Hydrogen Sulfide Absorption Phenomena in Brine/Oil Mixtures

SPE Journal ◽  
2011 ◽  
Vol 16 (04) ◽  
pp. 931-939 ◽  
Author(s):  
Luis Zea ◽  
David Cooper ◽  
Ranganathan Kumar
Keyword(s):  
Hydrogen Sulfide ◽  
Reservoir Simulation ◽  
Total Pressure ◽  
Room Temperature ◽  
Extraction Process ◽  
Minor Role ◽  
Oil Reservoir ◽  
Gas Concentration ◽  
Oil Mixtures ◽  
A Minor

Summary Brine and oil absorb hydrogen sulfide (H2S) under pressure in the underground oil reservoir and then undergo a decompression during the extraction process, during which a certain amount of H2S is released from the liquid phase. This paper reports experimental data on how much of the corrosive gas is absorbed into different brine/oil mixtures [0, 33, 66, and 100% water cuts (WCs)]. Different reservoir-simulation scenarios were created at 20 and 70 atm at room temperature. H2S gas concentration was varied as tests were conducted with 50, 100, and 300 ppm in nitrogen. These experiments took place in an autoclave system that simulates the hydrostatic process that occurs inside a reservoir. This paper also reports Henry's law constants for H2S in different WCs. It is found that for all WCs, total pressure plays only a minor role in the absorption phenomena when the initial H2S concentration is increased. In addition, the highest mass-absorption ratios are found at lower H2S concentrations.

Applying a most probable number method for enumerating planktonic, dissimilatory, ammonium-producing, nitrate-reducing bacteria in oil field waters

2005 ◽  
Vol 51 (8) ◽  
pp. 725-729 ◽  
Author(s):  
Ruth E Eckford ◽  
Phillip M Fedorak
Keyword(s):  
Hydrogen Sulfide ◽  
Water Samples ◽  
Oil Field ◽  
Most Probable Number ◽  
Minor Role ◽  
Probable Number ◽  
A Minor ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria ◽  
Oil Field Water

A most probable number (MPN) method was used to enumerate dissimilatory ammonium-producing, nitrate-reducing bacteria (DAP-NRB) in oil field waters and to determine whether they were stimulated by nitrate addition used to control hydrogen sulfide production. An ammonium production medium with 5 carbon and energy sources (acetate, glucose, glycerol, pyruvate, and succinate) and nitrate was used in a 3-tube MPN procedure to enumerate DAP-NRB. These bacteria were detected in 12 of 18 oil field water samples, but they were seldom detected in wellhead samples. Three oil field water samples were amended with nitrate in serum bottles and the numbers of different NRB were determined over a 38-day incubation time. This amendment stimulated increases in the numbers of heterotrophic NRB and autotrophic nitrate-reducing, sulfide-oxidizing bacteria, but DAP-NRB remained a minor portion of these communities. Overall, DAP-NRB were present in many of the oil field waters that were examined but their numbers were low. It appears that DAP-NRB would play a minor role in the consumption of nitrate injected into oil field waters for the control of hydrogen sulfide production.Key words: heterotroph, nitrate-reducing bacteria, dissimilatory nitrate reduction, ammonium, petroleum.

Interfacial Reactions of Mo with Al: Ion mixing Versus Thermal Annealing

1988 ◽  
Vol 100 ◽  
Author(s):  
E. Ma ◽  
A. J. Brunner ◽  
T. W. Workman ◽  
C. W. Nieh ◽  
X.-A. Zhao ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Room Temperature ◽  
Ion Beam ◽  
Dose Dependence ◽  
Interfacial Reactions ◽  
Mixing Efficiency ◽  
Minor Role ◽  
Thermal Spike ◽  
A Minor

ABSTRACTInterfacial reactions induced by ion beam mixing and furnace annealing in Al/Mo bilayers are investigated. The amount of interfacial ion m'xing, 4Dt, follows a linear dose dependence for irradiation temperatures ≤80 C. Below room temperature, the mixing efficiency, defined as d(4Dt)/dø, is temperature independent, and agrees fairly well with the prediction of the phenomenological model based on chemically biased diffusion in thermal spike. We conclude that thermal spike mixing dominates for Xe irradiation of Al/Mo at low temperatures. The mixing efficiency becomes temperature-dependent above room temperature with an apparent activation enthalpy of about 0.17±0.02eV. A layer of 15–20 at.% Mo forms by ion mixing, while oAl12 Mo forms upon thermal annealing in a nonuniform fashion starting at 500°C. Reaction of Mo with large-grained Al substrates shows the same nonuniform characteristics as in evaporated Al/Mo bilayers, implying a minor role of grain boundary effects. Oxygen gettered in the Mo film could be an important factor that influences the interfacial reaction.

