scholarly journals Two Phases, Three Runs

2001 ◽  
Vol 123 (10) ◽  
pp. 74-75
Author(s):  
John Krawczyk

Premcor Port Arthur Refinery, part of the Premcor Refining Group has been expanding the capacity of a vacuum tower processing almost one million pounds per hour of heavy hydrocarbon feed. The feed is deficient in lighter, more volatile components and is extremely viscous at room temperature. The process is intended to squeeze as much useful fuel as practical out of the oil feed. During the past 5 years, CFD has become noticeably more widespread in solving single-phase flow problems, but progress in solving multiphase flows has been much slower. There are at least three primary solution methods currently available to solve a dispersed multiphase flow problem. The contract with Premcor called for the use of a Eulerian method. Later, as an in-house test, Flow Simulations studied the model of the tower using two other methods.

2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Young Rang Uhm ◽  
Jae Cheong Lim ◽  
Sang Mu Choi

Antianemic medicament ferrous gluconate, ferrous fumarate, and a Dynabi tablet with a basic iron bearing ingredient were studied with the use of Mössbauer spectroscopy. Room temperature spectra of ferrous gluconate gave clear evidence that the two phases of iron were present: ferrous (Fe2+) as a major one with a contribution at and above 91 a.u.% and ferric (Fe3+) whose contribution was found to be ~9 a.u.%. In the case of ferrous fumarate, a single phase was measured corresponding to ferrous (Fe2+) state. A Dynabi tablet consists of ferrous fumarate and ferrous fumarate. The ferric phase in ferrous gluconate is able to be reached about ~3.6 a.u.% in a tablet.


2001 ◽  
Vol 79 (5-6) ◽  
pp. 705-708 ◽  
Author(s):  
Paul J Dyson ◽  
David J Ellis ◽  
Thomas Welton

An ionic liquid – water system that undergoes a reversible two phase – single phase transformation dependent upon temperature has been used as a novel medium for the transition-metal-catalyzed hydrogenation of a water soluble substrate. At room temperature, the ionic liquid 1-octyl-3-methylimidizolium tetrafluoroborate, containing [Rh(η4-C7H8)(PPh3)2][BF4] catalyst, forms a separate layer to water containing 2-butyne-1,4-diol. In a stirred autoclave the mixture was pressurized with hydrogen to 60 atm (1 atm = 101.325 kPa) and heated to 80°C giving a homogeneous single phase solution. On cooling to room temperature, two phases reform, with the ionic liquid phase containing the catalyst and the aqueous phase containing a mixture of 2-butene-1,4-diol and butane-1,4-diol products that can be simply removed without catalyst contamination.Key words: ionic liquids, biphasic catalysis, hydrogenation, rhodium.


Author(s):  
R. Varughese ◽  
S. W. Thompson ◽  
P. R. Howell

Ever since Habraken and Economopoulos first employed the term granular bainite to classify certain unconventional transformation products in continuously cooled steels, the term has been widely accepted and used, despite the lack of a clear consensus as to the detailed nature of the transformation products which constitute granular bainite. This paper presents the preliminary results of a TEM investigation of an 0.04 wt% C, copper-containing steel (designated HSLA-100). It is suggested that the term granular ferrite rather than granular bainite is a more accurate description of this multiphase reaction product.Figure 1 is a light micrograph of a sample which had been air-cooled from 900°C to room temperature. The microstructure is typical of that which has been termed granular bainite in the past and appears to consist of equiaxed ferritic grains together with other minor transformation products. In order to examine these structures in more detail, both continuously cooled and isothermally transformed and quenched materials have been examined with TEM. Granular bainite has been found in virtually all samples.


2020 ◽  
Vol 17 (5) ◽  
pp. 496-517
Author(s):  
Yangcheng Liu ◽  
Wei Liu ◽  
Jiaqi Wang ◽  
Yang Liu ◽  
Changlan Chen ◽  
...  

