELING OF (SEMI-) BATCH AND CONTINUOUS MULTI-MONOMER EMULSION POLYMERIZATION REACTORS 15 A dynamic model for multi-monomer emulsion polymerization in a series of ideally mixed isothermal continuous flow stirred tank reactors (CSTRs) has been developed. The residence time distribution in a CSTR and the nucleation behavior in emulsion polymerization processes result in a broad partiele size distribution. Therefore, population balances on the concentration of particles with a specific partiele diameter or polymer mass are defined. These balances tagether with the material balances on water, initiator, emulsifier, chain transfer agent, monomer, average composition and radical species describe the time evolution of the polymerization reaction. The model uses well established and recent theories on polymerization kinetics for radical initiation, propagation, termination by combination or disproportionation and chain transfer to monomer and agent and on mass transfer of radicals into and from the particles and micelles, and monomer diffusion in the particles. Because of the compartmentalized nature of emulsion polymerization it is necessary to describe the partitioning of monomer between the various phases. A finite difference technique has been used to solve the partial integrodifferential, ordinary differential and algebraic equations. The population balance equations were discretized and approximated by a set of first order differential equations. These equations are stiffly coupled and were solved with the numerical integration package DASSL. This routine uses a predietor-corrector integration scheme, which is based on backward differentiation formulas. Some of the features of the model are the prediction of the partiele size distribution, chemical composition, and the molecular weight distribution (only for linear chains and when monodispersity is assumed). Also the addition rates of the most reactive monomerscan he calculated in order to produce homogeneaus copolymers, i.e. polymer with a narrow chemical composition distribution.
Permeability of CO2 through chitosan membrane swollen by water vapor in feed gas

The permeation and separation of carbon dioxide through a water-swollen chitosan membrane was studied. A chitosan membrane was swollen by water vapor contained in a feed gas and, thus treated, exhibited a large gas permeability. Carbon dioxide preferentially permeated through the swollen chitosan membrane with a permeability of 2.5-10 -8 cm 3 (STP) cm(s cm 2 cmHg) -1 and a CO 2 /N 2 separation factor of 70 at room temperature. This separation performance for CO 2 resulted from the basic properties of the chitosan amino groups. The membrane preparation conditions, such as acetic acid concentration of the casting solution, affected the membrane permeation rate. The effect of the operation temperature was also measured. To increase the separation performance of the membrane, several methods of membrane treatment and operation were evaluated.
Non-methane volatile organic compounds in Africa: A view from space

Isoprene emissions affect human health, air quality, and the oxidative capacity of the atmosphere. Globally anthropogenic non-methane volatile organic compounds (NMVOC) emissions are lower than that of isoprene, but local hotspots are hazardous to human health and air quality. In Africa the tropics are a large source of isoprene, while Nigeria appears as a large contributor to regional anthropogenic NMVOC emissions. I make extensive use of space-based formaldehyde (HCHO) observations from the Ozone Monitoring Instrument (OMI) and the chemical transport model (CTM) GEOS-Chem to estimate and examine seasonality of isoprene emissions across Africa, and identify sources and air quality consequences of anthropogenic NMVOC emissions in Nigeria. To estimate isoprene emissions I first developed a filtering scheme to remove (1) contamination from biomass burning and anthropogenic influences; and (2) displacement of HCHO from the isoprene emission source diagnosed with the GEOS-Chem CTM. Conversion to isoprene emissions is with NOx-dependent GEOS-Chem HCHO yields, obtained as the local sensitivity S of the HCHO column ΩHCHO to a perturbation Δ in isoprene emissions EISOP (S = ΔΩHCHO/ΔEISOP). The error in OMI-derived isoprene emissions is 40% at low levels of NOx and 40-90% under high-NOx conditions and is reduced by spatial and temporal averaging to the extent that errors are random. Weak isoprene emission seasonality in equatorial forests is driven predominantly by temperature, while large seasonality in northern and southern savannas is driven by temperature and leaf area index. The largest contribution of African isoprene emissions
Sterole in Blättern und Chloroplasten

