Systematic bias in the measurement of water in oils by tubular oven evaporation and azeotropic distillation.

Water in oil has been measured by tubular oven evaporation and by azeotropic distillation into a coulometric moisture analyzer. The results of these measurements were compared to the results obtained by volumetric titration of water in oil. The volumetric measurements were consistently higher than the measurements made by tubular oven evaporation or azeotropic distillation. A mass balance study was performed by volumetric Karl Fischer titration of the water in the oil that remained in the tubular oven and in the distillation apparatus. This study indicated that measurable amounts of water were not removed after exhaustive evaporation or distillation. The sum of the water removed by distillation from toluene and that remaining in the distillation chamber was equal to the amount of water measured in the oil by the volumetric method. The data are consistent with the existence of an oil-water azeotrope that does not release water upon evaporation at 160 degrees C or upon dissolution in toluene and distillation of the water-toluene azeotrope. These results were obtained for oils varying in viscosity from 8 to 850 m2/s, and the amount of water remaining associated with the oil appears to be dependent upon the composition of the oil and the method of analysis.     

Factors affecting stability of z-ligustilide in the volatile oil of radix angelicae sinensis and ligusticum chuanxiong and its stability prediction

The purpose of this investigation is to obtain a suitable vehicle for Z-ligustilide in the volatile oil of Radix Angelicae Sinensis and Ligusticum Chuanxiong in which it is stable enough for the application in pharmaceutics, to investigate its degradation laws, and to predict its shelf-life at 25 degrees C. Factors including temperature, light, pH value, co-solvents and antioxidants can all influence the stability of Z-ligustilide, thereinto antioxidants could markedly improve its stability in aqueous solution by almost 35%. The suitable vehicle for Z-ligustilide contains 1.5% tween-80, 0.3% Vitamin C, and 20% propylene glycol (PG). Furthermore, the degradation rates of Z-ligustilide were found to conform to a rate equation following Weibull probability distribution within a range of degradation ratio, and the equation could be expressed as follow: ln ln (1/1-alpha) = ln k + m ln t. Where alpha is degradation ratio; t is time; m and k are constants relating to the degradation rate. The degradation rate will get greater as the increasing of parameter k. According to the degradation law obtained from the equation, the drug shelf-life (10% of active ingredient degraded, T90) in this vehicle was predicted to be more than 1.77 years at 25 degrees C through Arrehenius equation and accelerating experiments.The present investigation was undertaken to propose a kinetic treatment that may be applicable to any type of degradation of the active ingredient of pharmaceutical formulation, and also could provide a good foundation for the new drug development of Z-ligustilide, especially for injection formulation.     

Annealing dependence of residual stress and optical properties of TiO2 thin film deposited by different deposition methods

Titanium oxide (TiO(2)) thin films were prepared by different deposition methods. The methods were E-gun evaporation with ion-assisted deposition (IAD), radio-frequency (RF) ion-beam sputtering, and direct current (DC) magnetron sputtering. Residual stress was released after annealing the films deposited by RF ion-beam or DC magnetron sputtering but not evaporation, and the extinction coefficient varied significantly. The surface roughness of the evaporated films exceeded that of both sputtered films. At the annealing temperature of 300 degrees C, anatase crystallization occurred in evaporated film but not in the RF ion-beam or DC magnetron-sputtered films. TiO(2) films deposited by sputtering were generally more stable during annealing than those deposited by evaporation.     

真空条件下含银铅锑多元合金中锑的蒸发行为研究

根据真空冶金原理,以选择性分离银锑为目的,采用真空蒸馏法研究含银铅锑多元合金在真空(5～25 Pa)的条件下蒸馏过程中Sb的蒸发行为,考察蒸馏温度、蒸馏时间、多元合金中其它组元对锑蒸发的影响;并测定了不同温度下Sb元素的蒸发速率.实验结果表明:随着蒸馏温度的升高及恒温时间的延长,Sb的蒸发量和挥发率均增大.X射线衍射分析表明,蒸发物中锑为元素Sb,残留物中Cu与Sb形成化合物Cu2Sb及Cu10Sb3,Ag与Sb生成Ag3Sb,阻碍部分Sb的彻底蒸发.结合Sb元素的蒸发机制,根据实验结果计算得出Sb元素的蒸发速率为15.169～18.066g·cm-2·h-1.     

