Bon Dioxide Research Articles

Экономическая оценка выбросов СО2 в экологическом разделе ESG

The article presents the results of the conducted research, the purpose of which was to develop recommendations for the use of socio-economic benefits from the use of wind and so lar energy in the environmental section of ESG instead of the most toxic generation - coal. On the basis of theoretical assumptions, the methodology developed by the author for determining the achieved savings is described in detail on the example of the largest energy enterprises Enel, Eni. The article presents not only the author's model, but also the calculations themselves with com ments. The calculations carried out were carried out on the basis of the actual amount of car bon dioxide emissions charges, taking into account the damage caused, the number of people saved from premature death due to harmful emissions into the atmosphere, the economic cost of lives determined by the World Bank by country, the costs of treating emerging concomitant dis eases, the social discount rate. This makes it possible to determine the real socio-economic effect of replacing fossil energy sources with cleaner energy carriers. The argumentation refuting the argument about the occurrence of a significant increase in costs in the economy, which may arise due to the introduction of a fixed fee for harmful emissions, is presented. This allows you to set more accurate benchmarks and indicators in the environmental section of the ESG system and use them in attracting investors, forming ratings, and training specialists.

Enhancement of landfill methane oxidation using different types of organic wastes

Methane (CH4) is a greenhouse gas with a global warming potential that is 25 times higher than car- bon dioxide (CO2). Microbial oxidation of landfill CH4 is about 5 % and it plays a significant role in reducing emissions to the atmosphere. Previous studies have shown that microbial oxidation of CH4 in landfill cover soil can be enhanced using organic matter-rich substrates. This study aims to investigate the CH4 oxidation activity with the addition of different organic wastes in different combina- tions. Batch experiments with different organic wastes for CH4 oxidation activity showed that compost and sawdust required the shortest time to oxidize CH4 compared to empty fruit bunch and black soil. However, other organic wastes (spent yeast, sewage sludge and spent tea leaves) tested in this study produced CH4 instead. Compost and sawdust took 4 days for complete CH4 oxidation. Batch experiments with different combinations of organic waste showed potential CH4 reduction when combined with compost. The combination of 20 % spent yeast ? 80 % compost was able to completely oxidize CH4 at day 16. CH4 was fully oxidized on day 1 by 20 % sewage sludge ? 80 % compost, showing good CH4 oxidation potential; 100 % sawdust fully oxidized CH4 within 4 days, while a combination of 20 % sawdust ? 80 % compost and 40 % sawdust ? 60 % compost took 2 days for complete CH4 oxidation. From this study, it can be concluded that the addition of organic wastes at optimum ratio and combination with compost as landfill cover material will have a significant effect on CH4 emission reduction.

Input from a chemosensory organ, the osphradium, does not mediate aerial respiration in Lymnaea stagnalis

Breathing behaviour is driven by chemosensory information sensed by oxygen or car- bon dioxide receptors that detect the level of these substances either internally or in the external environment. In terrestrial species, oxygen chemosensation is primarily through internal sensors, whereas in aquatic animals, such as the pond snail Lymnaea stagnalis, external oxygen chemo - receptors are thought to be more important, due to the low partial pressure of oxygen in water. It has been hypothesized that an external chemosensory organ, the osphradium, modulates aerial respiratory behaviour in hypoxic conditions in Lymnaea, but recent data indicate that this may not be the case. In the present study, we removed the input from this organ to the central nervous system and measured aerial respiratory behaviour. We assessed breathing behaviour prior to surgery and then operated on the snails, severing either (1) the osphradial nerve proximal to the osphradium or (2) the right internal parietal (RIP) nerve into which the osphradial nerve, in addition to other axons from the lung/pneumostome area, projects. We also used a sham-operated control group. Severing either the osphradial or RIP nerve did not alter breathing behaviour in eumoxic or hypoxic conditions relative to the behaviour prior to surgery or that of sham-operated animals. Therefore, we conclude that input from the osphradium does not drive aerial respiratory behaviour.

