Relative Amount Of Gas Research Articles

An alternative methodology for the analysis of electrical resistivity data from a soil gas study

The aim of this paper is to present an alternative method for the analysis of resistivity data. The methodology was developed during a study to evaluate if electrical resistivity can be used as a tool for analysing subsurface gas dynamics and gas emissions from landfills. The main assumption of this study was that variations in time of resistivity data correspond to variations in the relative amount of gas and water in the soil pores. Field measurements of electrical resistivity, static chamber gas flux and weather data were collected at a landfill in Helsingborg, Sweden. The resistivity survey arrangement consisted of nine lines each with 21 electrodes in an investigation area of 16 x20 m. The ABEM Lund Imaging System provided vertical and horizontal resistivity profiles every second hour. The data were inverted in Res3Dinv using L-1-norm-based optimization method with a standard least-squares formulation. Each horizontal soil layer was then represented as a linear interpolated raster model. Different areas underneath the gas flux measurement points were defined in the resistivity model of the uppermost soil layer, and the vertical extension of the zones could be followed at greater depths in deeper layer models. The average resistivity values of the defined areas were calculated and plotted on a time axis, to provide graphs of the variation in resistivity with time in a specific section of the ground. Residual variation of resistivity was calculated by subtracting the resistivity variations caused by the diurnal temperature variations from the measured resistivity data. The resulting residual resistivity graphs were compared with field data of soil moisture, precipitation, soil temperature and methane flux. The results of the study were qualitative, but promising indications of relationships between electrical resistivity and variations in the relative amount of gas and water in the soil pores were found. Even though more research and better data quality is necessary for verification of the results presented here, we conclude that this alternative methodology of working with resistivity data seems to be a valuable and flexible tool for this application.

Investigation of Waste Wood as a Blast Furnace Injectant

National legislation within Japan has increased the need for the development of new process technologies that will utilize waste wood materials. In order to generate some fundamental data with respect to the possible injection of such materials into blast furnaces, a study has been made of the decomposition and gasification reactions that take place when biomass material, in this case Japanese cypress chips, are exposed to temperatures between 1673 and 2073K using a high frequency induction furnace. The relative amounts of gas, char and tar were determined as well as the concentration of the various species present in the gas phase. The results obtained from gas analysis were in good agreement with values calculated from thermodynamic equilibria.

Gases in Reservoirs: A Balance between Generation and Migration, Part I: Compositional Modelling: ABSTRACT

New developments in compositional cracking and generation as well as migration modeling allow a discussion about the origin of gases in reservoirs. Experimental closed system pyrolysis allows to describe compositional primary cracking of kerogen and secondary cracking of oil using a comprehensive kinetic scheme. In addition, experiments give us some indications as to the relative amount of gas that is generated. Kerogens of Type II or III show early gas generation, coinciding with oil generation. However for Type III kerogen, the most important gas generation is late gas generation. In contrast, gas generated from Type II kerogen comes mainly from secondary cracked oil. Whether or not oil generated in a source rock might migrate to a reservoir or crack to gas depends on geological time and temperature conditions and on its transport properties. An improved version of IFP's 2-D basin model has been developed to account for compositional generation, cracking during migration. In addition, the generated or migrating hydrocarbons may split into a gas and an oil phase. The model allows to distinguish between the generation of dry gas, condensate, light or heavy oil. Under geologic times and temperature evolution, oils seem to exhibit a higher thermal stability than previously more » assumed, resulting in a larger oil window and thus deeper gas window. « less

Comparison of growth and gibberellin concentrations in shoots from orchard‐grown standard and thermosensitive dwarf apple trees

