A DUAL EFFECT OF CARBON DIOXIDE ON INSECTS POISONED BY OXYGEN

Keeping inventory of carbon dioxide in liquid dominated geothermal reservoirs

The physiologic action of oxygen and carbon dioxide on the coronary circulation, as shown by blood gas and electrocardiographic studies

Color phenomena in thorium oxide

Economically and ecologically, the thermal decomposition of methane is a promising process for large scale hydrogen production. In this experimental study, the non-catalytic decomposition of methane in the presence of small amounts of carbon dioxide was analyzed. At large scales, natural gas or biomethane are possible feedstocks for the thermal decomposition and can obtain up to 5% carbon dioxide. Gas recycling can increase the amount of secondary components even further. Experiments were conducted in a packed flow reactor at temperatures from 1250 to 1350 K. The residence time and the amounts of carbon dioxide and hydrogen in the feed were varied. A methane conversion of up to 55.4% and a carbon dioxide conversion of up to 44.1% were observed. At 1300 K the hydrogen yield was 95% for a feed of methane diluted in nitrogen. If carbon dioxide was added to the feed at up to a tenth with regard to the amount of supplied methane, the hydrogen yield was reduced to 85%. Hydrogen in the feed decreases the reaction rate of the methane decomposition and increases the carbon dioxide conversion.

The solubility of methane in aqueous solutions has been determined over a broad range of temperature, pressure and salinities. The effect of dissolved carbon dioxide and ethane on methane solubility has been determined at 302{sup 0}F. Also the solubility of crude oil and water in methane has been determined over a broad range of temperatures and pressures. The solubility of methane is raised by increasing pressure and temperature (above about 170{sup 0}F). There is a solubility minimum near 170{sup 0}F at constant pressure and salinity. Ionic salts effectively salt methane out of solution at all concentrations investigated. The effect of the addition of small amounts of carbon dioxide or ethane to the gas dissolved in aqueous solutions is to enhance methane solubility compared to solutions without other gases. Higher concentrations of dissolved gases, depending upon the salinity and the gas involved, decrease aqueous methane solubility. The addition of carbon dioxide always increased total gas content even when reducing the concentration of methane. With increasing concentration of ethane in the dissolved gases the total gas content reaches a maximum and then both methane and total gas content decrease. Comparison of experimental methane solubilities with gas/water ratios, salinities, bottom hole temperatures andmore » pressures of geopressure test wells suggests that some formation fluids may be near saturation, while many others seem to be undersaturated. Petroleum is soluble in methane. Increasing pressure increases the solubility of crude oil in methane gas. At an elevated pressure, which depends upon the temperature, oil and gas form a single fluid phase.« less

The role of carbon dioxide in the dynamics of magma ascent in explosive eruptions is investigated by means of numerical modeling. The model is steady, one-dimensional, and isothermal; it calculates the separated flow of gas and a homogeneous mixture of liquid magma and crystals. The magma properties are calculated on the basis of magma composition and crystal content and are allowed to change along the conduit due to pressure decrease and gas exsolution. The effect of the presence of a two-component (water + carbon dioxide) exsolving gas phase is investigated by performing a parametric study on the CO2/(H2O+CO2) ratio, which is allowed to vary from 0 to 0.5 at either constant total volatile or constant water content. The relatively insoluble carbon dioxide component plays an important role in the location of the volatile-saturation and magma-fragmentation levels and in the distribution of the flow variables in the volcanic conduit. In detail, the results show that an increase of the proportion of carbon dioxide produces a decrease of the mass flow rate, pressure, and exit mixture density, and an increase of the exit gas volume fraction and depth of the fragmentation level. A relevant result is the different role played by water and carbon dioxide in the eruption dynamics; an increasing amount of water produces an increase of the mass flow rate, and an increasing amount of carbon dioxide produces a decrease. Even small amounts of carbon dioxide have major consequences on the eruption dynamics, implying that the multicomponent nature of the volcanic gas must be taken into account in the prediction of the eruption scenario and the forecasting of volcanic hazard.