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

Use of Different Tissue Thromboplastins in the Control of Anticoagulant-Therapy

1958 ◽  
Vol 02 (05/06) ◽  
pp. 462-480 ◽  
Author(s):  
Marc Verstraete ◽  
Patricia A. Clark ◽  
Irving S. Wright
Keyword(s):  
Prothrombin Time ◽  
Anticoagulant Therapy ◽  
Factor Vii ◽  
Rabbit Brain ◽  
Minor Role ◽  
Rabbit Lung ◽  
Coagulation Mechanism ◽  
Time Test ◽  
The One ◽  
A Minor

SummaryAn analysis of the results of prothrombin time tests with different types of thromboplastins sheds some light on the problem why the administration of coumarin is difficult to standardize in different centers. Our present ideas on the subject, based on experimental data may be summarized as follows.Several factors of the clotting mechanism are influenced by coumarin derivatives. The action of some of these factors is by-passed in the 1-stage prothrombin time test. The decrease of the prothrombin and factor VII levels may be evaluated in the 1-stage prothrombin time determination (Quick-test). The prolongation of the prothrombin times are, however, predominantly due to the decrease of factor VII activity, the prothrombin content remaining around 50 per cent of normal during an adequate anticoagulant therapy. It is unlikely that this degree of depression of prothrombin is of major significance in interfering with the coagulation mechanism in the protection against thromboembolism. It may, however, play a minor role, which has yet to be evaluated quantitatively. An exact evaluation of factor VII is, therefore, important for the guidance of anticoagulant therapy and the method of choice is the one which is most sensitive to changes in factor VII concentration. The 1-stage prothrombin time test with a rabbit lung thromboplastin seems the most suitable method because rabbit brain preparations exhibit a factor VII-like activity that is not present in rabbit lung preparations.

Produktivkraft als Versprechen

2016 ◽  
Vol 46 (185) ◽  
pp. 621-638 ◽  
Author(s):  
Christian Siefkes
Keyword(s):  
Private Consumption ◽  
Minor Role ◽  
Progressive Reduction ◽  
Internal Forces ◽  
A Minor

The ‘Fragment on Machines’ from Marx’s Grundrisse is often cited as an argument that the internal forces of capitalism will lead to its doom. But the argument that the progressive reduction of labor must doom capitalism lacks a proper foundation, as a comparison with the ‘Schemes of Reproduction’ given in Capital II shows. The latter, however, aren’t fully convincing either. In reality, more depends on the private consumption of capitalists than either model recognizes. Ultimately, most can be made of the ‘Fragment on Machines’ by reading it not as an exposure of capitalism’s internal contractions, but as a discussion of a possible communist future where labor (or work) will play but a minor role.

Effects of Myo-inositol Alone and in Combination with Seleno-Lmethionine on Cadmium-Induced Testicular Damage in Mice

2019 ◽  
Vol 12 (4) ◽  
pp. 311-323 ◽  
Author(s):  
Salvatore Benvenga ◽  
Antonio Micali ◽  
Giovanni Pallio ◽  
Roberto Vita ◽  
Consuelo Malta ◽  
...  
Keyword(s):  
Structural Changes ◽  
Natural Antioxidants ◽  
Minor Role ◽  
Positive Role ◽  
Testosterone Levels ◽  
Tnf Α ◽  
Testicular Lesions ◽  
A Minor ◽  
Immunohistochemical Analyses

Background: Cadmium (Cd) impairs gametogenesis and damages the blood-testis barrier. Objective: As the primary mechanism of Cd-induced damage is oxidative stress, the effects of two natural antioxidants, myo-inositol (MI) and seleno-L-methionine (Se), were evaluated in mice testes. Methods: Eighty-four male C57 BL/6J mice were divided into twelve groups: 0.9% NaCl (vehicle; 1 ml/kg/day i.p.); Se (0.2 mg/kg/day per os); Se (0.4 mg/kg/day per os); MI (360 mg/kg/day per os); MI plus Se (0.2 mg/kg/day); MI plus Se (0.4 mg/kg/day); CdCl2 (2 mg/kg/day i.p.) plus vehicle; CdCl2 plus MI; CdCl2 plus Se (0.2 mg/kg/day); CdCl2 plus Se (0.4 mg/kg/day); CdCl2 plus MI plus Se (0.2 mg/kg/day); and CdCl2 plus MI plus Se (0.4 mg/kg/day). After 14 days, testes were processed for biochemical, structural and immunohistochemical analyses. Results: CdCl2 increased iNOS and TNF-α expression and Malondialdehyde (MDA) levels, lowered glutathione (GSH) and testosterone, induced testicular lesions, and almost eliminated claudin-11 immunoreactivity. Se administration at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression, maintained GSH, MDA and testosterone levels, structural changes and low claudin-11 immunoreactivity. MI alone or associated with Se at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression and MDA levels, increased GSH and testosterone levels, ameliorated structural organization and increased claudin-11 patches number. Conclusion: We demonstrated a protective effect of MI, a minor role of Se and an evident positive role of the association between MI and Se on Cd-induced damages of the testis. MI alone or associated with Se might protect testes in subjects exposed to toxicants, at least to those with behavior similar to Cd.