Patrinia scabiosaefolia Fisch. Trev. and Patrinia villosa (Thunb.) Juss, are two species of Patrinia recorded in the Chinese Pharmacopoeia with the same Chinese name “Baijiangcao” and similar therapeutic effect in traditional Chinese medicine. The present article is the first comprehensive review on the chemical composition and pharmacological activities of these herbs. In this review, data on chemical constituents and pharmacological profile of the two herbs are provided. This review discusses all the classes of the 223 compounds (phenylpropanoids, flavonoids, terpenes, saponins and volatile components, etc.) detected in the two herbs providing information on the current state of knowledge of the phytochemicals present in them. In the past three years, our research group has isolated and identified about more than 100 ingredients from the two herbs. Therefore, we published a systematic review of our research papers and studies on the two herbs were carried out using resources such as classic books about Chinese herbal medicine and scientific databases including Pubmed, Web of Science, SciFinder, CNKI. etc. The present review discusses the most thoroughly studied pharmacological activities (antioxidant, anti-inflammatory, immunomodulatory, antimicrobial, antitumor and antiviral activities) of the two herbs. This comprehensive review will be informative for scientists searching for new properties of these herbs and will be important and significant for the discovery of bioactive compounds from the two herbs and in complete utilization of Patrinia scabiosaefolia Fisch. ex Trev. and Patrinia villosa (Thunb.) Juss.


Synthesis ◽  
2020 ◽  
Author(s):  
Narendra R. Chaubey ◽  
Anant R. Kapdi ◽  
Biswanath Maity

AbstractOrganophotocatalytic C–H bond functionalization has attracted a lot of attention in the past several years due to the possibility of catalyzing reactions in a metal- and peroxide-free environment. Continuing on these lines, an organophotoredox-catalyzed C–H functionalization of imidazo[1,2-a]pyridines and related heterocycles with bromomalonates under mild conditions is reported, providing excellent yields of the products at room temperature. This is the first report involving malonates as coupling partners leading to the synthesis of a range of functionalized products including total synthesis of zolpidem, a sedative­-hypnotic drug molecule.


1993 ◽  
Vol 8 (3) ◽  
pp. 605-610 ◽  
Author(s):  
M.C. Caracoche ◽  
P.C. Rivas ◽  
A.F. Pasquevich ◽  
A.R. López García ◽  
E. Aglietti ◽  
...  

The time-differential perturbed angular correlation technique has been used to investigate the thermal behavior of a ZrO2−13.6 mole % MgO ceramic between room temperature and 1423 K. Two different quadrupole hyperfine interactions corresponding to a tetragonal structure have been found to result on cooling the ceramic from the single-phase cubic field. One of them agrees with that depicting the pure t-ZrO2 tetragonal phase and the other one has been interpreted as describing a high-MgO-content nontransformable t'–ZrO2 phase. As temperature increases, the latter gives rise to a similar but fluctuating interaction related to the oxygen vacancies mobility and which shows a thermal behavior analogous to that already reported for the stabilized cubic ZrO2. Above 1100 K these dynamic t'-sites transform into pure tetragonal ones which behave ordinarily, suffering the t → m phase transition when cooling to room temperature. Differences found between TDPAC results and information drawn from other techniques are discussed.


2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.


2014 ◽  
Vol 989-994 ◽  
pp. 212-215
Author(s):  
J. Liu ◽  
G. Zhu ◽  
W. Mao

The effect of volume fraction of ferrite on the mechanical properties including strength, plasticity and wok hardening was systematically investigated in X80 pipeline steel in order to improve the plasticity. The microstructures with different volume fraction of ferrite and bainite were obtained by heat-treatment processing and the mechanical properties were tested. The work hardening behavior was analyzed by C-J method. The results show that the small amount of ferrite could effectively improve the plasticity. The work hardening ability and the ratio of yield/tensile strength with two phases of ferrite/bainite would be obviously better than that with single phase of bainite. The improvement of plasticity could be attributed to the ferrite in which more plastic deformation was afforded.


Development ◽  
1962 ◽  
Vol 10 (4) ◽  
pp. 530-562
Author(s):  
M. Enesco ◽  
C. P. Leblond

While the organs and tissues of the young rat are known to increase in size with age (Donaldson, 1924), little is known of the role played by the component cells in this increase. There is evidence that cells enlarge (Levi, 1906; Plenk, 1911) and new cells are added (Strasburger, 1893), but we do not know to what extent the enlargement and proliferation of the cells cause the growth of organs and tissues. The present work is an attempt to clarify this problem. In the past, the growth of organs and tissues has often been measured by weight gain (Donaldson, 1924). However, this approach might be misleading, since the body-weight may increase in the absence of growth, for instance as a result of fat-storage in old rats, of pregnancy in females, and even of changes in room temperature.


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