scholarly journals Coupled Simulation of a Vacuum Creation System and a Rectification Column Block

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1333
Author(s):  
Eduard Osipov ◽  
Eduard Telyakov ◽  
Sergey Ponikarov
Keyword(s):  
Vacuum System ◽  
Separation Unit ◽  
Capital Costs ◽  
Mixture Separation ◽  
System A ◽  
Computational Data ◽  
Individual Column ◽  
Economic Comparison ◽  
Generating System ◽  
System Layout

The purpose of this study was the coupling simulation of the vacuum block of the ethanolamine mixture separation unit to determine the optimal layout of the vacuum creation system. For this, a computational model of the vacuum unit, which was identified by comparing the computational data with the data of an industrial study of vacuum rectification columns, was synthesized in the Unisim Design R461 software package. To determine the required load on the vacuum system, a numerical experiment was carried out, during which it was discovered that the load on the system would be 9600 m3/h. It was proposed to replace individual column vacuum pumps with a single vacuum-generating system (VGS) based on a liquid ring vacuum pump (LRVP). When defining the layout, two possible schemes were considered, the models of which were created in Unisim Design R461. The system layout was determined by matching the characteristics of the system elements with the characteristics of the vacuum columns. A technical and economic comparison of the proposed solutions was carried out and the payback period for capital costs was calculated, which for Scheme 1 was 4.14 years, and for Scheme 2–3.59 years.

scholarly journals Detecting and Quantifying Polyhaloaromatic Environmental Pollutants by Chemiluminescence-Based Analytical Method

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3365
Author(s):  
Ben-Zhan Zhu ◽  
Miao Tang ◽  
Chun-Hua Huang ◽  
Li Mao
Keyword(s):  
Analytical Method ◽  
Degradation Kinetics ◽  
Environmental Pollutants ◽  
Environmental Implications ◽  
Future Studies ◽  
System A ◽  
Quinoid Structure ◽  
Fenton System ◽  
Generating System ◽  
H2o2 System

Polyhaloaromatic compounds (XAr) are ubiquitous and recalcitrant in the environment. They are potentially carcinogenic to organisms and may induce serious risks to the ecosystem, raising increasing public concern. Therefore, it is important to detect and quantify these ubiquitous XAr in the environment, and to monitor their degradation kinetics during the treatment of these recalcitrant pollutants. We have previously found that unprecedented intrinsic chemiluminescence (CL) can be produced by a haloquinones/H2O2 system, a newly-found ●OH-generating system different from the classic Fenton system. Recently, we found that the degradation of priority pollutant pentachlorophenol by the classic Fe(II)-Fenton system could produce intrinsic CL, which was mainly dependent on the generation of chloroquinone intermediates. Analogous effects were observed for all nineteen chlorophenols, other halophenols and several classes of XAr, and a novel, rapid and sensitive CL-based analytical method was developed to detect these XAr and monitor their degradation kinetics. Interestingly, for those XAr with halohydroxyl quinoid structure, a Co(II)-mediated Fenton-like system could induce a stronger CL emission and higher degradation, probably due to site-specific generation of highly-effective ●OH. These findings may have broad chemical and environmental implications for future studies, which would be helpful for developing new analytical methods and technologies to investigate those ubiquitous XAr.

scholarly journals Bactericidal activity of a superoxide anion-generating system. A model for the polymorphonuclear leukocyte.

1979 ◽  
Vol 149 (1) ◽  
pp. 27-39 ◽  
Author(s):  
H Rosen ◽  
S J Klebanoff
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Bactericidal Activity ◽  
Parent Strain ◽  
Carotenoid Pigments ◽  
Bacterial Killing ◽  
Oxidase System ◽  
System A ◽  
Presence And Absence ◽  
Generating System

The acetaldehyde-xanthine oxidase system in the presence and absence of myeloperoxidase (MPO) and chloride has been employed as a model of the oxygen-dependent antimicrobial systems of the PMN. The unsupplemented xanthine oxidase system was bactericidal at relatively high acetaldehyde concentrations. The bactericidal activity was inhibited by superoxide dismutase (SOD), catalase, the hydroxyl radical (OH.) scavengers, mannitol and benzoate, the singlet oxygen (1O2) quenchers, azide, histidine, and 1,4-diazabicyclo[2,2,2]octane (DABCO) and by the purines, xanthine, hypoxanthine, and uric acid. The latter effect may account for the relatively weak bactericidal activity of the xanthine oxidase system when purines are employed as substrate. A white, carotenoid-negative mutant strain of Sarcina lutea was more susceptible to the acetaldehyde-xanthine oxidase system than was the yellow, carotenoid-positive parent strain. Carotenoid pigments are potent 1O2 quenchers. The xanthine oxidase system catalyzes the conversion of 2,5-diphenylfuran to cis-dibenzoylethylene, a reaction which can occur by a 1O2 mechanism. This conversion is inhibited by SOD, catalase, azide, histidine, DABCO, xanthine, hypoxanthine, and uric acid but is only slightly inhibited by mannitol and benzoate. The addition of MPO and chloride to the acetaldehyde-xanthine oxidase system greatly increases bactericidal activity; the minimal effective acetaldehyde concentration is decreased 100-fold and the rate and extent of bacterial killing is increased. The bactericidal activity of the MPO-supplemented system is inhibited by catalase, benzoate, azide, DABCO, and histidine but not by SOD or mannitol. Thus, the acetaldehyde-xanthine oxidase system which like phagocytosing PMNs generates superoxide (O.2-) and hydrogen peroxide, is bactericidal both in the presence and absence of MPO and chloride. The MPO-supplemented system is considerably more potent; however, when MPO is absent, bactericidal activity is observed which may be mediated by the interaction of H2O2 and O.2- to form OH. and 1O2.

