High-Pressure Ignition of Oil Sands Samples in Oxygen Atmospheres Containing Various Concentrations of Diluents

1990 ◽  
Vol 112 (4) ◽  
pp. 264-267 ◽  
Author(s):  
S. A. Mehta ◽  
G. A. Karim
Keyword(s):  
High Pressure ◽  
Oil Sands ◽  
Morphological Changes ◽  
Pure Oxygen ◽  
Experimental Program ◽  
Nickel Chromium ◽  
Ignition Characteristics ◽  
Combustion Processes

In-situ recovery of oil from oil sands deposits by combustion requires the injection of vast quantities of oxygen into the bed of deposits. Accordingly, there is a need to establish the ignition characteristics of high-grade Athabasca oil sands in environments containing pure oxygen at high-pressure and including the role of the presence of various diluents with the oxygen. A high-pressure constant volume bomb with a water calorimeter was employed as the test apparatus over the pressure range of 0.1 MPa to 4.0 MPa at ambient temperature. The role of the presence of the diluents, helium, nitrogen and carbon dioxide, with the oxygen, was also considered. Controlled ignition was achieved by employing electrically fusable nickel-chromium wire looped around the sample. Moreover, the presence of an ignition promotor such as benzoic acid was also considered. The paper presents the results of an experimental program that examined the effects of changes in the pressure, amounts of diluents and ignition energy on the ignition limits and subsequent combustion processes at ambient initial temperature. Moreover, the morphological changes to the samples at various stages of the process were also examined and discussed.

A Study of Nuclei and Intercellular Ground Substance during the in situ Differentiation of Somites in Taricha torosa

Development ◽  
1961 ◽  
Vol 9 (4) ◽  
pp. 650-660
Author(s):  
Cyril V. Finnegan
Keyword(s):  
Morphological Changes ◽  
Periodic Acid ◽  
Ground Substance ◽  
Tail Bud ◽  
Interphase Nuclei ◽  
Taricha Torosa ◽  
Intercellular Matrix ◽  
Schiff Reagent

In order better to evaluate results obtained in this laboratory concerning the responses of differentiating postneurula somite tissue to other mesoderm tissue placed in its immediate vicinity (Finnegan, unpublished), it was necessary to examine somite differentiation in situ. A qualitative examination of somite interphase nuclei of tail-bud and later stages was performed to note their morphological changes since it was assumed, as suggested by Briggs & King (1955), that such changes indicate cellular differentiation and, conversely, that absence of such changes indicates that the cells are not actively differentiating. Because of the possible role of the intercellular matrix in histogenesis (see Grobstein, 1954, 1959; and Edds, 1958) a study was made of the development in the somite of that portion of the intercellular matrix which is demonstrable histochemically with the periodic acid-Schirf (PAS) technique. The visual clarity of the results has been materially aided by the fluorescent Schiff reagent of Culling & Vassar (1961) which makes possible a fluorescent Feulgen and a fluorescent PAS reaction.

In situobservation of morphological changes of γ′ precipitates in a pre-deformed single-crystal Ni-base superalloy

2011 ◽  
Vol 44 (5) ◽  
pp. 935-944 ◽  
Author(s):  
Pavel Strunz ◽  
Gerhard Schumacher ◽  
Hellmuth Klingelhöffer ◽  
Albrecht Wiedenmann ◽  
Jan Šaroun ◽  
...  
Keyword(s):  
External Load ◽  
Morphological Changes ◽  
The Past ◽  
Subsequent Heating ◽  
Detailed Evaluation ◽  
The Matrix ◽  
Base Superalloy

Exposure of a superalloy to an external load results in anisotropic coarsening of the γ′ precipitates, so-called rafting. It was reported in the past that γ′ rafting can also occur as a result of purely thermal treatment, without the simultaneous presence of an external load, if the specimen has been pre-deformed at relatively low temperature. The evolution of γ′ morphology in pre-deformed specimens of SCA425 Ni-base superalloy was examined in the present study. Unlike in the previous experiments, the compressive stress was used for pre-straining.In situsmall-angle neutron scattering (SANS) was employed, which enabled the determination of the morphology directly at high temperature. Both for strong and for weak pre-straining, rounding of the originally cuboidal precipitates towards an ellipsoidal shape on heating was observed. Weak pre-straining (0.1, 0.5%) does not cause rafting on subsequent heating. On the other hand, the detailed evaluation of SANS data provides some indication of rafting during the subsequent heating after severe compressive pre-straining (2%). The experiment indicates the role of dislocation rearrangement at the matrix/precipitate interface during pre-straining.