Successful Treatment of Buschke-Lowenstein Tumour of the Penis with Carbon Dioxide Laser Vaporization

Buschke-Lowenstein tumour (BLT) (1) is a rare, ano-genital tumour typified by florid warty growth and aggressive invasion into surrounding tissues. Treatment approaches have mostly involved surgery, often radical, and chemotherapy. Recurrence rates are high and appear to be irrespective of treatment choice. We report a case of BLT of the penis that has been successfully treated by a single treatment with carbon dioxide laser without adjunctive chemotherapy.CASE REPORTA 42-year-old heterosexual married man presented in 1999, with a 3-year history of an enlarging, bulky, warty lesion on the glans penis that had gradually grown from a smaller original lesion. He had no prior history of genital wart infections but had been circumcised several years previously for phimosis. A wedge biopsy was taken. The histology was consistent with BLT.Initial consideration was given to radical surgery (distal amputation of the penis) or, alternatively, micrographic (Mohs) surgery. However, in order to preserve as much tissue and function as possible, and to treat the lesion expeditiously, carbon dioxide laser vapourisation was performed. The procedure was carried out under general anaesthesia. A Sharplan 1040 carbon dioxide laser was used with a 125 mm hand piece. The lesion was initially debulked using high power densities (40 watts output, continuous wave, defocused beam). The output was then reduced to 15 watts and under operative microscopic control the tumour was vaporised down to normal tissue. In 2 areas the tumour extended deeply into subcutaneous tissue, over the dorsum of the glans and inferiorly around the corona. At these 2 sites, electrosurgery was required to obtain haemostasis. The patient stayed in hospital overnight to ensure normal micturition. Granulation and re-epithelialisation took 3 months. The outcome is a normal looking glans with a minimally scarred surface. Full erectile function and normal micturition have been preserved. There has been no recurrence over more than a decade of surveillance. DISCuSSIOnTo the best of our knowledge this is the first published case of penile BLT treated with carbon dioxide laser successfully and showing no recurrence over 10 years of follow-up. Maximal tissue conservation, excellent cosmesis and full preservation of penile function has been achieved in this young, sexually active patient. Locally the BLT behaves like a carcinoma with aggressive local growth and invasion into surrounding tissue. Morbidity occurs as a result of tumour expan-sion into important local structures and death occurs in about 20% of patients. There have been reported cases of malignant transformation of BLT into squamous cell carcinoma which can therefore show metastatic spread (2). A number of different treatments have been deployed but because of the rarity of this tumour there have been no controlled trials. Surgery is a well-established conventional option, although usually needs to be extensive given the bulky nature of these lesions. The result is often disabling for patients and recurrence may be as likely as with other treatments. Systemic and intralesional chemotherapy has been tried, as monotherapy or as an adjunct to surgery, such as with 5-fluorouracil and cisplatin. Intralesional interferon has been effective for deeply invading lesions but requires frequent treatments for a lengthy time period (3). Recur -rence of the tumour is common, up to 67% in a one series (4), and appears to be regardless of treatment type. Only a few case reports of BLT treated by laser have appeared, especially in the English literature (5–9). Lenk et al. (7) treated two patients with superficial pe-nile tumour with neodymium-YAG or carbon dioxide laser. Gilbert & Beckert (8) and Hohenleutner et al. (9) treated one patient each with neodymium-YAG and car -bon dioxide respectively but with concomitant systemic interferon. More recently there have been case reports of successful treatment of perianal BLT with carbon dioxide laser ablation, following surgical excision (10) or after initial imiquimod treatment (11). The use of car -bon dioxide laser treatment of BLT in the perineum and vulva has been reported by Frega et al. (12). Although there have been other cases of penile BLT treated with carbon dioxide laser, this is the first case to show no recurrence despite protracted follow-up.REFEREnCES

Mechanistic and Adsorption Studies of Relevance to Photocatalysts on Titanium Grafted Mesoporous Silicalites

Ti-SBA-15 and Ti-MCM-41 were synthesized and evaluated as possible photocatalysts for the reduction of CO2, and for the photo-Kolbe decomposition of acetic acid. UV-Raman was used to study the adsorption of car- bon dioxide, water, formic acid, and acetic acid over Ti-MCM-41 by monitoring the UV enhanced resonance peak of the totally symmetric stretching band of the grafted Ti species at 1,085 cm -1 . Acetic and formic acid dissociate on Ti-SBA-15 and Ti-MCM-41 to form acetate and for- mate, respectively. The conjugate bases subsequently interact strongly with Ti sites. Water interacts with the Ti sites, while no change in the amplitude of the 1,085 cm -1 band is observed in the presence of CO2. Photocatalysis experiments indicate that these mesoporous silicalites are active in the photo-Kolbe decomposition of acetic acid. CO2 is formed by reaction of a hole with the acetate car- boxylate groups. The methyl radical co-products react with a surface proton and an electron to form methane. No products resulting from the dimerization of methyl radicals are observed, presumably because of the highly dispersed active sites.