Properties of TiO(x) films prepared by electron-beam evaporation of titanium and titanium suboxides

The titanium suboxides TiO, Ti2O, and Ti3O5 are widely used to produce films of titanium dioxide by reactive evaporation. If they are evaporated in high vacuum, however, they yield absorbing TiO(x) films with a transmission color varying between blue and gray. We investigated the specific properties of these TiO(x) film. TiO, Ti2O3, Ti3O5, and titanium metal were evaporated in high vacuum upon glass substrates at 25 degrees and 250 degrees C. Differences in chemical composition, transmission and reflection, color, stress, and abrasion resistance of these fims, depending on the starting material and the substrate temperature, were evaluated.     

Estimation of potential impacts and natural resource damages of oil

Methods were developed to estimate the potential impacts and natural resource damages resulting from oil spills using probabilistic modeling techniques. The oil fates model uses wind data, current data, and transport and weathering algorithms to calculate mass balance of fuel components in various environmental compartments (water surface, shoreline, water column, atmosphere, sediments, etc.), oil pathway over time (trajectory), surface distribution, shoreline oiling, and concentrations of the fuel components in water and sediments. Exposure of aquatic habitats and organisms to whole oil and toxic components is estimated in the biological model, followed by estimation of resulting acute mortality and ecological losses. Natural resource damages are based on estimated costs to restore equivalent resources and/or ecological services, using Habitat Equivalency Analysis (HEA) and Resource Equivalency Analysis (REA) methods. Oil spill modeling was performed for two spill sites in central San Francisco Bay, three spill sizes (20th, 50th, and 95th percentile volumes from tankers and larger freight vessels, based on an analysis of likely spill volumes given a spill has occurred) and four oil types (gasoline, diesel, heavy fuel oil, and crude oil). The scenarios were run in stochastic mode to determine the frequency distribution, mean and standard deviation of fates, impacts, and damages. This work is significant as it demonstrates a statistically quantifiable method for estimating potential impacts and financial consequences that may be used in ecological risk assessment and cost-benefit analyses. The statistically-defined spill volumes and consequences provide an objective measure of the magnitude, range and variability of impacts to wildlife, aquatic organisms and shorelines for potential spills of four oil/fuel types, each having distinct environmental fates and effects.     

Characteristics of Climate Change in the Lake Basin Area of Gangcha County

This paper mainly was based on the average temperature, precipitation, humidity, and wind direction of Gangcha county from 1960 to 2013. By using wavelet analysis and Mann-Kendall (M-K) mutation analysis, specifically analyzed the climate change characteristics in the lake basin area of Gangcha county. The result showed that the climatic change in the lake basin area of Gangcha county is noticeable. The average temperature, average minimum temperature, average maximum temperature, and evaporation showed an increasing trend. But the evaporation in the study area was higher than precipitation. The average relative humidity showed a decreasing trend. And the sunshine and the average wind speed percentage showed a significant decreasing trend. Utilizing the Morelet wavelet, The time series of annual mean temperature, annual evaporation and annual sunshine percentage all have quasi3a and quasi4A periods, and the annual mean precipitation has quasi2–3A, quasi2–5A and quasi2–6A periods, which appear in 1996–2005, 1962–1978 and 1978–1996 respectively. The mean annual relative humidity has obvious quasi2–7A and quasi3A time series, which appear from 1960 to 1996, 1997 to 2005 and after 2008, respectively. The annual mean wind speed has quasi3–4A and quasi5A time series characteristics, which appear in 1964–1967, 1984–1995, after 2009 and 1971–1983, respectively. Through Mann-Kendall (M-K) mutation analysis, it is found that the mutations of evaporation and the average speed of wind are significant. The mutation of evaporation started in 2004, and the mutation of average started in 2003.     

Life in oil: Hydrocarbon-degrading bacterial mineralization in oil spill-polluted marine environment