1. The whole peel of Valencia oranges and the albedo of navel oranges were separated into alcohol-soluble and alcohol-insoluble fractions by extraction of the fresh material with hot 80% ethyl alcohol. The principal constituents of the two fractions were determined, and some of their chemical properties studied. 2. The alcohol-soluble fraction of the whole peel of Valencia orange and of the albedo of navel orange averaged 57.31% and 55.19%, respectively, of the total dry weights. Soluble sugars accounted for 55.4% of the total extractable material in Valencia peel and for 72.69% in navel albedo. This fraction also contained substances which produced a small amount of carbon dioxide on hydrolysis with 19% hydrochloric acid. This carbon dioxide was probably produced by low polymer galacturonides soluble in hot 80% alcohol. 3. The alcohol-insoluble fraction of Valencia orange whole peel and of navel albedo averaged 42.69% and 44.81%, respectively, of the total dry weights. The sum of the water-soluble and acid-soluble pectic substances (as calcium pectate) of the alcohol-insoluble fraction averaged 39.76% in Valencia peel and 34.87% in navel albedo; the insoluble residues averaged 30.53% and 30.41%, respectively. The undetermined portion consisted of hemicelluloses which contained small amounts of polyuronides and which were rendered soluble by the extraction treatment. 4. The purity of the extracted pectic material (as calcium pectate) was ascertained on each sample by determining contents of carbon dioxide, calcium, and furfural. 5. As the polyuronides yield carbon dioxide quantitatively on hydrolysis with hydrochloric acid, the carbon dioxide values determined are a fair measure of the total pectic substances in the alcohol-insoluble solids. When the carbon dioxide values were accompanied by corresponding values for methoxyl, the degree of methylation of the pectic substances was subsequently calculated by dividing the determined methoxyl by that equivalent to the total carbon dioxide. Methylation in Valencia peel averaged 83.38%, and in navel albedo, 82.39%. 6. The sum of the carbon dioxide in the aqueous extract, acid extract, and residue amounted to 95.20% and 97.47% (mean values) of the total carbon dioxide of the alcohol-insoluble solids in the Valencia orange peel and navel orange albedo, respectively. The total calcium pectate precipitated from the aqueous and acid extracts of Valencia peel yielded 94.12% of the carbon dioxide dissolved by the extractants. The corresponding value for navel albedo was 88.00%. 7. Since the alcohol-insoluble fraction contained the pectic substances, most of the carbon dioxide which could be liberated by hydrolysis with 19% hydrochloric acid, and all the methoxyl groups, occurred in this fraction. The ratio of methoxyl to carbon dioxide was approximately the same in Valencia orange peel and in navel orange albedo. 8. The carbon dioxide equivalent to the sum of the esterified and nonesterified carboxyl groups was equal to the total carbon dioxide of the alcohol-in-soluble fraction obtained on hydrolysis with 19% hydrochloric acid.

The preparation of a non‐stoichiometric basic carbonate of iron (III) is described. The amounts of carbon dioxide and water can vary in large limits, depending on the way the samples are dried. The ratio of Fe2O3:CO2 in a fresh product is nearly one, but decomposition takes place already at room temperature and ambient humidity. When heated slowly, the carbon dioxide is given of in two clear steps, an intermediate product being formed at about 200°C. The basic iron (III) carbonate decomposes between 400° and 500°C to an α‐Fe2O3 with still a small amount of carbon dioxide. The infrared spectra show that in the freshly prepared products the greater part of the CO ions are linked by two oxygen atoms to two iron atoms, and a smaller part probably only by one oxygen to one iron atom. In the intermediate product, part of the CO2_3 ions are linked by two oxygen atoms to one iron atom, or a hydrogenocarbonate group may be formed. The X‐ray diagrams taken with Mo Kα rays show only two broad lines.