Sensitivity of CO2 Exchange of Fen Ecosystem Components to Water Level Variation

Climate change is predicted to bring about a water level (WL) draw-down in boreal peatlands. This study aimed to assess the effect of WL on the car bon dioxide (C02) dynamics of a boreal oligo trophic fen ecosystem and its components; Sphagnum mosses, sedges, dwarf shrubs and the underlying peat. We measured C02 exchange with closed chambers during four growing seasons in a study site that comprised different vegetation treatments. WL gradient in the site was broadened by surrounding half of the site with a shallow ditch that lowered the WL by 10-25 cm. We modeled gross photosynthesis (PG) and ecosystem respira tion (r?ECO) and simulated the C02 exchange in three WL conditions: prevailing and WL draw down scenarios of 14 and 22 cm. WL draw-down both reduced the PG and increased the i?ECo thus leading to a smaller net C02 uptake in the ecosys tem. Of the different components, Sphagnum mos ses were most sensitive to WL draw-down and their physiological activities almost ceased. Vascular plant C02 exchange, en bloc, hardly changed but whereas sedges contributed twice as much to the C02 exchange as shrubs in the prevailing condi tions, the situation was reversed in the WL draw down scenarios. Peat respiration was the biggest component in RBco in a^ WL conditions and the increase in RECo following the WL draw-down was due to the increase in peat respiration. The results imply that functional diversity buffers the ecosys tem against environmental variability and that in the long term, WL draw-down changes the vege tation composition of boreal fens.

Carbon dioxide in laryngeal mask airway cuffs

The amount of carbon dioxide (CO2) diffusing into the cuff of a laryngeal mask airway can be measured by attaching the carbon dioxide analyser to the pilot balloon and using the monitor tracing to obtain a value for the concentration of CO2. We measured the CO2 content of the gas in the cuff of 38 different sized laryngeal mask airways (Intavent Orthofix, Maidenhead, UK) immediately after removal from patients in the recovery ward. After insertion into the patient, the cuffs of ProSeal™ LMAs were inflated to a pressure of 60 cm H2O, and Classic LMAs were inflated with a standard volume of air. Cuff volumes at the time of CO2 measurement were unknown. The cuff CO2, expressed as a percentage of the end-tidal CO2, was plotted against the time the laryngeal mask airway was in place (see Fig. 2). The CO2 in the cuff increased over time towards the end-tidal CO2 value. It appears that the Proseal™ LMA cuffs show more stability in reaching the end-tidal CO2 content. Bearing in mind the small numbers studied, the Classic and ProSeal™ LMA size did not affect the uptake of CO2, nor did the use of air/oxygen, oxygen/nitrous or pure oxygen breathing mixtures. No female/male differences were seen. The change in car,bon dioxide con,tent in air of cuffs of laryn,geal masks, as a per,cent,age of the end-tidal car,bon dioxide, over the dur,ation of inser,tion in the larynx. We think the surface area of the cuff applied to the mucous membrane of the pharynx is reflected in the amount of CO2 absorbed into the cuff. A better seal will give an earlier and ultimately higher CO2, which may be demonstrated by the ProSeal™ laryngeal mask with its larger cuff and its greater stability in the pharynx. When filled with a 5% CO2 calibration gas in vitro, a dry laryngeal mask airway cuff equilibrates with air after 15 min, so measurements should be performed with the mask in the patient or immediately after removal. Delay in measuring or twisting of the laryngeal mask airway [1] may account for low CO2 values.

Compositional changes in natural gas bubble plumes: observations from the Coal Oil Point marine hydrocarbon seep field

Detailed measurements of bubble composition, dissolved gas concentrations, and plume dynamics were conducted during a 9-month period at a very intense, shallow (22-m water depth) marine hydrocarbon seep in the Santa Barbara Channel, California. Methane, car- bon dioxide, and heavier hydrocarbons were lost from rising seep bubbles, while nitrogen and oxygen were gained. Within the rising seawater bubble plume, dis- solved methane concentrations were more than 4 orders of magnitude greater than atmospheric equilibrium concentrations. Strong upwelling flows were observed and bubble-rise times were � 40 s, demonstrating the rapid exchange of gases within the bubble plume.

