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The fate of potentially phytotoxic lactic acid, acetic acid, propionic acid and butyric acid during composting has been studied in self-heating bench scale bioreactors. To investigate the impact of air supply on these acids, the aeration was cut off the end of the mesophilic phase, at maximum temperature and in the cooling phase. Aeration was restored after 17 days and the control treatment was kept aerobic through out the whole experiment. Data on mass balances, temperature, pH, oxygen and carbon dioxide in the compost mixture are presented together with levels of volatile organic acids.

Almost half of the biomass synthesized by photosynthetic fixation of carbon dioxide is made up of cellulose. Cotton and wood fibers are the most common sources. It makes up for about 90% of cotton fibers but for only about 45% of the average wood fiber.

Syngas can be produced from a variety of different hydrocarbon molecules by the catalysed reaction with steam, carbon dioxide or oxygen (or with various combinations of these) at high temperatures. This chapter summarises some of the most significant work that has been reported for the use of CO2, with or without added steam or oxygen, in the reforming of hydrocarbons over a variety of different catalyst types, the main attention being given to reactions of methane. Although the so-called dry reforming of methane (i.e. the reaction of CH4 + CO2 alone) may have some limited applications in practice, problems such as carbon deposition on the catalysts used are likely to prevent widespread use of this process. It is therefore more likely that “mixed reforming” (i.e. CH4 + CO2 + H2O or perhaps CH4 + CO2 + O2) will be applied. This is not only because the mixed feed gives potentially more useful syngas ratios but also because its use helps prevent C deposition. Since the number of papers that have been published on the subject on the CO2 reforming of methane and higher hydrocarbons is very high, no attempt is made in this review to cover all of the literature on the subject. Instead, the review lists and, when appropriate, comments on the most significant papers related to the most promising catalyst types used for the CO2 reforming of methane. While emphasis is placed on the key literature of the last twenty years or so, some of the most recent papers on the subject are also listed.

This paper will deal with the injection of carbon-dioxide (CO2) for the purpose of enhanced oil recovery (EOR) in mature and depleted oil and gas reservoirs of Upper Assam basin, India. CO2 injection system is a procedure used to extract maximum oil from the reservoir. This system is performed through injecting natural gases like CO2 into the oil wells. The main objective of the CO2 injection is to stimulate the oil droplets that are inside the oil reservoir rock. Minimum Miscibility Pressure (MMP) is achieved by lowering the viscosity of the oil to make it flow easily to the surface. This paper will calculate the MMP at which miscible recovery takes place. This minimum dynamic miscibility pressure depends upon several factors, such as the composition of injected gas, reservoir temperature and pressure and the characteristics of the oil in place fluids.

This paper proposed the oxygen and carbon dioxide concentration monitoring system for freshness management based on RFID(Radio frequency identity). The freshness can be checked by various factors that are humidity, temperature, oxygen, carbon dioxide, and so on. This paper especially focuses oxygen and carbon dioxide. These two gases concentration is changed by freshness and affect the food too. So we use sensor for monitoring these gases and combine sensor with RFID. RFID system is easy to manage of application system. Through this combined system, we are easier to run freshness of food.

With China’s rapid economic development in recent years, the scale of foreign direct investment has been expanding.In the meantime, environmental issues have been receiving increasing attention, since the concept of a low carbon economy is prevalent in the world. Secondary Industry is the major energy consumers and the emitted carbon dioxide has a significant negative influence on the environment.This paper discusses the background of low carbon economy and conducts an empirical study of the carbon dioxide emission effect of foreign direct investment in the Secondary Industryin Shandong Province. The conclusion is that foreign direct investment leads to more carbon dioxide emissions, which is not conducive to the development of green productivity and a low carbon economy in Shandong Province.

This paper studied on the component of enriched oxygen gas from a self-developed small-size PSA medical oxygen generator. Through gas chromatography each concentration group of oxygen, nitrogen, argon, carbon dioxide and total hydrocarbon with different outlet flow was investigated, and the fluctuation of each group during continuous operation of 48 h was also measured. The result showed that the key factor to constrain the increase of oxygen purity was micro argon in the air, which can reach to 5.1101% in oxygen-rich gas and didn’t change with the variation of zeolite utilization or the increase of operating time, indicating the invalid of current molecular sieve materials. Another major gas nitrogen declined significantly with the improvement of the molecular sieve utilization, which was only account for 0.4643%. Other trace amount of impurity gas such as total hydrocarbon and carbon dioxide were only in ppm level.