Extraction of strontium and barium salts by the nitrobenzene solution of dicarbolide in the presence of glymes

1985 ◽  
Vol 50 (3) ◽  
pp. 581-599 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Minor Role ◽  
Nitrobenzene Solution ◽  
Ligand Structure ◽  
Stability Constants Of Complexes ◽  
Separation Factors ◽  
The Stability ◽  
A Minor

Extraction of microamounts of Sr2+ and Ba2+ (henceforth M2+) from the aqueous solutions of perchloric acid (0.0125-1.02 mol/l) by means of the nitrobenzene solutions of dicarbolide (0.004-0.05 mol/l of H+{Co(C2B9H11)2}-) was studied in the presence of monoglyme (only Ba2+), diglyme, triglyme, and tetraglyme (CH3O-(CH2-CH2O)nCH3, where n = 1, 2, 3, 4). The distribution of glyme betweeen the aqueous and organic phases, the extraction of the protonized glyme molecule HL+ together with the extraction of M2+ ion and of the glyme complex with the M2+ ion, i.e., ML2+ (where L is the molecule of glyme), were found to be the dominating reactions in the systems under study. In the systems with tri- and tetraglymes the extraction of H+ and M2+ ions solvated with two glyme molecules, i.e., the formation of HL2+ and ML22+ species, can probably play a minor role. The values of the respective equilibrium constants, of the stability constants of complexes formed in the organic phase, and the theoretical separation factors αBa/Sr were determined. The effect of the ligand structure on the values of extraction and stability constants in the organic phase is discussed.

scholarly journals The preendosomal compartment comprises distinct coated and noncoated endocytic vesicle populations.

1991 ◽  
Vol 113 (4) ◽  
pp. 731-741 ◽  
Author(s):  
S H Hansen ◽  
K Sandvig ◽  
B van Deurs
Keyword(s):  
Cell Surface ◽  
Coated Vesicles ◽  
Minor Role ◽  
Specific Marker ◽  
Con A ◽  
Early Endosomes ◽  
Gold Conjugate ◽  
Entire Cell ◽  
A Minor ◽  
Endocytic Vesicles

The transfer of molecules from the cell surface to the early endosomes is mediated by preendosomal vesicles. These vesicles, which have pinched off completely from the plasma membrane but not yet fused with endosomes, form the earliest compartment along the endocytic route. Using a new assay to distinguish between free and cell surface connected vesicle profiles, we have characterized the preedosomal compartment ultrastructurally. Our basic experimental setup was labeling of the entire cell surface at 4 degrees C with Con A-gold, warming of the cells to 37 degrees C to allow endocytosis, followed by replacing incubation medium with fixative, all within either 30 or 60 s. Then the fixed cells were incubated with anti-Con A-HRP to distinguish truly free (gold labeled) endocytic vesicles from surface-connected structures. Finally, analysis of thin (20-30 nm) serial sections and quantification of vesicle diameters were carried out. Based on this approach it is shown that the preendosomal compartment comprises both clathrin-coated and non-coated endocytic vesicles with approximately the same frequency but with distinct diameter distributions, the average noncoated vesicle being smaller (95 nm) than the average coated one (110 nm). In parallel experiments, using an anti-transferrin receptor gold-conjugate as a specific marker for clathrin-dependent endocytosis it is also shown that uncoating of coated vesicles plays only a minor role for the total frequency of noncoated vesicles. Furthermore, after perturbation of clathrin-dependent endocytosis by potassium depletion where uptake of transferrin is blocked, noncoated endocytic vesicles with Con A-gold, but not coated vesicles, exist already after 30 and 60 s. Finally, it is shown that the existence of small, free vesicles in the short-time experiments cannot be ascribed to recycling from the early endosomes.

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