A Mechanistic Model for Carbon Dioxide Corrosion of Mild Steel in the Presence of Protective Iron Carbonate Films—Part 3: Film Growth Model

‡, * and K.-L.J. Lee** ABSTRACT A model of iron carbonate (FeCO3) film growth is proposed, which is an extension of the recent mechanistic model of car- bon dioxide (CO2) corrosion by Nesic, et al. In the present model, the film growth occurs by precipitation of iron carbon- ate once saturation is exceeded. The kinetics of precipitation is dependent on temperature and local species concentra- tions that are calculated by solving the coupled species transport equations. Precipitation tends to build up a layer of FeCO3 on the surface of the steel and reduce the corrosion rate. On the other hand, the corrosion process induces voids under the precipitated film, thus increasing the porosity and leading to a higher corrosion rate. Depending on the environ- mental parameters such as temperature, pH, CO2 partial pressure, velocity, etc., the balance of the two processes can lead to a variety of outcomes. Very protective films and low corrosion rates are predicted at high pH, temperature, CO2 partial pressure, and Fe 2+ ion concentration due to formation of dense protective films as expected. The model has been successfully calibrated against limited experimental data. Parametric testing of the model has been done to gain insight into the effect of various environmental parameters on iron carbonate film formation. The trends shown in the predic- tions agreed well with the general understanding of the CO2 corrosion process in the presence of iron carbonate films. The present model confirms that the concept of scaling tendency is a good tool for predicting the likelihood of protective iron carbonate film formation.

The Arctic Flux Study: A Regional View of Trace Gas Release

Journal Of Biogeography (1995) 22, 365-374 The Al‘CtlC FIUX StUClV: a regional view Of trace gas release G. WELLER*1, F. S. CHAPIN2, K. R. EVERETT,3, J. E. HOBBIE4, D. KANE5, W. C. OECHEL6, C. L. PING7, W. S. REEBURGH8, D. WALKER9, and J. WALSH10, ILAII Science Management Ofiice, Center for Global Change, University of Alaska Fairbanks, PO Box 757740, Fairbanks, AK 99775, U.S.A. 2Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, U.S.A. 33610 Johnstown—Utica Rd., Johnstown, OH 43031, U.S.A. 4Ecosystem Center, Marine Biological Laboratory, 67 Water St., Woods Hole, MA 02543, U.S.A. 5Department of Civil Engineering, University of Alaska Fairbanks, PO Box 755900, Fairbanks, AK 99775, U.S.A. 6Biology Department, San Diego State University, San Diego, CA 92182-0001, U.S.A. 7Agriculture and Forestry Experimental Station, University of Alaska Fairbanks, 533 Fireweed, Palmer, AK 99645, U.S.A. 8Department of Geosciences, University of California Irvine, 205 Physical Sciences, Irvine, CA 92717-3100, U.S.A. 9Institute of Arctic and Alpine Research, University of Colorado, Campus Box 450, Boulder, CO 80309-0450, U.S.A. “Department of Atmospheric Sciences, University of Illinois, 105 S. Gregory Ave., Urbana, IL 6180], U.S.A. Abstract. Fluxes of trace gases from northern ecosystems represent a highly uncertain and potentially significant compo- nent of the arctic land——atmosphere system, especially in the context of greenhouse-induced climate change. The initial goal of the Arctic Flux Study (a part of NSF’s Arctic System Science Program)’ is a regional estimate of the present and future movement of materials between the land, atmosphere and ocean in the Kuparuk River basin in northern Alaska. We are measuring rates and controls of processes along a north~ south transect running from the marshy coastal plain to moun- tain valleys. Important vertical fluxes under study are the release of CO2 and CH4 from soils and water, lateral fluxes are surface water, nutrients, and organic matter. A hierarchy of measurements allow the rates and under- standing of processes to be scaled from plots to the landscape, regional, and circumarctic level. These include gas flux mea- surements in small chambers, measurements over larger areas by eddy correlation from small towers, and measurements at the landscape scale from airplane overflights. Experimental manipulations of carbon dioxide, soil moisture, nutrients and soil temperature from this and other studies give information on process controls. The distribution of plant communities has been described at several landscape-scale sites and a hier- archic GIS has been developed for the region at three scales (plot, landscape, region). Climate is measured at six sites and hydrological processes are being studied at each watershed scale. In the soils, measurements are being made of soil organic matter and active layer thickness and of availability of soil organic matter for microbial transformation into CO2 and CH4. Fluxes and process understanding have been incorporated into a hierarchy of models at different scales. These include models of regional climate nested in a GCM; of regional- and continental-scale plant productivity and carbon cycling includ- ing CO2 release under altered climates; watershed and regional models of hydrology; and surface energy budgets. After the first year of study the regional climate model has been successfully configured to the northern Alaska region. We have also measured a large release of carbon dioxide from tundra soils in all but the coldest and wettest parts of the transect. The rates from eddy correlation towers (landscape level) agree closely with rates from chambers (plot level). Observations, experimental manipulations and modelling analyses result in the prediction that the combination of warmer and drier soils is responsible for the large CO2 release. Key words. Arctic, tundra ecosystem, global warming, car- bon dioxide, methane, trace gases, modelling. INTRODUCTION Greenhouse warming in northern land areas is predicted by global climate models to be several times greater than the global mean of 1.5—4.5°C (IPCC, 1992). During the past *Corresponding author. © 1995 Blackwell Science Ltd. several decades, the observed warming has been much stronger over the northern land areas than over the Arctic Ocean (Kahl et al., 1993) or subpolar oceans (Chapman & Walsh, 1993). The warming has been particularly large over Siberia, north western Canada and much of Alaska, where warming rates over the past 30 years are approxi- 365