Apple (Malus domestica Borkh.) trees were propagated by budding from selected fully grown hybrids that ranged in height from 1.5 to 8 m. The growth and development of the selected budded trees after 7 years in the orchard was similar to that of the parent trees. Additional grafting studies showed that the dwarfism was not associated with the roots. Differences in photosynthetic activity and associated processes were not related to the size difference between tissue culture‐propagated orchard‐grown standard cv. Golden Delicious and dwarf hybrid trees. Applications of GA3 did not stimulate elongation of shoots of dwarf trees. Shoots of both standard and dwarf trees started to develop in mid‐April when they contained nearly the same amounts of GA1, GA3 and GA8, but standard shoots contained higher concentrations of GA19, GA20 and GA29. On 2 June standard shoots were almost three times the length of dwarf shoots, but the number of leaves and area per leaf were nearly the same. The relative amounts of GAs on 12 May and 2 June for both plant types were similar to those on 20 April, except that GA19, GA20, GA1 and GA29 levels had declined. Gibberellin levels in standard shoots declined further between 2 and 22 June, after which there was no further shoot elongation or production of new leaves. Between 2 June and the end of the growing season, when summer temperatures were high, dwarf shoots continued to elongate slowly and to develop new leaves, which expanded little. During this time, the GA19 content of dwarf shoots nearly doubled, whereas the amounts of GA20, GA1, GA29 and GA8 declined. By the end of the season, standard shoots were 40 cm in length with 20 leaves and dwarf shoots were 28 cm in length, but with 36 leaves. High summer temperatures appear to induce loss of GA‐responsiveness in orchard‐grown dwarf trees and to cause a reduced rate of conversion of GA19 to GA20 in these genotypes.

Disposal of sour caustic wastes with utilization of carbonated products

This article presents data obtained in the carbonation of sour caustic waste (SCW) from the Ufa refinery in a pilot unit. It is determined that when the ratio between the SCW and carbon dioxide is increased from 1:43 to 1:83, the residual content of hydrogen sulfide in the soda solution is lower, and the degree of removal of hydrogen sulfide from the SCW is greater. When the carbon dioxide input is further increased, the degree of removal of hydrogen sulfide drops off due to the increase in the relative amount of gas bypassing, the lower degree of purification, and poorer utilization of the carbon dioxide. A simplified flow plan of a proposed unit for SCW carbonation is presented. In the recommended scheme, the SCW from the process units is fed under pressure to a tank, where it is separated from the purge gas, and oily materials and solid contaminants are removed. The oily materials are returned as feed from the atmospheric-vacuum pipestill unit. The gas evolved from the SCW, consisting of hydrogen sulfide and light mercaptans along with carbon dioxide, passes through the carbonator and is discharged, along with the hydrogen sulfide, to the unit for sulfur utilization. The proposedmore » scheme makes it possible not only to dispose of the SCW, but also to utilize the carbonated products directly in the refinery.« less

Influence of Adsorbed Gas on Surface Diffusion and Nucleation

Experiments with the field-electron emission microscope show that residual gas pressures as low as 2×10−8 Torr increase the density of nucleation of copper on tungsten compared with the nucleation density at 4×10−10 Torr ambient pressure. The effect of adsorbed oxygen and nitrogen on the mobility of copper on tungsten depends on the relative amounts of gas and copper and on the local substrate crystallography. Generally stated, they increase the activation energy for surface diffusion.

Apparatus Study of Pore Formation Kinetics in Vulcanization

Abstract The investigation of the processes of formation of microporous vulcanizates is a complex matter, since pore formation depends upon a whole ensemble of simultaneous chemical and physical processes some of which are : the decomposition of the blowing agent with the formation of gaseous products; the solution of these gases in the rubber hydrocarbon; the formation of an independent gaseous phase inside the compounded rubber stock and the foaming of the vulcanizate, which changes its elastic and plastic properties in the course of vulcanization; the escape of the gas. The biggest difficulty is the lack of a satisfactory procedure for investigation. Many specialists have investigated the kinetics of various pure blowing agents, but this differs from the kinetics of the decomposition of a blowing agent in various media, including a compounded rubber stock. In other investigations the force of the blowing action has been assessed from the size of the pressure exerted from the direction of the compounded stock upon a steel diaphragm. Nevertheless this method does not enable us to investigate the kinetics of the process or the influence of external pressure acting upon the compounded stock. All the methods proposed hitherto for investigation of the decomposition of blowing agents enable us merely to judge the relative amount of gas liberated by the various blowing agents, or else the action of whatever blowing agent in the “foaming” of the compounded stock. But with these methods it is impossible to determine the actual amount of gas formed in the compounded stock in the vulcanization period.