The nature and quantity of sterols in leaves and chloroplasts of Spinacia oleracea, Antirrhinum majus, and Allium porrum were determined. From dried leaves 0.05 - 0.18% free and esterified sterols were isolated, and 0.04-0.09% from chloroplasts. Although approximately half the lipids of leaves is localized in chloroplasts we found no more than a quarter of leaf sterols in the chloroplasts. The mixture of sterols contains a major sterol and minor sterols in these species. In spinach a-spinasterol is the major sterol and in Antirrhinum and Allium β-sitosterol. Moreover, we established Δ7-stigmastenol and cholesterol in spinach. Besides for free sterols, leaves contain sterol esters and glycosides. Palmitic acid is the binding partner in the sterol esters of spinach, and glucose and mannose are the binding partners in sterol glycosides. Chloroplasts contain the same sterols as leaves do. Only a trace of sterol glycosides could be detected in chloroplast preparations.
An automated chamber system for measuring soil respiration

To quantify the net effect of agricultural systems on CO2 emissions to the atmosphere, the amount of carbon fixed (primary production) and emitted (soil respiration) under different agronomic management must be estimated. A dynamic chamber system was constructed to automatically measure CO2 concentration in chambers and provide diurnal flux estimates of soil respiration. In fallow, the mean respiration was measured over 4 d using four chambers and ranged from 6.5 to 8.6 g m−2 d−1. During this time, the coefficient of variation between chambers ranged from 9 to 18%. The mean daily soil respiration in fallow was also measured over a second period (13 d) using both chambers and a Bowen ratio technique. The mean value from the chambers was 6.4 g m−2 d−1, which was not significantly (P > 0.05) different from that Bowen ratio value of 7.1 g m−2 d−1. The chambers were also utilized to measure the impact of tillage on soil respiration for 11 d following tillage. During this period, the tilled plot lost 92 kg ha−1.
Iron Ore Pellet Dustiness Part I: Factors Affecting Dust Generation

Iron ore pellets abrade during handling and produce dust. This study was conducted to determine what factors affect pellet dustiness, and whether dustiness can be related to the abrasion index. Factors studied included bed depth within a straight grate furnace; pellet chemistry; firing temperature; coke breeze addition; and tumble index. Abrasion indices for all pellet samples ranged from 1.9–5.0% (20 samples) and from 7.1–27.5% (5 samples). Pellets were dropped in an enclosed tower, which enabled the collection of airborne particles generated during pellet breakdown. The quantity of airborne particles generated by each pellet type was 10–100 mg/kg-drop, or 50–500 mg/kg over five drops through the tower. Pellet dustiness was predominantly affected by pellet chemistry and by pellet firing temperature. Results showed a nearly 21% increase in dustiness for every percent decrease in firing temperature – this was based on a typical firing temperature of 1280°C. Pellet dustiness was regressed to the pellet abrasion index (for AI < 5%), which yielded a correlation coefficient of 0.22. These results show that, although AI is one of the best indicators of fired pellet quality and can indicate high levels of dust, it could not explain the dustiness of good quality pellets. The second paper (Iron Ore Pellet Dustiness Part II) explains the relationship between AI and dust for good-quality pellets; and compares fines generation between pellets fired in Straight-Grate (Traveling Grate) and Grate-Kiln furnaces.
Effects of Microorganisms on the Fate of Iodine in the Soil Environment

The roles of microbial activities in the accumulation of iodine in soils and its loss from soils were studied. Concentrations of stable iodine in several type of soils were determined by inductively coupled plasma-mass spectroscopy. High iodine concentrations were found in upland soils, particularly in Andosol, whereas the concentrations in lowland soils were considerably lower. Accumulation of iodine in soils was explained by the effects of microorganisms or their products (e.g., enzymes), or both. Iodine was observed to be desorbed from the flooded soils because of the reducing conditions (low Eh) created by the microbial activities. Evaporation of biogenerated methyl iodide from the soilplant system, specifically from rice plants, may also decrease the iodine concentrations in lowland soils.
Reconstruction of the past 1000-a temperature in Canada based on pollen data

Reconstructions of past climate based on pollen data have formed a robust approach and produced a great of products in time scales from a millennium to ten millenniums. However, it is an attempt for reconstruction of the past decade-century climate in the Global Change field. This note reports a reconstruction of the past 1000-a temperature in a 50-a scale in Canada based on pollen data. Because there were little human activities during the last 1000 years in North America, the climate in the period mainly responded to natural changes. The reconstruction of a natural-forcing change in the climate can provide a basis to recognize the climate changes impacted from human activities in China. The technique of modern analogue can be implemented to reconstruct the past millennium climate in China.