The biodegradation of hydrocarbons by microorganisms is one of the primary ways by which an oil spill is eliminated from contaminated sites. One such spill was that of the Russian tanker the Nakhodka that spilled heavy oil into the Sea of Japan on January 2, 1997. This paper describes the three main processes of the Nakhodka oil spill, including: (1) the weathering of hydrocarbon-degrading bacteria (genus Pseudomonas) and crystallized organic compounds from the Nakhodka oil spill-polluted seashores after nine years; (2) the laboratory-scale biodegradation of the Nakhodka oil spill over a 429-day period; and (3) the bioavailability of kaolinite clay minerals and the role they play in seawater polluted with the Nakhodka oil spill.Upon the slow evaporation of the Nakhodka oil spill during the 9-year weathering, the dendritic crystal growth of paraffin (a mixture of alkanes) occurred in the oil crust under natural conditions. Heavy metals were obtained in the original heavy oil samples of three seashores in the Sea of Japan. Si, S, Ti, Cr, Ni, Cu, and Zn were found in the original Nakhodka oil spill samples whereas these heavy metals and S were no longer present after 9 years. The anaerobic reverse side of the oil crust contained numerous coccus-type bacteria associated with halite. The hydrocarbon-degrading bacteria and paraffin wax in the oil crust may have a significant effect on the weathering processes of the Nakhodka oil spill during the 9-year bioremediation.A biodegradation process of heavy oil from the Nakhodka oil spill by indigenous microbial consortia was monitored over 429 days in the laboratory. The indigenous microbial consortia consisted of bacteria and fungi as well as the bacterium Pseudomonas aeruginosa isolated from Atake seashore, Ishikawa Prefecture, Japan. Both bacteria and fungi had a significant role in the observed biodegradation of heavy oil during the 429-day bioremediation with respect to the pH of the solution. Hydrocarbon-degrading bacteria had a tendency to play the greatest role under neutral to alkaline condition (pH; 7–7.8). On the contrary, when pH shifted to acidic (pH; 2–4) levels, the fungi took over to degrade heavy oil. During the period, the aliphatic hydrocarbons were reduced significantly but the aromatic hydrocarbons remained relatively constant even after 429 days of bioremediation.Experimental study was undertaken to investigate the bioavailability of kaolinite clay minerals and the role they play in seawater polluted with the Nakhodka oil spill. TEM/EDS imaging suggested that the clays present in oil-polluted seawater were capable of stimulating oil-degrading bacteria probably because Si from clays facilitates bacterial usage of oil and C-O-Na-Si complexes on the surfaces of bacterial cell walls are a stimulator for oil-degrading bacterial growth in seawater contaminated with the Nakhodka oil spill.     

Processes controlling aqueous concentrations for riverine spills.

The aqueous concentrations of sparingly soluble compounds resulting from oil, fuel, or chemical spills onto rivers predicted by numerical spill models contain an inherent degree of uncertainty due to the inaccuracies, or bias, of the user supplied rate coefficients. Methods for estimating the values of spreading, evaporation, dissolution, volatilization, and longitudinal dispersion coefficients for a small sheltered river are reviewed, and the uncertainties associated with each coefficient are estimated. The uncertainties in the predicted aqueous concentrations are then computed using a concurrently developed riverine spill model for a simulated spill of 10,000 kg of jet fuel. The resulting aqueous concentrations were found to be most sensitive to the saturation concentrations and the dissolution rates, moderately sensitive to the evaporation rates and longitudinal dispersion coefficient, and nearly completely insensitive to the volatilization coefficient.     

废铝合金真空蒸馏脱锌的研究

首先分析了用真空蒸馏的方法脱除废铝合金中金属Zn的可行性。对二种含Zn质量分数为10%,12.25%的废铝合金进行了真空蒸馏脱除锌的实验。最终的实验结果与理论分析是紧密一致的。本文利用真空蒸馏法脱除含锌废铝中的金属Zn,解决了废铝脱锌难的问题,且对环境友好,不会造成二次污染。     

Preparation of Benzene-Stabilized Aluminum Nanoparticles in Hydrogen Atmosphere

Benzene was shown to be a suitable organic matrix for stabilizing Al nanoparticles. The clustering and motion of evaporated atoms were studied by computer simulations using a Monte Carlo procedure. The emission spectra of metallic Mg, Ca, Cd, and Zn were measured during evaporation in atomic hydrogen atmosphere. The thermal effect of hydrogen recombination was found to notably reduce the evaporation temperature. Electron-microscopic examination showed that the benzene layer thickness had a significant effect on the particle size and aggregation of the deposited Al. IR spectroscopic studies revealed the formation of an aluminum compound with benzene.     

In Situ Burning of Oil Spills

For more than a decade NIST conducted research to understand, measure and predict the important features of burning oil on water. Results of that research have been included in nationally recognized guidelines for approval of intentional burning. NIST measurements and predictions have played a major role in establishing in situ burning as a primary oil spill response method. Data are given for pool fire burning rates, smoke yield, smoke particulate size distribution, smoke aging, and polycyclic aromatic hydrocarbon content of the smoke for crude and fuel oil fires with effective diameters up to 17.2 m. New user-friendly software, ALOFT, was developed to quantify the large-scale features and trajectory of wind blown smoke plumes in the atmosphere and estimate the ground level smoke particulate concentrations. Predictions using the model were tested successfully against data from large-scale tests. ALOFT software is being used by oil spill response teams to help assess the potential impact of intentional burning.     