An Analytical Study of the Compression Ignition Characteristics of H2-O2-N2 Mixtures in a Reciprocating Engine

1974 ◽  
Vol 16 (2) ◽  
pp. 88-94 ◽  
Author(s):  
G. A. Karim ◽  
M. Rashidi ◽  
M. Taylor
Keyword(s):  
Analytical Study ◽  
Pure Oxygen ◽  
Cylinder Pressure ◽  
Oxides Of Nitrogen ◽  
Detailed Chemical Kinetics ◽  
Reciprocating Engine ◽  
Auto Ignition ◽  
Ignition Characteristics ◽  
Detailed Chemical

A large portion of the literature about the use of hydrogen as a fuel in air-breathing reciprocating engines is devoted to the problems of auto-ignition and knock. Operation with oxygen-enriched air or pure oxygen, which in principle can reduce or even eliminate the production of oxides of nitrogen, is expected to be potentially more troublesome in this respect. The paper describes an analytical approach, incorporating detailed chemical kinetics, to the combustion of H2-O2-N2 mixtures in a reciprocating engine. The role of various operating parameters was determined primarily in relation to the length of the ignition delay and the associated peak values of cylinder pressure and temperature. Also, the extent of production of oxides of nitrogen in the exhaust was examined in terms of cycle parameters and the oxygen index of the charge.

The Role of Surfactant Additives In the In-situ Recovery of Bitumen From Oil Sands

1982 ◽  
Vol 21 (03) ◽  
Author(s):  
E. Eddy Isaacs ◽  
Daniel R. Prowse ◽  
Joseph P. Rankin
Keyword(s):  
Oil Sands ◽  
In Situ Recovery

In situ high-pressure single-crystal X-ray study of aegirine, NaFe3+Si2O6, and the role of M1 size in clinopyroxene compressibility

2008 ◽  
Vol 93 (11-12) ◽  
pp. 1829-1837 ◽  
Author(s):  
A. C. McCarthy ◽  
R. T. Downs ◽  
R. M. Thompson ◽  
G. J. Redhammer
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
X Ray

scholarly journals 271.Role of homeobox gene HLX expression in normal placental development

2004 ◽  
Vol 16 (9) ◽  
pp. 271
Author(s):  
P. Murthi ◽  
M. D. Bates ◽  
G. Sankaran ◽  
S. P. Brennecke ◽  
B. Kalionis
Keyword(s):  
Alkaline Phosphatase ◽  
Morphological Changes ◽  
Homeobox Gene ◽  
Giant Cells ◽  
Placental Development ◽  
Structural Support ◽  
Alkaline Phosphatase Staining ◽  
Phd Thesis

In a screen for homeobox genes in the human placenta, we cloned and characterised HLX1 (also known as HB24) (1). Furthermore, we provided evidence that HLX1 may be a regulator of human placental develolpment (2). We have since shown that the mouse homologue of HLX1, called Hlx, is expressed in the murine placenta. In situ mRNA hybridisation studies and antibody localisation of Hlx revealed expression in the labyrinth layer (LL), secondary giant cells (GC) and in the spongiotrophoblast layer (STL) (3). The STL is required for structural support of the placenta. Targeted gene mutation of Hlx resulted in embryonic defects in the developing gut and the liver (4) but the effects on placental development were not investigated. Histological preparations of placental tissues collected from Days 10.5, 13.5 and 19.5 from Hlx mutant mice were investigated for morphological changes. Our preliminary observations reveal that by haematoxylin and eosin staining the STL of the mutant murine placenta is severely disrupted but the overlying GC layer appears to be unaffected. Endogenous alkaline phosphatase staining of the LL further confirmed that the highly vascularised LL where fetal- maternal exchange occurs, is disorganised and expands into the region normally occupied by the STL. These observations indicate that Hlx is essential for normal placental development. (1) Quinn LM, Kalionis B. (1997) Gene 187, 55–61. (2) Quinn LM, Kalionis B. (1997) Repro. Dev. 9, 617–623. (3) Johnson B (1999) PhD Thesis, University of Adelaide. (4) Hentsch B, Harvey RP (1996) Gene Dev. 10, 70–79.