The pyrolysis behavior of two biomass fuels (E. adenophorum and tobacco stem) and their production were analyzed in this paper using Thermo gravimetric analyzer (TGA) combined with a Fourier transform infrared spectrometer (FTIR). The gaseous phase components derived from the samples decomposing were qualitatively evaluated, and a correlation between the yield of acetic acid and carbon dioxide with heating rate was observed. The global pyrolysis kinetic was determined by DAE method where Miura method was used for obtaining \( f(E) \), and a fixed pre-exponential factor of 2.2e13 was used to fit DTG curves. CO2 yield was found increased with the accretion of heating rate, while the other gaseous phase production and acetic acid were decreased simultaneously. The maximum of \( f(E) \) was found around 170–180 kJ/mol.

In this paper we present two applications of a recently developed method for obtaining analytical potential energy surfaces describing the intermolecular interaction of pairs of molecules made up of three or more atoms. The method is based on an empirical formulation of the intermolecular terms of the potential based on the idea that pairwise interaction terms, usually appearing in the many-body expansion of the potential energy, must be referred to pairs of interacting centers (group of atoms and/or bonds) of the molecular monomers, rather than, as traditionally done, to atomic centers. Such representation is incorporated in a grid empowered molecular simulator and coupled with dynamical calculations to evaluate observable properties of a simple CO2 dimer and a more complex chemical system (the N-methylacetamide dimer).

One of the major factors causing global warming is the amount of carbon dioxide (CO2) in the atmosphere. With this understanding, one should consider the influences of CO2 emission during planning. This paper uses carbon footprint caused by transportation as an objective to find an optimized travel route. We employ genetic algorithm (GA) as the tool to find solutions. The approach proposed by this study is found to be effective in planning travel route, which suggests an optimal route as well as transportation modes between scenic spots.

Methane is a kind of greenhouse gas that strongly absorbs Earth outward long-wave radiation, a gas whose greenhouse effect is 21 times worse than carbon dioxide. Coal mine area is one major source of industrial methane emission and the emission sources are principally coal mines and coal bed methane (CBM) ground development zones. One of the type areas at present is southern Qinshui Basin in Shanxi province. With the support from the advantages of remote sensing monitoring technology in real time monitoring of mine area environment and on the basis of the optimal waveband from the sieving process of remote sensing monitoring of methane, this paper takes southern Qinshui Basin as the focus of research in order to perfect and progress the theoretical model of methane remote sensing response, to develop the hyperspectral monitoring method of methane concentrations, with which furthermore, to make a preliminary analysis of the temporal and spatial distribution regularity of atmospheric concentrations of methane so as to provide groundwork for further research and development of real time and high sensitive monitoring method of the atmosphere environment in mine areas.

Nowadays, the problem of the environment goes worse, it urges people to research and study new energy-saving and environment-friendly refrigerants, such as carbon dioxide, at present, people do research on carbon dioxide at home and abroad. This paper introduces the property of carbon dioxide as a refrigerant, sums up and analyses carbon dioxide refrigeration cycles, and points out the development and research direction in the future.

According to the disadvantages of traditional box for preservation, including low oxygen and high carbon, a new control system of high oxygen is designed. This paper presents the design and implementation method in this system. The system combines traditional PID control with fuzzy control which can adjust parameters of the whole system automatically. The box can control the dynamic content of oxygen and carbon dioxide, and monitor nitrogen flow, temperature and humidity real-timely so that preservation time can be prolonged. It also can collect and keep the data of the dynamic content of oxygen and carbon dioxide which suits for fruit and vegetable for preservation. The former environment can be reappeared when need. The system works steadily and has strong functions.