Life in oil: Hydrocarbon-degrading bacterial mineralization in oil spill-polluted marine environment

The biodegradation of hydrocarbons by microorganisms is one of the primary ways by which an oil spill is eliminated from contaminated sites. One such spill was that of the Russian tanker the Nakhodka that spilled heavy oil into the Sea of Japan on January 2, 1997. This paper describes the three main processes of the Nakhodka oil spill, including: (1) the weathering of hydrocarbon-degrading bacteria (genus Pseudomonas) and crystallized organic compounds from the Nakhodka oil spill-polluted seashores after nine years; (2) the laboratory-scale biodegradation of the Nakhodka oil spill over a 429-day period; and (3) the bioavailability of kaolinite clay minerals and the role they play in seawater polluted with the Nakhodka oil spill. Upon the slow evaporation of the Nakhodka oil spill during the 9-year weathering, the dendritic crystal growth of paraffin (a mixture of alkanes) occurred in the oil crust under natural conditions. Heavy metals were obtained in the original heavy oil samples of three seashores in the Sea of Japan. Si, S, Ti, Cr, Ni, Cu, and Zn were found in the original Nakhodka oil spill samples whereas these heavy metals and S were no longer present after 9 years. The anaerobic reverse side of the oil crust contained numerous coccus-type bacteria associated with halite. The hydrocarbon-degrading bacteria and paraffin wax in the oil crust may have a significant effect on the weathering processes of the Nakhodka oil spill during the 9-year bioremediation. A biodegradation process of heavy oil from the Nakhodka oil spill by indigenous microbial consortia was monitored over 429 days in the laboratory. The indigenous microbial consortia consisted of bacteria and fungi as well as the bacterium Pseudomonas aeruginosa isolated from Atake seashore, Ishikawa Prefecture, Japan. Both bacteria and fungi had a significant role in the observed biodegradation of heavy oil during the 429-day bioremediation with respect to the pH of the solution. Hydrocarbon-degrading bacteria had a tendency to play the greatest role under neutral to alkaline condition (pH; 7–7.8). On the contrary, when pH shifted to acidic (pH; 2–4) levels, the fungi took over to degrade heavy oil. During the period, the aliphatic hydrocarbons were reduced significantly but the aromatic hydrocarbons remained relatively constant even after 429 days of bioremediation. Experimental study was undertaken to investigate the bioavailability of kaolinite clay minerals and the role they play in seawater polluted with the Nakhodka oil spill. TEM/EDS imaging suggested that the clays present in oil-polluted seawater were capable of stimulating oil-degrading bacteria probably because Si from clays facilitates bacterial usage of oil and C-O-Na-Si complexes on the surfaces of bacterial cell walls are a stimulator for oil-degrading bacterial growth in seawater contaminated with the Nakhodka oil spill.     

Morphological development on alkali halide surfaces during evaporation

The sequential changes of the surface morphology of evaporated alkali halide crystals were investigated. The origin of surface features and their dependence on temperature are described for cleaved (100) surfaces evaporated in vacuum. Qualitative and quantitative determinations of the velocity of atomic steps during evaporation were made through the use of the gold double decoration technique. The results are related to theoretical expectations and compared to previous studies.     

Modeling of the evaporation of liquids and condensation of their vapor during distillation

This paper considers the evaporation process in an evaporator–connecting tube–condenser system under conditions such that the evaporation rate is determined by the evaporation and condensation mechanisms and the hydraulic resistances of the evaporation and condensation compartments and connecting tube. We present a mathematical model and numerical simulation results that demonstrate quantitative patterns of a steady-state evaporation process in a closed evaporation–condensation system. For a particular example of selenium vacuum distillation, we have determined the evaporation coefficient of selenium from experimental data on the temperature dependences of the selenium evaporation rate and saturated vapor pressure.     

Free convection from a vertical permeable circular cone with non-uniform surface temperature

Summary Laminar free convection from a vertical permeable circular cone maintained at nonuniform surface temperature is considered. Non-similar solutions for boundary-layer equations are found to exist when the surface temperature follows the power law variations with the distance measured from the leading edge. The numerical solutions of the transformed non-similar boundary-layer equations are obtained by using three methods, namely, (i) a finite difference method, (ii) a series solution method, and (iii) an asymptotic solution method. Solutions are obtained in terms of skin friction, heat transfer, velocity profile and temperature profile for smaller values of Prandtl number and temperature gradient are displayed in both tabular and graphical forms. Finite difference solutions are compared with the solutions obtained by perturbation and asymptotic techniques and found to be in excellent agreement.     