We are trying to develop a methane-producing system using indigenous microbes in depleted oil fields as a new microbial enhanced oil recovery process. In particular, we aim to combine a microbial conversion of the residual oil into methane with the geological sequestration of carbon dioxide. The mechanism is as follows: Hydrocarbon-degrading bacteria are harnessed to produce hydrogen and/or acetate from residual oil in the depleted oil reservoir. Then, methane-producing microbes (methanogens) utilize the produced acetate or hydrogen and carbon dioxide, which is injected for geological sequestration, to generate methane. We successfully isolated hydrogen- and methane-producing microbes (hydrogen-producing bacteria and methanogens) from oil fields (Yabase and other oil fields) in Japan. Our analysis of microbial cultures incubated under high temperature and high pressure, the condition similar to in situ petroleum reservoir conditions, revealed that indigenous microbes in the reservoir brine are capable of generating methane by utilizing crude oil and carbon dioxide. Consumption/production rate of gases (methane and carbon dioxide) and acetic acid indicated that the methane production under reservoir conditions is likely mediated through two major pathways; the acetoclastic (acetic-acid utilizing) and the hydrogenotrophic (hydrogen and carbon-dioxide utilizing) pathways. Furthermore, by analyzing methane-producing ability of isolated microbes, we found that the syntrophic cooperation between hydrogen-producing bacteria and methanogens was critical for the methane producing under the reservoir condition. 0%.tures with carbon dioxideent Strikingly, addition of carbon dioxide accelerated methane production of the cultures. The methane production rate of the cultures, in which high concentration (10%) of carbon dioxide was supplied into the head spaces, was 0.30 mmol/L/Day. On the other hand, the cultures without the addition of carbon dioxide showed the methane production rate of 0.12 mmol/L/Day, significantly slower (ca. 40%) than the production rate of the cultures with carbon dioxide. These results suggested that addition (injection) of carbon dioxide into reservoirs might accelerate the microbial methane production. We further investigated the methanogenic communities and pathways in petroleum reservoirs by incubating the reservoir brine from the Yabase oil field, combined with radiotracer experiments and molecular biological analyses. The brine samples were incubated without exogenous-nutrient supplementation under the high-temperature and high-pressure condition (the in-reservoir condition). The radiotracer analysis (using 14C-biocarbonate and 14C-acetate) indicated that the methane production rate of hydrogenotrophic methanogenesis was 50-fold higher than that of acetoclastic methanogenesis, suggesting dominance of methane production by syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis in reservoir. In this study, we assessed the rate of oil biodegradation coupled with methanogenesis by using 14C-labeled toluene and hexadecane as tracers. The analysis revealed that the rate was very low, being only about one thousandth of that of the hydrogenotrophic methanogenesis. We are currently trying to enhance the crude-oil biodegradation for effective conversion of crude oil to methane. Our goal is to establish effective microbial conversion system from residual oil into methane in depleted oil fields as a new EOR technology.

Effects of simultaneous hydrogen enrichment and carbon dioxide dilution of fuel on soot formation in an axisymmetric coflow laminar ethylene/air diffusion flame