Crops capture solar energy and transform it into chemical energy by process of photosynthesis. Light energy is transformed into chemical energy, which, in turn is used for reduction of carbon dioxide to carbohydrates. With an extra supply of carbon dioxide both saturation light intensity and efficiency of light utilisation increases, which ultimately increases dry matter production. Crops with C4 pathway show less response to increased carbon dioxide as compared to crops with C3 pathway. Photosynthetic rate also fluctuates with diurnal variation of temperature. With this background an actual field experiment was conducted at adjacent plots of CAgMO (lat. 18° 32′, long. 73° 51′), Pune, with four crops viz., sunflower, soybean, mustard and jowar. All the crops were sown on 28 October 2003, in order to have better comparative study among the crops. Weekly observations were taken at 3 levels of carbon dioxide concentration viz., normal, 550 and 650 ppm by using LI 6400 portable photosynthatic system from 08 December 2003 to 19 January 2004 (i.e., from 42nd to 84th days after sowing or DAS). At each of the weekly intervals, observations were taken at 2 hourly intervals viz. 0800, 1,000, 1,200, 1,400 and 1,600 h IST to measure the rate of photosynthesis from which daily mean values were computed. Statistical analysis was carried out in Randomized Block Design (RBD) to find out critical differences in daily mean rate of photosynthesis at different levels of carbon dioxide concentration and various hours of observation, to identify statistically significant variation. The objective of the study was to quantify and compare mean rate of photosynthesis at various levels of carbon dioxide and at various hours of observation among different crops. The paper discussed about how the rate of photosynthesis varied with levels of carbon dioxide and different hours of observation. Among the four crops studied during the study period, the rate of photosynthesis was the highest for sunflower crop and the lowest for soybean crop. For all the crops studied, the rate of photosynthesis increased with levels of carbon dioxide at the earlier weekly observations. For sunflower crop, the rate of photosynthesis varied significantly between normal and 650 ppm CO2 level, though the difference between 550 and 650 ppm levels were not significant up to 4th weekly observations (i.e., up to 63 DAS). Low critical difference values were observed at later weekly observations (i.e., after 70 DAS). For soybean, significant variation in rate of photosynthesis was observed up to 4th weekly observations (i.e., up to 63 DAS). However, in case of mustard, the rate of photosynthesis at various levels of CO2 did not differ significantly at earlier weekly observations (i.e., up to 63 DAS), though low critical difference values were observed at later weekly observations (i.e., after 70 DAS). In case of jowar crop, rate of photosynthesis increased up to 3rd weekly observations (i.e., up to 56 DAS) and the critical difference values at normal and 550 ppm CO2 level were almost significant. Similarly, the diurnal rate of photosynthesis showed that the values increased up to 1,200 or 1,400 h IST for the crops studied. The rate of photosynthesis mostly differs significantly between morning/evening observations and 1,200 or 1,400 h IST observations up to 4th weekly observations (i.e., up to 63 DAS), though critical difference values were less in later observations (i.e., after 77 DAS). In the present context of climate change scenario and its possible impact on crops, the study will be useful in predicting net assimilation.

Chemical looping combustion (CLC) is a means of combusting carbonaceous fuels, which inherently separates the greenhouse gas carbon dioxide from the remaining combustion products, and has the potential to be used for the production of high-purity hydrogen. Iron-based oxygen carriers for CLC have been subject to considerable work; however, there are issues regarding the lifespan of iron-based oxygen carriers over repeated cycles. In this work, haematite (Fe2O3) was reduced in an N2+CO+CO2 mixture within a fluidised bed at 850°C, and oxidised back to magnetite (Fe3O4) in a H2O+N2 mixture, with the subsequent yield of hydrogen during oxidation being of interest. Subsequent cycles started from Fe3O4 and two transition regimes were studied; Fe3O4↔Fe0.947O and Fe3O4↔Fe. Particles were produced by mechanical mixing and co-precipitation. In the case of co-precipitated particles, Al was added such that the ratio of Fe:Al by weight was 9:1, and the final pH of the particles during precipitation was investigated for its subsequent effect on reactivity. This paper shows that co-precipitated particles containing additives such as Al may be able to achieve consistently high H2 yields when cycling between Fe3O4 and Fe, and that these yields are a function of the ratio of [CO2] to [CO] during reduction, where thermodynamic arguments suggest that the yield should be independent of this ratio. A striking feature with our materials was that particles made by mechanical mixing performed much better than those made by co-precipitation when cycling between Fe3O4 and Fe0.947O, but much worse than co-precipitated particles when cycling between Fe3O4 and Fe.