Design of Vacuum System of Steam Jet Bursting Unit for Chestnut Shell

2011 ◽  
Vol 291-294 ◽  
pp. 1685-1688
Author(s):  
Xi Nan Dang ◽  
Qiao Fu Chen ◽  
Li Jun Yang
Keyword(s):  
Energy Consumption ◽  
Vacuum System ◽  
Jet Pump ◽  
Waste Gas ◽  
System A ◽  
Start Up ◽  
Chestnut Shell ◽  
Bursting Process

According to the vacuum bursting process for fresh chestnut shell and requirements for relevant vacuum system, a vacuum system of steam jet pump was designed with a start-up jet pump attached to it. Of which the waste gas from ejector was used for reheating in the bursting process to lead the vacuum bursting unit to run more reliably and stably with efficiency improved and energy consumption reduced. The rate of bursting came up to 95% in the process test.

scholarly journals Yet Another Intelligent Code-Generating System: A Flexible and Low-Cost Solution

2018 ◽  
Vol 33 (5) ◽  
pp. 940-965 ◽  
Author(s):  
João Fabrício Filho ◽  
Luis Gustavo Araujo Rodriguez ◽  
Anderson Faustino da Silva
Keyword(s):  
Low Cost ◽  
System A ◽  
Generating System

scholarly journals Photonic crystals obtained by soap-free emulsion terpolymerization

2014 ◽  
Vol 12 (1) ◽  
pp. 126-130
Author(s):  
Edina Rusen ◽  
Aurel Diacon ◽  
Alexandra Mocanu
Keyword(s):  
Homogeneous Nucleation ◽  
Water Solubility ◽  
Gel Permeation Chromatography ◽  
Nucleation Mechanism ◽  
Hydroxyethyl Methacrylate ◽  
System A ◽  
Vis Spectroscopy ◽  
Gel Permeation ◽  
Nucleation Mechanisms ◽  
Generating System

AbstractThis paper presents the use of soap-free emulsion terpolymerization to obtainphotonic crystals (PCs). Monodisperse latexes resulted from the polymerization of styrene (ST) with 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) at different compositions defined as system A, B and C respectively. The water solubility of the macroradicals determined different nucleation mechanisms in all three cases. The micellar nucleation mechanism was more predominant for generating system A, whereas the homogeneous nucleation was specific for system C. For system B, both nucleation mechanisms werepossible with the same probability. The latexes and the resulted PCs were characterized by optical microscopy (OM), dynamic light scattering (DLS), gel permeation chromatography (GPC) and UV-VIS spectroscopy.

Influence of Plasma Torch Nozzle Design on Plasma Arc Analyzed with Finite Element Method

2015 ◽  
Vol 1095 ◽  
pp. 751-755
Author(s):  
Hai Yan Wang ◽  
Yi Jiang ◽  
Yuan Peng Xia ◽  
Yun Li Zhou
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Plasma Torch ◽  
Plasma Arc ◽  
Direction Parallel ◽  
System A ◽  
Welding Torch ◽  
Large Pressure ◽  
Generating System ◽  
Element Method

Plasma torch is one of the most important parts for plasma arc generating system. A design of orifices in a nozzle would decide the properties of plasma arc. However, mechanisms of orifice to plasma arc are seldom discussed. In this paper, the plasma arc with two assistant orifices were analyzed by finite element method. It was concluded that the plasma arc would be further compressed in the direction parallel to two assistant orifices, but expand perpendicular to assistant orifices. Through the constriction of two assistant orifices, the shape of the plasma arc would be elliptical other than circular of the oridinary plasma arc. The torch design with two assistant orifices could be available to many fields such as plasma arc welding, especially to a welding torch with a large pressure chamber.

Kiwi omnicup handheld versus Mityvac M-style conventional vacuum system: a retrospective observational study

2017 ◽  
Vol 31 (23) ◽  
pp. 3178-3182 ◽  
Author(s):  
Tal Weissbach ◽  
Nasreen Hag-Yahia ◽  
Michal Ovadia ◽  
Keren Tzadikevitch Geffen ◽  
Omer Weitzner ◽  
...  
Keyword(s):  
Observational Study ◽  
Retrospective Observational Study ◽  
Vacuum System ◽  
System A

The BNL STEM Facility

1997 ◽  
Vol 3 (S2) ◽  
pp. 277-278
Author(s):  
Joseph S. Wall ◽  
Martha N. Simon ◽  
James F. Hainfeld
Keyword(s):  
National Laboratory ◽  
Computer Control ◽  
Large Angle ◽  
Brookhaven National Laboratory ◽  
Dark Field ◽  
Vacuum System ◽  
Vacuum Chambers ◽  
System A ◽  
Freeze Dried ◽  
Individual Particles

The STEM facility at Brookhaven National Laboratory has been in operation since Oct. ‘77, using a custom-built instrument (STEM1) with cold field emission source, 2.5Å probe, -150°C cold stage, efficient dark field detectors and computer control & data acquisition system. A specimen changing air lock and several portable vacuum chambers permit vacuum transfer of specimens from a separate vacuum system where they were freeze dried overnight.The large angle dark-field signal produced by the STEM is directly proportional to the total mass within the probed area. STEM mass mapping is based on this linear relationship and the fact that only specimen-specific atoms remain on the substrate after washing with volatile buffer and freeze drying. All images are digital and available via Internet. PC software can be provided for analysis.STEM mass accuracy ranges from a fraction of a percent on well-defined individual particles such as viruses in the 50 MDa to 10 GDa range, to ∼1% around 1 MDa and ∼10% in the 50 kDa range.

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