1. Whole peel of grapefruit was extracted with 80% ethyl alcohol and separated into two distinct fractions, the alcohol-soluble and alcohol-insoluble solids. The carbohydrate constituents of these two fractions were investigated, and certain of their physical and chemical properties were determined. All analyses were made on fruit samples obtained from trees that had been fumigated with hydrocyanic acid or sprayed with oil for pest control during the growing season. 2. The alcohol-soluble fraction of the peel contained substances which liberated a small amount of carbon dioxide on hydrolysis with 12% hydrochloric acid. The total solids of this fraction composed 66.31% and 67.35% of the dry matter of the peel of fumigated and oil-sprayed fruit, respectively. 3. The soluble sugars in the peel averaged 40.29% and 41.28% of the dry weight of the fumigated and oil-sprayed fruit, respectively. These amounts of soluble sugars accounted for 60.76% and 61.28% (mean values) of the total alcoholic extractives. Approximately 40% of the dry weight of the alcohol-soluble fraction was composed of substances other than sugars, namely, essential oil, waxes, organic acids, naringin, and various concentrations of undetermined constituents. 4. The alcohol-insoluble fraction of the peel contains the cell-wall constituents-cellulose, hemicellulose, and pectin. This fraction comprised 33.69% and 32.65% of the dry weight of the peel. Lignin and starch were not present in sufficient quantities to be determined by the prevailing chemical methods. 5. Since the alcohol-insoluble fraction contains the pectin, most of the carbon dioxide which can be liberated by hydrolysis with 12% HCl and all the methoxyl groups occur in this fraction. The ratio of methoxyl to carbon dioxide was much lower in grapefruit peel than in lemon peel. 6. The carbon dioxide equivalent to the sum of the esterified and non-esterified carboxyl groups was equal to the total carbon dioxide of the alcohol-insoluble fraction obtained on hydrolysis with 12% hydrochloric acid. 7. The sum of the water-soluble and acid-soluble pectin (as calcium pectate) of the alcohol-insoluble fraction of the peel of the fumigated and oil-sprayed fruit amounted to 43.79% and 43.95%, respectively. These values are much lower than those for the total pectin calculated from the carbon dioxide and the methoxyl values. 8. To establish criteria of purity, the calcium pectate values are accompanied by corresponding values for carbon dioxide, calcium, and furfural. The percentages of calcium in the calcium pectates are somewhat higher than the 7.50% usually reported for pure calcium pectate. The percentages of carbon dioxide are slightly higher than the 17.40% reported for pure calcium pectate. The furfural values are in accord with those reported by other investigators. 9. The residue that remains after extracting the pectin from the alcohol-insoluble solids of the peel is composed of cellulose and hemicellulose and a comparatively small amount of firmly bound pectin that is difficult to extract and determine quantitatively. 10. The sum of the carbon dioxide in the aqueous extract, acid extract, and residue amounted to 94.26% and 95.19% of the total carbon dioxide of the alcoholinsoluble solids in the peel of fumigated and oil-sprayed fruit, respectively. In the aqueous and acid extracts, calcium pectate accounted for more than 90% of the carbon dioxide dissolved by the extractants.

Fruit physiologists have been concerned with carbon dioxide as a product of the respiratory process and as a factor in the environment surrounding the fruit. Measurement of CO, evolution was favored over determinations of oxygen uptake because of the simplicity of the determination, but a number of investigators realized that CO2 may be produced by anaerobic as well as aerobic pathways of metabolism. Therefore, carbon dioxide is not a sufficient index for establishing the nature of the biological oxidation in the material under study. This realization is of particular significance when fruits are subjected to atmospheric conditions that differ materially from those in air. The interest in modified atmospheres was prompted by the desirability of prolonging storage life, and the chief emphasis was on the observation of fruit quality in increased carbon dioxide and reduced oxygen in the storage environment as compared to ordinary air. Few investigators have concentrated on a systematic change in one component while maintaining constancy in the other. Still fewer have determined respiration as a function of CO, tension, since as long as CO2 measurements were employed by conventional techniques it was not feasible to determine the small amount of carbon dioxide added to the atmosphere containing a relatively high concentration of carbon dioxide. Attempts to develop infrared analysis to achieve such determinations proved excessively complicated. Lack of suitable analytical methods had limited the use of oxygen consumption as a measure of respiration in intact tissues, until Pauling, Wood, and Sturdivant (3) took advantage of the fact that oxygen has an unusually high paramagnetic susceptibility while most other gases are only slightly diamagnetic. They devised a simple and sensitive means of measuring this property of gases and built an instrument which would detect very small changes in the partial pressure of oxygen. The paramagnetic principle was used by the A. 0. Beckman Co. to develop a commercial oxygen analyzer. Since their null type instrument was capable of determining changes in oxygen concentration as small as 0.02 %, it seemed suited to the measurement of respiratory activity in atmospheres high in carbon dioxide. This instrument is characterized by excellent sensitivity, freedom from interference, and linearity over the required range. It also has the unique advantages of requiring no specially calibrated gas mixtures for standardization and of being easily adaptable for automatic sampling and recording. Since the gas is not altered by the determination it may be trapped for other analyses. On the other hand, it has the disadvantage, also inherent in most other methods, that the flow rate must be determined precisely. Several years ago the A. 0. Beckman Co. (Process Instrument Div., Beckman Instrument Co., Fullerton, Cal.) agreed to build an instrument designed to automatically sample and record respiratory activity of fruit subjected to gas mixtures high in CO, and containing from one to 25 % 02 Principle of the Oxygen Analyzer. A schematic illustration of an oxygen analyzer is shown in figure 1. This diagram was supplied by the Beckman Go. and depicts a simplified instrument which illustrates the principle of the analyzer. The paramagnetic detector is shown in the left section of the diagram and consists of a dumbbell-shaped test body suspended on a quartz fiber in the non-uniform field of a permanent magnet. The test body is free to rotate on the fiber in response to magnetic and electrostatic forces. The test body itself is paramagnetic and in the absence of a paramagnetic gas tends to orient in the position of maximum magnetic flux. As oxygen is admitted to the unit, the test body tends to rotate out of the position of maximum magnetic flux in response to the gas becoming more paramagnetic. The degree of rotation is proportional to the difference between the volume magnetic susceptibilities of the test body and the gas that it displaces. A mirror attached to the quartz fiber just above the dumbbell-shaped test body reflects a beam of light to the apex of a front silvered prism, which divides and directs the reflected light beam to two photocells in proportion to the angle of deflection of the test body. Thus any deflection from the null position of the test body causes an unbalance of the output of the two photocells which results in movement of the recorder pen. A precision potentiometer. 1 Received revised manuscript Dec. 20, 1961.

