scholarly journals Dynamics at Polarized Carbon Dioxide–Iron Oxyhydroxide Interfaces Unveil the Origin of Multicarbon Product Formation

ACS Catalysis ◽  
2021 ◽  
pp. 411-430
Author(s):  
Rosa Arrigo ◽  
Raoul Blume ◽  
Verena Streibel ◽  
Chiara Genovese ◽  
Alberto Roldan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Product Formation ◽  
Iron Oxyhydroxide

The anaerobic end-products of helminths

Parasitology ◽  
1984 ◽  
Vol 88 (1) ◽  
pp. 179-198 ◽  
Author(s):  
J. Barrett
Keyword(s):  
Carbon Dioxide ◽  
Tricarboxylic Acid Cycle ◽  
Metabolic Cost ◽  
Product Formation ◽  
Carbon Dioxide Fixation ◽  
Functional Adaptation ◽  
Catabolic Pathways ◽  
Parasitic Helminths ◽  
Wide Range ◽  
End Products

Parasitic helminths belong to 3 separate phyla and there is always the danger of over-generalization. The various routes of anaerobic carbohydrate breakdown in parasitic helminth differ in their efficiencies and in their power output. The choice of end-product represents a compromise between these two conflicting forces. In addition, anaerobic pathways must satisfy the redox requirements of the tissues and provide a source of intermediates for synthetic reactions. Other considerations include the metabolic cost of excretion and the effect of end-products on protein structure and function. The different end-products may fulfil additional functions such as pH control, nitrogenous excretion, osmotic regulation, intracellular signalling and the suppression of host responses.A complicating factor in parasitic helminths is the existence of strains with different biochemical characteristics, including marked variation in end-product formation. The various tissues of the same parasite can also produce different end-products and the pattern of end-product formation is influenced by a variety of extrinsic and intrinsic factors such as age, sex, length of incubation, pO2 and availability of substrates. The catabolic pathways of helminths thus show considerable functional adaptation.There is, as yet, no satisfactory explanation as to why helminths do not make the maximum use of any oxygen available to them; and the contribution of oxidative processes to the overall energy balance of parasites probably varies from species to species.The catabolic pathways of adult helminths are derived from the anaerobic pathways present in their free-living relatives. Two main trends are evident, homolactic fermentation and carbon dioxide fixation, the latter involving a partial reverse tricarboxylic acid cycle. In general, homolactic fermentation is found in blood and tissue parasites, carbon dioxide fixation in gut parasites. These two types of metabolism are, of course, in no way absolute, most homolactic fermentors fix carbon dioxide to a certain extent and many parasites which fix carbon dioxide also produce lactate. Parasitic helminths possess a wide range of different catabolic pathways, superimposed upon which is a high degree of functional plasticity.

scholarly journals The Effect of Filter Ventilation on the Yield and Composition of Mainstream and Sidestream Smokes

1980 ◽  
Vol 10 (2) ◽  
Author(s):  
C. L. Browne ◽  
C. H. Keith ◽  
R. E. Allen
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Combustion Product ◽  
Product Formation ◽  
Gradual Transition ◽  
Smoldering Combustion ◽  
Sidestream Smoke ◽  
Puff Volume

AbstractApparatus and procedures were developed to measure condensate, nicotine, water, carbon monoxide and carbon dioxide in mainstream and sidestream smoke. These were used to determine the effect of air dilution through filter ventilation on mainstream and sidestream smoke composition. It was found that there is a gradual transition from 'puffing combustion to smoldering combustion as the amount of diluting air entering the system increases. This is directly related to the decreased puff volume at the cone and decreased amount of tobacco consumed per puff. On a per· gram of tobacco consumed basis, sidestream combustion product formation is not changed but the amounts of carbon monoxide and water in the mainstream are decreased, as ventilation increases.

scholarly journals Metabolism of saturated and polyunsaturated fatty acids by normal and Zellweger syndrome skin fibroblasts

1989 ◽  
Vol 260 (3) ◽  
pp. 647-655 ◽  
Author(s):  
J M Street ◽  
D W Johnson ◽  
H Singh ◽  
A Poulos
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
De Novo ◽  
Zellweger Syndrome ◽  
Normal Skin ◽  
Product Formation ◽  
Water Soluble ◽  
Skin Fibroblasts