Greenhouse cooling up high

Greenhouse cooling up high

Removal of micro-air-bubbles from a dry type capillary artificial kidney by replacing with car bon dioxide.

Removal of micro-air-bubbles from a dry type capillary artificial kidney by replacing with car bon dioxide.

Sensory Reactions of Siphonaptera in Relation to Host-Finding

Fleas of four species were used in experiments on re- actions to various stimuli that might be associated with host-finding. Ctenocephalides felis showed definite ability to detect and react to car- bon dioxide level and warm objects, with the possibility that host odor may also be important. Ceratophyllus riparius and C. idius responded to air movement, although the former, at least, appears to respond to vibrations of the substrate under field conditions. Oropsylla arctomys showed no clear-cut responses in olfactometer tests and in tests with warm objects and air currents. In every species, nearly half of the tested individuals failed to respond in any given experimental situation. primary iinportance to fleas. Whereas many other ectoparasites re- main on or in the vicinity of the host throughout life, fleas are quite independent of the host during the larval stage, and in most species leave the host frequently even during adult life. Upon emergence from pupation, fleas must secure a blood meal within a relatively short time, perhaps two weeks. For species which have spent the immature stages in an occupied nest or burrow of the host, this should present no special problem. When the adult emerges in an unoccupied nest or burrow, as is true of many bird fleas, or when it emerges in the open, as is true of cat fleas and some others, special sensory modalities for host-finding must be involved. The sensory modalities by which fleas locate a host have been the subject of several studies. Sgonina (1939) made careful studies of the host-finding ability of the European hedgehog flea, Archaeopsylla erinacei (Bouche ). He found that this species reacted positively to hedgehogs and hedgehog hair, as well as to warm objects and to air currents. He generalized from these studies that all fleas prefer the specific odor of their principal host. Reactions of his fleas to odor appeared undirected and random. Reactions to warm objects and air currents, however, he believed to be directed. Stimuli from air currents are believed to be received by sensory hairs on the pygidium. Sgonina observed preferences of fleas for certain individuals of the host species, and concluded that this must be due to odor. His observations indicated that odor was of particular importance with regard to the initiation of sucking.

Carbon Dioxide Production in Early Anaerobiosis

1. Slices of swede tissue placed under nitrogen produce carbon dioxide and ethanol in equal amounts after an initial phase lasting about 1-5 hours. During this initial phase some 2 /xM./g. fr. wt. of extra carbon dioxide is produced. The production of such extra carbon dioxide is not affected by iodoacetate, fluoride, or arsenite which inhibit glycolysis or by dinitrophenol which stimulates glyco lysis. Slices incubated in air in the presence of cyanide also produce extra carbon dioxide. 2. A second extra burst of carbon dioxide can be induced after some hours of anaerobiosis by treating slices with methylene blue, DPN, or TPN, or as a result of a short air experience. 3. Experiments with labelled sugars support the view that the extra carbon dioxide originates ultimately from carbohydrate, being released, it is proposed, in the oxidative decarboxylation of either pyruvate or 6-phosphogluconate. Car bon dioxide production then continues so long as oxidants are available in the cell, finally coming to a standstill when cell components reach their reduced states.