inadequate tissue perfusion (ischemia) and oxygenation are likely to contribute to the development of organ failure resulting in an increased mortality of critically ill patients. An early detection of ischemia followed by an immediate treatment can save that organ or patient’s life. The measurement of partial pressure of carbon dioxide in tissue (PtCO2) has been suggested as an effective biological marker to detect ischemia. A conductivity based PtCO2 sensor has been suggested earlier, which can be simply built by two electrodes in contact with a liquid film placed behind a gas permeable membrane. The water molecules dissociate the carbon dioxide to hydrogen and bicarbonate ions changing the conductivity in the liquid film. Two electrode measurement technique is favoured if the sensor is to be maximally miniaturized. However, the measurements can be affected by electrode polarization and stray capacitance, which decreases the sensitivity of the sensor. A sensor design, based on a balance between these two phenomena may solve some of the problems. In this paper, a bridge design is presented where two electrodes placed in each reservoir are connected to a tiny liquid film.

This paper presents the results of gross carbon dioxide and methane emission measurements in several Brazilian hydro reservoirs. The term ‘gross emissions’ means gas flux measurements from the reservoir surface without correcting for natural pre-impoundment emissions by natural bodies such as the river channel, seasonal flooding and terrestrial ecosystems. The net emissions result from estimating pre-existing emissions by the reservoir. Measurements were carried in the Miranda, Barra Bonita, Segredo, Tres Marias, Xingo, Samuel and Tucurui reservoirs, located in two different climatological regimes. Additional data were used here from measurements taken at the Itaipu and Serra da Mesa reservoirs. Emissions of carbon dioxide and methane in each of the reservoirs selected, whether through bubbles or diffusive exchange between water and atmosphere, were assessed by sampling, with subsequent extrapolation of results to obtain a value for the reservoir. A great variability was found in the emissions, linked to the influence of various factors, including temperature, depth at the point of measurement, wind regime, sunlight, physical and chemical parameters of water, the composition of the local vegetation and the operational regime of the reservoir.

In this paper, we present the first carbon dioxide sensor designed for automotive applications. The sensor is based on the spectroscopic measurement principle. It includes a new robust micromachined infrared gas-detector and a corresponding, newly developed ASIC. First application studies show its suitability for automatic vehicle airmanagement systems and for leak detection in R744 air conditioning systems.

The interaction of the atmosphere and the ocean has a profound effect on climate, while the uptake by the oceans of a major fraction of atmospheric carbon dioxide has a moderating influence. By improving accuracy in the quantification of the ocean’s carbon dioxide budget, a more precise estimation can be made of the terrestrial fraction of global carbon dioxide budget and its subsequent effect on climate change. First steps have been taken towards this from an environmental and economic point of view, by using an instance based reasoning system, which incorporates a novel clustering and retrieval method. This paper reviews the problems of measuring the ocean’s carbon dioxide budget and presents the model developed to resolve them.

Coal gasification involves the conversion of coal with steam (allothermic gasification), or with steam and oxygen (autothermic gasification). In this paper, the effect of temperature and pressure on the thermodynamics of gasification are discussed. The most important products of gasification are carbon monoxide, hydrogen, carbon dioxide, and methane. With increasing temperature, the concentrations of hydrogen and carbon monoxide in the product gas increase, while both carbon dioxide and methane go through a maximum. A higher pressure negatively influences the hydrogen and carbon monoxide production. Lowering of the feed temperature very much increases the heat required in allothermic gasification, and the oxygen to steam ratio in autothermic gasification. A comparison is made between gasification of pure carbon and CH, which gives a more accurate representation of coal. Naturally, CH yields a product gas with higher hydrogen content. Finally, the thermodynamic equilibrium composition is related to typical operating ranges of industrial gasifiers. This gives an indication of optimal operating conditions for specific applications, although an absolute measure of performance cannot be based on these data.

According to the double-dividend hypothesis, the introduction of carbon taxes is expected to both reduce carbon dioxide emissions and the distortions of the existing tax system. Contrary to the common belief that emissions will decrease, this paper points out that an increase of carbon dioxide emissions due to the introduction of carbon taxes within a green tax reform cannot be ruled out in general. To determine the effect of such a green tax reform on the environment one has to take account of the possible feedback effects of all accompanying measures taken by a government. In the case of a revenue-neutral green tax reform, these may be tax rate cuts for at least one non-polluting good. Simulations show that an increase of carbon dioxide emissions due to a revenue-neutral introduction of carbon taxes might occur in an empirically relevant range of parameters.