The metabolism of 1-11C-labelled derivatives of palmitic (C16:0), arachidonic (C20:4,n-6) lignoceric (C21:0) and tetracosatetraenoic (C24:4,n-6) acids was studied in normal skin fibroblast cultures and in cultures of fibroblasts from peroxisome-deficient (Zellweger's syndrome) patients. Radiolabelled products of the fatty acids included carbon dioxide. C14-24 saturated and mono-unsaturated fatty acids formed from released acetate either by synthesis de novo or by elongation of endogenous fatty acids, fatty acids formed by 2-6-carbon elongation of added substrates, and a number of water-soluble compounds, some of which were tentatively identified as the amino acids glutamine, glutamic acid and asparagine. The labelled amino acids were found predominantly in the culture medium. Zellweger's syndrome fibroblasts showed a marked decrease in radiolabelled carbon dioxide and water-soluble-product formation from (I-14C)-labelled arachidonic, tetracosatetraenoic and lignoceric acids but not from [I-14C]palmitic acid, and the production of radiolabelled C14-18 fatty acids was also diminished. However, the elongation of individual fatty acids was either normal or above normal. Our data support the view that the oxidation of 20:4, 24:4 and 24:0 fatty acids in cultured skin fibroblasts takes place largely in peroxisomes, and further that the acetyl-CoA released by the beta-oxidation process is available for the synthesis of fatty acids and amino acids. We speculate that the generation of C2 units used for synthesis is a major peroxisomal function and that this function is absent or greatly impaired in Zellweger's syndrome cells.

Insights into Liquid Product Formation during Carbon Dioxide Reduction on Copper and Oxide-Derived Copper from Quantitative Real-Time Measurements

ACS Catalysis ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 6735-6740 ◽  
Author(s):  
Mario Löffler ◽  
Peyman Khanipour ◽  
Nadiia Kulyk ◽  
Karl J.J. Mayrhofer ◽  
Ioannis Katsounaros
Keyword(s):  
Carbon Dioxide ◽  
Real Time ◽  
Liquid Product ◽  
Carbon Dioxide Reduction ◽  
Product Formation

scholarly journals Corrosion product formation on zinc-coated steel in wet supercritical carbon dioxide

2021 ◽  
pp. 103636
Author(s):  
Ville Saarimaa ◽  
Aaretti Kaleva ◽  
Arnold Ismailov ◽  
Tero Laihinen ◽  
Markus Virtanen ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Corrosion Product ◽  
Product Formation ◽  
Coated Steel ◽  
Zinc Coated Steel ◽  
Supercritical Carbon

scholarly journals Sequestration of non-pure carbon dioxide streams in iron oxyhydroxide-containing saline repositories

2012 ◽  
Vol 7 ◽  
pp. 89-97 ◽  
Author(s):  
S. Garcia ◽  
R.J. Rosenbauer ◽  
J. Palandri ◽  
M.M. Maroto-Valer
Keyword(s):  
Carbon Dioxide ◽  
Iron Oxyhydroxide ◽  
Pure Carbon ◽  
Pure Carbon Dioxide

THE MECHANISM OF THE PHOTOOXIDATION OF ACETALDEHYDE AT ROOM TEMPERATURE

1959 ◽  
Vol 37 (10) ◽  
pp. 1671-1679 ◽  
Author(s):  
Jack G. Calvert ◽  
Philip L. Hanst
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Acetic Acid ◽  
Detection Limit ◽  
Formic Acid ◽  
Analytical Methods ◽  
Room Temperature ◽  
Product Formation ◽  
Infrared Spectrometry ◽  
Peroxyacetic Acid

The initial rates of product formation in the photooxidation of acetaldehyde at room temperature have been determined through the use of infrared spectrometry. The rates of formation of the products peroxyacetic acid, carbon monoxide, carbon dioxide, methanol, formic acid, and acetic acid were determined in experiments with various pressures of acetaldehyde, oxygen, and added gases. The amounts of methylhydroperoxide and acetylperoxide formed in all of the experiments were below the detection limit of the analytical methods. The results require that some modification and corrections be made to the mechanism suggested by McDowell and Sharples.

scholarly journals Crystal Geyser: An Unusual Cold Spring System, Grand County

Geosites ◽  
2019 ◽  
Vol 1 ◽  
pp. 1-6
Author(s):  
Sally Potter-McIntyre
Keyword(s):  
Carbon Dioxide ◽  
Land Surface ◽  
Microbial Mats ◽  
Iron Oxyhydroxide ◽  
Charged Fluid ◽  
Green River ◽  
Spring System ◽  
Cold Spring ◽  
Natural Spring ◽  
Carbon Dioxide Co2