BackgroundIron supplementation, especially in female athletes, is 1 of the influential factors in aerobic capacity, and its deficiency can lead to significant problems related to reduced aerobic capacity. ObjectivesThis study aimed to investigate the effect of 3 wk of iron supplementation on the aerobic capacity of female handball players. MethodsIn this randomized, double-blinded, and placebo control trial, 14 elite handball players (age: 21.6 ± 5.68 y; height: 169.5 ± 4.9 cm; weight: 62.2 ± 9.25 kg; body mass index (in kg/m2): 21.5 ± 2.9) randomly divided into 2 supplement groups (receiving a 100 mg/d of poly-maltose tri hydroxide iron complex in the form of tablets) and the placebo group (receiving a tablet containing 100 mg/d starch which is the same color and shape as iron tablets). The supplementation protocol was performed for 3 wk during the off-season. Maximal oxygen consumption (VO2max), amounts of carbon dioxide at the first ventilatory threshold, amounts of carbon dioxide at the second ventilatory threshold, time to exhaustion (TTE), pulmonary ventilation (VE), ventilatory equivalents for oxygen, amounts of oxygen at the first ventilatory threshold, amounts of oxygen at the second ventilatory threshold, time to reach first ventilatory threshold, end-tidal partial pressure of oxygen at the first ventilatory threshold, end-tidal partial pressure of carbon dioxide at the first ventilatory threshold and ventilatory equivalents for carbon dioxide were measured using the Bruce test and gas analyzer in 2 pretest and posttest stages. ResultsThere were significant improvements in oxygen at the first ventilatory threshold, time to reach first ventilatory threshold, and end-tidal partial pressure of carbon dioxide at the first ventilatory threshold and a significant decrease in end-tidal partial pressure of oxygen at the first ventilatory threshold (P < 0.05). Also, no significant changes were found in VO2max, carbon dioxide at the first ventilatory threshold, carbon dioxide at the second ventilatory threshold, oxygen at the second ventilatory threshold, TTE, VE, ventilatory equivalents for oxygen, and ventilatory equivalents for carbon dioxide after 3 wk of iron supplementation (P > 0.05). ConclusionsThe study found that 3 wk of off-season iron supplementation positively impacted female handball players’ aerobic capacity; however, it did not significantly improve their VO2max.

Potential use of highly insoluble carbonates as carbon sources by methanogens in the subsurface of Mars

A scheme is described for electricity production based on coal gasification with recovery of carbon dioxide. In this scheme, coal is gasified into a coal gas, consisting mainly of hydrogen and carbon monoxide. A membrane separates the coal gas into a hydrogen-rich gas and a carbon-rich gas. The hydrogen-rich gas is fed to a conventional gas turbine. The flue gases of this turbine along with a small amount of carbon dioxide are emitted to the atmosphere. The carbon-rich gas is fed to another gas turbine, where it is fired in a mixture of oxygen and carbon dioxide. The exhaust of the latter is almost pure carbon dioxide and can be stored outside the atmosphere.