The Role of Interfaces in Evolution of Structure and Thermal Stability of Cu-Nb Composite Processed by High-Pressure Torsion

2018 ◽  
Vol 383 ◽  
pp. 118-124 ◽  
Author(s):  
E.N. Popova ◽  
I.L. Deryagina ◽  
E.G. Valova-Zaharevskaya ◽  
Alexey V. Stolbovsky
Keyword(s):  
Thermal Stability ◽  
High Pressure ◽  
High Pressure Torsion ◽  
Cold Drawing ◽  
X Ray ◽  
Evolution Of Structure ◽  
Equiaxed Grains ◽  
Thermal Stability Of

The structure and thermal stability of Cu-18Nb multicore composite fabricated by repeated cold-drawing of in situ melted mixture of Cu and Nb and subjected to high-pressure torsion (HPT) have been studied by SEM, TEM, X-ray analysis and microhardness measurements. In the cold-drawn state ribbon-like Nb filaments the thickness of 30-70 nm are located in Cu-matrix with sharp texture <110>Nb║<111>Cu║drawing axis. The Nb lattice is distorted, the interplanar spacing (110)Nb being extended along the drawing axis and compressed perpendicular to it, which testifies a semi-coherent character of Cu/Nb interfaces. At annealing these distorsions gradually vanish, and coagulation of Nb ribbons starts at 400С, actively develops at 600С and finishes at 800С with the formation of sausage-like filaments with round transverse sections, which is accompanied with about two-fold decreasing of microhardness. Under the HPT the composite structure is considerably refined, and almost equiaxed grains the sizes of 20-30 nm are formed, which gives rise to a dramatic increase of microhardness. The thermal stability of Cu-Nb composite after cold drawing and HPT is appreciably higher than that of pure Nb and Cu nanostructured by severe plastic deformation.

Immobilization of a rhodium catalyst using a diphosphine-functionalized ionic liquid in RTIL for the efficient and recyclable biphasic hydroformylation of 1-octene

2016 ◽  
Vol 190 ◽  
pp. 219-230 ◽  
Author(s):  
Yong-Qi Li ◽  
Huan Liu ◽  
Peng Wang ◽  
Da Yang ◽  
Xiao-Li Zhao ◽  
...  
Keyword(s):  
High Pressure ◽  
Ionic Liquid ◽  
Spectral Analysis ◽  
Catalytic System ◽  
Active Species ◽  
Rhodium Catalyst ◽  
Functionalized Ionic Liquid ◽  
Ft Ir

A highly efficient and stable Rh–P catalytic system in the RTIL of [PEmim]BF4 was developed for the biphasic hydroformylation of 1-octene by using the diphosphine-functionalized ionic liquid (FIL) of 2. While 2-Rh(acac)(CO)2 was immobilized in [PEmim]BF4 (solvent), a typical biphasic catalysis was fulfilled with advantages of facile separation and recycling ability – 9 runs without any loss of activity. It was found that not only the acquired π-acceptor character of 2, but also the synergetic role of the piperidyl group in [PEmim]BF4 as an N-containing donor, cooperatively contributed to the efficient hydroformylation due to the facilitated formation and stability of the Rh-H active species (ν 2045 cm−1). This was supported by the in situ high-pressure FT-IR spectral analysis.

scholarly journals Liquid Phase Furfural Oxidation under Uncontrolled pH in Batch and Flow Conditions: The Role of In Situ Formed Base

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 73 ◽  
Author(s):  
Alessandra Roselli ◽  
Yuri Carvalho ◽  
Franck Dumeignil ◽  
Fabrizio Cavani ◽  
Sébastien Paul ◽  
...  
Keyword(s):  
Reaction Medium ◽  
Pure Oxygen ◽  
Continuous Stirred Tank Reactor ◽  
Flow Conditions ◽  
Furoic Acid ◽  
Continuous Stirred Tank ◽  
Supported Gold Nanoparticles ◽  
Supported Gold

Selective oxidation of furfural to furoic acid was performed with pure oxygen in aqueous phase under mild conditions and uncontrolled pH using hydrotalcite-supported gold nanoparticles as catalyst. Hydrotalcites with different Mg: Al ratios were tested as support. The effects of reaction time, temperature and furfural/catalyst ratio were evaluated. The catalyst Au/HT 4:1 showed the highest activity and selectivity to the desired product, achieving a complete conversion of furfural to furoic acid after 2 h at 110 °C. Further, stability tests were carried out in a continuous stirred-tank reactor and a progressive deactivation of the catalyst due to the leaching of Mg2+ cations from the support inducing changes in the pH of the reaction medium was observed.

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