Kurze Wege für große Moleküle

Short‐Path distillation, often also called incorrectly molecular distillation guarantees the advantages of a distillation at considerably reduced pressure and thus reduced evaporation temperature with the distillation rates of 100–200 kg per square meter of evaporator surface area and hour which can be achieved in the fine vacuum range, i.e. at a pressure range of 10⁻³ to 1 mbar and which are economical. Short‐Path Distillation is being applied whenever all other distillation methods lead to thermal product damages, or if the vapor pressures of the components to be separated are so small that an evaporation at atmospheric pressure or rough vacuum would required extremely high temperature. The article below describes the history and the basics of Short‐Path Distillation and is giving an typical example of nowadays applications.     

On a steady, viscous flow in two-dimensional collapsible channels

Two characteristic cases of steady, viscous flow in 2-D collapsible channels are considered in the paper: low Reynolds number, lubrication type flow, and moderately high Reynolds number, boundary-layer type flow. In the latter case the boundary layer occupies the whole cross-section of the channel, and, in order to treat the flow analytically, we apply an approximate method based strongly on the Karman-Pohlhausen method, known from early developments of the classical boundary-layer theory. In modeling the elastic behavior of channel walls, we show how the careful scaling employed in studying the fluid flow imposes the application of geometrically nonlinear Karman shell theory. For the lubrication type flow we derive a single integro-differential equation describing the wall configuration, while in the boundary-layer type flow a similar integro-differential equation is supplemented by two first order, nonlinear ordinary differential equations. In both cases the governing equations are solved numerically by finite differences, for a wide range of control parameters. At that, steady flow was found to exist in all cases considered (we did not perform the stability analysis of the obtained solutions). Also, in the boundary-layer type flow the boundary layer was shown to be very resistant to separation, so that the presented theory was valid over the whole length of the channel. The effect of control parameters, in particular of the volume flow rate and the entrance transmural pressure, upon the wall configuration was discussed.     

Application of CFD (Fluent) to LNG spills into geometrically complex environments

Recent discussions on the fate of LNG spills into impoundments have suggested that the commonly used combination of SOURCE5 and DEGADIS to predict the flammable vapor dispersion distances is not accurate, as it does not account for vapor entrainment by wind. SOURCE5 assumes the vapor layer to grow upward uniformly in the form of a quiescent saturated gas cloud that ultimately spills over impoundment walls. The rate of spillage is then used as the source term for DEGADIS. A more rigorous approach to predict the flammable vapor dispersion distance is to use a computational fluid dynamics (CFD) model. CFD codes can take into account the physical phenomena that govern the fate of LNG spills into impoundments, such as the mixing between air and the evaporated gas. Before a CFD code can be proposed as an alternate method for the prediction of flammable vapor cloud distances, it has to be validated with proper experimental data. This paper describes the use of Fluent, a widely-used commercial CFD code, to simulate one of the tests in the "Falcon" series of LNG spill tests. The "Falcon" test series was the only series that specifically addressed the effects of impoundment walls and construction obstructions on the behavior and dispersion of the vapor cloud. Most other tests, such as the Coyote and the Burro series, involved spills onto water and relatively flat ground. The paper discusses the critical parameters necessary for a CFD model to accurately predict the behavior of a cryogenic spill in a geometrically complex domain, and presents comparisons between the gas concentrations measured during the Falcon-1 test and those predicted using Fluent. Finally, the paper discusses the effect vapor barriers have in containing part of the spill thereby shortening the ignitable vapor cloud and therefore the required hazard area. This issue was addressed by comparing the Falcon-1 simulation (spill into the impoundment) with the simulation of an identical spill without any impoundment walls, or obstacles within the impoundment area.     

Density of <Emphasis Type="Italic">Jatropha curcas</Emphasis> Seed Oil and its Methyl Esters: Measurement and Estimations

Density data as a function of temperature have been measured for Jatropha curcas seed oil, as well as biodiesel jatropha methyl esters at temperatures from above their melting points to 90 ^° C. The data obtained were used to validate the method proposed by Spencer and Danner using a modified Rackett equation. The experimental and estimated density values using the modified Rackett equation gave almost identical values with average absolute percent deviations less than 0.03% for the jatropha oil and 0.04% for the jatropha methyl esters. The Janarthanan empirical equation was also employed to predict jatropha biodiesel densities. This equation performed equally well with average absolute percent deviations within 0.05%. Two simple linear equations for densities of jatropha oil and its methyl esters are also proposed in this study.