Crystal Geyser is a cold carbon dioxide (CO2) geyser, part of a natural spring system along the Little Grand Wash fault south of Green River, Utah (figure 1). The spring system hosts a series of CO2-driven geysers and springs with active and fossil microbial mats and tufa deposits composed of carbonate and iron oxide and iron oxyhydroxide minerals (Potter-McIntyre and others, 2017; Knuth and Potter-McIntyre, 2018) (figure 2). Additionally, progressively older carbonate spring deposits crop out on some of the topographic highs in the area because these relatively erosion-resistant deposits armor the paleo-land surface and slow down erosion (Shipton and others, 2004; Burnside, 2010). Recent radiometric U-Th dating of carbonate terraces and embedded veins reveal that CO2-charged fluid has constantly leaked to the surface for over 400 thousand years during the Pleistocene (Burnside, 2010). Crystal Geyser is a popular place for tourists, and it is not uncommon to see children playing in the spring.

scholarly journals Variation of the Gas Formation Regions within a Cigarette Combustion Coal during the Smoking Cycle

1981 ◽  
Vol 11 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Richard R Baker
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Diffusion Processes ◽  
Product Formation ◽  
Quadrupole Mass ◽  
Internal Contour ◽  
Formation Region ◽  
Gas Formation ◽  
Combustion Region ◽  
Filtration Unit

AbstractInternal contour distributions for gas temperatures and for the concentrations of carbon monoxide, carbon dioxide, hydrogen, propane and oxygen have been determined at successive times before, during and after a puff of a burning cigarette. The cigarette was smoked in an atmosphere of 21 % (v/v) oxygen in argon. The gases were withdrawn from the cigarette through a small sampling probe and filtration unit, and analysed using a quadrupole mass spectrometer. The contour distributions show that the gas formation and transmission processes occurring in the coal, and their variation during the smoking regime, are complex. The interior of the coal is almost entirely devoid of oxygen. The consumption of oxygen is so rapid that the position of its major influx into the coal, near the paper burn line, cannot be seen on the contour diagrams during a puff. However, the oxygen influx during the puff leaves burnt-out channels in the coal which become evident at later stages in the smoking cycle. When the puff ends, the product formation/transfer balance is interrupted, resulting in a local build-up of the product in its formation region. This local build-up reaches a maximum at 0.5-1.0 seconds after the end of the puff, after which time diffusion processes deplete the level. During the static smoulder period, distinct high and low temperature regions for the formation of carbon monoxide and dioxide are not evident inside the coal. However, towards the latter half of the puff, a distinct carbon dioxide formation region starts to appear behind the completely oxygen-deficient region. Application of the pyrolysis computer model, developed previously, confirms that this second region is a thermal decomposition region, and shows that such a region for carbon monoxide is not resolved from the combustion region.

scholarly journals Review on Carbon Dioxide Utilization for Cycloaddition of Epoxides by Ionic Liquid-Modified Hybrid Catalysts: Effect of Influential Parameters and Mechanisms Insight

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Jimmy Nelson Appaturi ◽  
Rajabathar. Jothi Ramalingam ◽  
Muthu Kumaran Gnanamani ◽  
Govindasami Periyasami ◽  
Prabhakarn Arunachalam ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ionic Liquid ◽  
Styrene Oxide ◽  
Research Work ◽  
Product Formation ◽  
Cyclic Carbonate ◽  
Process Conditions ◽  
Carbonate Formation ◽  
Carbon Dioxide Utilization

The storage, utilization, and control of the greenhouse (CO2) gas is a topic of interest for researchers in academia and society. The present review article is dedicating to cover the overall role of ionic liquid-modified hybrid materials in cycloaddition reactions. Special emphasis is on the synthesis of various cyclic carbonate using ionic liquid-based modified catalysts. Catalytic activity studies have discussed with respect to process conditions and their effects on conversion and product selectivity for the reaction of cycloaddition of CO2 with styrene oxide. The reaction temperature and the partial pressure of CO2 have found to play a key role in cyclic carbonate formation. The role of other influential parameter (solvent effect) is also discussed for the conversion of cyclic/aromatic oxides to polycarbonate production. Our own research work that deals with ionic liquid-based halide-modified mesoporous catalyst (MCM-41 type) derived from rice husk waste has also been discussed. Finally, the role of carbon dioxide activation and ring-opening mechanisms involved in the cyclic carbonate product formation from CO2 have been discussed.

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