Carbon dioxide is an important greenhouse gas, and its atmospheric increase causes concern because of a potential impact on the global climate. A prerequisite for assessing possible future climatic changes is a means to estimate the future development of the atmospheric CO2 concentration, given some energy consumption scenarios. For this purpose, models have been developed which represent the global carbon cycle and the processes which are important for the redistribution of anthropogenic CO2. This paper describes the carbon cycle mechanisms which are relevant in this context, the way in which they are integrated in models and some model results.

During the European Polarstern Study (EPOS leg 1 and leg 2) measurements of temperature, salinity, inorganic nutrients, chlorophyll-a, oxygen and total inorganic carbon dioxide were performed from October to January 1988–1989 in north-south sections at 47–49 °E in the NW Weddell Sea from approximately 58 °S to 63 °S (Hempel 1989; Hempel et al. 1989). In order to explain parts of the obtained data, a time-dependent ecological model was constructed by Svansson (1991). He found that a moderate mixing with a constant diffusion coefficient from sea surface downwards resulted in good agreement between computed and measured chlorophyll. In this paper we introduce the gas fluxes, mainly oxygen but also carbon dioxide, into the model work. It turns out that air-sea fluxes are necessary to explain the vertical oxygen distribution. The annual development of chlorophyll, phosphate, oxygen and total inorganic carbon dioxide are computed. Hours of day-light, losses and the eddy diffusion coefficient are allowed to vary during the year with the condition that the mean total chlorophyll at 14 selected leg 1 stations was nearly double the magnitude of that of 18 selected leg 2 stations. This yields variations consistent with the observations. Different steady-state solutions after 91 days are also tested to show effects of one selected variation at a time, for example the eddy diffusion coefficient or the loss rate. The oxygen air-sea flux, of about 90 mmol m−2day−1 in the time variable model computation, is compared to estimated fluxes by a gas transfer formula. The formula used gives a flux which is about 5 times smaller than the model flux. Some of the 91 days solutions give results of fluxes which are less than 90 mmol m−2 day−1, but still higher than the transfer formula result. Fluxes of total inorganic carbon dioxide in the model computation are always directed from air to sea.

The present paper deals with the circulation in the “swimming pool” of the tissue below the arterial and arteriolar level. Oxygen content decreases and carbon dioxide increases from the arterial to the venous end of the capillary. There is not a single oxygen tension in the tissue but an oxygen tension field: within the Krogh cylinder oxygen decreases both from the arterial to the venous end of the capillary, and perpendicularly from the capillary to the periphery of the cylinder. When oxygen transport and oxygen supply in the tissue is described, this oxygen tension field must be known.

From a recent paper on the history of the discovery of photosynthesis (Rabinovitch, 1971), it appears that many biologists equate photosynthesis with productivity and identify the raw materials of photosynthesis (water, carbon dioxide, and sunlight energy) as the direct controls of productivity. Photosynthesis and primary productivity are not so simply identical. Indeed, primary productivity—the actual energy bound into organic matter—is the product of photosynthesis. Yet primary productivity requires more than photosynthesis alone. The uptake and incorporation of inorganic nutrients into the diverse organic compounds of protoplasm are essential to the photosynthesizing organism. Temperatures govern annual productivity in various ways that do not result from temperature dependence of the photosynthetic process. On land, productivity is strongly affected by the availability of water, not primarily for use in the photosynthetic process itself, but to replace the water lost through the stomata that are open to allow carbon dioxide uptake.

A dissociation of the cerebral vasomotor response in the form of a preserved vasoconstriction to hypocapnia and an abolished vasoconstriction to hypertension was reported in a patient with a parasagittal meningeoma by Easton and Palvolgyi [1]. The present paper analyzes the frequency of such partial vasoparalysis in a material of 23 cases of apoplexy studied with the 16 channel rCBF technique. These 23 cases represent all cases of Paulson’s series of 41 apoplexies in which both carbon dioxide reactivity and autoregulation studies were per- formed [5]. 4 of the patients (group O) had occlusion of the middle cerebral artery, while 19 (group NO) had no occlusions on the angiographic films.